/*
* Copyright 2011 The Netty Project
*
* The Netty Project 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.
*/
package org.jboss.netty.buffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.util.ArrayList;
import java.util.List;
import org.jboss.netty.util.CharsetUtil;
/**
* Creates a new {@link ChannelBuffer} by allocating new space or by wrapping
* or copying existing byte arrays, byte buffers and a string.
*
* <h3>Use static import</h3>
* This classes is intended to be used with Java 5 static import statement:
*
* <pre>
* import static org.jboss.netty.buffer.{@link ChannelBuffers}.*;
*
* {@link ChannelBuffer} heapBuffer = buffer(128);
* {@link ChannelBuffer} directBuffer = directBuffer(256);
* {@link ChannelBuffer} dynamicBuffer = dynamicBuffer(512);
* {@link ChannelBuffer} wrappedBuffer = wrappedBuffer(new byte[128], new byte[256]);
* {@link ChannelBuffer} copiedBuffe r = copiedBuffer({@link ByteBuffer}.allocate(128));
* </pre>
*
* <h3>Allocating a new buffer</h3>
*
* Three buffer types are provided out of the box.
*
* <ul>
* <li>{@link #buffer(int)} allocates a new fixed-capacity heap buffer.</li>
* <li>{@link #directBuffer(int)} allocates a new fixed-capacity direct buffer.</li>
* <li>{@link #dynamicBuffer(int)} allocates a new dynamic-capacity heap
* buffer, whose capacity increases automatically as needed by a write
* operation.</li>
* </ul>
*
* <h3>Creating a wrapped buffer</h3>
*
* Wrapped buffer is a buffer which is a view of one or more existing
* byte arrays and byte buffers. Any changes in the content of the original
* array or buffer will be visible in the wrapped buffer. Various wrapper
* methods are provided and their name is all {@code wrappedBuffer()}.
* You might want to take a look at the methods that accept varargs closely if
* you want to create a buffer which is composed of more than one array to
* reduce the number of memory copy.
*
* <h3>Creating a copied buffer</h3>
*
* Copied buffer is a deep copy of one or more existing byte arrays, byte
* buffers or a string. Unlike a wrapped buffer, there's no shared data
* between the original data and the copied buffer. Various copy methods are
* provided and their name is all {@code copiedBuffer()}. It is also convenient
* to use this operation to merge multiple buffers into one buffer.
*
* <h3>Miscellaneous utility methods</h3>
*
* This class also provides various utility methods to help implementation
* of a new buffer type, generation of hex dump and swapping an integer's
* byte order.
*
* @apiviz.landmark
* @apiviz.has org.jboss.netty.buffer.ChannelBuffer oneway - - creates
*/
public final class ChannelBuffers {
/**
* Big endian byte order.
*/
public static final ByteOrder BIG_ENDIAN = ByteOrder.BIG_ENDIAN;
/**
* Little endian byte order.
*/
public static final ByteOrder LITTLE_ENDIAN = ByteOrder.LITTLE_ENDIAN;
/**
* A buffer whose capacity is {@code 0}.
*/
public static final ChannelBuffer EMPTY_BUFFER = new BigEndianHeapChannelBuffer(0);
private static final char[] HEXDUMP_TABLE = new char[256 * 4];
static {
final char[] DIGITS = "0123456789abcdef".toCharArray();
for (int i = 0; i < 256; i ++) {
HEXDUMP_TABLE[(i << 1) + 0] = DIGITS[i >>> 4 & 0x0F];
HEXDUMP_TABLE[(i << 1) + 1] = DIGITS[i >>> 0 & 0x0F];
}
}
/**
* Creates a new big-endian Java heap buffer with the specified
* {@code capacity}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer buffer(int capacity) {
return buffer(BIG_ENDIAN, capacity);
}
/**
* Creates a new Java heap buffer with the specified {@code endianness}
* and {@code capacity}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer buffer(ByteOrder endianness, int capacity) {
if (endianness == BIG_ENDIAN) {
if (capacity == 0) {
return EMPTY_BUFFER;
}
return new BigEndianHeapChannelBuffer(capacity);
} else if (endianness == LITTLE_ENDIAN) {
if (capacity == 0) {
return EMPTY_BUFFER;
}
return new LittleEndianHeapChannelBuffer(capacity);
} else {
throw new NullPointerException("endianness");
}
}
/**
* Creates a new big-endian direct buffer with the specified
* {@code capacity}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer directBuffer(int capacity) {
return directBuffer(BIG_ENDIAN, capacity);
}
/**
* Creates a new direct buffer with the specified {@code endianness} and
* {@code capacity}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer directBuffer(ByteOrder endianness, int capacity) {
if (endianness == null) {
throw new NullPointerException("endianness");
}
if (capacity == 0) {
return EMPTY_BUFFER;
}
ChannelBuffer buffer = new ByteBufferBackedChannelBuffer(
ByteBuffer.allocateDirect(capacity).order(endianness));
buffer.clear();
return buffer;
}
/**
* Creates a new big-endian dynamic buffer whose estimated data length is
* {@code 256} bytes. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer dynamicBuffer() {
return dynamicBuffer(BIG_ENDIAN, 256);
}
public static ChannelBuffer dynamicBuffer(ChannelBufferFactory factory) {
if (factory == null) {
throw new NullPointerException("factory");
}
return new DynamicChannelBuffer(factory.getDefaultOrder(), 256, factory);
}
/**
* Creates a new big-endian dynamic buffer with the specified estimated
* data length. More accurate estimation yields less unexpected
* reallocation overhead. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer dynamicBuffer(int estimatedLength) {
return dynamicBuffer(BIG_ENDIAN, estimatedLength);
}
/**
* Creates a new dynamic buffer with the specified endianness and
* the specified estimated data length. More accurate estimation yields
* less unexpected reallocation overhead. The new buffer's
* {@code readerIndex} and {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer dynamicBuffer(ByteOrder endianness, int estimatedLength) {
return new DynamicChannelBuffer(endianness, estimatedLength);
}
/**
* Creates a new big-endian dynamic buffer with the specified estimated
* data length using the specified factory. More accurate estimation yields
* less unexpected reallocation overhead. The new buffer's {@code readerIndex}
* and {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer dynamicBuffer(int estimatedLength, ChannelBufferFactory factory) {
if (factory == null) {
throw new NullPointerException("factory");
}
return new DynamicChannelBuffer(factory.getDefaultOrder(), estimatedLength, factory);
}
/**
* Creates a new dynamic buffer with the specified endianness and
* the specified estimated data length using the specified factory.
* More accurate estimation yields less unexpected reallocation overhead.
* The new buffer's {@code readerIndex} and {@code writerIndex} are {@code 0}.
*/
public static ChannelBuffer dynamicBuffer(ByteOrder endianness, int estimatedLength, ChannelBufferFactory factory) {
return new DynamicChannelBuffer(endianness, estimatedLength, factory);
}
/**
* Creates a new big-endian buffer which wraps the specified {@code array}.
* A modification on the specified array's content will be visible to the
* returned buffer.
*/
public static ChannelBuffer wrappedBuffer(byte[] array) {
return wrappedBuffer(BIG_ENDIAN, array);
}
/**
* Creates a new buffer which wraps the specified {@code array} with the
* specified {@code endianness}. A modification on the specified array's
* content will be visible to the returned buffer.
*/
public static ChannelBuffer wrappedBuffer(ByteOrder endianness, byte[] array) {
if (endianness == BIG_ENDIAN) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return new BigEndianHeapChannelBuffer(array);
} else if (endianness == LITTLE_ENDIAN) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return new LittleEndianHeapChannelBuffer(array);
} else {
throw new NullPointerException("endianness");
}
}
/**
* Creates a new big-endian buffer which wraps the sub-region of the
* specified {@code array}. A modification on the specified array's
* content will be visible to the returned buffer.
*/
public static ChannelBuffer wrappedBuffer(byte[] array, int offset, int length) {
return wrappedBuffer(BIG_ENDIAN, array, offset, length);
}
/**
* Creates a new buffer which wraps the sub-region of the specified
* {@code array} with the specified {@code endianness}. A modification on
* the specified array's content will be visible to the returned buffer.
*/
public static ChannelBuffer wrappedBuffer(ByteOrder endianness, byte[] array, int offset, int length) {
if (endianness == null) {
throw new NullPointerException("endianness");
}
if (offset == 0) {
if (length == array.length) {
return wrappedBuffer(endianness, array);
} else {
if (length == 0) {
return EMPTY_BUFFER;
} else {
return new TruncatedChannelBuffer(wrappedBuffer(endianness, array), length);
}
}
} else {
if (length == 0) {
return EMPTY_BUFFER;
} else {
return new SlicedChannelBuffer(wrappedBuffer(endianness, array), offset, length);
}
}
}
/**
* Creates a new buffer which wraps the specified NIO buffer's current
* slice. A modification on the specified buffer's content will be
* visible to the returned buffer.
*/
public static ChannelBuffer wrappedBuffer(ByteBuffer buffer) {
if (!buffer.hasRemaining()) {
return EMPTY_BUFFER;
}
if (buffer.hasArray()) {
return wrappedBuffer(buffer.order(), buffer.array(), buffer.arrayOffset() + buffer.position(), buffer.remaining());
} else {
return new ByteBufferBackedChannelBuffer(buffer);
}
}
/**
* Creates a new buffer which wraps the specified buffer's readable bytes.
* A modification on the specified buffer's content will be visible to the
* returned buffer.
*/
public static ChannelBuffer wrappedBuffer(ChannelBuffer buffer) {
if (buffer.readable()) {
return buffer.slice();
} else {
return EMPTY_BUFFER;
}
}
/**
* Creates a new big-endian composite buffer which wraps the specified
* arrays without copying them. A modification on the specified arrays'
* content will be visible to the returned buffer.
*/
public static ChannelBuffer wrappedBuffer(byte[]... arrays) {
return wrappedBuffer(BIG_ENDIAN, arrays);
}
/**
* Creates a new composite buffer which wraps the specified arrays without
* copying them. A modification on the specified arrays' content will be
* visible to the returned buffer.
*
* @param endianness the endianness of the new buffer
*/
public static ChannelBuffer wrappedBuffer(ByteOrder endianness, byte[]... arrays) {
switch (arrays.length) {
case 0:
break;
case 1:
if (arrays[0].length != 0) {
return wrappedBuffer(endianness, arrays[0]);
}
break;
default:
// Get the list of the component, while guessing the byte order.
final List<ChannelBuffer> components = new ArrayList<ChannelBuffer>(arrays.length);
for (byte[] a: arrays) {
if (a == null) {
break;
}
if (a.length > 0) {
components.add(wrappedBuffer(endianness, a));
}
}
return compositeBuffer(endianness, components);
}
return EMPTY_BUFFER;
}
private static ChannelBuffer compositeBuffer(
ByteOrder endianness, List<ChannelBuffer> components) {
switch (components.size()) {
case 0:
return EMPTY_BUFFER;
case 1:
return components.get(0);
default:
return new CompositeChannelBuffer(endianness, components);
}
}
/**
* Creates a new composite buffer which wraps the readable bytes of the
* specified buffers without copying them. A modification on the content
* of the specified buffers will be visible to the returned buffer.
*
* @throws IllegalArgumentException
* if the specified buffers' endianness are different from each
* other
*/
public static ChannelBuffer wrappedBuffer(ChannelBuffer... buffers) {
switch (buffers.length) {
case 0:
break;
case 1:
if (buffers[0].readable()) {
return wrappedBuffer(buffers[0]);
}
break;
default:
ByteOrder order = null;
final List<ChannelBuffer> components = new ArrayList<ChannelBuffer>(buffers.length);
for (ChannelBuffer c: buffers) {
if (c == null) {
break;
}
if (c.readable()) {
if (order != null) {
if (!order.equals(c.order())) {
throw new IllegalArgumentException(
"inconsistent byte order");
}
} else {
order = c.order();
}
if (c instanceof CompositeChannelBuffer) {
// Expand nested composition.
components.addAll(
((CompositeChannelBuffer) c).decompose(
c.readerIndex(), c.readableBytes()));
} else {
// An ordinary buffer (non-composite)
components.add(c.slice());
}
}
}
return compositeBuffer(order, components);
}
return EMPTY_BUFFER;
}
/**
* Creates a new composite buffer which wraps the slices of the specified
* NIO buffers without copying them. A modification on the content of the
* specified buffers will be visible to the returned buffer.
*
* @throws IllegalArgumentException
* if the specified buffers' endianness are different from each
* other
*/
public static ChannelBuffer wrappedBuffer(ByteBuffer... buffers) {
switch (buffers.length) {
case 0:
break;
case 1:
if (buffers[0].hasRemaining()) {
return wrappedBuffer(buffers[0]);
}
break;
default:
ByteOrder order = null;
final List<ChannelBuffer> components = new ArrayList<ChannelBuffer>(buffers.length);
for (ByteBuffer b: buffers) {
if (b == null) {
break;
}
if (b.hasRemaining()) {
if (order != null) {
if (!order.equals(b.order())) {
throw new IllegalArgumentException(
"inconsistent byte order");
}
} else {
order = b.order();
}
components.add(wrappedBuffer(b));
}
}
return compositeBuffer(order, components);
}
return EMPTY_BUFFER;
}
/**
* Creates a new big-endian buffer whose content is a copy of the
* specified {@code array}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and {@code array.length} respectively.
*/
public static ChannelBuffer copiedBuffer(byte[] array) {
return copiedBuffer(BIG_ENDIAN, array);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is a copy of the specified {@code array}. The new buffer's
* {@code readerIndex} and {@code writerIndex} are {@code 0} and
* {@code array.length} respectively.
*/
public static ChannelBuffer copiedBuffer(ByteOrder endianness, byte[] array) {
if (endianness == BIG_ENDIAN) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return new BigEndianHeapChannelBuffer(array.clone());
} else if (endianness == LITTLE_ENDIAN) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return new LittleEndianHeapChannelBuffer(array.clone());
} else {
throw new NullPointerException("endianness");
}
}
/**
* Creates a new big-endian buffer whose content is a copy of the
* specified {@code array}'s sub-region. The new buffer's
* {@code readerIndex} and {@code writerIndex} are {@code 0} and
* the specified {@code length} respectively.
*/
public static ChannelBuffer copiedBuffer(byte[] array, int offset, int length) {
return copiedBuffer(BIG_ENDIAN, array, offset, length);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is a copy of the specified {@code array}'s sub-region. The new
* buffer's {@code readerIndex} and {@code writerIndex} are {@code 0} and
* the specified {@code length} respectively.
*/
public static ChannelBuffer copiedBuffer(ByteOrder endianness, byte[] array, int offset, int length) {
if (endianness == null) {
throw new NullPointerException("endianness");
}
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] copy = new byte[length];
System.arraycopy(array, offset, copy, 0, length);
return wrappedBuffer(endianness, copy);
}
/**
* Creates a new buffer whose content is a copy of the specified
* {@code buffer}'s current slice. The new buffer's {@code readerIndex}
* and {@code writerIndex} are {@code 0} and {@code buffer.remaining}
* respectively.
*/
public static ChannelBuffer copiedBuffer(ByteBuffer buffer) {
int length = buffer.remaining();
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] copy = new byte[length];
int position = buffer.position();
try {
buffer.get(copy);
} finally {
buffer.position(position);
}
return wrappedBuffer(buffer.order(), copy);
}
/**
* Creates a new buffer whose content is a copy of the specified
* {@code buffer}'s readable bytes. The new buffer's {@code readerIndex}
* and {@code writerIndex} are {@code 0} and {@code buffer.readableBytes}
* respectively.
*/
public static ChannelBuffer copiedBuffer(ChannelBuffer buffer) {
if (buffer.readable()) {
return buffer.copy();
} else {
return EMPTY_BUFFER;
}
}
/**
* Creates a new big-endian buffer whose content is a merged copy of
* the specified {@code arrays}. The new buffer's {@code readerIndex}
* and {@code writerIndex} are {@code 0} and the sum of all arrays'
* {@code length} respectively.
*/
public static ChannelBuffer copiedBuffer(byte[]... arrays) {
return copiedBuffer(BIG_ENDIAN, arrays);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is a merged copy of the specified {@code arrays}. The new
* buffer's {@code readerIndex} and {@code writerIndex} are {@code 0}
* and the sum of all arrays' {@code length} respectively.
*/
public static ChannelBuffer copiedBuffer(ByteOrder endianness, byte[]... arrays) {
switch (arrays.length) {
case 0:
return EMPTY_BUFFER;
case 1:
if (arrays[0].length == 0) {
return EMPTY_BUFFER;
} else {
return copiedBuffer(endianness, arrays[0]);
}
}
// Merge the specified arrays into one array.
int length = 0;
for (byte[] a: arrays) {
if (Integer.MAX_VALUE - length < a.length) {
throw new IllegalArgumentException(
"The total length of the specified arrays is too big.");
}
length += a.length;
}
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] mergedArray = new byte[length];
for (int i = 0, j = 0; i < arrays.length; i ++) {
byte[] a = arrays[i];
System.arraycopy(a, 0, mergedArray, j, a.length);
j += a.length;
}
return wrappedBuffer(endianness, mergedArray);
}
/**
* Creates a new buffer whose content is a merged copy of the specified
* {@code buffers}' readable bytes. The new buffer's {@code readerIndex}
* and {@code writerIndex} are {@code 0} and the sum of all buffers'
* {@code readableBytes} respectively.
*
* @throws IllegalArgumentException
* if the specified buffers' endianness are different from each
* other
*/
public static ChannelBuffer copiedBuffer(ChannelBuffer... buffers) {
switch (buffers.length) {
case 0:
return EMPTY_BUFFER;
case 1:
return copiedBuffer(buffers[0]);
}
ChannelBuffer[] copiedBuffers = new ChannelBuffer[buffers.length];
for (int i = 0; i < buffers.length; i ++) {
copiedBuffers[i] = copiedBuffer(buffers[i]);
}
return wrappedBuffer(copiedBuffers);
}
/**
* Creates a new buffer whose content is a merged copy of the specified
* {@code buffers}' slices. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and the sum of all buffers'
* {@code remaining} respectively.
*
* @throws IllegalArgumentException
* if the specified buffers' endianness are different from each
* other
*/
public static ChannelBuffer copiedBuffer(ByteBuffer... buffers) {
switch (buffers.length) {
case 0:
return EMPTY_BUFFER;
case 1:
return copiedBuffer(buffers[0]);
}
ChannelBuffer[] copiedBuffers = new ChannelBuffer[buffers.length];
for (int i = 0; i < buffers.length; i ++) {
copiedBuffers[i] = copiedBuffer(buffers[i]);
}
return wrappedBuffer(copiedBuffers);
}
/**
* Creates a new big-endian buffer whose content is the specified
* {@code string} encoded in the specified {@code charset}.
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0} and the length of the encoded string respectively.
*/
public static ChannelBuffer copiedBuffer(CharSequence string, Charset charset) {
return copiedBuffer(BIG_ENDIAN, string, charset);
}
/**
* Creates a new big-endian buffer whose content is a subregion of
* the specified {@code string} encoded in the specified {@code charset}.
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0} and the length of the encoded string respectively.
*/
public static ChannelBuffer copiedBuffer(
CharSequence string, int offset, int length, Charset charset) {
return copiedBuffer(BIG_ENDIAN, string, offset, length, charset);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is the specified {@code string} encoded in the specified
* {@code charset}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and the length of the encoded string
* respectively.
*/
public static ChannelBuffer copiedBuffer(ByteOrder endianness, CharSequence string, Charset charset) {
if (string == null) {
throw new NullPointerException("string");
}
if (string instanceof CharBuffer) {
return copiedBuffer(endianness, (CharBuffer) string, charset);
}
return copiedBuffer(endianness, CharBuffer.wrap(string), charset);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is a subregion of the specified {@code string} encoded in the
* specified {@code charset}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and the length of the encoded string
* respectively.
*/
public static ChannelBuffer copiedBuffer(
ByteOrder endianness, CharSequence string, int offset, int length, Charset charset) {
if (string == null) {
throw new NullPointerException("string");
}
if (length == 0) {
return EMPTY_BUFFER;
}
if (string instanceof CharBuffer) {
CharBuffer buf = (CharBuffer) string;
if (buf.hasArray()) {
return copiedBuffer(
endianness,
buf.array(),
buf.arrayOffset() + buf.position() + offset,
length, charset);
}
buf = buf.slice();
buf.limit(length);
buf.position(offset);
return copiedBuffer(endianness, buf, charset);
}
return copiedBuffer(
endianness, CharBuffer.wrap(string, offset, offset + length),
charset);
}
/**
* Creates a new big-endian buffer whose content is the specified
* {@code array} encoded in the specified {@code charset}.
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0} and the length of the encoded string respectively.
*/
public static ChannelBuffer copiedBuffer(char[] array, Charset charset) {
return copiedBuffer(BIG_ENDIAN, array, 0, array.length, charset);
}
/**
* Creates a new big-endian buffer whose content is a subregion of
* the specified {@code array} encoded in the specified {@code charset}.
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0} and the length of the encoded string respectively.
*/
public static ChannelBuffer copiedBuffer(
char[] array, int offset, int length, Charset charset) {
return copiedBuffer(BIG_ENDIAN, array, offset, length, charset);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is the specified {@code array} encoded in the specified
* {@code charset}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and the length of the encoded string
* respectively.
*/
public static ChannelBuffer copiedBuffer(ByteOrder endianness, char[] array, Charset charset) {
return copiedBuffer(endianness, array, 0, array.length, charset);
}
/**
* Creates a new buffer with the specified {@code endianness} whose
* content is a subregion of the specified {@code array} encoded in the
* specified {@code charset}. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0} and the length of the encoded string
* respectively.
*/
public static ChannelBuffer copiedBuffer(
ByteOrder endianness, char[] array, int offset, int length, Charset charset) {
if (array == null) {
throw new NullPointerException("array");
}
if (length == 0) {
return EMPTY_BUFFER;
}
return copiedBuffer(
endianness, CharBuffer.wrap(array, offset, length), charset);
}
private static ChannelBuffer copiedBuffer(ByteOrder endianness, CharBuffer buffer, Charset charset) {
CharBuffer src = buffer;
ByteBuffer dst = ChannelBuffers.encodeString(src, charset);
ChannelBuffer result = wrappedBuffer(endianness, dst.array());
result.writerIndex(dst.remaining());
return result;
}
/**
* @deprecated Use {@link #copiedBuffer(CharSequence, Charset)} instead.
*/
@Deprecated
public static ChannelBuffer copiedBuffer(String string, String charsetName) {
return copiedBuffer(string, Charset.forName(charsetName));
}
/**
* @deprecated Use {@link #copiedBuffer(ByteOrder, CharSequence, Charset)} instead.
*/
@Deprecated
public static ChannelBuffer copiedBuffer(ByteOrder endianness, String string, String charsetName) {
return copiedBuffer(endianness, string, Charset.forName(charsetName));
}
/**
* Creates a read-only buffer which disallows any modification operations
* on the specified {@code buffer}. The new buffer has the same
* {@code readerIndex} and {@code writerIndex} with the specified
* {@code buffer}.
*/
public static ChannelBuffer unmodifiableBuffer(ChannelBuffer buffer) {
if (buffer instanceof ReadOnlyChannelBuffer) {
buffer = ((ReadOnlyChannelBuffer) buffer).unwrap();
}
return new ReadOnlyChannelBuffer(buffer);
}
/**
* Returns a <a href="http://en.wikipedia.org/wiki/Hex_dump">hex dump</a>
* of the specified buffer's readable bytes.
*/
public static String hexDump(ChannelBuffer buffer) {
return hexDump(buffer, buffer.readerIndex(), buffer.readableBytes());
}
/**
* Returns a <a href="http://en.wikipedia.org/wiki/Hex_dump">hex dump</a>
* of the specified buffer's sub-region.
*/
public static String hexDump(ChannelBuffer buffer, int fromIndex, int length) {
if (length < 0) {
throw new IllegalArgumentException("length: " + length);
}
if (length == 0) {
return "";
}
int endIndex = fromIndex + length;
char[] buf = new char[length << 1];
int srcIdx = fromIndex;
int dstIdx = 0;
for (; srcIdx < endIndex; srcIdx ++, dstIdx += 2) {
System.arraycopy(
HEXDUMP_TABLE, buffer.getUnsignedByte(srcIdx) << 1,
buf, dstIdx, 2);
}
return new String(buf);
}
/**
* Calculates the hash code of the specified buffer. This method is
* useful when implementing a new buffer type.
*/
public static int hashCode(ChannelBuffer buffer) {
final int aLen = buffer.readableBytes();
final int intCount = aLen >>> 2;
final int byteCount = aLen & 3;
int hashCode = 1;
int arrayIndex = buffer.readerIndex();
if (buffer.order() == BIG_ENDIAN) {
for (int i = intCount; i > 0; i --) {
hashCode = 31 * hashCode + buffer.getInt(arrayIndex);
arrayIndex += 4;
}
} else {
for (int i = intCount; i > 0; i --) {
hashCode = 31 * hashCode + swapInt(buffer.getInt(arrayIndex));
arrayIndex += 4;
}
}
for (int i = byteCount; i > 0; i --) {
hashCode = 31 * hashCode + buffer.getByte(arrayIndex ++);
}
if (hashCode == 0) {
hashCode = 1;
}
return hashCode;
}
/**
* Returns {@code true} if and only if the two specified buffers are
* identical to each other as described in {@code ChannelBuffer#equals(Object)}.
* This method is useful when implementing a new buffer type.
*/
public static boolean equals(ChannelBuffer bufferA, ChannelBuffer bufferB) {
final int aLen = bufferA.readableBytes();
if (aLen != bufferB.readableBytes()) {
return false;
}
final int longCount = aLen >>> 3;
final int byteCount = aLen & 7;
int aIndex = bufferA.readerIndex();
int bIndex = bufferB.readerIndex();
if (bufferA.order() == bufferB.order()) {
for (int i = longCount; i > 0; i --) {
if (bufferA.getLong(aIndex) != bufferB.getLong(bIndex)) {
return false;
}
aIndex += 8;
bIndex += 8;
}
} else {
for (int i = longCount; i > 0; i --) {
if (bufferA.getLong(aIndex) != swapLong(bufferB.getLong(bIndex))) {
return false;
}
aIndex += 8;
bIndex += 8;
}
}
for (int i = byteCount; i > 0; i --) {
if (bufferA.getByte(aIndex) != bufferB.getByte(bIndex)) {
return false;
}
aIndex ++;
bIndex ++;
}
return true;
}
/**
* Compares the two specified buffers as described in {@link ChannelBuffer#compareTo(ChannelBuffer)}.
* This method is useful when implementing a new buffer type.
*/
public static int compare(ChannelBuffer bufferA, ChannelBuffer bufferB) {
final int aLen = bufferA.readableBytes();
final int bLen = bufferB.readableBytes();
final int minLength = Math.min(aLen, bLen);
final int uintCount = minLength >>> 2;
final int byteCount = minLength & 3;
int aIndex = bufferA.readerIndex();
int bIndex = bufferB.readerIndex();
if (bufferA.order() == bufferB.order()) {
for (int i = uintCount; i > 0; i --) {
long va = bufferA.getUnsignedInt(aIndex);
long vb = bufferB.getUnsignedInt(bIndex);
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex += 4;
bIndex += 4;
}
} else {
for (int i = uintCount; i > 0; i --) {
long va = bufferA.getUnsignedInt(aIndex);
long vb = swapInt(bufferB.getInt(bIndex)) & 0xFFFFFFFFL;
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex += 4;
bIndex += 4;
}
}
for (int i = byteCount; i > 0; i --) {
short va = bufferA.getUnsignedByte(aIndex);
short vb = bufferB.getUnsignedByte(bIndex);
if (va > vb) {
return 1;
} else if (va < vb) {
return -1;
}
aIndex ++;
bIndex ++;
}
return aLen - bLen;
}
/**
* The default implementation of {@link ChannelBuffer#indexOf(int, int, byte)}.
* This method is useful when implementing a new buffer type.
*/
public static int indexOf(ChannelBuffer buffer, int fromIndex, int toIndex, byte value) {
if (fromIndex <= toIndex) {
return firstIndexOf(buffer, fromIndex, toIndex, value);
} else {
return lastIndexOf(buffer, fromIndex, toIndex, value);
}
}
/**
* The default implementation of {@link ChannelBuffer#indexOf(int, int, ChannelBufferIndexFinder)}.
* This method is useful when implementing a new buffer type.
*/
public static int indexOf(ChannelBuffer buffer, int fromIndex, int toIndex, ChannelBufferIndexFinder indexFinder) {
if (fromIndex <= toIndex) {
return firstIndexOf(buffer, fromIndex, toIndex, indexFinder);
} else {
return lastIndexOf(buffer, fromIndex, toIndex, indexFinder);
}
}
/**
* Toggles the endianness of the specified 16-bit short integer.
*/
public static short swapShort(short value) {
return (short) (value << 8 | value >>> 8 & 0xff);
}
/**
* Toggles the endianness of the specified 24-bit medium integer.
*/
public static int swapMedium(int value) {
return value << 16 & 0xff0000 | value & 0xff00 | value >>> 16 & 0xff;
}
/**
* Toggles the endianness of the specified 32-bit integer.
*/
public static int swapInt(int value) {
return swapShort((short) value) << 16 |
swapShort((short) (value >>> 16)) & 0xffff;
}
/**
* Toggles the endianness of the specified 64-bit long integer.
*/
public static long swapLong(long value) {
return (long) swapInt((int) value) << 32 |
swapInt((int) (value >>> 32)) & 0xffffffffL;
}
private static int firstIndexOf(ChannelBuffer buffer, int fromIndex, int toIndex, byte value) {
fromIndex = Math.max(fromIndex, 0);
if (fromIndex >= toIndex || buffer.capacity() == 0) {
return -1;
}
for (int i = fromIndex; i < toIndex; i ++) {
if (buffer.getByte(i) == value) {
return i;
}
}
return -1;
}
private static int lastIndexOf(ChannelBuffer buffer, int fromIndex, int toIndex, byte value) {
fromIndex = Math.min(fromIndex, buffer.capacity());
if (fromIndex < 0 || buffer.capacity() == 0) {
return -1;
}
for (int i = fromIndex - 1; i >= toIndex; i --) {
if (buffer.getByte(i) == value) {
return i;
}
}
return -1;
}
private static int firstIndexOf(ChannelBuffer buffer, int fromIndex, int toIndex, ChannelBufferIndexFinder indexFinder) {
fromIndex = Math.max(fromIndex, 0);
if (fromIndex >= toIndex || buffer.capacity() == 0) {
return -1;
}
for (int i = fromIndex; i < toIndex; i ++) {
if (indexFinder.find(buffer, i)) {
return i;
}
}
return -1;
}
private static int lastIndexOf(ChannelBuffer buffer, int fromIndex, int toIndex, ChannelBufferIndexFinder indexFinder) {
fromIndex = Math.min(fromIndex, buffer.capacity());
if (fromIndex < 0 || buffer.capacity() == 0) {
return -1;
}
for (int i = fromIndex - 1; i >= toIndex; i --) {
if (indexFinder.find(buffer, i)) {
return i;
}
}
return -1;
}
static ByteBuffer encodeString(CharBuffer src, Charset charset) {
final CharsetEncoder encoder = CharsetUtil.getEncoder(charset);
final ByteBuffer dst = ByteBuffer.allocate(
(int) ((double) src.remaining() * encoder.maxBytesPerChar()));
try {
CoderResult cr = encoder.encode(src, dst, true);
if (!cr.isUnderflow()) {
cr.throwException();
}
cr = encoder.flush(dst);
if (!cr.isUnderflow()) {
cr.throwException();
}
} catch (CharacterCodingException x) {
throw new IllegalStateException(x);
}
dst.flip();
return dst;
}
static String decodeString(ByteBuffer src, Charset charset) {
final CharsetDecoder decoder = CharsetUtil.getDecoder(charset);
final CharBuffer dst = CharBuffer.allocate(
(int) ((double) src.remaining() * decoder.maxCharsPerByte()));
try {
CoderResult cr = decoder.decode(src, dst, true);
if (!cr.isUnderflow()) {
cr.throwException();
}
cr = decoder.flush(dst);
if (!cr.isUnderflow()) {
cr.throwException();
}
} catch (CharacterCodingException x) {
throw new IllegalStateException(x);
}
return dst.flip().toString();
}
private ChannelBuffers() {
// Unused
}
}