+++ /dev/null
-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.
- */
-
-import java.io.File;
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.nio.channels.ClosedChannelException; // javadoc
-import java.nio.channels.FileChannel;
-import java.util.concurrent.Future; // javadoc
-
-/**
- * An {@link FSDirectory} implementation that uses java.nio's FileChannel's
- * positional read, which allows multiple threads to read from the same file
- * without synchronizing.
- * <p>
- * This class only uses FileChannel when reading; writing is achieved with
- * {@link FSDirectory.FSIndexOutput}.
- * <p>
- * <b>NOTE</b>: NIOFSDirectory is not recommended on Windows because of a bug in
- * how FileChannel.read is implemented in Sun's JRE. Inside of the
- * implementation the position is apparently synchronized. See <a
- * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6265734">here</a>
- * for details.
- * </p>
- * <p>
- * <font color="red"><b>NOTE:</b> Accessing this class either directly or
- * indirectly from a thread while it's interrupted can close the
- * underlying file descriptor immediately if at the same time the thread is
- * blocked on IO. The file descriptor will remain closed and subsequent access
- * to {@link NIOFSDirectory} will throw a {@link ClosedChannelException}. If
- * your application uses either {@link Thread#interrupt()} or
- * {@link Future#cancel(boolean)} you should use {@link SimpleFSDirectory} in
- * favor of {@link NIOFSDirectory}.</font>
- * </p>
- */
-public class NIOFSDirectory extends FSDirectory {
-
- /** Create a new NIOFSDirectory for the named location.
- *
- * @param path the path of the directory
- * @param lockFactory the lock factory to use, or null for the default
- * ({@link NativeFSLockFactory});
- * @throws IOException
- */
- public NIOFSDirectory(File path, LockFactory lockFactory) throws IOException {
- super(path, lockFactory);
- }
-
- /** Create a new NIOFSDirectory for the named location and {@link NativeFSLockFactory}.
- *
- * @param path the path of the directory
- * @throws IOException
- */
- public NIOFSDirectory(File path) throws IOException {
- super(path, null);
- }
-
- /** Creates an IndexInput for the file with the given name. */
- @Override
- public IndexInput openInput(String name, int bufferSize) throws IOException {
- ensureOpen();
- return new NIOFSIndexInput(new File(getDirectory(), name), bufferSize, getReadChunkSize());
- }
-
- protected static class NIOFSIndexInput extends SimpleFSDirectory.SimpleFSIndexInput {
-
- private ByteBuffer byteBuf; // wraps the buffer for NIO
-
- private byte[] otherBuffer;
- private ByteBuffer otherByteBuf;
-
- final FileChannel channel;
-
- public NIOFSIndexInput(File path, int bufferSize, int chunkSize) throws IOException {
- super(path, bufferSize, chunkSize);
- channel = file.getChannel();
- }
-
- @Override
- protected void newBuffer(byte[] newBuffer) {
- super.newBuffer(newBuffer);
- byteBuf = ByteBuffer.wrap(newBuffer);
- }
-
- @Override
- public void close() throws IOException {
- if (!isClone && file.isOpen) {
- // Close the channel & file
- try {
- channel.close();
- } finally {
- file.close();
- }
- }
- }
-
- @Override
- protected void readInternal(byte[] b, int offset, int len) throws IOException {
-
- final ByteBuffer bb;
-
- // Determine the ByteBuffer we should use
- if (b == buffer && 0 == offset) {
- // Use our own pre-wrapped byteBuf:
- assert byteBuf != null;
- byteBuf.clear();
- byteBuf.limit(len);
- bb = byteBuf;
- } else {
- if (offset == 0) {
- if (otherBuffer != b) {
- // Now wrap this other buffer; with compound
- // file, we are repeatedly called with its
- // buffer, so we wrap it once and then re-use it
- // on subsequent calls
- otherBuffer = b;
- otherByteBuf = ByteBuffer.wrap(b);
- } else
- otherByteBuf.clear();
- otherByteBuf.limit(len);
- bb = otherByteBuf;
- } else {
- // Always wrap when offset != 0
- bb = ByteBuffer.wrap(b, offset, len);
- }
- }
-
- int readOffset = bb.position();
- int readLength = bb.limit() - readOffset;
- assert readLength == len;
-
- long pos = getFilePointer();
-
- try {
- while (readLength > 0) {
- final int limit;
- if (readLength > chunkSize) {
- // LUCENE-1566 - work around JVM Bug by breaking
- // very large reads into chunks
- limit = readOffset + chunkSize;
- } else {
- limit = readOffset + readLength;
- }
- bb.limit(limit);
- int i = channel.read(bb, pos);
- if (i == -1) {
- throw new IOException("read past EOF");
- }
- pos += i;
- readOffset += i;
- readLength -= i;
- }
- } catch (OutOfMemoryError e) {
- // propagate OOM up and add a hint for 32bit VM Users hitting the bug
- // with a large chunk size in the fast path.
- final OutOfMemoryError outOfMemoryError = new OutOfMemoryError(
- "OutOfMemoryError likely caused by the Sun VM Bug described in "
- + "https://issues.apache.org/jira/browse/LUCENE-1566; try calling FSDirectory.setReadChunkSize "
- + "with a value smaller than the current chunk size (" + chunkSize + ")");
- outOfMemoryError.initCause(e);
- throw outOfMemoryError;
- }
- }
- }
-}
fnp / pylucene.git / blobdiff