obtain write.lock while deleting documents

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@149670 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/lucene/index/IndexReader.java

@@ -75,7 +75,12 @@ import org.apache.lucene.document.Document;
   rely on a given document having the same number between sessions. */
 
 abstract public class IndexReader {
-  protected IndexReader() {}
+  protected IndexReader(Directory directory) {
+    this.directory = directory;
+  }
+
+  Directory directory;
+  private Lock writeLock;
 
   /** Returns an IndexReader reading the index in an FSDirectory in the named
   path. */
@@ -102,7 +107,7 @@ abstract public class IndexReader {
 	    SegmentReader[] readers = new SegmentReader[infos.size()];
 	    for (int i = 0; i < infos.size(); i++)
 	      readers[i] = new SegmentReader(infos.info(i), i==infos.size()-1);
-	    return new SegmentsReader(readers);
+	    return new SegmentsReader(directory, readers);
 	  }
 	}.run();
     }
@@ -240,7 +245,16 @@ abstract public class IndexReader {
     method will result in an error.  The presence of this document may still be
     reflected in the {@link #docFreq} statistic, though
     this will be corrected eventually as the index is further modified.  */
-  abstract public void delete(int docNum) throws IOException;
+  public synchronized final void delete(int docNum) throws IOException {
+    if (writeLock == null) {
+      Lock writeLock = directory.makeLock("write.lock");
+      if (!writeLock.obtain())			  // obtain write lock
+        throw new IOException("Index locked for write: " + writeLock);
+      this.writeLock = writeLock;
+    }
+    doDelete(docNum);
+  }
+  abstract void doDelete(int docNum) throws IOException;
 
   /** Deletes all documents containing <code>term</code>.
     This is useful if one uses a document field to hold a unique ID string for
@@ -267,7 +281,24 @@ abstract public class IndexReader {
    * Also saves any new deletions to disk.
    * No other methods should be called after this has been called.
    */
-    abstract public void close() throws IOException;
+  public final synchronized void close() throws IOException {
+    doClose();
+    if (writeLock != null) {
+      writeLock.release();  // release write lock
+      writeLock = null;
+    }
+  }
+
+  /** Implements close. */
+  abstract void doClose() throws IOException;
+
+  /** Release the write lock, if needed. */
+  protected final void finalize() throws IOException {
+    if (writeLock != null) {
+      writeLock.release();                        // release write lock
+      writeLock = null;
+    }
+  }
 
   /**
    * Returns <code>true</code> iff the index in the named directory is

src/java/org/apache/lucene/index/IndexWriter.java

@@ -91,6 +91,8 @@ public final class IndexWriter {
   private SegmentInfos segmentInfos = new SegmentInfos(); // the segments
   private final Directory ramDirectory = new RAMDirectory(); // for temp segs
 
+  private Lock writeLock;
+
   /** Constructs an IndexWriter for the index in <code>path</code>.  Text will
     be analyzed with <code>a</code>.  If <code>create</code> is true, then a
     new, empty index will be created in <code>path</code>, replacing the index
@@ -119,8 +121,9 @@ public final class IndexWriter {
     analyzer = a;
 
     Lock writeLock = directory.makeLock("write.lock");
-    if (!writeLock.obtain())			  // obtain write lock
+    if (!writeLock.obtain())                      // obtain write lock
       throw new IOException("Index locked for write: " + writeLock);
+    this.writeLock = writeLock;                   // save it
 
     synchronized (directory) {			  // in- & inter-process sync
       new Lock.With(directory.makeLock("commit.lock")) {
@@ -140,10 +143,19 @@ public final class IndexWriter {
   public final synchronized void close() throws IOException {
     flushRamSegments();
     ramDirectory.close();
-    directory.makeLock("write.lock").release();  // release write lock
+    writeLock.release();                          // release write lock
+    writeLock = null;
     directory.close();
   }
 
+  /** Release the write lock, if needed. */
+  protected final void finalize() throws IOException {
+    if (writeLock != null) {
+      writeLock.release();                        // release write lock
+      writeLock = null;
+    }
+  }
+
   /** Returns the number of documents currently in this index. */
   public final synchronized int docCount() {
     int count = 0;

src/java/org/apache/lucene/index/SegmentReader.java

@@ -66,7 +66,6 @@ import org.apache.lucene.store.InputStream;
 import org.apache.lucene.document.Document;
 
 final class SegmentReader extends IndexReader {
-  Directory directory;
   private boolean closeDirectory = false;
   private String segment;
 
@@ -97,7 +96,7 @@ final class SegmentReader extends IndexReader {
 
   SegmentReader(SegmentInfo si)
        throws IOException {
-    directory = si.dir;
+    super(si.dir);
     segment = si.name;
 
     fieldInfos = new FieldInfos(directory, segment + ".fnm");
@@ -115,7 +114,7 @@ final class SegmentReader extends IndexReader {
     openNorms();
   }
   
-  public final synchronized void close() throws IOException {
+  final synchronized void doClose() throws IOException {
     if (deletedDocsDirty) {
       synchronized (directory) {		  // in- & inter-process sync
 	new Lock.With(directory.makeLock("commit.lock")) {
@@ -147,7 +146,7 @@ final class SegmentReader extends IndexReader {
     return si.dir.fileExists(si.name + ".del");
   }
 
-  public final synchronized void delete(int docNum) throws IOException {
+  final synchronized void doDelete(int docNum) throws IOException {
     if (deletedDocs == null)
       deletedDocs = new BitVector(maxDoc());
     deletedDocsDirty = true;

src/java/org/apache/lucene/index/SegmentsReader.java

@@ -67,7 +67,8 @@ final class SegmentsReader extends IndexReader {
   private int maxDoc = 0;
   private int numDocs = -1;
 
-  SegmentsReader(SegmentReader[] r) throws IOException {
+  SegmentsReader(Directory directory, SegmentReader[] r) throws IOException {
+    super(directory);
     readers = r;
     starts = new int[readers.length + 1];	  // build starts array
     for (int i = 0; i < readers.length; i++) {
@@ -101,7 +102,7 @@ final class SegmentsReader extends IndexReader {
     return readers[i].isDeleted(n - starts[i]);	  // dispatch to segment reader
   }
 
-  public synchronized final void delete(int n) throws IOException {
+  synchronized final void doDelete(int n) throws IOException {
     numDocs = -1;				  // invalidate cache
     int i = readerIndex(n);			  // find segment num
     readers[i].delete(n - starts[i]);		  // dispatch to segment reader
@@ -159,7 +160,7 @@ final class SegmentsReader extends IndexReader {
     return new SegmentsTermPositions(readers, starts);
   }
 
-  public final void close() throws IOException {
+  final synchronized void doClose() throws IOException {
     for (int i = 0; i < readers.length; i++)
       readers[i].close();
   }