true if the given object is the same identifier,
+ * false otherwise
+ */
+ public boolean equals(Object object) {
+ return (object instanceof DataIdentifier)
+ && identifier.equals(object.toString());
+ }
+
+ /**
+ * Returns the hash code of the identifier string.
+ *
+ * @return hash code
+ */
+ public int hashCode() {
+ return identifier.hashCode();
+ }
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\StringDataIdentifier.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/DataStore.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/DataStore.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/DataStore.java (revision 0)
@@ -0,0 +1,73 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Append-only store for binary streams. A data store consists of a number
+ * of identifiable data records that each contain a distinct binary stream.
+ * New binary streams can be added to the data store, but existing streams
+ * are never removed or modified.
+ * + * A data store should be fully thread-safe, i.e. it should be possible to + * add and access data records concurrently. Optimally even separate processes + * should be able to concurrently access the data store with zero interprocess + * synchronization. + */ +public interface DataStore { + + /** + * Returns the identified data record. The given identifier should be + * the identifier of a previously saved data record. Since records are + * never removed, there should never be cases where the identified record + * is not found. Abnormal cases like that are treated as errors and + * handled by throwing an exception. + * + * @param identifier data identifier + * @return identified data record + * @throws IOException if the data store could not be accessed, + * or if the given identifier is invalid + */ + DataRecord getRecord(DataIdentifier identifier) throws IOException; + + /** + * Creates a new data record. The given binary stream is consumed and + * a binary record containing the consumed stream is created and returned. + * If the same stream already exists in another record, then that record + * is returned instead of creating a new one. + *
+ * The given stream is consumed and not closed by this + * method. It is the responsibility of the caller to close the stream. + * A typical call pattern would be: + *
+ * InputStream stream = ...;
+ * try {
+ * record = store.addRecord(stream);
+ * } finally {
+ * stream.close();
+ * }
+ *
+ *
+ * @param stream binary stream
+ * @return data record that contains the given stream
+ * @throws IOException if the data store could not be accessed
+ */
+ DataRecord addRecord(InputStream stream) throws IOException;
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\DataStore.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/FileDataStore.java (revision 0)
@@ -0,0 +1,198 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Random;
+
+/**
+ * Simple file-based data store. Data records are stored as normal files
+ * named using a message digest of the contained binary stream.
+ * + * A three level directory structure is used to avoid placing too many + * files in a single directory. The chosen structure is designed to scale + * up to billions of distinct records. + *
+ * This implementation relies on the underlying file system to support + * atomic O(1) move operations with {@link File#renameTo(File)}. + */ +public class FileDataStore implements DataStore { + + /** + * The digest algorithm used to uniquely identify records. + */ + private static final String DIGEST = "SHA-1"; + + /** + * Name of the directory used for temporary files. + */ + private static final String TMP = "tmp"; + + /** + * Temporary file counter used to guarantee that concurrent threads + * in this JVM do not accidentally use the same temporary file names. + *
+ * This variable is static to allow multiple separate data store + * instances in the same JVM to access the same data store directory + * on disk. The counter is initialized to a random number based on the + * time when this class was first loaded to minimize the chance of two + * separate JVM processes (or class loaders within the same JVM) using + * the same temporary file names. + */ + private static long counter = new Random().nextLong(); + + /** + * Returns the next value of the internal temporary file counter. + * + * @return next counter value + */ + private static synchronized long nextCount() { + return counter++; + } + + /** + * The directory that contains all the data record files. The structure + * of content within this directory is controlled by this class. + */ + private final File directory; + + /** + * Creates a data store based on the given directory. + * + * @param directory data store directory + */ + public FileDataStore(File directory) { + this.directory = directory; + } + + /** + * Returns the record with the given identifier. Note that this method + * performs no sanity checks on the given identifier. It is up to the + * caller to ensure that only identifiers of previously created data + * records are used. + * + * @param identifier data identifier + * @return identified data record + */ + public DataRecord getRecord(DataIdentifier identifier) { + return new FileDataRecord(identifier, getFile(identifier)); + } + + /** + * Creates a new record based on the given input stream. The stream + * is first consumed and the contents are saved in a temporary file + * and the SHA-1 message digest of the stream is calculated. If a + * record with the same SHA-1 digest (and length) is found then it is + * returned. Otherwise the temporary file is moved in place to become + * the new data record that gets returned. + * + * @param input binary stream + * @return data record that contains the given stream + * @throws IOException if the record could not be created + */ + public DataRecord addRecord(InputStream input) throws IOException { + File temporary = newTemporaryFile(); + try { + // Copy the stream to the temporary file and calculate the + // stream length and the message digest of the stream + long length = 0; + MessageDigest digest = MessageDigest.getInstance(DIGEST); + OutputStream output = new FileOutputStream(temporary); + try { + byte[] b = new byte[4096]; + for (int n = input.read(b); n != -1; n = input.read(b)) { + output.write(b, 0, n); + digest.update(b, 0, n); + length += n; + } + } finally { + output.close(); + } + + // Check if the same record already exists, or + // move the temporary file in place if needed + DataIdentifier identifier = + new StringDataIdentifier(digest.digest()); + File file = getFile(identifier); + File parent = file.getParentFile(); + if (!parent.isDirectory()) { + parent.mkdirs(); + } + if (!file.exists()) { + temporary.renameTo(file); + } + + // Sanity checks on the record file. These should never fail, + // but better safe than sorry... + if (!file.isFile()) { + throw new IOException("Not a file: " + file); + } + if (file.length() != length) { + throw new IOException(DIGEST + " collision: " + file); + } + + return new FileDataRecord(identifier, file); + } catch (NoSuchAlgorithmException e) { + throw new IOException(DIGEST + " not available: " + e.getMessage()); + } finally { + temporary.delete(); + } + } + + /** + * Returns the identified file. This method implements the pattern + * used to avoid problems with too many files in a single directory. + *
+ * No sanity checks are performed on the given identifier.
+ *
+ * @param identifier data identifier
+ * @return identified file
+ */
+ private File getFile(DataIdentifier identifier) {
+ String string = identifier.toString();
+ File file = directory;
+ file = new File(file, string.substring(0, 2));
+ file = new File(file, string.substring(2, 4));
+ file = new File(file, string.substring(4, 6));
+ return new File(file, string);
+ }
+
+ /**
+ * Returns a unique temporary file to be used for creating a new
+ * data record. A synchronized counter value and the current time are
+ * used to construct the name of the temporary file in a way that
+ * minimizes the chance of collisions across concurrent threads or
+ * processes.
+ *
+ * @return temporary file
+ */
+ private File newTemporaryFile() {
+ File temporary = new File(directory, TMP);
+ if (!temporary.isDirectory()) {
+ temporary.mkdirs();
+ }
+ String name = TMP + "-" + nextCount() + "-" + System.currentTimeMillis();
+ return new File(temporary, name);
+ }
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\FileDataStore.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/DataRecord.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/DataRecord.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/DataRecord.java (revision 0)
@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Immutable data record that consists of a binary stream.
+ */
+public interface DataRecord {
+
+ /**
+ * Returns the identifier of this record.
+ *
+ * @return data identifier
+ */
+ DataIdentifier getIdentifier();
+
+ /**
+ * Returns the length of the binary stream in this record.
+ *
+ * @return length of the binary stream
+ * @throws IOException if the record could not be accessed
+ */
+ long getLength() throws IOException;
+
+ /**
+ * Returns the the binary stream in this record.
+ *
+ * @return binary stream
+ * @throws IOException if the record could not be accessed
+ */
+ InputStream getStream() throws IOException;
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\DataRecord.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/FileDataRecord.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/FileDataRecord.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/FileDataRecord.java (revision 0)
@@ -0,0 +1,66 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+
+/**
+ * Data record that is based on a normal file.
+ */
+class FileDataRecord extends AbstractDataRecord {
+
+ /**
+ * The file that contains the binary stream.
+ */
+ private final File file;
+
+ /**
+ * Creates a data record based on the given identifier and file.
+ *
+ * @param identifier data identifier
+ * @param file file that contains the binary stream
+ */
+ public FileDataRecord(DataIdentifier identifier, File file) {
+ super(identifier);
+ assert file.isFile();
+ this.file = file;
+ }
+
+ /**
+ * Returns the length of the file.
+ *
+ * @return file length
+ */
+ public long getLength() {
+ return file.length();
+ }
+
+ /**
+ * Returns an input stream for reading the file.
+ *
+ * @return file input stream
+ * @throws IOException if the file could not be opened
+ */
+ public InputStream getStream() throws IOException {
+ return new FileInputStream(file);
+ }
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\FileDataRecord.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/AbstractDataRecord.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/AbstractDataRecord.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/AbstractDataRecord.java (revision 0)
@@ -0,0 +1,81 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+/**
+ * Abstract data record base class. This base class contains only
+ * a reference to the data identifier of the record and implements
+ * the standard {@link Object} equality, hash code, and string
+ * representation methods based on the identifier.
+ */
+public abstract class AbstractDataRecord implements DataRecord {
+
+ /**
+ * The binary identifier;
+ */
+ private final DataIdentifier identifier;
+
+ /**
+ * Creates a data record with the given identifier.
+ *
+ * @param identifier data identifier
+ */
+ public AbstractDataRecord(DataIdentifier identifier) {
+ this.identifier = identifier;
+ }
+
+ /**
+ * Returns the data identifier.
+ *
+ * @param data identifier
+ */
+ public DataIdentifier getIdentifier() {
+ return identifier;
+ }
+
+ /**
+ * Returns the string representation of the data identifier.
+ *
+ * @return string representation
+ */
+ public String toString() {
+ return identifier.toString();
+ }
+
+ /**
+ * Checks if the given object is a data record with the same identifier
+ * as this one.
+ *
+ * @param object other object
+ * @return true if the other object is a data record and has
+ * the same identifier as this one, false otherwise
+ */
+ public boolean equals(Object object) {
+ return (object instanceof DataRecord)
+ && identifier.equals(((DataRecord) object).getIdentifier());
+ }
+
+ /**
+ * Returns the hash code of the data identifier.
+ *
+ * @return hash code
+ */
+ public int hashCode() {
+ return identifier.hashCode();
+ }
+
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\AbstractDataRecord.java
___________________________________________________________________
Name: svn:eol-style
+ native
Index: src/main/java/org/apache/jackrabbit/core/data/DataIdentifier.java
===================================================================
--- src/main/java/org/apache/jackrabbit/core/data/DataIdentifier.java (revision 0)
+++ src/main/java/org/apache/jackrabbit/core/data/DataIdentifier.java (revision 0)
@@ -0,0 +1,27 @@
+/*
+ * 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.
+ */
+package org.apache.jackrabbit.core.data;
+
+import java.io.Serializable;
+
+/**
+ * Opaque data identifier used to identify records in a data store.
+ * All identifiers must be serializable and implement the standard
+ * object equality and hash code methods.
+ */
+public interface DataIdentifier extends Serializable {
+}
Property changes on: src\main\java\org\apache\jackrabbit\core\data\DataIdentifier.java
___________________________________________________________________
Name: svn:eol-style
+ native