+++ /dev/null
-package org.apache.lucene.util;
-
-import java.util.concurrent.atomic.AtomicLong;
-
-import org.apache.lucene.util.ByteBlockPool.Allocator;
-
-/**
- * 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.
- */
-
-/**
- * A {@link ByteBlockPool.Allocator} implementation that recycles unused byte
- * blocks in a buffer and reuses them in subsequent calls to
- * {@link #getByteBlock()}.
- *
- * @lucene.internal
- */
-public final class RecyclingByteBlockAllocator extends ByteBlockPool.Allocator {
- private byte[][] freeByteBlocks;
- private final int maxBufferedBlocks;
- private int freeBlocks = 0;
- private final AtomicLong bytesUsed;
- public static final int DEFAULT_BUFFERED_BLOCKS = 64;
-
- /**
- * Creates a new {@link RecyclingByteBlockAllocator}
- *
- * @param blockSize
- * the block size in bytes
- * @param maxBufferedBlocks
- * maximum number of buffered byte block
- * @param bytesUsed
- * {@link AtomicLong} reference counting internally allocated bytes
- *
- * @see DummyConcurrentLock
- */
- public RecyclingByteBlockAllocator(int blockSize, int maxBufferedBlocks,
- AtomicLong bytesUsed) {
- super(blockSize);
- freeByteBlocks = new byte[Math.min(10, maxBufferedBlocks)][];
- this.maxBufferedBlocks = maxBufferedBlocks;
- this.bytesUsed = bytesUsed;
- }
-
- /**
- * Creates a new {@link RecyclingByteBlockAllocator} with a
- * {@link DummyConcurrentLock} instance.
- *
- * @param blockSize
- * the block size in bytes
- * @param maxBufferedBlocks
- * maximum number of buffered byte block
- */
- public RecyclingByteBlockAllocator(int blockSize, int maxBufferedBlocks) {
- this(blockSize, maxBufferedBlocks, new AtomicLong());
- }
-
- /**
- * Creates a new {@link RecyclingByteBlockAllocator} with a block size of
- * {@link ByteBlockPool#BYTE_BLOCK_SIZE}, upper buffered docs limit of
- * {@link #DEFAULT_BUFFERED_BLOCKS} ({@value #DEFAULT_BUFFERED_BLOCKS}) and a
- * {@link DummyConcurrentLock} instance.
- *
- */
- public RecyclingByteBlockAllocator() {
- this(ByteBlockPool.BYTE_BLOCK_SIZE, 64, new AtomicLong());
- }
-
- @Override
- public synchronized byte[] getByteBlock() {
- if (freeBlocks == 0) {
- bytesUsed.addAndGet(blockSize);
- return new byte[blockSize];
- }
- final byte[] b = freeByteBlocks[--freeBlocks];
- freeByteBlocks[freeBlocks] = null;
- return b;
- }
-
- @Override
- public synchronized void recycleByteBlocks(byte[][] blocks, int start, int end) {
- final int numBlocks = Math.min(maxBufferedBlocks - freeBlocks, end - start);
- final int size = freeBlocks + numBlocks;
- if (size >= freeByteBlocks.length) {
- final byte[][] newBlocks = new byte[ArrayUtil.oversize(size,
- RamUsageEstimator.NUM_BYTES_OBJECT_REF)][];
- System.arraycopy(freeByteBlocks, 0, newBlocks, 0, freeBlocks);
- freeByteBlocks = newBlocks;
- }
- final int stop = start + numBlocks;
- for (int i = start; i < stop; i++) {
- freeByteBlocks[freeBlocks++] = blocks[i];
- blocks[i] = null;
- }
- for (int i = stop; i < end; i++) {
- blocks[i] = null;
- }
- bytesUsed.addAndGet(-(end - stop) * blockSize);
- assert bytesUsed.get() >= 0;
- }
-
- /**
- * @return the number of currently buffered blocks
- */
- public synchronized int numBufferedBlocks() {
- return freeBlocks;
- }
-
- /**
- * @return the number of bytes currently allocated by this {@link Allocator}
- */
- public long bytesUsed() {
- return bytesUsed.get();
- }
-
- /**
- * @return the maximum number of buffered byte blocks
- */
- public int maxBufferedBlocks() {
- return maxBufferedBlocks;
- }
-
- /**
- * Removes the given number of byte blocks from the buffer if possible.
- *
- * @param num
- * the number of byte blocks to remove
- * @return the number of actually removed buffers
- */
- public synchronized int freeBlocks(int num) {
- assert num >= 0;
- final int stop;
- final int count;
- if (num > freeBlocks) {
- stop = 0;
- count = freeBlocks;
- } else {
- stop = freeBlocks - num;
- count = num;
- }
- while (freeBlocks > stop) {
- freeByteBlocks[--freeBlocks] = null;
- }
- bytesUsed.addAndGet(-count*blockSize);
- assert bytesUsed.get() >= 0;
- return count;
- }
-}
\ No newline at end of file
fnp / pylucene.git / blobdiff