a. If create is true, then a new,
empty index will be created in d, replacing the index already
there, if any. */
- public IndexWriter(Directory d, Analyzer a, boolean create)
+ public IndexWriter(Directory d, Analyzer a, final boolean create)
throws IOException {
directory = d;
analyzer = a;
- synchronized (directory) {
- if (create)
- segmentInfos.write(directory);
- else
- segmentInfos.read(directory);
+ Lock writeLock = directory.makeLock("write.lock");
+ if (!writeLock.obtain()) // obtain write lock
+ throw new IOException("Index locked for write: " + writeLock);
+
+ synchronized (directory) { // in- & inter-process sync
+ new Lock.With(directory.makeLock("commit.lock")) {
+ public Object doBody() throws IOException {
+ if (create)
+ segmentInfos.write(directory);
+ else
+ segmentInfos.read(directory);
+ return null;
+ }
+ }.run();
}
}
@@ -130,6 +140,7 @@ public final class IndexWriter {
public final synchronized void close() throws IOException {
flushRamSegments();
ramDirectory.close();
+ directory.makeLock("write.lock").release(); // release write lock
directory.close();
}
@@ -286,7 +297,7 @@ public final class IndexWriter {
int mergedDocCount = 0;
if (infoStream != null) infoStream.print("merging segments");
SegmentMerger merger = new SegmentMerger(directory, mergedName);
- Vector segmentsToDelete = new Vector();
+ final Vector segmentsToDelete = new Vector();
for (int i = minSegment; i < segmentInfos.size(); i++) {
SegmentInfo si = segmentInfos.info(i);
if (infoStream != null)
@@ -307,9 +318,14 @@ public final class IndexWriter {
segmentInfos.addElement(new SegmentInfo(mergedName, mergedDocCount,
directory));
- synchronized (directory) {
- segmentInfos.write(directory); // commit before deleting
- deleteSegments(segmentsToDelete); // delete now-unused segments
+ synchronized (directory) { // in- & inter-process sync
+ new Lock.With(directory.makeLock("commit.lock")) {
+ public Object doBody() throws IOException {
+ segmentInfos.write(directory); // commit before deleting
+ deleteSegments(segmentsToDelete); // delete now-unused segments
+ return null;
+ }
+ }.run();
}
}
diff --git a/src/java/org/apache/lucene/index/SegmentReader.java b/src/java/org/apache/lucene/index/SegmentReader.java
index 67292205c7a..ac054f7d8f4 100644
--- a/src/java/org/apache/lucene/index/SegmentReader.java
+++ b/src/java/org/apache/lucene/index/SegmentReader.java
@@ -61,6 +61,7 @@ import java.util.Vector;
import org.apache.lucene.util.BitVector;
import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.Lock;
import org.apache.lucene.store.InputStream;
import org.apache.lucene.document.Document;
@@ -116,9 +117,14 @@ final class SegmentReader extends IndexReader {
public final synchronized void close() throws IOException {
if (deletedDocsDirty) {
- synchronized (directory) {
- deletedDocs.write(directory, segment + ".tmp");
- directory.renameFile(segment + ".tmp", segment + ".del");
+ synchronized (directory) { // in- & inter-process sync
+ new Lock.With(directory.makeLock("commit.lock")) {
+ public Object doBody() throws IOException {
+ deletedDocs.write(directory, segment + ".tmp");
+ directory.renameFile(segment + ".tmp", segment + ".del");
+ return null;
+ }
+ }.run();
}
deletedDocsDirty = false;
}
diff --git a/src/java/org/apache/lucene/store/Directory.java b/src/java/org/apache/lucene/store/Directory.java
index 2660c03b5e4..2aaacbfa83d 100644
--- a/src/java/org/apache/lucene/store/Directory.java
+++ b/src/java/org/apache/lucene/store/Directory.java
@@ -108,6 +108,11 @@ abstract public class Directory {
abstract public InputStream openFile(String name)
throws IOException, SecurityException;
+ /** Construct a {@link Lock}.
+ * @param name the name of the lock file
+ */
+ abstract public Lock makeLock(String name);
+
/** Closes the store. */
abstract public void close()
throws IOException, SecurityException;
diff --git a/src/java/org/apache/lucene/store/FSDirectory.java b/src/java/org/apache/lucene/store/FSDirectory.java
index e158501c465..6587e4f6019 100644
--- a/src/java/org/apache/lucene/store/FSDirectory.java
+++ b/src/java/org/apache/lucene/store/FSDirectory.java
@@ -206,6 +206,24 @@ final public class FSDirectory extends Directory {
return new FSInputStream(new File(directory, name));
}
+ /** Construct a {@link Lock}.
+ * @param name the name of the lock file
+ */
+ public final Lock makeLock(String name) {
+ final File lockFile = new File(directory, name);
+ return new Lock() {
+ public boolean obtain() throws IOException {
+ return lockFile.createNewFile();
+ }
+ public void release() {
+ lockFile.delete();
+ }
+ public String toString() {
+ return "Lock@" + lockFile;
+ }
+ };
+ }
+
/** Closes the store to future operations. */
public final synchronized void close() throws IOException {
if (--refCount <= 0) {
@@ -214,6 +232,11 @@ final public class FSDirectory extends Directory {
}
}
}
+
+ /** For debug output. */
+ public String toString() {
+ return "FSDirectory@" + directory;
+ }
}
@@ -278,8 +301,6 @@ final class FSOutputStream extends OutputStream {
RandomAccessFile file = null;
public FSOutputStream(File path) throws IOException {
- if (path.isFile())
- throw new IOException(path + " already exists");
file = new RandomAccessFile(path, "rw");
}
diff --git a/src/java/org/apache/lucene/store/Lock.java b/src/java/org/apache/lucene/store/Lock.java
new file mode 100644
index 00000000000..46d8a03c0c6
--- /dev/null
+++ b/src/java/org/apache/lucene/store/Lock.java
@@ -0,0 +1,125 @@
+package org.apache.lucene.store;
+
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation. All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ * if any, must include the following acknowledgment:
+ * "This product includes software developed by the
+ * Apache Software Foundation (http://www.apache.org/)."
+ * Alternately, this acknowledgment may appear in the software itself,
+ * if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" and
+ * "Apache Lucene" must not be used to endorse or promote products
+ * derived from this software without prior written permission. For
+ * written permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ * "Apache Lucene", nor may "Apache" appear in their name, without
+ * prior written permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation. For more
+ * information on the Apache Software Foundation, please see
+ * Typical use might look like:
+ * new Lock.With(directory.makeLock("my.lock")) {
+ * public Object doBody() {
+ * ... code to execute while locked ...
+ * }
+ * }.run();
+ *
+ *
+ * @author Doug Cutting
+ * @see Directory#makeLock(String)
+*/
+
+public abstract class Lock {
+ /** Attempt to obtain exclusive access.
+ *
+ * @return true iff exclusive access is obtained
+ */
+ public abstract boolean obtain() throws IOException;
+
+ /** Release exclusive access. */
+ public abstract void release();
+
+ /** Utility class for executing code with exclusive access. */
+ public abstract static class With {
+ private Lock lock;
+ private int sleepInterval = 1000;
+ private int maxSleeps = 10;
+
+ /** Constructs an executor that will grab the named lock. */
+ public With(Lock lock) {
+ this.lock = lock;
+ }
+
+ /** Code to execute with exclusive access. */
+ protected abstract Object doBody() throws IOException;
+
+ /** Calls {@link #doBody} while