Index: solr/src/java/org/apache/solr/core/RefCntRamDirectory.java
===================================================================
--- solr/src/java/org/apache/solr/core/RefCntRamDirectory.java	(revision 1140355)
+++ solr/src/java/org/apache/solr/core/RefCntRamDirectory.java	(working copy)
@@ -20,8 +20,8 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.RAMDirectory;
 
 public class RefCntRamDirectory extends RAMDirectory {
Index: lucene/contrib/misc/src/test/org/apache/lucene/index/codecs/appending/TestAppendingCodec.java
===================================================================
--- lucene/contrib/misc/src/test/org/apache/lucene/index/codecs/appending/TestAppendingCodec.java	(revision 1140355)
+++ lucene/contrib/misc/src/test/org/apache/lucene/index/codecs/appending/TestAppendingCodec.java	(working copy)
@@ -27,7 +27,6 @@
 import org.apache.lucene.document.Field.TermVector;
 import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.Fields;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
@@ -41,6 +40,7 @@
 import org.apache.lucene.index.codecs.SegmentInfosReader;
 import org.apache.lucene.index.codecs.SegmentInfosWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
Index: lucene/contrib/misc/src/test/org/apache/lucene/store/TestNRTCachingDirectory.java
===================================================================
--- lucene/contrib/misc/src/test/org/apache/lucene/store/TestNRTCachingDirectory.java	(revision 1140355)
+++ lucene/contrib/misc/src/test/org/apache/lucene/store/TestNRTCachingDirectory.java	(working copy)
@@ -24,7 +24,6 @@
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingCodec.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingCodec.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingCodec.java	(working copy)
@@ -105,7 +105,7 @@
               state.segmentInfo.name,
               state.termsIndexDivisor,
               BytesRef.getUTF8SortedAsUnicodeComparator(),
-              state.codecId);
+              state.codecId, state.context);
       success = true;
     } finally {
       if (!success) {
@@ -155,6 +155,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosWriter.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosWriter.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosWriter.java	(working copy)
@@ -19,9 +19,9 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.DefaultSegmentInfosWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 
 public class AppendingSegmentInfosWriter extends DefaultSegmentInfosWriter {
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsDictReader.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsDictReader.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsDictReader.java	(working copy)
@@ -20,12 +20,12 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.PostingsReaderBase;
 import org.apache.lucene.index.codecs.BlockTermsReader;
 import org.apache.lucene.index.codecs.BlockTermsWriter;
 import org.apache.lucene.index.codecs.TermsIndexReaderBase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.CodecUtil;
 
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosReader.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosReader.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingSegmentInfosReader.java	(working copy)
@@ -20,9 +20,9 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.CorruptIndexException;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.DefaultSegmentInfosReader;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 
 public class AppendingSegmentInfosReader extends DefaultSegmentInfosReader {
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsIndexReader.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsIndexReader.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/codecs/appending/AppendingTermsIndexReader.java	(working copy)
@@ -21,9 +21,9 @@
 import java.util.Comparator;
 
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.FixedGapTermsIndexReader;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CodecUtil;
@@ -31,9 +31,9 @@
 public class AppendingTermsIndexReader extends FixedGapTermsIndexReader {
 
   public AppendingTermsIndexReader(Directory dir, FieldInfos fieldInfos,
-          String segment, int indexDivisor, Comparator<BytesRef> termComp, int codecId)
+          String segment, int indexDivisor, Comparator<BytesRef> termComp, int codecId, IOContext context)
           throws IOException {
-    super(dir, fieldInfos, segment, indexDivisor, termComp, codecId, IOContext.DEFAULT);
+    super(dir, fieldInfos, segment, indexDivisor, termComp, codecId, context);
   }
   
   @Override
Index: lucene/contrib/misc/src/java/org/apache/lucene/store/WindowsDirectory.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/store/WindowsDirectory.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/store/WindowsDirectory.java	(working copy)
@@ -20,7 +20,6 @@
 import java.io.File;
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.store.Directory; // javadoc
 import org.apache.lucene.store.NativeFSLockFactory; // javadoc
 
Index: lucene/contrib/misc/src/java/org/apache/lucene/store/NRTCachingDirectory.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/store/NRTCachingDirectory.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/store/NRTCachingDirectory.java	(working copy)
@@ -24,10 +24,8 @@
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.lucene.index.ConcurrentMergeScheduler;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexWriter;       // javadocs
-import org.apache.lucene.index.MergeInfo;
 import org.apache.lucene.index.MergePolicy;
 import org.apache.lucene.index.MergeScheduler;
 import org.apache.lucene.store.RAMDirectory;      // javadocs
Index: lucene/contrib/misc/src/java/org/apache/lucene/store/DirectIOLinuxDirectory.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/store/DirectIOLinuxDirectory.java	(revision 1140355)
+++ lucene/contrib/misc/src/java/org/apache/lucene/store/DirectIOLinuxDirectory.java	(working copy)
@@ -25,7 +25,6 @@
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.store.Directory; // javadoc
 import org.apache.lucene.store.NativeFSLockFactory; // javadoc
 
Index: lucene/src/test/org/apache/lucene/search/TestBoolean2.java
===================================================================
--- lucene/src/test/org/apache/lucene/search/TestBoolean2.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/search/TestBoolean2.java	(working copy)
@@ -23,13 +23,13 @@
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.queryParser.ParseException;
 import org.apache.lucene.queryParser.QueryParser;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.util.LuceneTestCase;
Index: lucene/src/test/org/apache/lucene/index/TestSnapshotDeletionPolicy.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestSnapshotDeletionPolicy.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestSnapshotDeletionPolicy.java	(working copy)
@@ -25,6 +25,7 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.index.IndexCommit;
@@ -202,7 +203,7 @@
   byte[] buffer = new byte[4096];
 
   private void readFile(Directory dir, String name) throws Exception {
-    IndexInput input = dir.openInput(name, IOContext.DEFAULT);
+    IndexInput input = dir.openInput(name, newIOContext(random));
     try {
       long size = dir.fileLength(name);
       long bytesLeft = size;
Index: lucene/src/test/org/apache/lucene/index/TestDoc.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestDoc.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestDoc.java	(working copy)
@@ -32,11 +32,10 @@
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexWriterConfig.OpenMode;
-import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 import org.apache.lucene.index.codecs.CodecProvider;
@@ -199,7 +198,7 @@
       SegmentReader r1 = SegmentReader.get(true, si1, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, context);
       SegmentReader r2 = SegmentReader.get(true, si2, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, context);
 
-      SegmentMerger merger = new SegmentMerger(si1.dir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL, merged, null, null, new FieldInfos());
+      SegmentMerger merger = new SegmentMerger(si1.dir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL, merged, null, null, new FieldInfos(), context);
 
       merger.add(r1);
       merger.add(r2);
@@ -211,7 +210,7 @@
                                                false, merger.getSegmentCodecs(), fieldInfos);
       
       if (useCompoundFile) {
-        Collection<String> filesToDelete = merger.createCompoundFile(merged + ".cfs", info, IOContext.DEFAULT);
+        Collection<String> filesToDelete = merger.createCompoundFile(merged + ".cfs", info, newIOContext(random));
         info.setUseCompoundFile(true);
         for (final String fileToDelete : filesToDelete) 
           si1.dir.deleteFile(fileToDelete);
Index: lucene/src/test/org/apache/lucene/index/TestIndexReaderOnDiskFull.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexReaderOnDiskFull.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexReaderOnDiskFull.java	(working copy)
@@ -84,7 +84,7 @@
 
     // Iterate w/ ever increasing free disk space:
     while(!done) {
-      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, IOContext.DEFAULT));
+      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, newIOContext(random)));
 
       // If IndexReader hits disk full, it can write to
       // the same files again.
Index: lucene/src/test/org/apache/lucene/index/TestIndexInput.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexInput.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexInput.java	(working copy)
@@ -99,10 +99,10 @@
   // this test checks the raw IndexInput methods as it uses RAMIndexInput which extends IndexInput directly
   public void testRawIndexInputRead() throws IOException {
     final RAMDirectory dir = new RAMDirectory();
-    final IndexOutput os = dir.createOutput("foo", IOContext.DEFAULT);
+    final IndexOutput os = dir.createOutput("foo", newIOContext(random));
     os.writeBytes(READ_TEST_BYTES, READ_TEST_BYTES.length);
     os.close();
-    final IndexInput is = dir.openInput("foo", IOContext.DEFAULT);
+    final IndexInput is = dir.openInput("foo", newIOContext(random));
     checkReads(is);
     is.close();
     dir.close();
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterOnDiskFull.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterOnDiskFull.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterOnDiskFull.java	(working copy)
@@ -27,6 +27,7 @@
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.util.LuceneTestCase;
@@ -230,7 +231,7 @@
         }
         
         // Make a new dir that will enforce disk usage:
-        MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, IOContext.DEFAULT));
+        MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, newIOContext(random)));
         writer = new IndexWriter(dir, newIndexWriterConfig( TEST_VERSION_CURRENT, new MockAnalyzer(random)).setOpenMode(OpenMode.APPEND).setMergePolicy(newLogMergePolicy()));
         IOException err = null;
         writer.setInfoStream(VERBOSE ? System.out : null);
Index: lucene/src/test/org/apache/lucene/index/TestTermVectorsReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestTermVectorsReader.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestTermVectorsReader.java	(working copy)
@@ -31,8 +31,9 @@
 import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.LuceneTestCase;
 
@@ -175,7 +176,7 @@
   }
 
   public void testReader() throws IOException {
-    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
     for (int j = 0; j < 5; j++) {
       TermFreqVector vector = reader.get(j, testFields[0]);
       assertTrue(vector != null);
@@ -192,7 +193,7 @@
   }
 
   public void testPositionReader() throws IOException {
-    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
     TermPositionVector vector;
     BytesRef[] terms;
     vector = (TermPositionVector) reader.get(0, testFields[0]);
@@ -235,7 +236,7 @@
   }
 
   public void testOffsetReader() throws IOException {
-    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
     TermPositionVector vector = (TermPositionVector) reader.get(0, testFields[0]);
     assertTrue(vector != null);
     BytesRef[] terms = vector.getTerms();
@@ -264,7 +265,7 @@
   }
 
   public void testMapper() throws IOException {
-    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+    TermVectorsReader reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
     SortedTermVectorMapper mapper = new SortedTermVectorMapper(new TermVectorEntryFreqSortedComparator());
     reader.get(0, mapper);
     SortedSet<TermVectorEntry> set = mapper.getTermVectorEntrySet();
@@ -385,7 +386,7 @@
   public void testBadParams() throws IOException {
     TermVectorsReader reader = null;
     try {
-      reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+      reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
       //Bad document number, good field number
       reader.get(50, testFields[0]);
       fail();
@@ -395,7 +396,7 @@
       reader.close();
     }
     try {
-      reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+      reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
       //Bad document number, no field
       reader.get(50);
       fail();
@@ -405,7 +406,7 @@
       reader.close();
     }
     try {
-      reader = new TermVectorsReader(dir, seg, fieldInfos, IOContext.READ);
+      reader = new TermVectorsReader(dir, seg, fieldInfos, newIOContext(random));
       //good document number, bad field number
       TermFreqVector vector = reader.get(0, "f50");
       assertTrue(vector == null);
Index: lucene/src/test/org/apache/lucene/index/TestSegmentTermDocs.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestSegmentTermDocs.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestSegmentTermDocs.java	(working copy)
@@ -19,6 +19,7 @@
 
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
@@ -55,7 +56,7 @@
 
   public void testTermDocs(int indexDivisor) throws IOException {
     //After adding the document, we should be able to read it back in
-    SegmentReader reader = SegmentReader.get(true, info, indexDivisor, IOContext.DEFAULT);
+    SegmentReader reader = SegmentReader.get(true, info, indexDivisor, newIOContext(random));
     assertTrue(reader != null);
     assertEquals(indexDivisor, reader.getTermInfosIndexDivisor());
 
@@ -78,7 +79,7 @@
   public void testBadSeek(int indexDivisor) throws IOException {
     {
       //After adding the document, we should be able to read it back in
-      SegmentReader reader = SegmentReader.get(true, info, indexDivisor, IOContext.DEFAULT);
+      SegmentReader reader = SegmentReader.get(true, info, indexDivisor, newIOContext(random));
       assertTrue(reader != null);
       DocsEnum termDocs = reader.termDocsEnum(reader.getDeletedDocs(),
                                               "textField2",
@@ -89,7 +90,7 @@
     }
     {
       //After adding the document, we should be able to read it back in
-      SegmentReader reader = SegmentReader.get(true, info, indexDivisor, IOContext.DEFAULT);
+      SegmentReader reader = SegmentReader.get(true, info, indexDivisor, newIOContext(random));
       assertTrue(reader != null);
       DocsEnum termDocs = reader.termDocsEnum(reader.getDeletedDocs(),
                                               "junk",
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(working copy)
@@ -60,6 +60,7 @@
 import org.apache.lucene.search.spans.SpanTermQuery;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockFactory;
@@ -1029,7 +1030,7 @@
     Directory dir = newDirectory();
     try {
       // Create my own random file:
-      IndexOutput out = dir.createOutput("myrandomfile", IOContext.DEFAULT);
+      IndexOutput out = dir.createOutput("myrandomfile", newIOContext(random));
       out.writeByte((byte) 42);
       out.close();
 
Index: lucene/src/test/org/apache/lucene/index/TestMultiLevelSkipList.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestMultiLevelSkipList.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestMultiLevelSkipList.java	(working copy)
@@ -30,6 +30,7 @@
 import org.apache.lucene.document.Field.Index;
 import org.apache.lucene.document.Field.Store;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(working copy)
@@ -39,6 +39,7 @@
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.PhraseQuery;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.MockDirectoryWrapper;
@@ -935,7 +936,7 @@
       if (VERBOSE) {
         System.out.println("TEST: iter " + i);
       }
-      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, IOContext.DEFAULT));
+      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, newIOContext(random)));
       conf = newIndexWriterConfig( TEST_VERSION_CURRENT, new MockAnalyzer(random)).setMergeScheduler(new ConcurrentMergeScheduler());
       ((ConcurrentMergeScheduler) conf.getMergeScheduler()).setSuppressExceptions();
       w = new IndexWriter(dir, conf);
@@ -1039,8 +1040,8 @@
     assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
     final String segmentsFileName = SegmentInfos.getCurrentSegmentFileName(dir);
-    IndexInput in = dir.openInput(segmentsFileName, IOContext.DEFAULT);
-    IndexOutput out = dir.createOutput(IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, "", 1+gen), IOContext.DEFAULT);
+    IndexInput in = dir.openInput(segmentsFileName, newIOContext(random));
+    IndexOutput out = dir.createOutput(IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS, "", 1+gen), newIOContext(random));
     out.copyBytes(in, in.length()-1);
     byte b = in.readByte();
     out.writeByte((byte) (1+b));
@@ -1084,8 +1085,8 @@
       String fileNameOut = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS,
                                                                  "",
                                                                  1+gen);
-      IndexInput in = dir.openInput(fileNameIn, IOContext.DEFAULT);
-      IndexOutput out = dir.createOutput(fileNameOut, IOContext.DEFAULT);
+      IndexInput in = dir.openInput(fileNameIn, newIOContext(random));
+      IndexOutput out = dir.createOutput(fileNameOut, newIOContext(random));
       long length = in.length();
       for(int i=0;i<length-1;i++) {
         out.writeByte(in.readByte());
@@ -1185,8 +1186,8 @@
       String fileNameOut = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS,
                                                                  "",
                                                                  1+gen);
-      IndexInput in = dir.openInput(fileNameIn, IOContext.DEFAULT);
-      IndexOutput out = dir.createOutput(fileNameOut, IOContext.DEFAULT);
+      IndexInput in = dir.openInput(fileNameIn, newIOContext(random));
+      IndexOutput out = dir.createOutput(fileNameOut, newIOContext(random));
       long length = in.length();
       for(int i=0;i<length-1;i++) {
         out.writeByte(in.readByte());
Index: lucene/src/test/org/apache/lucene/index/TestTermVectorsWriter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestTermVectorsWriter.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestTermVectorsWriter.java	(working copy)
@@ -299,7 +299,7 @@
           .setMergeScheduler(new SerialMergeScheduler()).setMergePolicy(
               new LogDocMergePolicy()));
 
-      Directory[] indexDirs = {new MockDirectoryWrapper(random, new RAMDirectory(dir, IOContext.DEFAULT))};
+      Directory[] indexDirs = {new MockDirectoryWrapper(random, new RAMDirectory(dir, newIOContext(random)))};
       writer.addIndexes(indexDirs);
       writer.optimize();
       writer.close();
Index: lucene/src/test/org/apache/lucene/index/TestDocumentWriter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestDocumentWriter.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestDocumentWriter.java	(working copy)
@@ -34,8 +34,9 @@
 import org.apache.lucene.document.Field.Store;
 import org.apache.lucene.document.Field.TermVector;
 import org.apache.lucene.document.Fieldable;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.LuceneTestCase;
@@ -69,7 +70,7 @@
     SegmentInfo info = writer.newestSegment();
     writer.close();
     //After adding the document, we should be able to read it back in
-    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.READ);
+    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
     assertTrue(reader != null);
     Document doc = reader.document(0);
     assertTrue(doc != null);
@@ -130,7 +131,7 @@
     writer.commit();
     SegmentInfo info = writer.newestSegment();
     writer.close();
-    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.READ);
+    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
 
     DocsAndPositionsEnum termPositions = MultiFields.getTermPositionsEnum(reader, MultiFields.getDeletedDocs(reader),
                                                                           "repeated", new BytesRef("repeated"));
@@ -194,7 +195,7 @@
     writer.commit();
     SegmentInfo info = writer.newestSegment();
     writer.close();
-    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.READ);
+    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
 
     DocsAndPositionsEnum termPositions = reader.fields().terms("f1").docsAndPositions(reader.getDeletedDocs(), new BytesRef("a"), null);
     assertTrue(termPositions.nextDoc() != termPositions.NO_MORE_DOCS);
@@ -238,7 +239,7 @@
     writer.commit();
     SegmentInfo info = writer.newestSegment();
     writer.close();
-    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.READ);
+    SegmentReader reader = SegmentReader.get(true, info, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
 
     DocsAndPositionsEnum termPositions = reader.fields().terms("preanalyzed").docsAndPositions(reader.getDeletedDocs(), new BytesRef("term1"), null);
     assertTrue(termPositions.nextDoc() != termPositions.NO_MORE_DOCS);
Index: lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(working copy)
@@ -21,6 +21,7 @@
 import org.apache.lucene.search.DefaultSimilarity;
 import org.apache.lucene.search.Similarity;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.MockDirectoryWrapper;
@@ -91,7 +92,7 @@
     // figure out which field number corresponds to
     // "content", and then set our expected file names below
     // accordingly:
-    CompoundFileReader cfsReader = new CompoundFileReader(dir, "_2.cfs", IOContext.DEFAULT);
+    CompoundFileReader cfsReader = new CompoundFileReader(dir, "_2.cfs", newIOContext(random));
     FieldInfos fieldInfos = new FieldInfos(cfsReader, "_2.fnm");
     int contentFieldIndex = -1;
     for (FieldInfo fi : fieldInfos) {
@@ -212,8 +213,8 @@
   }
 
   public void copyFile(Directory dir, String src, String dest) throws IOException {
-    IndexInput in = dir.openInput(src, IOContext.DEFAULT);
-    IndexOutput out = dir.createOutput(dest, IOContext.DEFAULT);
+    IndexInput in = dir.openInput(src, newIOContext(random));
+    IndexOutput out = dir.createOutput(dest, newIOContext(random));
     byte[] b = new byte[1024];
     long remainder = in.length();
     while(remainder > 0) {
Index: lucene/src/test/org/apache/lucene/index/values/TestDocValues.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/values/TestDocValues.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/values/TestDocValues.java	(working copy)
@@ -24,6 +24,7 @@
 import org.apache.lucene.index.values.IndexDocValues.SortedSource;
 import org.apache.lucene.index.values.IndexDocValues.Source;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.FloatsRef;
 import org.apache.lucene.util.LongsRef;
@@ -61,7 +62,7 @@
 
     Directory dir = newDirectory();
     final AtomicLong trackBytes = new AtomicLong(0);
-    Writer w = Bytes.getWriter(dir, "test", mode, comp, fixedSize, trackBytes);
+    Writer w = Bytes.getWriter(dir, "test", mode, comp, fixedSize, trackBytes, newIOContext(random));
     int maxDoc = 220;
     final String[] values = new String[maxDoc];
     final int fixedLength = 3 + random.nextInt(7);
@@ -81,7 +82,7 @@
     w.finish(maxDoc);
     assertEquals(0, trackBytes.get());
 
-    IndexDocValues r = Bytes.getValues(dir, "test", mode, fixedSize, maxDoc);
+    IndexDocValues r = Bytes.getValues(dir, "test", mode, fixedSize, maxDoc, newIOContext(random));
     for (int iter = 0; iter < 2; iter++) {
       ValuesEnum bytesEnum = getEnum(r);
       assertNotNull("enum is null", bytesEnum);
@@ -185,7 +186,7 @@
       for (int rx = 1; rx < 63; rx++, maxV *= 2) {
         Directory dir = newDirectory();
         final AtomicLong trackBytes = new AtomicLong(0);
-        Writer w = Ints.getWriter(dir, "test", false, trackBytes);
+        Writer w = Ints.getWriter(dir, "test", false, trackBytes, newIOContext(random));
         values[0] = maxMin[j];
         w.add(0, values[0]);
         values[1] = maxMin[j+1];
@@ -199,7 +200,7 @@
         w.finish(NUM_VALUES + additionalDocs);
         assertEquals(0, trackBytes.get());
 
-        IndexDocValues r = Ints.getValues(dir, "test", false);
+        IndexDocValues r = Ints.getValues(dir, "test", false, newIOContext(random));
         for (int iter = 0; iter < 2; iter++) {
           Source s = getSource(r);
           for (int i = 0; i < NUM_VALUES; i++) {
@@ -250,7 +251,7 @@
   private void runTestFloats(int precision, double delta) throws IOException {
     Directory dir = newDirectory();
     final AtomicLong trackBytes = new AtomicLong(0);
-    Writer w = Floats.getWriter(dir, "test", precision, trackBytes);
+    Writer w = Floats.getWriter(dir, "test", precision, trackBytes, newIOContext(random));
     final int NUM_VALUES = 777 + random.nextInt(777);;
     final double[] values = new double[NUM_VALUES];
     for (int i = 0; i < NUM_VALUES; i++) {
@@ -263,7 +264,7 @@
     w.finish(NUM_VALUES + additionalValues);
     assertEquals(0, trackBytes.get());
 
-    IndexDocValues r = Floats.getValues(dir, "test", NUM_VALUES + additionalValues);
+    IndexDocValues r = Floats.getValues(dir, "test", NUM_VALUES + additionalValues, newIOContext(random));
     for (int iter = 0; iter < 2; iter++) {
       Source s = getSource(r);
       for (int i = 0; i < NUM_VALUES; i++) {
Index: lucene/src/test/org/apache/lucene/index/TestCodecs.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestCodecs.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestCodecs.java	(working copy)
@@ -25,7 +25,6 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.Field.Store;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.FieldsConsumer;
 import org.apache.lucene.index.codecs.FieldsProducer;
@@ -40,6 +39,8 @@
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util.Version;
@@ -243,7 +244,7 @@
     this.write(fieldInfos, dir, fields, true);
     final SegmentInfo si = new SegmentInfo(SEGMENT, 10000, dir, false, clonedFieldInfos.buildSegmentCodecs(false), clonedFieldInfos);
 
-    final FieldsProducer reader = si.getSegmentCodecs().codec().fieldsProducer(new SegmentReadState(dir, si, fieldInfos, IOContext.READ, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR));
+    final FieldsProducer reader = si.getSegmentCodecs().codec().fieldsProducer(new SegmentReadState(dir, si, fieldInfos, newIOContext(random), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR));
 
     final FieldsEnum fieldsEnum = reader.iterator();
     assertNotNull(fieldsEnum.next());
@@ -298,7 +299,7 @@
     if (VERBOSE) {
       System.out.println("TEST: now read postings");
     }
-    final FieldsProducer terms = si.getSegmentCodecs().codec().fieldsProducer(new SegmentReadState(dir, si, fieldInfos, IOContext.READ, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR));
+    final FieldsProducer terms = si.getSegmentCodecs().codec().fieldsProducer(new SegmentReadState(dir, si, fieldInfos, newIOContext(random), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR));
 
     final Verify[] threads = new Verify[NUM_TEST_THREADS-1];
     for(int i=0;i<NUM_TEST_THREADS-1;i++) {
@@ -592,7 +593,7 @@
 
     final int termIndexInterval = _TestUtil.nextInt(random, 13, 27);
     final SegmentCodecs codecInfo =  fieldInfos.buildSegmentCodecs(false);
-    final SegmentWriteState state = new SegmentWriteState(null, dir, SEGMENT, fieldInfos, 10000, termIndexInterval, codecInfo, null, new IOContext(Context.FLUSH));
+    final SegmentWriteState state = new SegmentWriteState(null, dir, SEGMENT, fieldInfos, 10000, termIndexInterval, codecInfo, null, newIOContext(random));
 
     final FieldsConsumer consumer = state.segmentCodecs.codec().fieldsConsumer(state);
     Arrays.sort(fields);
Index: lucene/src/test/org/apache/lucene/index/TestMultiReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestMultiReader.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestMultiReader.java	(working copy)
@@ -19,6 +19,8 @@
 
 import java.io.IOException;
 
+import org.apache.lucene.store.IOContext;
+
 public class TestMultiReader extends TestDirectoryReader {
 
   @Override
@@ -26,8 +28,8 @@
     IndexReader reader;
 
     sis.read(dir);
-    SegmentReader reader1 = SegmentReader.get(false, sis.info(0), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.DEFAULT);
-    SegmentReader reader2 = SegmentReader.get(false, sis.info(1), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.DEFAULT);
+    SegmentReader reader1 = SegmentReader.get(false, sis.info(0), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
+    SegmentReader reader2 = SegmentReader.get(false, sis.info(1), IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
     readers[0] = reader1;
     readers[1] = reader2;
     assertTrue(reader1 != null);
Index: lucene/src/test/org/apache/lucene/index/TestFieldInfos.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestFieldInfos.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestFieldInfos.java	(working copy)
@@ -20,7 +20,6 @@
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IndexOutput;
 
@@ -48,7 +47,7 @@
     assertTrue(fieldInfos.size() == DocHelper.all.size()); //this is all b/c we are using the no-arg constructor
     
     
-    IndexOutput output = dir.createOutput(filename, IOContext.DEFAULT);
+    IndexOutput output = dir.createOutput(filename, newIOContext(random));
     assertTrue(output != null);
     //Use a RAMOutputStream
   
Index: lucene/src/test/org/apache/lucene/index/TestCompoundFile.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestCompoundFile.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestCompoundFile.java	(working copy)
@@ -24,12 +24,13 @@
 import junit.framework.TestSuite;
 import junit.textui.TestRunner;
 
-import org.apache.lucene.index.IOContext.Context;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.SimpleFSDirectory;
 import org.apache.lucene.store._TestHelper;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util._TestUtil;
 
 
@@ -74,7 +75,7 @@
     private void createRandomFile(Directory dir, String name, int size)
     throws IOException
     {
-        IndexOutput os = dir.createOutput(name, new IOContext(Context.FLUSH));
+        IndexOutput os = dir.createOutput(name, newIOContext(random));
         for (int i=0; i<size; i++) {
             byte b = (byte) (Math.random() * 256);
             os.writeByte(b);
@@ -92,7 +93,7 @@
                                     int size)
     throws IOException
     {
-        IndexOutput os = dir.createOutput(name, new IOContext(Context.FLUSH));
+        IndexOutput os = dir.createOutput(name, newIOContext(random));
         for (int i=0; i < size; i++) {
             os.writeByte(start);
             start ++;
@@ -202,13 +203,13 @@
         for (int i=0; i<data.length; i++) {
             String name = "t" + data[i];
             createSequenceFile(dir, name, (byte) 0, data[i]);
-            CompoundFileWriter csw = new CompoundFileWriter(dir, name + ".cfs", IOContext.DEFAULT);
+            CompoundFileWriter csw = new CompoundFileWriter(dir, name + ".cfs", newIOContext(random));
             csw.addFile(name);
             csw.close();
 
-            CompoundFileReader csr = new CompoundFileReader(dir, name + ".cfs", IOContext.DEFAULT);
-            IndexInput expected = dir.openInput(name, IOContext.DEFAULT);
-            IndexInput actual = csr.openInput(name, IOContext.DEFAULT);
+            CompoundFileReader csr = new CompoundFileReader(dir, name + ".cfs", newIOContext(random));
+            IndexInput expected = dir.openInput(name, newIOContext(random));
+            IndexInput actual = csr.openInput(name, newIOContext(random));
             assertSameStreams(name, expected, actual);
             assertSameSeekBehavior(name, expected, actual);
             expected.close();
@@ -225,21 +226,21 @@
         createSequenceFile(dir, "d1", (byte) 0, 15);
         createSequenceFile(dir, "d2", (byte) 0, 114);
 
-        CompoundFileWriter csw = new CompoundFileWriter(dir, "d.csf", IOContext.DEFAULT);
+        CompoundFileWriter csw = new CompoundFileWriter(dir, "d.csf", newIOContext(random));
         csw.addFile("d1");
         csw.addFile("d2");
         csw.close();
 
-        CompoundFileReader csr = new CompoundFileReader(dir, "d.csf", IOContext.DEFAULT);
-        IndexInput expected = dir.openInput("d1", IOContext.DEFAULT);
-        IndexInput actual = csr.openInput("d1", IOContext.DEFAULT);
+        CompoundFileReader csr = new CompoundFileReader(dir, "d.csf", newIOContext(random));
+        IndexInput expected = dir.openInput("d1", newIOContext(random));
+        IndexInput actual = csr.openInput("d1", newIOContext(random));
         assertSameStreams("d1", expected, actual);
         assertSameSeekBehavior("d1", expected, actual);
         expected.close();
         actual.close();
 
-        expected = dir.openInput("d2", IOContext.DEFAULT);
-        actual = csr.openInput("d2", IOContext.DEFAULT);
+        expected = dir.openInput("d2", newIOContext(random));
+        actual = csr.openInput("d2", newIOContext(random));
         assertSameStreams("d2", expected, actual);
         assertSameSeekBehavior("d2", expected, actual);
         expected.close();
@@ -275,7 +276,7 @@
         createRandomFile(dir, segment + ".notIn2", 51);
 
         // Now test
-        CompoundFileWriter csw = new CompoundFileWriter(dir, "test.cfs", IOContext.DEFAULT);
+        CompoundFileWriter csw = new CompoundFileWriter(dir, "test.cfs", newIOContext(random));
         final String data[] = new String[] {
             ".zero", ".one", ".ten", ".hundred", ".big1", ".big2", ".big3",
             ".big4", ".big5", ".big6", ".big7"
@@ -285,10 +286,10 @@
         }
         csw.close();
 
-        CompoundFileReader csr = new CompoundFileReader(dir, "test.cfs", IOContext.DEFAULT);
+        CompoundFileReader csr = new CompoundFileReader(dir, "test.cfs", newIOContext(random));
         for (int i=0; i<data.length; i++) {
-            IndexInput check = dir.openInput(segment + data[i], IOContext.DEFAULT);
-            IndexInput test = csr.openInput(segment + data[i], IOContext.DEFAULT);
+            IndexInput check = dir.openInput(segment + data[i], newIOContext(random));
+            IndexInput test = csr.openInput(segment + data[i], newIOContext(random));
             assertSameStreams(data[i], check, test);
             assertSameSeekBehavior(data[i], check, test);
             test.close();
@@ -304,7 +305,7 @@
      *  the size of each file is 1000 bytes.
      */
     private void setUp_2() throws IOException {
-        CompoundFileWriter cw = new CompoundFileWriter(dir, "f.comp", IOContext.DEFAULT);
+        CompoundFileWriter cw = new CompoundFileWriter(dir, "f.comp", newIOContext(random));
         for (int i=0; i<20; i++) {
             createSequenceFile(dir, "f" + i, (byte) 0, 2000);
             cw.addFile("f" + i);
@@ -321,13 +322,13 @@
     throws IOException
     {
         // Setup the test file - we need more than 1024 bytes
-        IndexOutput os = fsdir.createOutput(file, IOContext.DEFAULT);
+        IndexOutput os = fsdir.createOutput(file, newIOContext(random));
         for(int i=0; i<2000; i++) {
             os.writeByte((byte) i);
         }
         os.close();
 
-        IndexInput in = fsdir.openInput(file, IOContext.DEFAULT);
+        IndexInput in = fsdir.openInput(file, newIOContext(random));
 
         // This read primes the buffer in IndexInput
         in.readByte();
@@ -371,16 +372,16 @@
 
     public void testClonedStreamsClosing() throws IOException {
         setUp_2();
-        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", IOContext.DEFAULT);
+        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", newIOContext(random));
 
         // basic clone
-        IndexInput expected = dir.openInput("f11", IOContext.DEFAULT);
+        IndexInput expected = dir.openInput("f11", newIOContext(random));
 
         // this test only works for FSIndexInput
         assertTrue(_TestHelper.isSimpleFSIndexInput(expected));
         assertTrue(_TestHelper.isSimpleFSIndexInputOpen(expected));
 
-        IndexInput one = cr.openInput("f11", IOContext.DEFAULT);
+        IndexInput one = cr.openInput("f11", newIOContext(random));
         assertTrue(isCSIndexInputOpen(one));
 
         IndexInput two = (IndexInput) one.clone();
@@ -428,14 +429,14 @@
      */
     public void testRandomAccess() throws IOException {
         setUp_2();
-        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", IOContext.DEFAULT);
+        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", newIOContext(random));
 
         // Open two files
-        IndexInput e1 = dir.openInput("f11", IOContext.DEFAULT);
-        IndexInput e2 = dir.openInput("f3", IOContext.DEFAULT);
+        IndexInput e1 = dir.openInput("f11", newIOContext(random));
+        IndexInput e2 = dir.openInput("f3", newIOContext(random));
 
-        IndexInput a1 = cr.openInput("f11", IOContext.DEFAULT);
-        IndexInput a2 = dir.openInput("f3", IOContext.DEFAULT);
+        IndexInput a1 = cr.openInput("f11", newIOContext(random));
+        IndexInput a2 = dir.openInput("f3", newIOContext(random));
 
         // Seek the first pair
         e1.seek(100);
@@ -507,11 +508,11 @@
      */
     public void testRandomAccessClones() throws IOException {
         setUp_2();
-        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", IOContext.DEFAULT);
+        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", newIOContext(random));
 
         // Open two files
-        IndexInput e1 = cr.openInput("f11", IOContext.DEFAULT);
-        IndexInput e2 = cr.openInput("f3", IOContext.DEFAULT);
+        IndexInput e1 = cr.openInput("f11", newIOContext(random));
+        IndexInput e2 = cr.openInput("f3", newIOContext(random));
 
         IndexInput a1 = (IndexInput) e1.clone();
         IndexInput a2 = (IndexInput) e2.clone();
@@ -584,11 +585,11 @@
 
     public void testFileNotFound() throws IOException {
         setUp_2();
-        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", IOContext.DEFAULT);
+        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", newIOContext(random));
 
         // Open two files
         try {
-            cr.openInput("bogus", IOContext.DEFAULT);
+            cr.openInput("bogus", newIOContext(random));
             fail("File not found");
 
         } catch (IOException e) {
@@ -602,8 +603,8 @@
 
     public void testReadPastEOF() throws IOException {
         setUp_2();
-        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", IOContext.DEFAULT);
-        IndexInput is = cr.openInput("f2", IOContext.DEFAULT);
+        CompoundFileReader cr = new CompoundFileReader(dir, "f.comp", newIOContext(random));
+        IndexInput is = cr.openInput("f2", newIOContext(random));
         is.seek(is.length() - 10);
         byte b[] = new byte[100];
         is.readBytes(b, 0, 10);
@@ -633,7 +634,7 @@
      * will correctly increment the file pointer.
      */
     public void testLargeWrites() throws IOException {
-        IndexOutput os = dir.createOutput("testBufferStart.txt", IOContext.DEFAULT);
+        IndexOutput os = dir.createOutput("testBufferStart.txt", newIOContext(random));
 
         byte[] largeBuf = new byte[2048];
         for (int i=0; i<largeBuf.length; i++) {
@@ -655,13 +656,13 @@
        createSequenceFile(dir, "d1", (byte) 0, 15);
 
        Directory newDir = newDirectory();
-       CompoundFileWriter csw = new CompoundFileWriter(newDir, "d.csf", IOContext.DEFAULT);
+       CompoundFileWriter csw = new CompoundFileWriter(newDir, "d.csf", newIOContext(random));
        csw.addFile("d1", dir);
        csw.close();
 
-       CompoundFileReader csr = new CompoundFileReader(newDir, "d.csf", IOContext.DEFAULT);
-       IndexInput expected = dir.openInput("d1", IOContext.DEFAULT);
-       IndexInput actual = csr.openInput("d1", IOContext.DEFAULT);
+       CompoundFileReader csr = new CompoundFileReader(newDir, "d.csf", newIOContext(random));
+       IndexInput expected = dir.openInput("d1", newIOContext(random));
+       IndexInput actual = csr.openInput("d1", newIOContext(random));
        assertSameStreams("d1", expected, actual);
        assertSameSeekBehavior("d1", expected, actual);
        expected.close();
Index: lucene/src/test/org/apache/lucene/index/TestDocTermOrds.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestDocTermOrds.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestDocTermOrds.java	(working copy)
@@ -223,7 +223,7 @@
 
     @Override
     public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-      return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+      return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
     }
   }
 
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(working copy)
@@ -36,6 +36,7 @@
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TopDocs;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.RAMDirectory;
@@ -469,7 +470,7 @@
             try {
               final Directory[] dirs = new Directory[numDirs];
               for (int k = 0; k < numDirs; k++)
-                dirs[k] = new MockDirectoryWrapper(random, new RAMDirectory(addDir, IOContext.DEFAULT));
+                dirs[k] = new MockDirectoryWrapper(random, new RAMDirectory(addDir, newIOContext(random)));
               //int j = 0;
               //while (true) {
                 // System.out.println(Thread.currentThread().getName() + ": iter
@@ -754,7 +755,7 @@
 
     final Directory[] dirs = new Directory[10];
     for (int i=0;i<10;i++) {
-      dirs[i] = new MockDirectoryWrapper(random, new RAMDirectory(dir1, IOContext.DEFAULT));
+      dirs[i] = new MockDirectoryWrapper(random, new RAMDirectory(dir1, newIOContext(random)));
     }
 
     IndexReader r = writer.getReader();
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(working copy)
@@ -456,7 +456,7 @@
       if (VERBOSE) {
         System.out.println("TEST: cycle");
       }
-      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, IOContext.DEFAULT));
+      MockDirectoryWrapper dir = new MockDirectoryWrapper(random, new RAMDirectory(startDir, newIOContext(random)));
       dir.setPreventDoubleWrite(false);
       IndexWriter modifier = new IndexWriter(dir,
                                              newIndexWriterConfig(
Index: lucene/src/test/org/apache/lucene/index/TestFieldsReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestFieldsReader.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestFieldsReader.java	(working copy)
@@ -35,6 +35,7 @@
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.LuceneTestCase;
Index: lucene/src/test/org/apache/lucene/index/TestSegmentMerger.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestSegmentMerger.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestSegmentMerger.java	(working copy)
@@ -20,6 +20,7 @@
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
@@ -54,8 +55,8 @@
     SegmentInfo info1 = DocHelper.writeDoc(random, merge1Dir, doc1);
     DocHelper.setupDoc(doc2);
     SegmentInfo info2 = DocHelper.writeDoc(random, merge2Dir, doc2);
-    reader1 = SegmentReader.get(true, info1, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.DEFAULT);
-    reader2 = SegmentReader.get(true, info2, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.DEFAULT);
+    reader1 = SegmentReader.get(true, info1, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
+    reader2 = SegmentReader.get(true, info2, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
   }
 
   @Override
@@ -77,7 +78,7 @@
   }
 
   public void testMerge() throws IOException {
-    SegmentMerger merger = new SegmentMerger(mergedDir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL, mergedSegment, null, null, new FieldInfos());
+    SegmentMerger merger = new SegmentMerger(mergedDir, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL, mergedSegment, null, null, new FieldInfos(), newIOContext(random));
     merger.add(reader1);
     merger.add(reader2);
     int docsMerged = merger.merge();
@@ -86,7 +87,7 @@
     //Should be able to open a new SegmentReader against the new directory
     SegmentReader mergedReader = SegmentReader.get(false, mergedDir, new SegmentInfo(mergedSegment, docsMerged, mergedDir, false,
                                                                                      merger.getSegmentCodecs(), fieldInfos),
-                                                   true, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, IOContext.DEFAULT);
+                                                   true, IndexReader.DEFAULT_TERMS_INDEX_DIVISOR, newIOContext(random));
     assertTrue(mergedReader != null);
     assertTrue(mergedReader.numDocs() == 2);
     Document newDoc1 = mergedReader.document(0);
@@ -148,9 +149,9 @@
     w.close();
     
     // Assert that SM fails if .del exists
-    SegmentMerger sm = new SegmentMerger(dir, 1, "a", null, null, null);
+    SegmentMerger sm = new SegmentMerger(dir, 1, "a", null, null, null, newIOContext(random));
     try {
-      sm.createCompoundFile("b1", w.segmentInfos.info(0), IOContext.DEFAULT);
+      sm.createCompoundFile("b1", w.segmentInfos.info(0), newIOContext(random));
       fail("should not have been able to create a .cfs with .del and .s* files");
     } catch (AssertionError e) {
       // expected
@@ -168,7 +169,7 @@
     
     // Assert that SM fails if .s* exists
     try {
-      sm.createCompoundFile("b2", w.segmentInfos.info(0), IOContext.DEFAULT);
+      sm.createCompoundFile("b2", w.segmentInfos.info(0), newIOContext(random));
       fail("should not have been able to create a .cfs with .del and .s* files");
     } catch (AssertionError e) {
       // expected
Index: lucene/src/test/org/apache/lucene/index/TestAddIndexes.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestAddIndexes.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestAddIndexes.java	(working copy)
@@ -38,6 +38,7 @@
 import org.apache.lucene.search.PhraseQuery;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.util.LuceneTestCase;
@@ -395,7 +396,7 @@
             setMergePolicy(newLogMergePolicy(4))
     );
 
-    writer.addIndexes(aux, new MockDirectoryWrapper(random, new RAMDirectory(aux, IOContext.DEFAULT)));
+    writer.addIndexes(aux, new MockDirectoryWrapper(random, new RAMDirectory(aux, newIOContext(random))));
     assertEquals(1060, writer.maxDoc());
     assertEquals(1000, writer.getDocCount(0));
     writer.close();
@@ -430,7 +431,7 @@
             setMergePolicy(newLogMergePolicy(4))
     );
 
-    writer.addIndexes(aux, new MockDirectoryWrapper(random, new RAMDirectory(aux, IOContext.DEFAULT)));
+    writer.addIndexes(aux, new MockDirectoryWrapper(random, new RAMDirectory(aux, newIOContext(random))));
     assertEquals(1020, writer.maxDoc());
     assertEquals(1000, writer.getDocCount(0));
     writer.close();
@@ -665,7 +666,7 @@
 
                 final Directory[] dirs = new Directory[NUM_COPY];
                 for(int k=0;k<NUM_COPY;k++)
-                  dirs[k] = new MockDirectoryWrapper(random, new RAMDirectory(dir, IOContext.DEFAULT));
+                  dirs[k] = new MockDirectoryWrapper(random, new RAMDirectory(dir, newIOContext(random)));
 
                 int j=0;
 
Index: lucene/src/test/org/apache/lucene/index/codecs/intblock/TestIntBlockCodec.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/codecs/intblock/TestIntBlockCodec.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/codecs/intblock/TestIntBlockCodec.java	(working copy)
@@ -19,7 +19,6 @@
 
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.store.*;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.sep.*;
 import org.apache.lucene.index.codecs.mockintblock.*;
 
@@ -30,13 +29,13 @@
 
     IntStreamFactory f = new MockFixedIntBlockCodec(128).getIntFactory();
 
-    IntIndexOutput out = f.createOutput(dir, "test");
+    IntIndexOutput out = f.createOutput(dir, "test", newIOContext(random));
     for(int i=0;i<11777;i++) {
       out.write(i);
     }
     out.close();
 
-    IntIndexInput in = f.openInput(dir, "test", IOContext.DEFAULT);
+    IntIndexInput in = f.openInput(dir, "test", newIOContext(random));
     IntIndexInput.Reader r = in.reader();
 
     for(int i=0;i<11777;i++) {
@@ -51,12 +50,12 @@
     Directory dir = newDirectory();
 
     IntStreamFactory f = new MockFixedIntBlockCodec(128).getIntFactory();
-    IntIndexOutput out = f.createOutput(dir, "test");
+    IntIndexOutput out = f.createOutput(dir, "test", newIOContext(random));
 
     // write no ints
     out.close();
 
-    IntIndexInput in = f.openInput(dir, "test", IOContext.DEFAULT);
+    IntIndexInput in = f.openInput(dir, "test", newIOContext(random));
     in.reader();
     // read no ints
     in.close();
Index: lucene/src/test/org/apache/lucene/index/TestSegmentReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestSegmentReader.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestSegmentReader.java	(working copy)
@@ -27,8 +27,9 @@
 
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Fieldable;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IOContext.Context;
 
 public class TestSegmentReader extends LuceneTestCase {
   private Directory dir;
Index: lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(working copy)
@@ -31,7 +31,6 @@
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.Fieldable;
 import org.apache.lucene.document.NumericField;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexWriterConfig.OpenMode;
 import org.apache.lucene.search.DefaultSimilarity;
 import org.apache.lucene.search.DocIdSetIterator;
@@ -43,7 +42,9 @@
 import org.apache.lucene.search.SimilarityProvider;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.LuceneTestCase;
Index: lucene/src/test/org/apache/lucene/index/TestLazyProxSkipping.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestLazyProxSkipping.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/index/TestLazyProxSkipping.java	(working copy)
@@ -31,6 +31,7 @@
 import org.apache.lucene.search.PhraseQuery;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
Index: lucene/src/test/org/apache/lucene/store/TestCopyBytes.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestCopyBytes.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/store/TestCopyBytes.java	(working copy)
@@ -17,36 +17,33 @@
  * limitations under the License.
  */
 
-
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 
 import org.junit.Test;
 
 public class TestCopyBytes extends LuceneTestCase {
-
+  
   private byte value(int idx) {
-    return (byte) ((idx%256) * (1+(idx/256)));
+    return (byte) ((idx % 256) * (1 + (idx / 256)));
   }
-
-
+  
   @Test
   public void testCopyBytes() throws Exception {
     int num = atLeast(10);
-    for(int iter=0;iter<num;iter++) {
+    for (int iter = 0; iter < num; iter++) {
       Directory dir = newDirectory();
       if (VERBOSE) {
         System.out.println("TEST: iter=" + iter + " dir=" + dir);
       }
-
+      
       // make random file
-      IndexOutput out = dir.createOutput("test", IOContext.DEFAULT);
+      IndexOutput out = dir.createOutput("test", newIOContext(random));
       byte[] bytes = new byte[_TestUtil.nextInt(random, 1, 77777)];
       final int size = _TestUtil.nextInt(random, 1, 1777777);
       int upto = 0;
       int byteUpto = 0;
-      while(upto < size) {
+      while (upto < size) {
         bytes[byteUpto++] = value(upto);
         upto++;
         if (byteUpto == bytes.length) {
@@ -54,24 +51,25 @@
           byteUpto = 0;
         }
       }
-
+      
       out.writeBytes(bytes, 0, byteUpto);
       assertEquals(size, out.getFilePointer());
       out.close();
       assertEquals(size, dir.fileLength("test"));
-
+      
       // copy from test -> test2
-      final IndexInput in = dir.openInput("test", IOContext.DEFAULT);
-
-      out = dir.createOutput("test2", IOContext.DEFAULT);
-
+      final IndexInput in = dir.openInput("test", newIOContext(random));
+      
+      out = dir.createOutput("test2", newIOContext(random));
+      
       upto = 0;
-      while(upto < size) {
+      while (upto < size) {
         if (random.nextBoolean()) {
           out.writeByte(in.readByte());
           upto++;
         } else {
-          final int chunk = Math.min(_TestUtil.nextInt(random, 1, bytes.length), size-upto);
+          final int chunk = Math.min(
+              _TestUtil.nextInt(random, 1, bytes.length), size - upto);
           out.copyBytes(in, chunk);
           upto += chunk;
         }
@@ -79,26 +77,27 @@
       assertEquals(size, upto);
       out.close();
       in.close();
-
+      
       // verify
-      IndexInput in2 = dir.openInput("test2", IOContext.DEFAULT);
+      IndexInput in2 = dir.openInput("test2", newIOContext(random));
       upto = 0;
-      while(upto < size) {
+      while (upto < size) {
         if (random.nextBoolean()) {
           final byte v = in2.readByte();
           assertEquals(value(upto), v);
           upto++;
         } else {
-          final int limit = Math.min(_TestUtil.nextInt(random, 1, bytes.length), size-upto);
+          final int limit = Math.min(
+              _TestUtil.nextInt(random, 1, bytes.length), size - upto);
           in2.readBytes(bytes, 0, limit);
-          for(int byteIdx=0;byteIdx<limit;byteIdx++) {
+          for (int byteIdx = 0; byteIdx < limit; byteIdx++) {
             assertEquals(value(upto), bytes[byteIdx]);
             upto++;
           }
         }
       }
       in2.close();
-
+      
       dir.deleteFile("test");
       dir.deleteFile("test2");
       
Index: lucene/src/test/org/apache/lucene/store/TestDirectory.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestDirectory.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/store/TestDirectory.java	(working copy)
@@ -17,7 +17,6 @@
  * limitations under the License.
  */
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 
@@ -32,7 +31,7 @@
     for (Directory dir : dirs) {
       dir.close();
       try {
-        dir.createOutput("test", IOContext.DEFAULT);
+        dir.createOutput("test", newIOContext(random));
         fail("did not hit expected exception");
       } catch (AlreadyClosedException ace) {
       }
@@ -57,7 +56,7 @@
       dir.ensureOpen();
       String fname = "foo." + i;
       String lockname = "foo" + i + ".lck";
-      IndexOutput out = dir.createOutput(fname, IOContext.DEFAULT);
+      IndexOutput out = dir.createOutput(fname, newIOContext(random));
       out.writeByte((byte)i);
       out.close();
 
@@ -71,7 +70,7 @@
         // closed and will cause a failure to delete the file.
         if (d2 instanceof MMapDirectory) continue;
         
-        IndexInput input = d2.openInput(fname, IOContext.DEFAULT);
+        IndexInput input = d2.openInput(fname, newIOContext(random));
         assertEquals((byte)i, input.readByte());
         input.close();
       }
@@ -142,7 +141,7 @@
   private void checkDirectoryFilter(Directory dir) throws IOException {
     String name = "file";
     try {
-      dir.createOutput(name, IOContext.DEFAULT).close();
+      dir.createOutput(name, newIOContext(random)).close();
       assertTrue(dir.fileExists(name));
       assertTrue(Arrays.asList(dir.listAll()).contains(name));
     } finally {
@@ -157,7 +156,7 @@
       path.mkdirs();
       new File(path, "subdir").mkdirs();
       Directory fsDir = new SimpleFSDirectory(path, null);
-      assertEquals(0, new RAMDirectory(fsDir, IOContext.DEFAULT).listAll().length);
+      assertEquals(0, new RAMDirectory(fsDir, newIOContext(random)).listAll().length);
     } finally {
       _TestUtil.rmDir(path);
     }
@@ -168,7 +167,7 @@
     File path = _TestUtil.getTempDir("testnotdir");
     Directory fsDir = new SimpleFSDirectory(path, null);
     try {
-      IndexOutput out = fsDir.createOutput("afile", IOContext.DEFAULT);
+      IndexOutput out = fsDir.createOutput("afile", newIOContext(random));
       out.close();
       assertTrue(fsDir.fileExists("afile"));
       try {
Index: lucene/src/test/org/apache/lucene/store/TestRAMDirectory.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestRAMDirectory.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/store/TestRAMDirectory.java	(working copy)
@@ -28,7 +28,6 @@
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
@@ -71,7 +70,7 @@
   public void testRAMDirectory () throws IOException {
     
     Directory dir = newFSDirectory(indexDir);
-    MockDirectoryWrapper ramDir = new MockDirectoryWrapper(random, new RAMDirectory(dir, IOContext.DEFAULT));
+    MockDirectoryWrapper ramDir = new MockDirectoryWrapper(random, new RAMDirectory(dir, newIOContext(random)));
     
     // close the underlaying directory
     dir.close();
@@ -103,7 +102,7 @@
   public void testRAMDirectorySize() throws IOException, InterruptedException {
       
     Directory dir = newFSDirectory(indexDir);
-    final MockDirectoryWrapper ramDir = new MockDirectoryWrapper(random, new RAMDirectory(dir, IOContext.DEFAULT));
+    final MockDirectoryWrapper ramDir = new MockDirectoryWrapper(random, new RAMDirectory(dir, newIOContext(random)));
     dir.close();
     
     final IndexWriter writer = new IndexWriter(ramDir, new IndexWriterConfig(
@@ -153,11 +152,11 @@
   // LUCENE-1196
   public void testIllegalEOF() throws Exception {
     RAMDirectory dir = new RAMDirectory();
-    IndexOutput o = dir.createOutput("out", IOContext.DEFAULT);
+    IndexOutput o = dir.createOutput("out", newIOContext(random));
     byte[] b = new byte[1024];
     o.writeBytes(b, 0, 1024);
     o.close();
-    IndexInput i = dir.openInput("out", IOContext.DEFAULT);
+    IndexInput i = dir.openInput("out", newIOContext(random));
     i.seek(1024);
     i.close();
     dir.close();
@@ -175,12 +174,12 @@
   public void testSeekToEOFThenBack() throws Exception {
     RAMDirectory dir = new RAMDirectory();
 
-    IndexOutput o = dir.createOutput("out", IOContext.DEFAULT);
+    IndexOutput o = dir.createOutput("out", newIOContext(random));
     byte[] bytes = new byte[3*RAMInputStream.BUFFER_SIZE];
     o.writeBytes(bytes, 0, bytes.length);
     o.close();
 
-    IndexInput i = dir.openInput("out", IOContext.DEFAULT);
+    IndexInput i = dir.openInput("out", newIOContext(random));
     i.seek(2*RAMInputStream.BUFFER_SIZE-1);
     i.seek(3*RAMInputStream.BUFFER_SIZE);
     i.seek(RAMInputStream.BUFFER_SIZE);
Index: lucene/src/test/org/apache/lucene/store/TestMultiMMap.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestMultiMMap.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/store/TestMultiMMap.java	(working copy)
@@ -23,7 +23,6 @@
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.util.BytesRef;
@@ -52,9 +51,9 @@
     for (int i = 0; i < 31; i++) {
       MMapDirectory mmapDir = new MMapDirectory(_TestUtil.getTempDir("testSeekZero"));
       mmapDir.setMaxChunkSize(1<<i);
-      IndexOutput io = mmapDir.createOutput("zeroBytes", IOContext.DEFAULT);
+      IndexOutput io = mmapDir.createOutput("zeroBytes", newIOContext(random));
       io.close();
-      IndexInput ii = mmapDir.openInput("zeroBytes", IOContext.DEFAULT);
+      IndexInput ii = mmapDir.openInput("zeroBytes", newIOContext(random));
       ii.seek(0L);
       ii.close();
       mmapDir.close();
@@ -65,12 +64,12 @@
     for (int i = 0; i < 17; i++) {
       MMapDirectory mmapDir = new MMapDirectory(_TestUtil.getTempDir("testSeekEnd"));
       mmapDir.setMaxChunkSize(1<<i);
-      IndexOutput io = mmapDir.createOutput("bytes", IOContext.DEFAULT);
+      IndexOutput io = mmapDir.createOutput("bytes", newIOContext(random));
       byte bytes[] = new byte[1<<i];
       random.nextBytes(bytes);
       io.writeBytes(bytes, bytes.length);
       io.close();
-      IndexInput ii = mmapDir.openInput("bytes", IOContext.DEFAULT);
+      IndexInput ii = mmapDir.openInput("bytes", newIOContext(random));
       byte actual[] = new byte[1<<i];
       ii.readBytes(actual, 0, actual.length);
       assertEquals(new BytesRef(bytes), new BytesRef(actual));
@@ -84,12 +83,12 @@
     for (int i = 0; i < 10; i++) {
       MMapDirectory mmapDir = new MMapDirectory(_TestUtil.getTempDir("testSeeking"));
       mmapDir.setMaxChunkSize(1<<i);
-      IndexOutput io = mmapDir.createOutput("bytes", IOContext.DEFAULT);
+      IndexOutput io = mmapDir.createOutput("bytes", newIOContext(random));
       byte bytes[] = new byte[1<<(i+1)]; // make sure we switch buffers
       random.nextBytes(bytes);
       io.writeBytes(bytes, bytes.length);
       io.close();
-      IndexInput ii = mmapDir.openInput("bytes", IOContext.DEFAULT);
+      IndexInput ii = mmapDir.openInput("bytes", newIOContext(random));
       byte actual[] = new byte[1<<(i+1)]; // first read all bytes
       ii.readBytes(actual, 0, actual.length);
       assertEquals(new BytesRef(bytes), new BytesRef(actual));
Index: lucene/src/test/org/apache/lucene/store/TestBufferedIndexInput.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestBufferedIndexInput.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/store/TestBufferedIndexInput.java	(working copy)
@@ -29,7 +29,6 @@
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
@@ -94,11 +93,11 @@
 
     // run test with chunk size of 10 bytes
     runReadBytesAndClose(new SimpleFSIndexInput(tmpInputFile,
-                                                IOContext.DEFAULT, 10), inputBufferSize, random);
+        newIOContext(random), 10), inputBufferSize, random);
 
     // run test with chunk size of 10 bytes
     runReadBytesAndClose(new NIOFSIndexInput(tmpInputFile,
-                                             IOContext.DEFAULT, 10), inputBufferSize, random);
+        newIOContext(random), 10), inputBufferSize, random);
   }
 
   private void runReadBytesAndClose(IndexInput input, int bufferSize, Random r)
Index: lucene/src/test/org/apache/lucene/util/TestBitVector.java
===================================================================
--- lucene/src/test/org/apache/lucene/util/TestBitVector.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/util/TestBitVector.java	(working copy)
@@ -19,7 +19,7 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.RAMDirectory;
 
@@ -147,8 +147,8 @@
             bv.set(i);
             assertTrue(bv.get(i));
             assertEquals(i+1,bv.count());
-            bv.write(d, "TESTBV", IOContext.DEFAULT);
-            BitVector compare = new BitVector(d, "TESTBV", IOContext.DEFAULT);
+            bv.write(d, "TESTBV", newIOContext(random));
+            BitVector compare = new BitVector(d, "TESTBV", newIOContext(random));
             // compare bit vectors with bits set incrementally
             assertTrue(doCompare(bv,compare));
         }
@@ -175,24 +175,24 @@
         bv.set(i);
         assertEquals(i+1,bv.count());
       }
-      bv.write(d, "TESTBV", IOContext.DEFAULT);
+      bv.write(d, "TESTBV", newIOContext(random));
       // gradually increase number of set bits
       for (int i=count1; i<count2; i++) {
-        BitVector bv2 = new BitVector(d, "TESTBV", IOContext.DEFAULT);
+        BitVector bv2 = new BitVector(d, "TESTBV", newIOContext(random));
         assertTrue(doCompare(bv,bv2));
         bv = bv2;
         bv.set(i);
         assertEquals(i+1,bv.count());
-        bv.write(d, "TESTBV", IOContext.DEFAULT);
+        bv.write(d, "TESTBV", newIOContext(random));
       }
       // now start decreasing number of set bits
       for (int i=count2-1; i>=count1; i--) {
-        BitVector bv2 = new BitVector(d, "TESTBV", IOContext.DEFAULT);
+        BitVector bv2 = new BitVector(d, "TESTBV", newIOContext(random));
         assertTrue(doCompare(bv,bv2));
         bv = bv2;
         bv.clear(i);
         assertEquals(i,bv.count());
-        bv.write(d, "TESTBV", IOContext.DEFAULT);
+        bv.write(d, "TESTBV", newIOContext(random));
       }
     }
     /**
Index: lucene/src/test/org/apache/lucene/util/packed/TestPackedInts.java
===================================================================
--- lucene/src/test/org/apache/lucene/util/packed/TestPackedInts.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/util/packed/TestPackedInts.java	(working copy)
@@ -17,7 +17,6 @@
  * limitations under the License.
  */
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.store.*;
 import org.apache.lucene.util.LuceneTestCase;
 
@@ -55,7 +54,7 @@
         final int valueCount = 100+random.nextInt(500);
         final Directory d = newDirectory();
 
-        IndexOutput out = d.createOutput("out.bin", IOContext.DEFAULT);
+        IndexOutput out = d.createOutput("out.bin", newIOContext(random));
         PackedInts.Writer w = PackedInts.getWriter(
                 out, valueCount, nbits);
 
@@ -72,7 +71,7 @@
         final long fp = out.getFilePointer();
         out.close();
         {// test reader
-          IndexInput in = d.openInput("out.bin", IOContext.DEFAULT);
+          IndexInput in = d.openInput("out.bin", newIOContext(random));
           PackedInts.Reader r = PackedInts.getReader(in);
           assertEquals(fp, in.getFilePointer());
           for(int i=0;i<valueCount;i++) {
@@ -83,7 +82,7 @@
           in.close();
         }
         { // test reader iterator next
-          IndexInput in = d.openInput("out.bin", IOContext.DEFAULT);
+          IndexInput in = d.openInput("out.bin", newIOContext(random));
           PackedInts.ReaderIterator r = PackedInts.getReaderIterator(in);
           for(int i=0;i<valueCount;i++) {
             assertEquals("index=" + i + " ceil=" + ceil + " valueCount="
@@ -94,7 +93,7 @@
           in.close();
         }
         { // test reader iterator next vs. advance
-          IndexInput in = d.openInput("out.bin", IOContext.DEFAULT);
+          IndexInput in = d.openInput("out.bin", newIOContext(random));
           PackedInts.ReaderIterator intsEnum = PackedInts.getReaderIterator(in);
           for (int i = 0; i < valueCount; i += 
             1 + ((valueCount - i) <= 20 ? random.nextInt(valueCount - i)
@@ -230,14 +229,14 @@
 
   public void testSingleValue() throws Exception {
     Directory dir = newDirectory();
-    IndexOutput out = dir.createOutput("out", IOContext.DEFAULT);
+    IndexOutput out = dir.createOutput("out", newIOContext(random));
     PackedInts.Writer w = PackedInts.getWriter(out, 1, 8);
     w.add(17);
     w.finish();
     final long end = out.getFilePointer();
     out.close();
 
-    IndexInput in = dir.openInput("out", IOContext.DEFAULT);
+    IndexInput in = dir.openInput("out", newIOContext(random));
     PackedInts.getReader(in);
     assertEquals(end, in.getFilePointer());
     in.close();
Index: lucene/src/test/org/apache/lucene/util/fst/TestFSTs.java
===================================================================
--- lucene/src/test/org/apache/lucene/util/fst/TestFSTs.java	(revision 1140355)
+++ lucene/src/test/org/apache/lucene/util/fst/TestFSTs.java	(working copy)
@@ -29,7 +29,7 @@
 
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IOContext;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriterConfig;
Index: lucene/src/java/org/apache/lucene/index/SegmentNorms.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentNorms.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentNorms.java	(working copy)
@@ -20,11 +20,10 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.apache.lucene.index.IOContext.Context;
-import org.apache.lucene.index.MergePolicy.OneMerge;
+import org.apache.lucene.store.FlushInfo;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
-
 /**
  * Byte[] referencing is used because a new norm object needs 
  * to be created for each clone, and the byte array is all 
@@ -221,7 +220,8 @@
     // NOTE: norms are re-written in regular directory, not cfs
     si.advanceNormGen(this.number);
     final String normFileName = si.getNormFileName(this.number);
-    IndexOutput out = owner.directory().createOutput(normFileName, IOContext.DEFAULT);
+    //nocommit not sure if this is the correct information provided to FlushInfo
+    IndexOutput out = owner.directory().createOutput(normFileName, new IOContext(new FlushInfo(si.docCount, 0)));
     boolean success = false;
     try {
       try {
Index: lucene/src/java/org/apache/lucene/index/FieldInfos.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/FieldInfos.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/FieldInfos.java	(working copy)
@@ -33,6 +33,7 @@
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.values.ValueType;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.CodecUtil;
Index: lucene/src/java/org/apache/lucene/index/FieldsReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/FieldsReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/FieldsReader.java	(working copy)
@@ -25,11 +25,10 @@
 import org.apache.lucene.document.FieldSelectorResult;
 import org.apache.lucene.document.Fieldable;
 import org.apache.lucene.document.NumericField;
-import org.apache.lucene.index.IOContext.Context;
-import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.CloseableThreadLocal;
 
Index: lucene/src/java/org/apache/lucene/index/DocumentsWriterPerThread.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/DocumentsWriterPerThread.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/DocumentsWriterPerThread.java	(working copy)
@@ -28,9 +28,11 @@
 import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.DocumentsWriterDeleteQueue.DeleteSlice;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.search.SimilarityProvider;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FlushInfo;
+import org.apache.lucene.store.IOContext;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.BitVector;
 import org.apache.lucene.util.ByteBlockPool.Allocator;
 import org.apache.lucene.util.ByteBlockPool.DirectTrackingAllocator;
@@ -429,7 +431,7 @@
     assert deleteSlice == null : "all deletes must be applied in prepareFlush";
     flushState = new SegmentWriteState(infoStream, directory, segment, fieldInfos,
         numDocsInRAM, writer.getConfig().getTermIndexInterval(),
-        fieldInfos.buildSegmentCodecs(true), pendingDeletes, new IOContext(Context.FLUSH));
+        fieldInfos.buildSegmentCodecs(true), pendingDeletes, new IOContext(new FlushInfo(numDocsInRAM, bytesUsed())));
     final double startMBUsed = parent.flushControl.netBytes() / 1024. / 1024.;
     // Apply delete-by-docID now (delete-byDocID only
     // happens when an exception is hit processing that
Index: lucene/src/java/org/apache/lucene/index/FieldsWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/FieldsWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/FieldsWriter.java	(working copy)
@@ -23,6 +23,7 @@
 import org.apache.lucene.document.Fieldable;
 import org.apache.lucene.document.NumericField;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.IOUtils;
Index: lucene/src/java/org/apache/lucene/index/SegmentInfo.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentInfo.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentInfo.java	(working copy)
@@ -31,6 +31,7 @@
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.DefaultSegmentInfosWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.Constants;
Index: lucene/src/java/org/apache/lucene/index/values/IntsImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/IntsImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/IntsImpl.java	(working copy)
@@ -20,9 +20,9 @@
 import java.util.Collection;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.ArrayUtil;
Index: lucene/src/java/org/apache/lucene/index/values/VarSortedBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/VarSortedBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/VarSortedBytesImpl.java	(working copy)
@@ -22,11 +22,11 @@
 import java.util.Comparator;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSortedSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.AttributeSource;
@@ -62,16 +62,15 @@
             BytesRefHash.DEFAULT_CAPACITY, bytesUsed));
 
     public Writer(Directory dir, String id, Comparator<BytesRef> comp,
-        AtomicLong bytesUsed) throws IOException {
-      //nocommit this needs an IOContext too
+        AtomicLong bytesUsed, IOContext context) throws IOException {
       this(dir, id, comp, new DirectTrackingAllocator(ByteBlockPool.BYTE_BLOCK_SIZE, bytesUsed),
-          bytesUsed);
+          bytesUsed, context);
     }
 
     public Writer(Directory dir, String id, Comparator<BytesRef> comp,
-        Allocator allocator, AtomicLong bytesUsed) throws IOException {
+        Allocator allocator, AtomicLong bytesUsed, IOContext context) throws IOException {
       super(dir, id, CODEC_NAME, VERSION_CURRENT, true,
-          new ByteBlockPool(allocator), bytesUsed, IOContext.DEFAULT);
+          new ByteBlockPool(allocator), bytesUsed, context);
       this.comp = comp;
       docToEntry = new int[1];
       docToEntry[0] = -1;
@@ -158,8 +157,8 @@
 
   public static class Reader extends BytesReaderBase {
 
-    Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, true, IOContext.DEFAULT);
+    Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, true, context);
     }
 
     @Override
Index: lucene/src/java/org/apache/lucene/index/values/FixedSortedBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/FixedSortedBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/FixedSortedBytesImpl.java	(working copy)
@@ -21,12 +21,12 @@
 import java.util.Comparator;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSortedSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.index.values.FixedDerefBytesImpl.Reader.DerefBytesEnum;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.AttributeSource;
@@ -63,16 +63,15 @@
             BytesRefHash.DEFAULT_CAPACITY, bytesUsed));
 
     public Writer(Directory dir, String id, Comparator<BytesRef> comp,
-        AtomicLong bytesUsed) throws IOException {
-      //nocommit this needs an IOContext too
+        AtomicLong bytesUsed, IOContext context) throws IOException {
       this(dir, id, comp, new DirectTrackingAllocator(ByteBlockPool.BYTE_BLOCK_SIZE, bytesUsed),
-          bytesUsed);
+          bytesUsed, context);
     }
 
     public Writer(Directory dir, String id, Comparator<BytesRef> comp,
-        Allocator allocator, AtomicLong bytesUsed) throws IOException {
+        Allocator allocator, AtomicLong bytesUsed, IOContext context) throws IOException {
       super(dir, id, CODEC_NAME, VERSION_CURRENT, true,
-          new ByteBlockPool(allocator), bytesUsed, IOContext.DEFAULT);
+          new ByteBlockPool(allocator), bytesUsed, context);
       docToEntry = new int[1];
       // docToEntry[0] = -1;
       bytesUsed.addAndGet(RamUsageEstimator.NUM_BYTES_INT);
@@ -162,8 +161,8 @@
   public static class Reader extends BytesReaderBase {
     private final int size;
 
-    public Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, true, IOContext.DEFAULT);
+    public Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, true, context);
       size = datIn.readInt();
     }
 
Index: lucene/src/java/org/apache/lucene/index/values/Writer.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/Writer.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/Writer.java	(working copy)
@@ -22,6 +22,7 @@
 
 import org.apache.lucene.index.codecs.DocValuesConsumer;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 
@@ -192,35 +193,35 @@
    * @throws IOException
    */
   public static Writer create(ValueType type, String id, Directory directory,
-      Comparator<BytesRef> comp, AtomicLong bytesUsed) throws IOException {
+      Comparator<BytesRef> comp, AtomicLong bytesUsed, IOContext context) throws IOException {
     if (comp == null) {
       comp = BytesRef.getUTF8SortedAsUnicodeComparator();
     }
     switch (type) {
     case INTS:
-      return Ints.getWriter(directory, id, true, bytesUsed);
+      return Ints.getWriter(directory, id, true, bytesUsed, context);
     case FLOAT_32:
-      return Floats.getWriter(directory, id, 4, bytesUsed);
+      return Floats.getWriter(directory, id, 4, bytesUsed, context);
     case FLOAT_64:
-      return Floats.getWriter(directory, id, 8, bytesUsed);
+      return Floats.getWriter(directory, id, 8, bytesUsed, context);
     case BYTES_FIXED_STRAIGHT:
       return Bytes.getWriter(directory, id, Bytes.Mode.STRAIGHT, comp, true,
-          bytesUsed);
+          bytesUsed, context);
     case BYTES_FIXED_DEREF:
       return Bytes.getWriter(directory, id, Bytes.Mode.DEREF, comp, true,
-          bytesUsed);
+          bytesUsed, context);
     case BYTES_FIXED_SORTED:
       return Bytes.getWriter(directory, id, Bytes.Mode.SORTED, comp, true,
-          bytesUsed);
+          bytesUsed, context);
     case BYTES_VAR_STRAIGHT:
       return Bytes.getWriter(directory, id, Bytes.Mode.STRAIGHT, comp, false,
-          bytesUsed);
+          bytesUsed, context);
     case BYTES_VAR_DEREF:
       return Bytes.getWriter(directory, id, Bytes.Mode.DEREF, comp, false,
-          bytesUsed);
+          bytesUsed, context);
     case BYTES_VAR_SORTED:
       return Bytes.getWriter(directory, id, Bytes.Mode.SORTED, comp, false,
-          bytesUsed);
+          bytesUsed, context);
     default:
       throw new IllegalArgumentException("Unknown Values: " + type);
     }
Index: lucene/src/java/org/apache/lucene/index/values/Ints.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/Ints.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/Ints.java	(working copy)
@@ -20,10 +20,10 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.IntsImpl.IntsReader;
 import org.apache.lucene.index.values.IntsImpl.IntsWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /**
  * @lucene.experimental
@@ -35,14 +35,13 @@
   }
 
   public static Writer getWriter(Directory dir, String id,
-      boolean useFixedArray, AtomicLong bytesUsed) throws IOException {
+      boolean useFixedArray, AtomicLong bytesUsed, IOContext context) throws IOException {
     // TODO - implement fixed?!
-    return new IntsWriter(dir, id, bytesUsed, IOContext.DEFAULT);
+    return new IntsWriter(dir, id, bytesUsed, context);
   }
 
   public static IndexDocValues getValues(Directory dir, String id,
-      boolean useFixedArray) throws IOException {
-    //nocommit this needs an IOContext too
-    return new IntsReader(dir, id, IOContext.DEFAULT);
+      boolean useFixedArray, IOContext context) throws IOException {
+    return new IntsReader(dir, id, context);
   }
 }
Index: lucene/src/java/org/apache/lucene/index/values/Bytes.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/Bytes.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/Bytes.java	(working copy)
@@ -23,12 +23,12 @@
 import java.util.Comparator;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.values.IndexDocValues.SortedSource;
 import org.apache.lucene.index.values.IndexDocValues.Source;
 import org.apache.lucene.index.values.IndexDocValues.SourceEnum;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.AttributeSource;
@@ -107,7 +107,7 @@
    *           if the files for the writer can not be created.
    */
   public static Writer getWriter(Directory dir, String id, Mode mode,
-      Comparator<BytesRef> comp, boolean fixedSize, AtomicLong bytesUsed)
+      Comparator<BytesRef> comp, boolean fixedSize, AtomicLong bytesUsed, IOContext context)
       throws IOException {
     //nocommit this and all the blow need an IOContext too
 
@@ -119,19 +119,19 @@
 
     if (fixedSize) {
       if (mode == Mode.STRAIGHT) {
-        return new FixedStraightBytesImpl.Writer(dir, id);
+        return new FixedStraightBytesImpl.Writer(dir, id, context);
       } else if (mode == Mode.DEREF) {
-        return new FixedDerefBytesImpl.Writer(dir, id, bytesUsed);
+        return new FixedDerefBytesImpl.Writer(dir, id, bytesUsed, context);
       } else if (mode == Mode.SORTED) {
-        return new FixedSortedBytesImpl.Writer(dir, id, comp, bytesUsed);
+        return new FixedSortedBytesImpl.Writer(dir, id, comp, bytesUsed, context);
       }
     } else {
       if (mode == Mode.STRAIGHT) {
-        return new VarStraightBytesImpl.Writer(dir, id, bytesUsed);
+        return new VarStraightBytesImpl.Writer(dir, id, bytesUsed, context);
       } else if (mode == Mode.DEREF) {
-        return new VarDerefBytesImpl.Writer(dir, id, bytesUsed);
+        return new VarDerefBytesImpl.Writer(dir, id, bytesUsed, context);
       } else if (mode == Mode.SORTED) {
-        return new VarSortedBytesImpl.Writer(dir, id, comp, bytesUsed);
+        return new VarSortedBytesImpl.Writer(dir, id, comp, bytesUsed, context);
       }
     }
 
@@ -160,25 +160,25 @@
    *           if an {@link IOException} occurs
    */
   public static IndexDocValues getValues(Directory dir, String id, Mode mode,
-      boolean fixedSize, int maxDoc) throws IOException {
+      boolean fixedSize, int maxDoc, IOContext context) throws IOException {
     //nocommit this and all the readers below need an IOContext too
 
     // TODO -- I can peek @ header to determing fixed/mode?
     if (fixedSize) {
       if (mode == Mode.STRAIGHT) {
-        return new FixedStraightBytesImpl.Reader(dir, id, maxDoc);
+        return new FixedStraightBytesImpl.Reader(dir, id, maxDoc, context);
       } else if (mode == Mode.DEREF) {
-        return new FixedDerefBytesImpl.Reader(dir, id, maxDoc);
+        return new FixedDerefBytesImpl.Reader(dir, id, maxDoc, context);
       } else if (mode == Mode.SORTED) {
-        return new FixedSortedBytesImpl.Reader(dir, id, maxDoc);
+        return new FixedSortedBytesImpl.Reader(dir, id, maxDoc, context);
       }
     } else {
       if (mode == Mode.STRAIGHT) {
-        return new VarStraightBytesImpl.Reader(dir, id, maxDoc);
+        return new VarStraightBytesImpl.Reader(dir, id, maxDoc, context);
       } else if (mode == Mode.DEREF) {
-        return new VarDerefBytesImpl.Reader(dir, id, maxDoc);
+        return new VarDerefBytesImpl.Reader(dir, id, maxDoc, context);
       } else if (mode == Mode.SORTED) {
-        return new VarSortedBytesImpl.Reader(dir, id, maxDoc);
+        return new VarSortedBytesImpl.Reader(dir, id, maxDoc, context);
       }
     }
 
Index: lucene/src/java/org/apache/lucene/index/values/VarStraightBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/VarStraightBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/VarStraightBytesImpl.java	(working copy)
@@ -20,11 +20,11 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.AttributeSource;
@@ -50,16 +50,16 @@
     private int lastDocID = -1;
     private long[] docToAddress;
 
-    public Writer(Directory dir, String id, AtomicLong bytesUsed)
+    public Writer(Directory dir, String id, AtomicLong bytesUsed, IOContext context)
         throws IOException {
       //nocommit this needs an IOContext too
-      super(dir, id, CODEC_NAME, VERSION_CURRENT, true, null, bytesUsed, IOContext.DEFAULT);
+      super(dir, id, CODEC_NAME, VERSION_CURRENT, true, null, bytesUsed, context);
       docToAddress = new long[1];
       bytesUsed.addAndGet(RamUsageEstimator.NUM_BYTES_INT);
     }
 
-    public Writer(Directory dir, String id) throws IOException {
-      this(dir, id, new AtomicLong());
+    public Writer(Directory dir, String id, IOContext context) throws IOException {
+      this(dir, id, new AtomicLong(), context);
     }
 
     // Fills up to but not including this docID
@@ -123,8 +123,8 @@
   public static class Reader extends BytesReaderBase {
     private final int maxDoc;
 
-    Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, true, IOContext.DEFAULT);
+    Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, true, context);
       this.maxDoc = maxDoc;
     }
 
Index: lucene/src/java/org/apache/lucene/index/values/VarDerefBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/VarDerefBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/VarDerefBytesImpl.java	(working copy)
@@ -20,13 +20,13 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.index.values.FixedDerefBytesImpl.Reader.DerefBytesEnum;
 import org.apache.lucene.store.DataOutput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.AttributeSource;
@@ -116,17 +116,16 @@
         bytesUsed);
     private final BytesRefHash hash = new BytesRefHash(pool, 16, array);
 
-    public Writer(Directory dir, String id, AtomicLong bytesUsed)
+    public Writer(Directory dir, String id, AtomicLong bytesUsed, IOContext context)
         throws IOException {
-      //nocommit this needs an IOContext too
       this(dir, id, new DirectTrackingAllocator(ByteBlockPool.BYTE_BLOCK_SIZE, bytesUsed),
-          bytesUsed);
+          bytesUsed, context);
     }
 
     public Writer(Directory dir, String id, Allocator allocator,
-        AtomicLong bytesUsed) throws IOException {
+        AtomicLong bytesUsed, IOContext context) throws IOException {
       super(dir, id, CODEC_NAME, VERSION_CURRENT, true,
-          new ByteBlockPool(allocator), bytesUsed, IOContext.DEFAULT);
+          new ByteBlockPool(allocator), bytesUsed, context);
       docToAddress = new int[1];
       bytesUsed.addAndGet(RamUsageEstimator.NUM_BYTES_INT);
     }
@@ -203,8 +202,8 @@
 
   public static class Reader extends BytesReaderBase {
 
-    Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, true, IOContext.DEFAULT);
+    Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, true, context);
     }
 
     @Override
Index: lucene/src/java/org/apache/lucene/index/values/Floats.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/Floats.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/Floats.java	(working copy)
@@ -20,11 +20,10 @@
 import java.util.Collection;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.values.IndexDocValues.Source;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.AttributeSource;
@@ -53,22 +52,21 @@
 
   
   public static Writer getWriter(Directory dir, String id, int precisionBytes,
-      AtomicLong bytesUsed) throws IOException {
+      AtomicLong bytesUsed, IOContext context) throws IOException {
     if (precisionBytes != 4 && precisionBytes != 8) {
       throw new IllegalArgumentException("precisionBytes must be 4 or 8; got "
           + precisionBytes);
     }
     if (precisionBytes == 4) {
-      return new Float4Writer(dir, id, bytesUsed);
+      return new Float4Writer(dir, id, bytesUsed, context);
     } else {
-      return new Float8Writer(dir, id, bytesUsed);
+      return new Float8Writer(dir, id, bytesUsed, context);
     }
   }
 
-  public static IndexDocValues getValues(Directory dir, String id, int maxDoc)
+  public static IndexDocValues getValues(Directory dir, String id, int maxDoc, IOContext context)
       throws IOException {
-    //nocommit this needs an IOContext too
-    return new FloatsReader(dir, id, maxDoc, IOContext.READ);
+    return new FloatsReader(dir, id, maxDoc, context);
   }
 
   abstract static class FloatsWriter extends Writer {
@@ -147,9 +145,9 @@
   // Writes 4 bytes (float) per value
   static class Float4Writer extends FloatsWriter {
 
-    protected Float4Writer(Directory dir, String id, AtomicLong bytesUsed)
+    protected Float4Writer(Directory dir, String id, AtomicLong bytesUsed, IOContext context)
         throws IOException {
-      super(dir, id, 4, bytesUsed, new IOContext(Context.FLUSH));
+      super(dir, id, 4, bytesUsed, context);
     }
 
     @Override
@@ -190,9 +188,9 @@
   // Writes 8 bytes (double) per value
   static class Float8Writer extends FloatsWriter {
 
-    protected Float8Writer(Directory dir, String id, AtomicLong bytesUsed)
+    protected Float8Writer(Directory dir, String id, AtomicLong bytesUsed, IOContext context)
         throws IOException {
-      super(dir, id, 8, bytesUsed, new IOContext(Context.FLUSH));
+      super(dir, id, 8, bytesUsed, context);
     }
 
     @Override
Index: lucene/src/java/org/apache/lucene/index/values/FixedStraightBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/FixedStraightBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/FixedStraightBytesImpl.java	(working copy)
@@ -19,11 +19,11 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.AttributeSource;
 import org.apache.lucene.util.BytesRef;
@@ -47,9 +47,9 @@
     private int lastDocID = -1;
     private byte[] oneRecord;
 
-    public Writer(Directory dir, String id) throws IOException {
+    public Writer(Directory dir, String id, IOContext context) throws IOException {
       //nocommit this needs an IOContext too
-      super(dir, id, CODEC_NAME, VERSION_CURRENT, false, null, null, IOContext.DEFAULT);
+      super(dir, id, CODEC_NAME, VERSION_CURRENT, false, null, null, context);
     }
 
 
@@ -127,8 +127,8 @@
     private final int size;
     private final int maxDoc;
 
-    Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, false, IOContext.DEFAULT);
+    Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, false, context);
       size = datIn.readInt();
       this.maxDoc = maxDoc;
     }
Index: lucene/src/java/org/apache/lucene/index/values/FixedDerefBytesImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/values/FixedDerefBytesImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/values/FixedDerefBytesImpl.java	(working copy)
@@ -20,11 +20,11 @@
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.values.Bytes.BytesBaseSource;
 import org.apache.lucene.index.values.Bytes.BytesReaderBase;
 import org.apache.lucene.index.values.Bytes.BytesWriterBase;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.AttributeSource;
@@ -55,17 +55,16 @@
     private final BytesRefHash hash = new BytesRefHash(pool,
         BytesRefHash.DEFAULT_CAPACITY, new TrackingDirectBytesStartArray(
             BytesRefHash.DEFAULT_CAPACITY, bytesUsed));
-    public Writer(Directory dir, String id, AtomicLong bytesUsed)
+    public Writer(Directory dir, String id, AtomicLong bytesUsed, IOContext context)
         throws IOException {
-      //nocommit this needs an IOContext too
       this(dir, id, new DirectTrackingAllocator(ByteBlockPool.BYTE_BLOCK_SIZE, bytesUsed),
-          bytesUsed);
+          bytesUsed, context);
     }
 
     public Writer(Directory dir, String id, Allocator allocator,
-        AtomicLong bytesUsed) throws IOException {
+        AtomicLong bytesUsed, IOContext context) throws IOException {
       super(dir, id, CODEC_NAME, VERSION_CURRENT, true,
-          new ByteBlockPool(allocator), bytesUsed, IOContext.DEFAULT);
+          new ByteBlockPool(allocator), bytesUsed, context);
       docToID = new int[1];
       bytesUsed.addAndGet(RamUsageEstimator.NUM_BYTES_INT); // TODO BytesRefHash
                                                             // uses bytes too!
@@ -135,8 +134,8 @@
   public static class Reader extends BytesReaderBase {
     private final int size;
 
-    Reader(Directory dir, String id, int maxDoc) throws IOException {
-      super(dir, id, CODEC_NAME, VERSION_START, true, IOContext.DEFAULT);
+    Reader(Directory dir, String id, int maxDoc, IOContext context) throws IOException {
+      super(dir, id, CODEC_NAME, VERSION_START, true, context);
       size = datIn.readInt();
     }
 
Index: lucene/src/java/org/apache/lucene/index/SegmentReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentReader.java	(working copy)
@@ -31,6 +31,7 @@
 import org.apache.lucene.document.FieldSelector;
 import org.apache.lucene.index.codecs.PerDocValues;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.BitVector;
 import org.apache.lucene.util.Bits;
Index: lucene/src/java/org/apache/lucene/index/BufferedDeletesStream.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/BufferedDeletesStream.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/BufferedDeletesStream.java	(working copy)
@@ -32,6 +32,7 @@
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.QueryWrapperFilter;
+import org.apache.lucene.store.IOContext;
 
 /* Tracks the stream of {@link BufferedDeletes}.
  * When DocumentsWriterPerThread flushes, its buffered
@@ -224,8 +225,7 @@
 
         // Lock order: IW -> BD -> RP
         assert readerPool.infoIsLive(info);
-        //nocommit is IOContext.DEFAULT the right thing to do here?
-        final SegmentReader reader = readerPool.get(info, false, IOContext.DEFAULT);
+        final SegmentReader reader = readerPool.get(info, false, IOContext.READ);
         int delCount = 0;
         final boolean segAllDeletes;
         try {
Index: lucene/src/java/org/apache/lucene/index/CompoundFileReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/CompoundFileReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/CompoundFileReader.java	(working copy)
@@ -18,6 +18,7 @@
  */
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.IndexOutput;
Index: lucene/src/java/org/apache/lucene/index/MergePolicy.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/MergePolicy.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/MergePolicy.java	(working copy)
@@ -18,6 +18,7 @@
  */
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.MergeInfo;
 import org.apache.lucene.util.SetOnce;
 import org.apache.lucene.util.SetOnce.AlreadySetException;
 
Index: lucene/src/java/org/apache/lucene/index/CompoundFileWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/CompoundFileWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/CompoundFileWriter.java	(working copy)
@@ -23,6 +23,7 @@
 
 import org.apache.lucene.index.codecs.MergeState;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.IOUtils;
Index: lucene/src/java/org/apache/lucene/index/StoredFieldsWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/StoredFieldsWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/StoredFieldsWriter.java	(working copy)
@@ -20,7 +20,7 @@
 import java.io.IOException;
 
 import org.apache.lucene.document.Fieldable;
-import org.apache.lucene.index.IOContext.Context;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.RamUsageEstimator;
 
@@ -60,7 +60,7 @@
       // It's possible that all documents seen in this segment
       // hit non-aborting exceptions, in which case we will
       // not have yet init'd the FieldsWriter:
-      initFieldsWriter();
+      initFieldsWriter(state.context);
       fill(state.numDocs);
     }
 
@@ -76,10 +76,10 @@
     }
   }
 
-  private synchronized void initFieldsWriter() throws IOException {
+  private synchronized void initFieldsWriter(IOContext context) throws IOException {
     if (fieldsWriter == null) {
       // nocommit - is this always a flush here or should we have a IOContext argument?
-      fieldsWriter = new FieldsWriter(docWriter.directory, docWriter.getSegment(), new IOContext(Context.FLUSH));
+      fieldsWriter = new FieldsWriter(docWriter.directory, docWriter.getSegment(), context);
       lastDocID = 0;
     }
   }
@@ -109,7 +109,7 @@
   void finishDocument() throws IOException {
     assert docWriter.writer.testPoint("StoredFieldsWriter.finishDocument start");
 
-    initFieldsWriter();
+    initFieldsWriter(IOContext.DEFAULT);
     fill(docState.docID);
 
     if (fieldsWriter != null && numStoredFields > 0) {
Index: lucene/src/java/org/apache/lucene/index/SegmentReadState.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentReadState.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentReadState.java	(working copy)
@@ -18,6 +18,7 @@
  */
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /**
  * @lucene.experimental
Index: lucene/src/java/org/apache/lucene/index/SegmentInfos.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(working copy)
@@ -32,12 +32,12 @@
 import java.util.Set;
 
 import org.apache.lucene.index.FieldInfos.FieldNumberBiMap;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.DefaultSegmentInfosWriter;
 import org.apache.lucene.index.codecs.SegmentInfosReader;
 import org.apache.lucene.index.codecs.SegmentInfosWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.NoSuchDirectoryException;
Index: lucene/src/java/org/apache/lucene/index/CheckIndex.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/CheckIndex.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/CheckIndex.java	(working copy)
@@ -22,11 +22,10 @@
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.document.AbstractField;  // for javadocs
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IOContext.Context;
-import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.DefaultSegmentInfosWriter;
 import org.apache.lucene.index.codecs.PerDocValues;
Index: lucene/src/java/org/apache/lucene/index/DirectoryReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/DirectoryReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/DirectoryReader.java	(working copy)
@@ -32,9 +32,9 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.FieldSelector;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockObtainFailedException;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.PerDocValues;
 import org.apache.lucene.util.Bits;
Index: lucene/src/java/org/apache/lucene/index/SegmentMerger.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentMerger.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentMerger.java	(working copy)
@@ -24,7 +24,6 @@
 import java.util.List;
 
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexReader.FieldOption;
 import org.apache.lucene.index.MergePolicy.MergeAbortedException;
 import org.apache.lucene.index.codecs.Codec;
@@ -33,6 +32,7 @@
 import org.apache.lucene.index.codecs.PerDocConsumer;
 import org.apache.lucene.index.codecs.PerDocValues;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.Bits;
@@ -68,8 +68,10 @@
   private SegmentWriteState segmentWriteState;
 
   private PayloadProcessorProvider payloadProcessorProvider;
+  
+  private IOContext context;
 
-  SegmentMerger(Directory dir, int termIndexInterval, String name, MergePolicy.OneMerge merge, PayloadProcessorProvider payloadProcessorProvider, FieldInfos fieldInfos) {
+  SegmentMerger(Directory dir, int termIndexInterval, String name, MergePolicy.OneMerge merge, PayloadProcessorProvider payloadProcessorProvider, FieldInfos fieldInfos, IOContext context) {
     this.payloadProcessorProvider = payloadProcessorProvider;
     directory = dir;
     segment = name;
@@ -85,6 +87,7 @@
       };
     }
     this.termIndexInterval = termIndexInterval;
+    this.context = context;
   }
 
   public FieldInfos fieldInfos() {
@@ -234,8 +237,7 @@
 
     setMatchingSegmentReaders();
     // nocommit - should we rather use IOContext.MERGE here?
-    final FieldsWriter fieldsWriter = new FieldsWriter(directory, segment, IOContext.DEFAULT);
-
+    final FieldsWriter fieldsWriter = new FieldsWriter(directory, segment, context);
     try {
       int idx = 0;
       for (IndexReader reader : readers) {
@@ -269,8 +271,7 @@
       // entering the index.  See LUCENE-1282 for
       // details.
       throw new RuntimeException("mergeFields produced an invalid result: docCount is " + docCount + " but fdx file size is " + fdxFileLength + " file=" + fileName + " file exists?=" + directory.fileExists(fileName) + "; now aborting this merge to prevent index corruption");
-    //nocommit if Merge then what to initialize OneMerge with ?
-    segmentWriteState = new SegmentWriteState(null, directory, segment, fieldInfos, docCount, termIndexInterval, codecInfo, null, IOContext.DEFAULT);
+    segmentWriteState = new SegmentWriteState(null, directory, segment, fieldInfos, docCount, termIndexInterval, codecInfo, null, context);
 
     return docCount;
   }
@@ -357,7 +358,7 @@
   private final void mergeVectors() throws IOException {
     //nocommit Putting MERGE context here would lead to assert error. What should MergeInfo be initialized with here?
     TermVectorsWriter termVectorsWriter =
-      new TermVectorsWriter(directory, segment, fieldInfos, new IOContext(Context.DEFAULT));
+      new TermVectorsWriter(directory, segment, fieldInfos, context);
 
     try {
       int idx = 0;
@@ -616,8 +617,7 @@
       for (FieldInfo fi : fieldInfos) {
         if (fi.isIndexed && !fi.omitNorms) {
           if (output == null) {
-            //nocommit Putting MERGE context here would lead to assert error. What should MergeInfo be initialized with here?
-            output = directory.createOutput(IndexFileNames.segmentFileName(segment, "", IndexFileNames.NORMS_EXTENSION), new IOContext(Context.DEFAULT));
+            output = directory.createOutput(IndexFileNames.segmentFileName(segment, "", IndexFileNames.NORMS_EXTENSION), context);
             output.writeBytes(SegmentNorms.NORMS_HEADER, SegmentNorms.NORMS_HEADER.length);
           }
           for (IndexReader reader : readers) {
Index: lucene/src/java/org/apache/lucene/index/IOContext.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IOContext.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/IOContext.java	(working copy)
@@ -1,73 +0,0 @@
-package org.apache.lucene.index;
-
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
-* Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/**
- * IOContext holds additional details on the merge/search context. A IOContext
- * object can never be initialized as null as passed as a parameter to either
- * {@link #org.apache.lucene.store.Directory.openInput()} or
- * {@link #org.apache.lucene.store.Directory.createInput()}
- */
-public class IOContext {
-
-  /**
-   * Context is a enumerator which specifies the context in which the Directory is being used for.
-   */
-  public enum Context {MERGE,READ,FLUSH,DEFAULT};
-  
-  /**
-   * An object of a enumerator Context type
-   */
-  public final Context context;
-  
-  public final MergeInfo mergeInfo;
-  
-  public final boolean readOnce;
-  
-  public static final IOContext DEFAULT = new IOContext(Context.DEFAULT);
-  
-  public static final IOContext READONCE = new IOContext(true);
-  
-  public static final IOContext READ = new IOContext(false);
-  
-  public IOContext () {
-    this(false);
-  }
-  
-  public IOContext(Context context) {
-    this(context, null);    
-  }
-  
-  private IOContext(boolean readOnce) {
-    this.context = Context.READ;
-    this.mergeInfo = null;    
-    this.readOnce = readOnce;
-  }
-  
-  public IOContext (MergeInfo mergeInfo) {    
-    this(Context.MERGE, mergeInfo);
-  }
-
-  private IOContext (Context context, MergeInfo mergeInfo ) {
-    assert context != Context.MERGE || mergeInfo != null;
-    this.context = context;
-    this.readOnce = false;
-    this.mergeInfo = mergeInfo;
-  }
-  
-}
\ No newline at end of file
Index: lucene/src/java/org/apache/lucene/index/TermVectorsTermsWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/TermVectorsTermsWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/TermVectorsTermsWriter.java	(working copy)
@@ -20,8 +20,10 @@
 import java.io.IOException;
 import java.util.Map;
 
-import org.apache.lucene.index.IOContext.Context;
+import org.apache.lucene.store.FlushInfo;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
@@ -90,7 +92,7 @@
     if (tvx == null) {
       boolean success = false;
       try {
-        IOContext context = new IOContext(Context.FLUSH);
+        IOContext context = new IOContext(new FlushInfo(docWriter.getNumDocsInRAM(), docWriter.bytesUsed()));
         // If we hit an exception while init'ing the term
         // vector output files, we must abort this segment
         // because those files will be in an unknown
Index: lucene/src/java/org/apache/lucene/index/PerFieldCodecWrapper.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/PerFieldCodecWrapper.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/PerFieldCodecWrapper.java	(working copy)
@@ -36,6 +36,7 @@
 import org.apache.lucene.index.codecs.DocValuesConsumer;
 import org.apache.lucene.index.values.IndexDocValues;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.IOUtils;
 
 /**
Index: lucene/src/java/org/apache/lucene/index/IndexReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/IndexReader.java	(working copy)
@@ -21,7 +21,6 @@
 import org.apache.lucene.document.FieldSelector;
 import org.apache.lucene.search.FieldCache; // javadocs
 import org.apache.lucene.search.Similarity;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.codecs.Codec;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.index.codecs.PerDocValues;
Index: lucene/src/java/org/apache/lucene/index/TermVectorsReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/TermVectorsReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/TermVectorsReader.java	(working copy)
@@ -17,11 +17,12 @@
  * limitations under the License.
  */
 
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.BytesRef;
 
Index: lucene/src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -39,9 +39,7 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.DocumentsWriterPerThread.FlushedSegment;
 import org.apache.lucene.index.FieldInfos.FieldNumberBiMap;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexWriterConfig.OpenMode;
-import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.index.PayloadProcessorProvider.DirPayloadProcessor;
 import org.apache.lucene.index.SegmentCodecs.SegmentCodecsBuilder;
 import org.apache.lucene.index.codecs.CodecProvider;
@@ -49,8 +47,12 @@
 import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.FlushInfo;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockObtainFailedException;
+import org.apache.lucene.store.MergeInfo;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.BitVector;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.Constants;
@@ -2188,7 +2190,7 @@
 
     setDiagnostics(newSegment, "flush");
     
-    IOContext context = new IOContext(Context.FLUSH);
+    IOContext context = new IOContext(new FlushInfo(newSegment.docCount, newSegment.sizeInBytes(true)));
 
     boolean success = false;
     try {
@@ -2447,6 +2449,7 @@
    */
   public void addIndexes(IndexReader... readers) throws CorruptIndexException, IOException {
     ensureOpen();
+    int numDocs = 0;
 
     try {
       if (infoStream != null)
@@ -2454,11 +2457,16 @@
       flush(false, true);
 
       String mergedName = newSegmentName();
+      for (IndexReader indexReader : readers) {
+        numDocs += indexReader.numDocs();
+       }
+       final IOContext context = new IOContext(new MergeInfo(numDocs, -1, true, false));      
+
       // TODO: somehow we should fix this merge so it's
       // abortable so that IW.close(false) is able to stop it
       SegmentMerger merger = new SegmentMerger(directory, config.getTermIndexInterval(),
                                                mergedName, null, payloadProcessorProvider,
-                                               globalFieldNumberMap.newFieldInfos(SegmentCodecsBuilder.create(codecs)));
+                                               globalFieldNumberMap.newFieldInfos(SegmentCodecsBuilder.create(codecs)), context);
 
       for (IndexReader reader : readers)      // add new indexes
         merger.add(reader);
@@ -2483,7 +2491,6 @@
 
       // Now create the compound file if needed
       if (useCompoundFile) {
-        IOContext context = new IOContext(new MergeInfo(info.docCount, info.sizeInBytes(true), true, false));
         merger.createCompoundFile(mergedName + ".cfs", info, context);
 
         // delete new non cfs files directly: they were never
@@ -3429,7 +3436,7 @@
     IOContext context = new IOContext(merge.getMergeInfo());
 
     SegmentMerger merger = new SegmentMerger(directory, config.getTermIndexInterval(), mergedName, merge,
-                                             payloadProcessorProvider, merge.info.getFieldInfos());
+                                             payloadProcessorProvider, merge.info.getFieldInfos(), context);
 
     if (infoStream != null) {
       message("merging " + merge.segString(directory) + " mergeVectors=" + merge.info.getFieldInfos().hasVectors());
Index: lucene/src/java/org/apache/lucene/index/TermVectorsWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/TermVectorsWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/TermVectorsWriter.java	(working copy)
@@ -18,6 +18,7 @@
  */
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.IOUtils;
Index: lucene/src/java/org/apache/lucene/index/MergeInfo.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/MergeInfo.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/MergeInfo.java	(working copy)
@@ -1,35 +0,0 @@
-package org.apache.lucene.index;
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-//nocommit javadoc
-public class MergeInfo {
-  
-  public int totalDocCount;
-  
-  public long estimatedMergeBytes;  // used by IndexWriter
-  
-  boolean isExternal;               // used by IndexWriter
-  
-  boolean optimize;                 // used by IndexWriter
-
-  public MergeInfo(int totalDocCount, long estimatedMergeBytes, boolean isExternal, boolean optimize) {
-    this.totalDocCount = totalDocCount;
-    this.estimatedMergeBytes = estimatedMergeBytes;
-    this.isExternal = isExternal;
-    this.optimize = optimize;
-  }
-}
\ No newline at end of file
Index: lucene/src/java/org/apache/lucene/index/SegmentWriteState.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentWriteState.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentWriteState.java	(working copy)
@@ -20,6 +20,7 @@
 import java.io.PrintStream;
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.BitVector;
 
 /**
Index: lucene/src/java/org/apache/lucene/index/codecs/pulsing/PulsingCodec.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/pulsing/PulsingCodec.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/pulsing/PulsingCodec.java	(working copy)
@@ -173,6 +173,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosWriter.java	(working copy)
@@ -19,12 +19,11 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentInfos;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.ChecksumIndexOutput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.IOUtils;
 
Index: lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesConsumer.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesConsumer.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesConsumer.java	(working copy)
@@ -29,6 +29,7 @@
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.values.Writer;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.BytesRef;
 
 public class DefaultDocValuesConsumer extends PerDocConsumer {
@@ -55,7 +56,7 @@
         docValuesId(segmentName, codecId, field.number),
         // TODO can we have a compound file per segment and codec for
         // docvalues?
-        directory, comparator, bytesUsed);
+        directory, comparator, bytesUsed, IOContext.DEFAULT);
   }
   
   @SuppressWarnings("fallthrough")
Index: lucene/src/java/org/apache/lucene/index/codecs/FixedGapTermsIndexReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/FixedGapTermsIndexReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/FixedGapTermsIndexReader.java	(working copy)
@@ -18,11 +18,11 @@
  */
 
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.FieldInfo;
-import org.apache.lucene.index.IOContext;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CodecUtil;
Index: lucene/src/java/org/apache/lucene/index/codecs/simpletext/SimpleTextCodec.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/simpletext/SimpleTextCodec.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/simpletext/SimpleTextCodec.java	(working copy)
@@ -86,6 +86,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReader.java	(working copy)
@@ -23,7 +23,6 @@
 import org.apache.lucene.index.DocsAndPositionsEnum;
 import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.FieldInfo;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.TermState;
@@ -31,6 +30,7 @@
 import org.apache.lucene.index.codecs.PostingsReaderBase;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.Bits;
Index: lucene/src/java/org/apache/lucene/index/codecs/standard/StandardCodec.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/standard/StandardCodec.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/standard/StandardCodec.java	(working copy)
@@ -163,6 +163,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosReader.java	(working copy)
@@ -19,9 +19,9 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /**
  * Specifies an API for classes that can read {@link SegmentInfos} information.
Index: lucene/src/java/org/apache/lucene/index/codecs/preflex/TermInfosReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/preflex/TermInfosReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/preflex/TermInfosReader.java	(working copy)
@@ -21,10 +21,10 @@
 
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.util.CloseableThreadLocal;
 import org.apache.lucene.util.DoubleBarrelLRUCache;
 
Index: lucene/src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java	(working copy)
@@ -31,7 +31,6 @@
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.FieldsEnum;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.Term;
@@ -39,6 +38,7 @@
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.codecs.FieldsProducer;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
Index: lucene/src/java/org/apache/lucene/index/codecs/memory/MemoryCodec.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/memory/MemoryCodec.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/memory/MemoryCodec.java	(working copy)
@@ -48,6 +48,7 @@
 import org.apache.lucene.index.codecs.TermsConsumer;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.RAMOutputStream;
@@ -699,7 +700,7 @@
   public FieldsProducer fieldsProducer(SegmentReadState state) throws IOException {
     //nocommit its seems due to the nature of this codec that we should use IOContext.READONCE here where applicable. 
     final String fileName = IndexFileNames.segmentFileName(state.segmentInfo.name, state.codecId, EXTENSION);
-    final IndexInput in = state.dir.openInput(fileName, state.context);
+    final IndexInput in = state.dir.openInput(fileName, IOContext.READONCE);
 
     final SortedMap<String,TermsReader> fields = new TreeMap<String,TermsReader>();
 
@@ -776,6 +777,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, IOContext.READONCE);
   }
 }
Index: lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/SegmentInfosWriter.java	(working copy)
@@ -19,9 +19,9 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 
 /**
Index: lucene/src/java/org/apache/lucene/index/codecs/VariableGapTermsIndexReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/VariableGapTermsIndexReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/VariableGapTermsIndexReader.java	(working copy)
@@ -27,12 +27,12 @@
 
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CodecUtil;
 import org.apache.lucene.util.fst.Builder;
Index: lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsReaderImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsReaderImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsReaderImpl.java	(working copy)
@@ -23,7 +23,6 @@
 import org.apache.lucene.index.DocsAndPositionsEnum;
 import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.FieldInfo;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.TermState;
@@ -31,6 +30,7 @@
 import org.apache.lucene.index.codecs.PostingsReaderBase;
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.Bits;
Index: lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsWriterImpl.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsWriterImpl.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/sep/SepPostingsWriterImpl.java	(working copy)
@@ -118,16 +118,16 @@
       this.skipInterval = skipInterval;
       this.skipMinimum = skipInterval; /* set to the same for now */
       final String docFileName = IndexFileNames.segmentFileName(state.segmentName, state.codecId, DOC_EXTENSION);
-      docOut = factory.createOutput(state.directory, docFileName);
+      docOut = factory.createOutput(state.directory, docFileName, state.context);
       docIndex = docOut.index();
       
       if (state.fieldInfos.hasProx()) {
         final String frqFileName = IndexFileNames.segmentFileName(state.segmentName, state.codecId, FREQ_EXTENSION);
-        freqOut = factory.createOutput(state.directory, frqFileName);
+        freqOut = factory.createOutput(state.directory, frqFileName, state.context);
         freqIndex = freqOut.index();
         
         final String posFileName = IndexFileNames.segmentFileName(state.segmentName, state.codecId, POS_EXTENSION);
-        posOut = factory.createOutput(state.directory, posFileName);
+        posOut = factory.createOutput(state.directory, posFileName, state.context);
         posIndex = posOut.index();
         
         // TODO: -- only if at least one field stores payloads?
Index: lucene/src/java/org/apache/lucene/index/codecs/sep/IntStreamFactory.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/sep/IntStreamFactory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/sep/IntStreamFactory.java	(working copy)
@@ -17,9 +17,8 @@
  * limitations under the License.
  */
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.store.Directory;
-import org.apache.lucene.store.BufferedIndexInput;
+import org.apache.lucene.store.IOContext;
 
 import java.io.IOException;
 
@@ -30,5 +29,5 @@
   }
 
 //  public abstract IntIndexInput openInput(Directory dir, String fileName, IOContext context) throws IOException;
-  public abstract IntIndexOutput createOutput(Directory dir, String fileName) throws IOException;
+  public abstract IntIndexOutput createOutput(Directory dir, String fileName, IOContext context) throws IOException;
 }
Index: lucene/src/java/org/apache/lucene/index/codecs/BlockTermsReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/BlockTermsReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/BlockTermsReader.java	(working copy)
@@ -29,7 +29,6 @@
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
 import org.apache.lucene.index.FieldsEnum;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.TermState;
@@ -38,6 +37,7 @@
 import org.apache.lucene.index.codecs.standard.StandardPostingsReader; // javadocs
 import org.apache.lucene.store.ByteArrayDataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.ArrayUtil;
 import org.apache.lucene.util.Bits;
Index: lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosReader.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/DefaultSegmentInfosReader.java	(working copy)
@@ -22,15 +22,14 @@
 import org.apache.lucene.index.CompoundFileReader;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.index.FieldsReader;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.IndexFormatTooOldException;
 import org.apache.lucene.index.IndexFormatTooNewException;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentInfos;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.ChecksumIndexInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 
 /**
Index: lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesProducer.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesProducer.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/codecs/DefaultDocValuesProducer.java	(working copy)
@@ -22,7 +22,6 @@
 
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.values.Bytes;
 import org.apache.lucene.index.values.IndexDocValues;
@@ -30,6 +29,7 @@
 import org.apache.lucene.index.values.Ints;
 import org.apache.lucene.index.values.ValueType;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /**
  * Abstract base class for FieldsProducer implementations supporting
@@ -57,9 +57,9 @@
    *           if an {@link IOException} occurs
    */
   public DefaultDocValuesProducer(SegmentInfo si, Directory dir,
-      FieldInfos fieldInfo, int codecId) throws IOException {
+      FieldInfos fieldInfo, int codecId, IOContext context) throws IOException {
     //nocommit this needs an IOContext
-    docValues = load(fieldInfo, si.name, si.docCount, dir, codecId);
+    docValues = load(fieldInfo, si.name, si.docCount, dir, codecId, context);
   }
 
   /**
@@ -73,7 +73,7 @@
 
   // Only opens files... doesn't actually load any values
   protected TreeMap<String, IndexDocValues> load(FieldInfos fieldInfos,
-      String segment, int docCount, Directory dir, int codecId)
+      String segment, int docCount, Directory dir, int codecId, IOContext context)
       throws IOException {
     TreeMap<String, IndexDocValues> values = new TreeMap<String, IndexDocValues>();
     boolean success = false;
@@ -87,7 +87,7 @@
           final String id = DefaultDocValuesConsumer.docValuesId(segment,
               codecId, fieldInfo.number);
           values.put(field,
-              loadDocValues(docCount, dir, id, fieldInfo.getDocValues()));
+              loadDocValues(docCount, dir, id, fieldInfo.getDocValues(), context));
         }
       }
       success = true;
@@ -121,27 +121,27 @@
    *           if the given {@link ValueType} is not supported
    */
   protected IndexDocValues loadDocValues(int docCount, Directory dir, String id,
-      ValueType type) throws IOException {
+      ValueType type, IOContext context) throws IOException {
     // nocommit this needs an IOContext too
     switch (type) {
     case INTS:
-      return Ints.getValues(dir, id, false);
+      return Ints.getValues(dir, id, false, context);
     case FLOAT_32:
-      return Floats.getValues(dir, id, docCount);
+      return Floats.getValues(dir, id, docCount, context);
     case FLOAT_64:
-      return Floats.getValues(dir, id, docCount);
+      return Floats.getValues(dir, id, docCount, context);
     case BYTES_FIXED_STRAIGHT:
-      return Bytes.getValues(dir, id, Bytes.Mode.STRAIGHT, true, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.STRAIGHT, true, docCount, context);
     case BYTES_FIXED_DEREF:
-      return Bytes.getValues(dir, id, Bytes.Mode.DEREF, true, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.DEREF, true, docCount, context);
     case BYTES_FIXED_SORTED:
-      return Bytes.getValues(dir, id, Bytes.Mode.SORTED, true, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.SORTED, true, docCount, context);
     case BYTES_VAR_STRAIGHT:
-      return Bytes.getValues(dir, id, Bytes.Mode.STRAIGHT, false, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.STRAIGHT, false, docCount, context);
     case BYTES_VAR_DEREF:
-      return Bytes.getValues(dir, id, Bytes.Mode.DEREF, false, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.DEREF, false, docCount, context);
     case BYTES_VAR_SORTED:
-      return Bytes.getValues(dir, id, Bytes.Mode.SORTED, false, docCount);
+      return Bytes.getValues(dir, id, Bytes.Mode.SORTED, false, docCount, context);
     default:
       throw new IllegalStateException("unrecognized index values mode " + type);
     }
Index: lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/SegmentCoreReaders.java	(working copy)
@@ -24,6 +24,7 @@
 import org.apache.lucene.index.codecs.FieldsProducer;
 import org.apache.lucene.index.codecs.PerDocValues;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 
 /** Holds core readers that are shared (unchanged) when
  * SegmentReader is cloned or reopened */
Index: lucene/src/java/org/apache/lucene/index/NormsWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/NormsWriter.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/index/NormsWriter.java	(working copy)
@@ -21,8 +21,8 @@
 import java.util.Collection;
 import java.util.Map;
 
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.IOContext.Context;
 import org.apache.lucene.util.IOUtils;
 
 // TODO FI: norms could actually be stored as doc store
Index: lucene/src/java/org/apache/lucene/store/NIOFSDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/NIOFSDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/NIOFSDirectory.java	(working copy)
@@ -23,7 +23,6 @@
 import java.nio.channels.ClosedChannelException; // javadoc @link
 import java.nio.channels.FileChannel;
 import java.util.concurrent.Future; // javadoc
-import org.apache.lucene.index.IOContext;
 
 /**
  * An {@link FSDirectory} implementation that uses java.nio's FileChannel's
Index: lucene/src/java/org/apache/lucene/store/MMapDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/MMapDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/MMapDirectory.java	(working copy)
@@ -31,7 +31,6 @@
 import java.security.PrivilegedActionException;
 import java.lang.reflect.Method;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.util.Constants;
 
 /** File-based {@link Directory} implementation that uses
Index: lucene/src/java/org/apache/lucene/store/FlushInfo.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/FlushInfo.java	(revision 0)
+++ lucene/src/java/org/apache/lucene/store/FlushInfo.java	(revision 0)
@@ -0,0 +1,33 @@
+package org.apache.lucene.store;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//nocommit to add javadoc
+
+public class FlushInfo {
+  
+  public int numDocs;
+  
+  public long estimatedSegmentSize;
+  
+  public FlushInfo(int numDocs, long estimatedSegmentSize) {
+    this.numDocs = numDocs;
+    this.estimatedSegmentSize = estimatedSegmentSize;
+  }
+
+}
Index: lucene/src/java/org/apache/lucene/store/Directory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/Directory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/Directory.java	(working copy)
@@ -22,7 +22,6 @@
 import java.io.Closeable;
 import java.util.Collection; // for javadocs
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.util.IOUtils;
 
 /** A Directory is a flat list of files.  Files may be written once, when they
Index: lucene/src/java/org/apache/lucene/store/RAMDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/RAMDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/RAMDirectory.java	(working copy)
@@ -27,7 +27,6 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 
-import org.apache.lucene.index.IOContext;
 
 /**
  * A memory-resident {@link Directory} implementation.  Locking
Index: lucene/src/java/org/apache/lucene/store/SimpleFSDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/SimpleFSDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/SimpleFSDirectory.java	(working copy)
@@ -21,7 +21,6 @@
 import java.io.IOException;
 import java.io.RandomAccessFile;
 
-import org.apache.lucene.index.IOContext;
 
 /** A straightforward implementation of {@link FSDirectory}
  *  using java.io.RandomAccessFile.  However, this class has
Index: lucene/src/java/org/apache/lucene/store/MergeInfo.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/MergeInfo.java	(revision 1138659)
+++ lucene/src/java/org/apache/lucene/store/MergeInfo.java	(working copy)
@@ -1,4 +1,4 @@
-package org.apache.lucene.index;
+package org.apache.lucene.store;
 /**
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -15,7 +15,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-//nocommit javadoc
+
+/**
+ * <p>A MergeInfo provides information required for a merge and optimization operations.
+ *  It is used as part of a <code>IOContext</code> in case of merges.</p>
+ */
+
 public class MergeInfo {
   
   public int totalDocCount;
@@ -25,7 +30,18 @@
   boolean isExternal;               // used by IndexWriter
   
   boolean optimize;                 // used by IndexWriter
+  
 
+  /**
+   * <p>Creates a new <code>MergeInfo</code> instance from
+   * the values required for a merge <code>IOContext</code> context.
+   * 
+   * @param int totalDocCount
+   * @param long estimatedMergeBytes
+   * @param boolean isExternal
+   * @param boolean optimize
+   */
+
   public MergeInfo(int totalDocCount, long estimatedMergeBytes, boolean isExternal, boolean optimize) {
     this.totalDocCount = totalDocCount;
     this.estimatedMergeBytes = estimatedMergeBytes;
Index: lucene/src/java/org/apache/lucene/store/IOContext.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/IOContext.java	(revision 1138659)
+++ lucene/src/java/org/apache/lucene/store/IOContext.java	(working copy)
@@ -1,4 +1,4 @@
-package org.apache.lucene.index;
+package org.apache.lucene.store;
 
 /**
  * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -37,6 +37,8 @@
   
   public final MergeInfo mergeInfo;
   
+  public final FlushInfo flushInfo;
+  
   public final boolean readOnce;
   
   public static final IOContext DEFAULT = new IOContext(Context.DEFAULT);
@@ -49,14 +51,23 @@
     this(false);
   }
   
-  public IOContext(Context context) {
+  public IOContext (FlushInfo flushInfo) {
+    assert flushInfo != null;
+    this.context = Context.FLUSH;
+    this.mergeInfo = null;
+    this.readOnce = false;
+    this.flushInfo = flushInfo;    
+  }
+  
+  public IOContext (Context context) {
     this(context, null);    
   }
   
-  private IOContext(boolean readOnce) {
+  private IOContext (boolean readOnce) {
     this.context = Context.READ;
     this.mergeInfo = null;    
     this.readOnce = readOnce;
+    this.flushInfo = null;
   }
   
   public IOContext (MergeInfo mergeInfo) {    
@@ -64,10 +75,11 @@
   }
 
   private IOContext (Context context, MergeInfo mergeInfo ) {
-    assert context != Context.MERGE || mergeInfo != null;
+    assert context != Context.MERGE || context != Context.FLUSH || mergeInfo != null;
     this.context = context;
     this.readOnce = false;
     this.mergeInfo = mergeInfo;
+    this.flushInfo = null;
   }
   
 }
\ No newline at end of file
Index: lucene/src/java/org/apache/lucene/store/FileSwitchDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/FileSwitchDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/FileSwitchDirectory.java	(working copy)
@@ -25,7 +25,6 @@
 import java.util.Set;
 import java.util.HashSet;
 
-import org.apache.lucene.index.IOContext;
 
 /**
  * Expert: A Directory instance that switches files between
Index: lucene/src/java/org/apache/lucene/store/FSDirectory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/FSDirectory.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/store/FSDirectory.java	(working copy)
@@ -29,7 +29,6 @@
 import java.util.Set;
 import java.util.concurrent.Future;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.util.ThreadInterruptedException;
 import org.apache.lucene.util.Constants;
 
Index: lucene/src/java/org/apache/lucene/util/BitVector.java
===================================================================
--- lucene/src/java/org/apache/lucene/util/BitVector.java	(revision 1140355)
+++ lucene/src/java/org/apache/lucene/util/BitVector.java	(working copy)
@@ -19,12 +19,12 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
-import org.apache.lucene.index.IOContext.Context;
 import org.apache.lucene.index.MergePolicy.OneMerge;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
+import org.apache.lucene.store.IOContext.Context;
 
 /** Optimized implementation of a vector of bits.  This is more-or-less like
   java.util.BitSet, but also includes the following:
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockVariableIntBlockCodec.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockVariableIntBlockCodec.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockVariableIntBlockCodec.java	(working copy)
@@ -20,7 +20,6 @@
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentWriteState;
@@ -49,6 +48,7 @@
 import org.apache.lucene.index.codecs.TermsIndexWriterBase;
 import org.apache.lucene.index.codecs.standard.StandardCodec;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.BytesRef;
@@ -107,8 +107,8 @@
     }
 
     @Override
-    public IntIndexOutput createOutput(Directory dir, String fileName) throws IOException {
-      final IndexOutput out = dir.createOutput(fileName, IOContext.DEFAULT);
+    public IntIndexOutput createOutput(Directory dir, String fileName, IOContext context) throws IOException {
+      final IndexOutput out = dir.createOutput(fileName, context);
       boolean success = false;
       try {
         out.writeInt(baseBlockSize);
@@ -248,6 +248,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockFixedIntBlockCodec.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockFixedIntBlockCodec.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mockintblock/MockFixedIntBlockCodec.java	(working copy)
@@ -20,7 +20,6 @@
 import java.io.IOException;
 import java.util.Set;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
 import org.apache.lucene.index.SegmentWriteState;
@@ -103,8 +102,8 @@
     }
 
     @Override
-    public IntIndexOutput createOutput(Directory dir, String fileName) throws IOException {
-      IndexOutput out = dir.createOutput(fileName, IOContext.DEFAULT);
+    public IntIndexOutput createOutput(Directory dir, String fileName, IOContext context) throws IOException {
+      IndexOutput out = dir.createOutput(fileName, context);
       boolean success = false;
       try {
         FixedIntBlockIndexOutput ret = new FixedIntBlockIndexOutput(out, blockSize) {
@@ -226,6 +225,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSepCodec.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSepCodec.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSepCodec.java	(working copy)
@@ -161,6 +161,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexOutput.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexOutput.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexOutput.java	(working copy)
@@ -17,11 +17,11 @@
  * limitations under the License.
  */
 
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.CodecUtil;
 import org.apache.lucene.util.IOUtils;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.sep.IntIndexOutput;
 import java.io.IOException;
 
@@ -36,9 +36,9 @@
   final static int VERSION_START = 0;
   final static int VERSION_CURRENT = VERSION_START;
 
-  public MockSingleIntIndexOutput(Directory dir, String fileName) throws IOException {
+  public MockSingleIntIndexOutput(Directory dir, String fileName, IOContext context) throws IOException {
     //nocommit pass IOContext in via ctor!
-    out = dir.createOutput(fileName, IOContext.DEFAULT);
+    out = dir.createOutput(fileName, context);
     boolean success = false;
     try {
       CodecUtil.writeHeader(out, CODEC, VERSION_CURRENT);
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntFactory.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntFactory.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntFactory.java	(working copy)
@@ -18,7 +18,7 @@
  */
 
 import org.apache.lucene.store.Directory;
-import org.apache.lucene.index.IOContext;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.index.codecs.sep.IntStreamFactory;
 import org.apache.lucene.index.codecs.sep.IntIndexInput;
 import org.apache.lucene.index.codecs.sep.IntIndexOutput;
@@ -32,7 +32,7 @@
     return new MockSingleIntIndexInput(dir, fileName, context);
   }
   @Override
-  public IntIndexOutput createOutput(Directory dir, String fileName) throws IOException {
-    return new MockSingleIntIndexOutput(dir, fileName);
+  public IntIndexOutput createOutput(Directory dir, String fileName, IOContext context) throws IOException {
+    return new MockSingleIntIndexOutput(dir, fileName, context);
   }
 }
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexInput.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexInput.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mocksep/MockSingleIntIndexInput.java	(working copy)
@@ -19,10 +19,10 @@
 
 import java.io.IOException;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.codecs.sep.IntIndexInput;
 import org.apache.lucene.store.DataInput;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.util.CodecUtil;
 
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/mockrandom/MockRandomCodec.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/mockrandom/MockRandomCodec.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/mockrandom/MockRandomCodec.java	(working copy)
@@ -25,7 +25,6 @@
 import java.util.Set;
 
 import org.apache.lucene.index.FieldInfo;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.PerDocWriteState;
 import org.apache.lucene.index.SegmentInfo;
@@ -62,6 +61,7 @@
 import org.apache.lucene.index.codecs.standard.StandardPostingsReader;
 import org.apache.lucene.index.codecs.standard.StandardPostingsWriter;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.BytesRef;
@@ -115,12 +115,12 @@
     }
 
     @Override
-    public IntIndexOutput createOutput(Directory dir, String fileName) throws IOException {
+    public IntIndexOutput createOutput(Directory dir, String fileName, IOContext context) throws IOException {
       final IntStreamFactory f = delegates.get((Math.abs(salt ^ getExtension(fileName).hashCode())) % delegates.size());
       if (LuceneTestCase.VERBOSE) {
         System.out.println("MockRandomCodec: write using int factory " + f + " to fileName=" + fileName);
       }
-      return f.createOutput(dir, fileName);
+      return f.createOutput(dir, fileName, context);
     }
   }
 
@@ -386,6 +386,6 @@
 
   @Override
   public PerDocValues docsProducer(SegmentReadState state) throws IOException {
-    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId);
+    return new DefaultDocValuesProducer(state.segmentInfo, state.dir, state.fieldInfos, state.codecId, state.context);
   }
 }
Index: lucene/src/test-framework/org/apache/lucene/index/codecs/preflexrw/TermInfosWriter.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/index/codecs/preflexrw/TermInfosWriter.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/index/codecs/preflexrw/TermInfosWriter.java	(working copy)
@@ -22,11 +22,11 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.FieldInfos;
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.index.codecs.preflex.PreFlexCodec;
 import org.apache.lucene.index.codecs.preflex.TermInfo;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CharsRef;
Index: lucene/src/test-framework/org/apache/lucene/store/MockDirectoryWrapper.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/store/MockDirectoryWrapper.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/store/MockDirectoryWrapper.java	(working copy)
@@ -31,7 +31,6 @@
 import java.util.Random;
 import java.util.Set;
 
-import org.apache.lucene.index.IOContext;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.util.LuceneTestCase;
@@ -198,7 +197,8 @@
         byte[] zeroes = new byte[256];
         long upto = 0;
         //nocommit - randomize the IOContext here?
-        IndexOutput out = delegate.createOutput(name, IOContext.DEFAULT);
+        int contextSelect = randomState.nextInt(1);
+        IndexOutput out = delegate.createOutput(name, contextSelect > 0 ? IOContext.DEFAULT : IOContext.READONCE);
         while(upto < length) {
           final int limit = (int) Math.min(length-upto, zeroes.length);
           out.writeBytes(zeroes, 0, limit);
@@ -208,7 +208,7 @@
       } else if (count % 3 == 2) {
         // Truncate the file:
         //nocommit - randomize the IOContext here?
-        IndexOutput out = delegate.createOutput(name, IOContext.DEFAULT);
+        IndexOutput out = delegate.createOutput(name, new IOContext(new MergeInfo(4192,1024,true,false)));
         out.setLength(fileLength(name)/2);
         out.close();
       }
Index: lucene/src/test-framework/org/apache/lucene/util/LuceneTestCase.java
===================================================================
--- lucene/src/test-framework/org/apache/lucene/util/LuceneTestCase.java	(revision 1140355)
+++ lucene/src/test-framework/org/apache/lucene/util/LuceneTestCase.java	(working copy)
@@ -60,7 +60,10 @@
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.FSDirectory;
+import org.apache.lucene.store.FlushInfo;
+import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.LockFactory;
+import org.apache.lucene.store.MergeInfo;
 import org.apache.lucene.store.MockDirectoryWrapper;
 import org.apache.lucene.store.MockDirectoryWrapper.Throttling;
 import org.apache.lucene.util.FieldCacheSanityChecker.Insanity;
@@ -1312,6 +1315,24 @@
     return sb.toString();
   }
 
+  public IOContext newIOContext(Random random) {
+    int type = random.nextInt(5);
+    IOContext context = IOContext.DEFAULT;
+    switch(type) {
+      case 0:
+        context = IOContext.DEFAULT;
+      case 1:
+        context = IOContext.READ;
+      case 2:
+        context = IOContext.READONCE;
+      case 3:
+        context = new IOContext(new MergeInfo(4192, 1024, true, false));
+      case 4:
+        context = new IOContext(new FlushInfo(4192, 1024));       
+    }
+    return context;
+  }
+  
   // recorded seed: for beforeClass
   private static long staticSeed;
   // seed for individual test methods, changed in @before