/*
* Copyright 2012 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 io.netty.buffer;
import io.netty.util.internal.PlatformDependent;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
/**
* Creates a new {@link ByteBuf} 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 io.netty.buffer.{@link Unpooled}.*;
*
* {@link ByteBuf} heapBuffer = buffer(128);
* {@link ByteBuf} directBuffer = directBuffer(256);
* {@link ByteBuf} wrappedBuffer = wrappedBuffer(new byte[128], new byte[256]);
* {@link ByteBuf} 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>
* </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.
*/
public final class Unpooled {
private static final ByteBufAllocator ALLOC = UnpooledByteBufAllocator.DEFAULT;
/**
* 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 ByteBuf EMPTY_BUFFER = ALLOC.buffer(0, 0);
static {
assert EMPTY_BUFFER instanceof EmptyByteBuf: "EMPTY_BUFFER must be an EmptyByteBuf.";
}
/**
* Creates a new big-endian Java heap buffer with reasonably small initial capacity, which
* expands its capacity boundlessly on demand.
*/
public static ByteBuf buffer() {
return ALLOC.heapBuffer();
}
/**
* Creates a new big-endian direct buffer with reasonably small initial capacity, which
* expands its capacity boundlessly on demand.
*/
public static ByteBuf directBuffer() {
return ALLOC.directBuffer();
}
/**
* Creates a new big-endian Java heap buffer with the specified {@code capacity}, which
* expands its capacity boundlessly on demand. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ByteBuf buffer(int initialCapacity) {
return ALLOC.heapBuffer(initialCapacity);
}
/**
* Creates a new big-endian direct buffer with the specified {@code capacity}, which
* expands its capacity boundlessly on demand. The new buffer's {@code readerIndex} and
* {@code writerIndex} are {@code 0}.
*/
public static ByteBuf directBuffer(int initialCapacity) {
return ALLOC.directBuffer(initialCapacity);
}
/**
* Creates a new big-endian Java heap buffer with the specified
* {@code initialCapacity}, that may grow up to {@code maxCapacity}
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0}.
*/
public static ByteBuf buffer(int initialCapacity, int maxCapacity) {
return ALLOC.heapBuffer(initialCapacity, maxCapacity);
}
/**
* Creates a new big-endian direct buffer with the specified
* {@code initialCapacity}, that may grow up to {@code maxCapacity}.
* The new buffer's {@code readerIndex} and {@code writerIndex} are
* {@code 0}.
*/
public static ByteBuf directBuffer(int initialCapacity, int maxCapacity) {
return ALLOC.directBuffer(initialCapacity, maxCapacity);
}
/**
* 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 ByteBuf wrappedBuffer(byte[] array) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return new UnpooledHeapByteBuf(ALLOC, array, array.length);
}
/**
* 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 ByteBuf wrappedBuffer(byte[] array, int offset, int length) {
if (length == 0) {
return EMPTY_BUFFER;
}
if (offset == 0 && length == array.length) {
return wrappedBuffer(array);
}
return wrappedBuffer(array).slice(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 ByteBuf wrappedBuffer(ByteBuffer buffer) {
if (!buffer.hasRemaining()) {
return EMPTY_BUFFER;
}
if (buffer.hasArray()) {
return wrappedBuffer(
buffer.array(),
buffer.arrayOffset() + buffer.position(),
buffer.remaining()).order(buffer.order());
} else if (PlatformDependent.hasUnsafe()) {
if (buffer.isReadOnly()) {
if (buffer.isDirect()) {
return new ReadOnlyUnsafeDirectByteBuf(ALLOC, buffer);
} else {
return new ReadOnlyByteBufferBuf(ALLOC, buffer);
}
} else {
return new UnpooledUnsafeDirectByteBuf(ALLOC, buffer, buffer.remaining());
}
} else {
if (buffer.isReadOnly()) {
return new ReadOnlyByteBufferBuf(ALLOC, buffer);
} else {
return new UnpooledDirectByteBuf(ALLOC, buffer, buffer.remaining());
}
}
}
/**
* 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 ByteBuf wrappedBuffer(ByteBuf buffer) {
if (buffer.isReadable()) {
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 ByteBuf wrappedBuffer(byte[]... arrays) {
return wrappedBuffer(16, arrays);
}
/**
* Creates a new big-endian 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.
*/
public static ByteBuf wrappedBuffer(ByteBuf... buffers) {
return wrappedBuffer(16, buffers);
}
/**
* Creates a new big-endian 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.
*/
public static ByteBuf wrappedBuffer(ByteBuffer... buffers) {
return wrappedBuffer(16, buffers);
}
/**
* 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 ByteBuf wrappedBuffer(int maxNumComponents, byte[]... arrays) {
switch (arrays.length) {
case 0:
break;
case 1:
if (arrays[0].length != 0) {
return wrappedBuffer(arrays[0]);
}
break;
default:
// Get the list of the component, while guessing the byte order.
final List<ByteBuf> components = new ArrayList<ByteBuf>(arrays.length);
for (byte[] a: arrays) {
if (a == null) {
break;
}
if (a.length > 0) {
components.add(wrappedBuffer(a));
}
}
if (!components.isEmpty()) {
return new CompositeByteBuf(ALLOC, false, maxNumComponents, components);
}
}
return EMPTY_BUFFER;
}
/**
* Creates a new big-endian 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.
*/
public static ByteBuf wrappedBuffer(int maxNumComponents, ByteBuf... buffers) {
switch (buffers.length) {
case 0:
break;
case 1:
if (buffers[0].isReadable()) {
return wrappedBuffer(buffers[0].order(BIG_ENDIAN));
}
break;
default:
for (ByteBuf b: buffers) {
if (b.isReadable()) {
return new CompositeByteBuf(ALLOC, false, maxNumComponents, buffers);
}
}
}
return EMPTY_BUFFER;
}
/**
* Creates a new big-endian 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.
*/
public static ByteBuf wrappedBuffer(int maxNumComponents, ByteBuffer... buffers) {
switch (buffers.length) {
case 0:
break;
case 1:
if (buffers[0].hasRemaining()) {
return wrappedBuffer(buffers[0].order(BIG_ENDIAN));
}
break;
default:
// Get the list of the component, while guessing the byte order.
final List<ByteBuf> components = new ArrayList<ByteBuf>(buffers.length);
for (ByteBuffer b: buffers) {
if (b == null) {
break;
}
if (b.remaining() > 0) {
components.add(wrappedBuffer(b.order(BIG_ENDIAN)));
}
}
if (!components.isEmpty()) {
return new CompositeByteBuf(ALLOC, false, maxNumComponents, components);
}
}
return EMPTY_BUFFER;
}
/**
* Returns a new big-endian composite buffer with no components.
*/
public static CompositeByteBuf compositeBuffer() {
return compositeBuffer(16);
}
/**
* Returns a new big-endian composite buffer with no components.
*/
public static CompositeByteBuf compositeBuffer(int maxNumComponents) {
return new CompositeByteBuf(ALLOC, false, maxNumComponents);
}
/**
* 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 ByteBuf copiedBuffer(byte[] array) {
if (array.length == 0) {
return EMPTY_BUFFER;
}
return wrappedBuffer(array.clone());
}
/**
* 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 ByteBuf copiedBuffer(byte[] array, int offset, int length) {
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] copy = new byte[length];
System.arraycopy(array, offset, copy, 0, length);
return wrappedBuffer(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 ByteBuf 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(copy).order(buffer.order());
}
/**
* 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 ByteBuf copiedBuffer(ByteBuf buffer) {
int readable = buffer.readableBytes();
if (readable > 0) {
ByteBuf copy = buffer(readable);
copy.writeBytes(buffer, buffer.readerIndex(), readable);
return 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 ByteBuf copiedBuffer(byte[]... arrays) {
switch (arrays.length) {
case 0:
return EMPTY_BUFFER;
case 1:
if (arrays[0].length == 0) {
return EMPTY_BUFFER;
} else {
return copiedBuffer(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(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 ByteBuf copiedBuffer(ByteBuf... buffers) {
switch (buffers.length) {
case 0:
return EMPTY_BUFFER;
case 1:
return copiedBuffer(buffers[0]);
}
// Merge the specified buffers into one buffer.
ByteOrder order = null;
int length = 0;
for (ByteBuf b: buffers) {
int bLen = b.readableBytes();
if (bLen <= 0) {
continue;
}
if (Integer.MAX_VALUE - length < bLen) {
throw new IllegalArgumentException(
"The total length of the specified buffers is too big.");
}
length += bLen;
if (order != null) {
if (!order.equals(b.order())) {
throw new IllegalArgumentException("inconsistent byte order");
}
} else {
order = b.order();
}
}
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] mergedArray = new byte[length];
for (int i = 0, j = 0; i < buffers.length; i ++) {
ByteBuf b = buffers[i];
int bLen = b.readableBytes();
b.getBytes(b.readerIndex(), mergedArray, j, bLen);
j += bLen;
}
return wrappedBuffer(mergedArray).order(order);
}
/**
* 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 ByteBuf copiedBuffer(ByteBuffer... buffers) {
switch (buffers.length) {
case 0:
return EMPTY_BUFFER;
case 1:
return copiedBuffer(buffers[0]);
}
// Merge the specified buffers into one buffer.
ByteOrder order = null;
int length = 0;
for (ByteBuffer b: buffers) {
int bLen = b.remaining();
if (bLen <= 0) {
continue;
}
if (Integer.MAX_VALUE - length < bLen) {
throw new IllegalArgumentException(
"The total length of the specified buffers is too big.");
}
length += bLen;
if (order != null) {
if (!order.equals(b.order())) {
throw new IllegalArgumentException("inconsistent byte order");
}
} else {
order = b.order();
}
}
if (length == 0) {
return EMPTY_BUFFER;
}
byte[] mergedArray = new byte[length];
for (int i = 0, j = 0; i < buffers.length; i ++) {
ByteBuffer b = buffers[i];
int bLen = b.remaining();
int oldPos = b.position();
b.get(mergedArray, j, bLen);
b.position(oldPos);
j += bLen;
}
return wrappedBuffer(mergedArray).order(order);
}
/**
* 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 ByteBuf copiedBuffer(CharSequence string, Charset charset) {
if (string == null) {
throw new NullPointerException("string");
}
if (string instanceof CharBuffer) {
return copiedBuffer((CharBuffer) string, charset);
}
return copiedBuffer(CharBuffer.wrap(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 ByteBuf copiedBuffer(
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(
buf.array(),
buf.arrayOffset() + buf.position() + offset,
length, charset);
}
buf = buf.slice();
buf.limit(length);
buf.position(offset);
return copiedBuffer(buf, charset);
}
return copiedBuffer(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 ByteBuf copiedBuffer(char[] array, Charset charset) {
if (array == null) {
throw new NullPointerException("array");
}
return copiedBuffer(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 ByteBuf copiedBuffer(char[] array, int offset, int length, Charset charset) {
if (array == null) {
throw new NullPointerException("array");
}
if (length == 0) {
return EMPTY_BUFFER;
}
return copiedBuffer(CharBuffer.wrap(array, offset, length), charset);
}
private static ByteBuf copiedBuffer(CharBuffer buffer, Charset charset) {
return ByteBufUtil.encodeString0(ALLOC, true, buffer, charset);
}
/**
* 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 ByteBuf unmodifiableBuffer(ByteBuf buffer) {
ByteOrder endianness = buffer.order();
if (endianness == BIG_ENDIAN) {
return new ReadOnlyByteBuf(buffer);
}
return new ReadOnlyByteBuf(buffer.order(BIG_ENDIAN)).order(LITTLE_ENDIAN);
}
/**
* Creates a new 4-byte big-endian buffer that holds the specified 32-bit integer.
*/
public static ByteBuf copyInt(int value) {
ByteBuf buf = buffer(4);
buf.writeInt(value);
return buf;
}
/**
* Create a big-endian buffer that holds a sequence of the specified 32-bit integers.
*/
public static ByteBuf copyInt(int... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 4);
for (int v: values) {
buffer.writeInt(v);
}
return buffer;
}
/**
* Creates a new 2-byte big-endian buffer that holds the specified 16-bit integer.
*/
public static ByteBuf copyShort(int value) {
ByteBuf buf = buffer(2);
buf.writeShort(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 16-bit integers.
*/
public static ByteBuf copyShort(short... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 2);
for (int v: values) {
buffer.writeShort(v);
}
return buffer;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 16-bit integers.
*/
public static ByteBuf copyShort(int... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 2);
for (int v: values) {
buffer.writeShort(v);
}
return buffer;
}
/**
* Creates a new 3-byte big-endian buffer that holds the specified 24-bit integer.
*/
public static ByteBuf copyMedium(int value) {
ByteBuf buf = buffer(3);
buf.writeMedium(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 24-bit integers.
*/
public static ByteBuf copyMedium(int... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 3);
for (int v: values) {
buffer.writeMedium(v);
}
return buffer;
}
/**
* Creates a new 8-byte big-endian buffer that holds the specified 64-bit integer.
*/
public static ByteBuf copyLong(long value) {
ByteBuf buf = buffer(8);
buf.writeLong(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 64-bit integers.
*/
public static ByteBuf copyLong(long... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 8);
for (long v: values) {
buffer.writeLong(v);
}
return buffer;
}
/**
* Creates a new single-byte big-endian buffer that holds the specified boolean value.
*/
public static ByteBuf copyBoolean(boolean value) {
ByteBuf buf = buffer(1);
buf.writeBoolean(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified boolean values.
*/
public static ByteBuf copyBoolean(boolean... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length);
for (boolean v: values) {
buffer.writeBoolean(v);
}
return buffer;
}
/**
* Creates a new 4-byte big-endian buffer that holds the specified 32-bit floating point number.
*/
public static ByteBuf copyFloat(float value) {
ByteBuf buf = buffer(4);
buf.writeFloat(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 32-bit floating point numbers.
*/
public static ByteBuf copyFloat(float... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 4);
for (float v: values) {
buffer.writeFloat(v);
}
return buffer;
}
/**
* Creates a new 8-byte big-endian buffer that holds the specified 64-bit floating point number.
*/
public static ByteBuf copyDouble(double value) {
ByteBuf buf = buffer(8);
buf.writeDouble(value);
return buf;
}
/**
* Create a new big-endian buffer that holds a sequence of the specified 64-bit floating point numbers.
*/
public static ByteBuf copyDouble(double... values) {
if (values == null || values.length == 0) {
return EMPTY_BUFFER;
}
ByteBuf buffer = buffer(values.length * 8);
for (double v: values) {
buffer.writeDouble(v);
}
return buffer;
}
/**
* Return a unreleasable view on the given {@link ByteBuf} which will just ignore release and retain calls.
*/
public static ByteBuf unreleasableBuffer(ByteBuf buf) {
return new UnreleasableByteBuf(buf);
}
private Unpooled() {
// Unused
}
}