Index: ../lucene/src/java/org/apache/lucene/util/SimpleStringInterner.java
===================================================================
--- ../lucene/src/java/org/apache/lucene/util/SimpleStringInterner.java	(revision 801344)
+++ ../lucene/src/java/org/apache/lucene/util/SimpleStringInterner.java	Mon Aug 24 15:09:01 IST 2009
@@ -79,4 +79,50 @@
     }
     return s;
   }
+
+  public String intern(char[] arr, int offset, int len) {
+     int h = hash(arr, offset, len);
+    // In the future, it may be worth augmenting the string hash
+    // if the lower bits need better distribution.
+    int slot = h & (cache.length-1);
+
+    Entry first = this.cache[slot];
+    Entry nextToLast = null;
+
+    int chainLength = 0;
+
+    for(Entry e=first; e!=null; e=e.next) {
+      if (e.hash == h && isEqual(e.str,arr,offset, len)) {
+        return e.str;
-}
\ No newline at end of file
+      }
+
+      chainLength++;
+      if (e.next != null) {
+        nextToLast = e;
+      }
+    }
+    // insertion-order cache: add new entry at head
+    String s = new String(arr, offset, len).intern();
+    this.cache[slot] = new Entry(s, h, first);
+    if (chainLength >= maxChainLength) {
+      // prune last entry
+      nextToLast.next = null;
+    }
+    return s;
+  }
+
+  private static boolean isEqual(String s, char[] arr, int offset, int len) {
+    for (int i = 0; i < len; i++) {
+      if(s.charAt(i) != arr[i + offset]) return false;
+    }
+    return true;
+  }
+
+  private static int hash(char[] val, int offset, int len) {
+    int h = 0;
+    for (int i = 0; i < len; i++) {
+      h = 31 * h + val[offset++];
+    }
+    return h;
+  }
+}
\ No newline at end of file