/*
* (C) 2007-2012 Alibaba Group Holding Limited.
*
* Licensed 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.
*/
package com.taobao.gecko.core.util;
/*
* Copyright 2004-2005 the original author or authors.
*
* Licensed 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.
*/
/**
* 来自于cindy2.4的工具类，做了简化和新增
*/
import java.nio.ByteBuffer;
import com.taobao.gecko.core.config.Configuration;
public class ByteBufferUtils {
/**
*
* @param byteBuffer
* @return *
*/
public static final ByteBuffer increaseBufferCapatity(final ByteBuffer byteBuffer) {
return increaseBufferCapatity(byteBuffer, Configuration.DEFAULT_INCREASE_BUFF_SIZE);
}
/**
*
* @param byteBuffer
* @param size
* �ݼ��ķ���
* @param minSize
* ��С��С
* @return
*/
public static final ByteBuffer decreaseBufferCapatity(final ByteBuffer byteBuffer, final int size, final int minSize) {
if (byteBuffer == null) {
throw new IllegalArgumentException("buffer is null");
}
if (minSize <= 0) {
throw new IllegalArgumentException("minSize must be great than zero");
}
if (byteBuffer.capacity() == minSize) {
return byteBuffer;
}
int capacity = byteBuffer.capacity() - size;
// ����С����С��С
if (capacity < minSize) {
capacity = minSize;
}
// �����ϲ���������������µĻ�������������ԭ�е����ݣ���ֱ�ӷ���ԭʼbuffer
if (capacity < byteBuffer.position()) {
return byteBuffer;
}
final ByteBuffer result =
byteBuffer.isDirect() ? ByteBuffer.allocateDirect(capacity) : ByteBuffer.allocate(capacity);
result.order(byteBuffer.order());
byteBuffer.flip();
result.put(byteBuffer);
return result;
}
/**
*
* @param byteBuffer
* @return *
*/
public static final ByteBuffer increaseBufferCapatity(final ByteBuffer byteBuffer, final int increaseSize) {
if (byteBuffer == null) {
throw new IllegalArgumentException("buffer is null");
}
if (increaseSize <= 0) {
throw new IllegalArgumentException("increaseSize<=0");
}
final int capacity = byteBuffer.capacity() + increaseSize;
if (capacity < 0) {
throw new IllegalArgumentException("capacity can't be negative");
}
final ByteBuffer result =
byteBuffer.isDirect() ? ByteBuffer.allocateDirect(capacity) : ByteBuffer.allocate(capacity);
result.order(byteBuffer.order());
byteBuffer.flip();
result.put(byteBuffer);
return result;
}
public static final void flip(final ByteBuffer[] buffers) {
if (buffers == null) {
return;
}
for (final ByteBuffer buffer : buffers) {
if (buffer != null) {
buffer.flip();
}
}
}
public static final ByteBuffer gather(final ByteBuffer[] buffers) {
if (buffers == null || buffers.length == 0) {
return null;
}
final ByteBuffer result = ByteBuffer.allocate(remaining(buffers));
result.order(buffers[0].order());
for (int i = 0; i < buffers.length; i++) {
if (buffers[i] != null) {
result.put(buffers[i]);
}
}
result.flip();
return result;
}
public static final int remaining(final ByteBuffer[] buffers) {
if (buffers == null) {
return 0;
}
int remaining = 0;
for (int i = 0; i < buffers.length; i++) {
if (buffers[i] != null) {
remaining += buffers[i].remaining();
}
}
return remaining;
}
public static final void clear(final ByteBuffer[] buffers) {
if (buffers == null) {
return;
}
for (final ByteBuffer buffer : buffers) {
if (buffer != null) {
buffer.clear();
}
}
}
public static final String toHex(final byte b) {
return "" + "0123456789ABCDEF".charAt(0xf & b >> 4) + "0123456789ABCDEF".charAt(b & 0xf);
}
public static final int indexOf(final ByteBuffer buffer, final ByteBuffer pattern) {
if (pattern == null || buffer == null) {
return -1;
}
final int n = buffer.remaining();
final int m = pattern.remaining();
final int patternPos = pattern.position();
final int bufferPos = buffer.position();
if (n < m) {
return -1;
}
for (int s = 0; s <= n - m; s++) {
boolean match = true;
for (int i = 0; i < m; i++) {
if (buffer.get(s + i + bufferPos) != pattern.get(patternPos + i)) {
match = false;
break;
}
}
if (match) {
return bufferPos + s;
}
}
return -1;
}
public static final int indexOf(final ByteBuffer buffer, final ByteBuffer pattern, final int offset) {
if (offset < 0) {
throw new IllegalArgumentException("offset must be greater than 0");
}
if (pattern == null || buffer == null) {
return -1;
}
final int patternPos = pattern.position();
final int n = buffer.remaining();
final int m = pattern.remaining();
if (n < m) {
return -1;
}
if (offset < buffer.position() || offset > buffer.limit()) {
return -1;
}
for (int s = 0; s <= n - m; s++) {
boolean match = true;
for (int i = 0; i < m; i++) {
if (buffer.get(s + i + offset) != pattern.get(patternPos + i)) {
match = false;
break;
}
}
if (match) {
return offset + s;
}
}
return -1;
}
/**
* 查看ByteBuffer数组是否还有剩余
*
* @param buffers
* ByteBuffers
* @return have remaining
*/
public static final boolean hasRemaining(final ByteBuffer[] buffers) {
if (buffers == null) {
return false;
}
for (int i = 0; i < buffers.length; i++) {
if (buffers[i] != null && buffers[i].hasRemaining()) {
return true;
}
}
return false;
}
public static final int uByte(final byte b) {
return b & 0xFF;
}
}