1c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta/* 2c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Copyright (C) 2012 The Android Open Source Project 3c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * 4c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Licensed under the Apache License, Version 2.0 (the "License"); 5c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * you may not use this file except in compliance with the License. 6c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * You may obtain a copy of the License at 7c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * 8c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * http://www.apache.org/licenses/LICENSE-2.0 9c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * 10c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Unless required by applicable law or agreed to in writing, software 11c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * distributed under the License is distributed on an "AS IS" BASIS, 12c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * See the License for the specific language governing permissions and 14c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * limitations under the License. 15c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 16c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 17c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Bartapackage com.android.volley.toolbox; 18c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 19c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Bartaimport java.io.ByteArrayOutputStream; 20c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Bartaimport java.io.IOException; 21c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 22c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta/** 23c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * A variation of {@link java.io.ByteArrayOutputStream} that uses a pool of byte[] buffers instead 24c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * of always allocating them fresh, saving on heap churn. 25c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 26c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Bartapublic class PoolingByteArrayOutputStream extends ByteArrayOutputStream { 27c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta /** 28c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * If the {@link #PoolingByteArrayOutputStream(ByteArrayPool)} constructor is called, this is 29c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * the default size to which the underlying byte array is initialized. 30c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 31c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta private static final int DEFAULT_SIZE = 256; 32c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 33c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta private final ByteArrayPool mPool; 34c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 35c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta /** 36c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Constructs a new PoolingByteArrayOutputStream with a default size. If more bytes are written 37c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * to this instance, the underlying byte array will expand. 38c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 39c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public PoolingByteArrayOutputStream(ByteArrayPool pool) { 40c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta this(pool, DEFAULT_SIZE); 41c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 42c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 43c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta /** 44c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Constructs a new {@code ByteArrayOutputStream} with a default size of {@code size} bytes. If 45c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * more than {@code size} bytes are written to this instance, the underlying byte array will 46c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * expand. 47c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * 48c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * @param size initial size for the underlying byte array. The value will be pinned to a default 49c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * minimum size. 50c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 51c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public PoolingByteArrayOutputStream(ByteArrayPool pool, int size) { 52c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta mPool = pool; 53c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta buf = mPool.getBuf(Math.max(size, DEFAULT_SIZE)); 54c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 55c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 56c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta @Override 57c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public void close() throws IOException { 58c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta mPool.returnBuf(buf); 59c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta buf = null; 60c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta super.close(); 61c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 62c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 63c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta @Override 64c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public void finalize() { 65c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta mPool.returnBuf(buf); 66c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 67c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 68c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta /** 69c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta * Ensures there is enough space in the buffer for the given number of additional bytes. 70c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta */ 71c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta private void expand(int i) { 72c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta /* Can the buffer handle @i more bytes, if not expand it */ 73c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta if (count + i <= buf.length) { 74c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta return; 75c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 76c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta byte[] newbuf = mPool.getBuf((count + i) * 2); 77c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta System.arraycopy(buf, 0, newbuf, 0, count); 78c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta mPool.returnBuf(buf); 79c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta buf = newbuf; 80c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 81c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 82c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta @Override 83c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public synchronized void write(byte[] buffer, int offset, int len) { 84c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta expand(len); 85c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta super.write(buffer, offset, len); 86c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 87c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta 88c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta @Override 89c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta public synchronized void write(int oneByte) { 90c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta expand(1); 91c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta super.write(oneByte); 92c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta } 93c4cbfcb8d044cea99e2471ce5c401cd959b6cdfeScott Barta} 94