/*
* 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.
*
*/
package org.apache.mina.common;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.OutputStream;
import java.io.StreamCorruptedException;
import java.nio.BufferOverflowException;
import java.nio.BufferUnderflowException;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.LongBuffer;
import java.nio.ShortBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.util.HashSet;
import java.util.Set;
import org.apache.mina.common.support.ByteBufferHexDumper;
import org.apache.mina.filter.codec.ProtocolEncoderOutput;
/**
* A byte buffer used by MINA applications.
* <p>
* This is a replacement for {@link java.nio.ByteBuffer}. Please refer to
* {@link java.nio.ByteBuffer} and {@link java.nio.Buffer} documentation for
* usage. MINA does not use NIO {@link java.nio.ByteBuffer} directly for two
* reasons:
* <ul>
* <li>It doesn't provide useful getters and putters such as
* <code>fill</code>, <code>get/putString</code>, and
* <code>get/putAsciiInt()</code> enough.</li>
* <li>It is hard to distinguish if the buffer is created from MINA buffer
* pool or not. MINA have to return used buffers back to pool.</li>
* <li>It is difficult to write variable-length data due to its fixed
* capacity</li>
* </ul>
* </p>
*
* <h2>Allocation</h2>
* <p>
* You can get a heap buffer from buffer pool:
* <pre>
* ByteBuffer buf = ByteBuffer.allocate(1024, false);
* </pre>
* you can also get a direct buffer from buffer pool:
* <pre>
* ByteBuffer buf = ByteBuffer.allocate(1024, true);
* </pre>
* or you can let MINA choose:
* <pre>
* ByteBuffer buf = ByteBuffer.allocate(1024);
* </pre>
* </p>
*
* <h2>Acquire/Release</h2>
* <p>
* <b>Please note that you never need to release the allocated buffer</b>
* because MINA will release it automatically when:
* <ul>
* <li>You pass the buffer by calling {@link IoSession#write(Object)}.</li>
* <li>You pass the buffer by calling {@link IoFilter.NextFilter#filterWrite(IoSession,IoFilter.WriteRequest)}.</li>
* <li>You pass the buffer by calling {@link ProtocolEncoderOutput#write(ByteBuffer)}.</li>
* </ul>
* And, you don't need to release any {@link ByteBuffer} which is passed as a parameter
* of {@link IoHandler#messageReceived(IoSession, Object)} method. They are released
* automatically when the method returns.
* <p>
* You have to release buffers manually by calling {@link #release()} when:
* <ul>
* <li>You allocated a buffer, but didn't pass the buffer to any of two methods above.</li>
* <li>You called {@link #acquire()} to prevent the buffer from being released.</li>
* </ul>
* </p>
*
* <h2>Wrapping existing NIO buffers and arrays</h2>
* <p>
* This class provides a few <tt>wrap(...)</tt> methods that wraps
* any NIO buffers and byte arrays. Wrapped MINA buffers are not returned
* to the buffer pool by default to prevent unexpected memory leakage by default.
* In case you want to make it pooled, you can call {@link #setPooled(boolean)}
* with <tt>true</tt> flag to enable pooling.
*
* <h2>AutoExpand</h2>
* <p>
* Writing variable-length data using NIO <tt>ByteBuffers</tt> is not really
* easy, and it is because its size is fixed. MINA <tt>ByteBuffer</tt>
* introduces <tt>autoExpand</tt> property. If <tt>autoExpand</tt> property
* is true, you never get {@link BufferOverflowException} or
* {@link IndexOutOfBoundsException} (except when index is negative).
* It automatically expands its capacity and limit value. For example:
* <pre>
* String greeting = messageBundle.getMessage( "hello" );
* ByteBuffer buf = ByteBuffer.allocate( 16 );
* // Turn on autoExpand (it is off by default)
* buf.setAutoExpand( true );
* buf.putString( greeting, utf8encoder );
* </pre>
* NIO <tt>ByteBuffer</tt> is reallocated by MINA <tt>ByteBuffer</tt> behind
* the scene if the encoded data is larger than 16 bytes. Its capacity will
* increase by two times, and its limit will increase to the last position
* the string is written.
* </p>
*
* <h2>Derived Buffers</h2>
* <p>
* Derived buffers are the buffers which were created by
* {@link #duplicate()}, {@link #slice()}, or {@link #asReadOnlyBuffer()}.
* They are useful especially when you broadcast the same messages to
* multiple {@link IoSession}s. Please note that the derived buffers are
* neither pooled nor auto-expandable. Trying to expand a derived buffer will
* raise {@link IllegalStateException}.
* </p>
*
* <h2>Changing Buffer Allocation and Management Policy</h2>
* <p>
* MINA provides a {@link ByteBufferAllocator} interface to let you override
* the default buffer management behavior. There are two allocators provided
* out-of-the-box:
* <ul>
* <li>{@link PooledByteBufferAllocator} (Default)</li>
* <li>{@link SimpleByteBufferAllocator}</li>
* </ul>
* You can change the allocator by calling {@link #setAllocator(ByteBufferAllocator)}.
* </p>
*
* @author The Apache Directory Project (mina-dev@directory.apache.org)
* @version $Rev: 595517 $, $Date: 2007-11-16 10:31:56 +0900 (금, 16 11월 2007) $
* @noinspection StaticNonFinalField
* @see ByteBufferAllocator
*/
public abstract class ByteBuffer implements Comparable {
private static ByteBufferAllocator allocator = new PooledByteBufferAllocator();
private static boolean useDirectBuffers = true;
/**
* Returns the current allocator which manages the allocated buffers.
*/
public static ByteBufferAllocator getAllocator() {
return allocator;
}
/**
* Changes the current allocator with the specified one to manage
* the allocated buffers from now.
*/
public static void setAllocator(ByteBufferAllocator newAllocator) {
if (newAllocator == null) {
throw new NullPointerException("allocator");
}
ByteBufferAllocator oldAllocator = allocator;
allocator = newAllocator;
if (null != oldAllocator) {
oldAllocator.dispose();
}
}
public static boolean isUseDirectBuffers() {
return useDirectBuffers;
}
public static void setUseDirectBuffers(boolean useDirectBuffers) {
ByteBuffer.useDirectBuffers = useDirectBuffers;
}
/**
* Returns the direct or heap buffer which is capable of the specified
* size. This method tries to allocate direct buffer first, and then
* tries heap buffer if direct buffer memory is exhausted. Please use
* {@link #allocate(int, boolean)} to allocate buffers of specific type.
*
* @param capacity the capacity of the buffer
*/
public static ByteBuffer allocate(int capacity) {
if (useDirectBuffers) {
try {
// first try to allocate direct buffer
return allocate(capacity, true);
} catch (OutOfMemoryError e) {
// fall through to heap buffer
}
}
return allocate(capacity, false);
}
/**
* Returns the buffer which is capable of the specified size.
*
* @param capacity the capacity of the buffer
* @param direct <tt>true</tt> to get a direct buffer,
* <tt>false</tt> to get a heap buffer.
*/
public static ByteBuffer allocate(int capacity, boolean direct) {
return allocator.allocate(capacity, direct);
}
/**
* Wraps the specified NIO {@link java.nio.ByteBuffer} into MINA buffer.
*/
public static ByteBuffer wrap(java.nio.ByteBuffer nioBuffer) {
return allocator.wrap(nioBuffer);
}
/**
* Wraps the specified byte array into MINA heap buffer.
*/
public static ByteBuffer wrap(byte[] byteArray) {
return wrap(java.nio.ByteBuffer.wrap(byteArray));
}
/**
* Wraps the specified byte array into MINA heap buffer.
* Please note that MINA buffers are going to be pooled, and
* therefore there can be waste of memory if you wrap
* your byte array specifying <tt>offset</tt> and <tt>length</tt>.
*/
public static ByteBuffer wrap(byte[] byteArray, int offset, int length) {
return wrap(java.nio.ByteBuffer.wrap(byteArray, offset, length));
}
private static final Set primitiveTypeNames = new HashSet();
static {
primitiveTypeNames.add("void");
primitiveTypeNames.add("boolean");
primitiveTypeNames.add("byte");
primitiveTypeNames.add("char");
primitiveTypeNames.add("short");
primitiveTypeNames.add("int");
primitiveTypeNames.add("long");
primitiveTypeNames.add("float");
primitiveTypeNames.add("double");
}
protected ByteBuffer() {
}
/**
* Increases the internal reference count of this buffer to defer
* automatic release. You have to invoke {@link #release()} as many
* as you invoked this method to release this buffer.
*
* @throws IllegalStateException if you attempt to acquire already
* released buffer.
*/
public abstract void acquire();
/**
* Releases the specified buffer to buffer pool.
*
* @throws IllegalStateException if you attempt to release already
* released buffer.
*/
public abstract void release();
/**
* Returns the underlying NIO buffer instance.
*/
public abstract java.nio.ByteBuffer buf();
/**
* @see java.nio.ByteBuffer#isDirect()
*/
public abstract boolean isDirect();
/**
* @see java.nio.ByteBuffer#isReadOnly()
*/
public abstract boolean isReadOnly();
/**
* @see java.nio.ByteBuffer#capacity()
*/
public abstract int capacity();
/**
* Changes the capacity of this buffer.
*/
public abstract ByteBuffer capacity(int newCapacity);
/**
* Returns <tt>true</tt> if and only if <tt>autoExpand</tt> is turned on.
*/
public abstract boolean isAutoExpand();
/**
* Turns on or off <tt>autoExpand</tt>.
*/
public abstract ByteBuffer setAutoExpand(boolean autoExpand);
/**
* Changes the capacity and limit of this buffer so this buffer get
* the specified <tt>expectedRemaining</tt> room from the current position.
* This method works even if you didn't set <tt>autoExpand</tt> to
* <tt>true</tt>.
*/
public ByteBuffer expand(int expectedRemaining) {
return expand(position(), expectedRemaining);
}
/**
* Changes the capacity and limit of this buffer so this buffer get
* the specified <tt>expectedRemaining</tt> room from the specified
* <tt>pos</tt>.
* This method works even if you didn't set <tt>autoExpand</tt> to
* <tt>true</tt>.
*/
public abstract ByteBuffer expand(int pos, int expectedRemaining);
/**
* Returns <tt>true</tt> if and only if this buffer is returned back
* to the buffer pool when released.
* <p>
* The default value of this property is <tt>true</tt> if and only if you
* allocated this buffer using {@link #allocate(int)} or {@link #allocate(int, boolean)},
* or <tt>false</tt> otherwise. (i.e. {@link #wrap(byte[])}, {@link #wrap(byte[], int, int)},
* and {@link #wrap(java.nio.ByteBuffer)})
*/
public abstract boolean isPooled();
/**
* Sets whether this buffer is returned back to the buffer pool when released.
* <p>
* The default value of this property is <tt>true</tt> if and only if you
* allocated this buffer using {@link #allocate(int)} or {@link #allocate(int, boolean)},
* or <tt>false</tt> otherwise. (i.e. {@link #wrap(byte[])}, {@link #wrap(byte[], int, int)},
* and {@link #wrap(java.nio.ByteBuffer)})
*/
public abstract void setPooled(boolean pooled);
/**
* @see java.nio.Buffer#position()
*/
public abstract int position();
/**
* @see java.nio.Buffer#position(int)
*/
public abstract ByteBuffer position(int newPosition);
/**
* @see java.nio.Buffer#limit()
*/
public abstract int limit();
/**
* @see java.nio.Buffer#limit(int)
*/
public abstract ByteBuffer limit(int newLimit);
/**
* @see java.nio.Buffer#mark()
*/
public abstract ByteBuffer mark();
/**
* Returns the position of the current mark. This method returns <tt>-1</tt> if no
* mark is set.
*/
public abstract int markValue();
/**
* @see java.nio.Buffer#reset()
*/
public abstract ByteBuffer reset();
/**
* @see java.nio.Buffer#clear()
*/
public abstract ByteBuffer clear();
/**
* Clears this buffer and fills its content with <tt>NUL</tt>.
* The position is set to zero, the limit is set to the capacity,
* and the mark is discarded.
*/
public ByteBuffer sweep() {
clear();
return fillAndReset(remaining());
}
/**
* Clears this buffer and fills its content with <tt>value</tt>.
* The position is set to zero, the limit is set to the capacity,
* and the mark is discarded.
*/
public ByteBuffer sweep(byte value) {
clear();
return fillAndReset(value, remaining());
}
/**
* @see java.nio.Buffer#flip()
*/
public abstract ByteBuffer flip();
/**
* @see java.nio.Buffer#rewind()
*/
public abstract ByteBuffer rewind();
/**
* @see java.nio.Buffer#remaining()
*/
public int remaining() {
return limit() - position();
}
/**
* @see java.nio.Buffer#hasRemaining()
*/
public boolean hasRemaining() {
return remaining() > 0;
}
/**
* @see java.nio.ByteBuffer#duplicate()
*/
public abstract ByteBuffer duplicate();
/**
* @see java.nio.ByteBuffer#slice()
*/
public abstract ByteBuffer slice();
/**
* @see java.nio.ByteBuffer#asReadOnlyBuffer()
*/
public abstract ByteBuffer asReadOnlyBuffer();
/**
* @see java.nio.ByteBuffer#array()
*/
public abstract byte[] array();
/**
* @see java.nio.ByteBuffer#arrayOffset()
*/
public abstract int arrayOffset();
/**
* @see java.nio.ByteBuffer#get()
*/
public abstract byte get();
/**
* Reads one unsigned byte as a short integer.
*/
public short getUnsigned() {
return (short) (get() & 0xff);
}
/**
* @see java.nio.ByteBuffer#put(byte)
*/
public abstract ByteBuffer put(byte b);
/**
* @see java.nio.ByteBuffer#get(int)
*/
public abstract byte get(int index);
/**
* Reads one byte as an unsigned short integer.
*/
public short getUnsigned(int index) {
return (short) (get(index) & 0xff);
}
/**
* @see java.nio.ByteBuffer#put(int, byte)
*/
public abstract ByteBuffer put(int index, byte b);
/**
* @see java.nio.ByteBuffer#get(byte[], int, int)
*/
public abstract ByteBuffer get(byte[] dst, int offset, int length);
/**
* @see java.nio.ByteBuffer#get(byte[])
*/
public ByteBuffer get(byte[] dst) {
return get(dst, 0, dst.length);
}
/**
* Writes the content of the specified <tt>src</tt> into this buffer.
*/
public abstract ByteBuffer put(java.nio.ByteBuffer src);
/**
* Writes the content of the specified <tt>src</tt> into this buffer.
*/
public ByteBuffer put(ByteBuffer src) {
return put(src.buf());
}
/**
* @see java.nio.ByteBuffer#put(byte[], int, int)
*/
public abstract ByteBuffer put(byte[] src, int offset, int length);
/**
* @see java.nio.ByteBuffer#put(byte[])
*/
public ByteBuffer put(byte[] src) {
return put(src, 0, src.length);
}
/**
* @see java.nio.ByteBuffer#compact()
*/
public abstract ByteBuffer compact();
public String toString() {
StringBuffer buf = new StringBuffer();
if (isDirect()) {
buf.append("DirectBuffer");
} else {
buf.append("HeapBuffer");
}
buf.append("[pos=");
buf.append(position());
buf.append(" lim=");
buf.append(limit());
buf.append(" cap=");
buf.append(capacity());
buf.append(": ");
buf.append(getHexDump());
buf.append(']');
return buf.toString();
}
public int hashCode() {
int h = 1;
int p = position();
for (int i = limit() - 1; i >= p; i--) {
h = 31 * h + get(i);
}
return h;
}
public boolean equals(Object o) {
if (!(o instanceof ByteBuffer)) {
return false;
}
ByteBuffer that = (ByteBuffer) o;
if (this.remaining() != that.remaining()) {
return false;
}
int p = this.position();
for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--) {
byte v1 = this.get(i);
byte v2 = that.get(j);
if (v1 != v2) {
return false;
}
}
return true;
}
public int compareTo(Object o) {
ByteBuffer that = (ByteBuffer) o;
int n = this.position() + Math.min(this.remaining(), that.remaining());
for (int i = this.position(), j = that.position(); i < n; i++, j++) {
byte v1 = this.get(i);
byte v2 = that.get(j);
if (v1 == v2) {
continue;
}
if (v1 < v2) {
return -1;
}
return +1;
}
return this.remaining() - that.remaining();
}
/**
* @see java.nio.ByteBuffer#order()
*/
public abstract ByteOrder order();
/**
* @see java.nio.ByteBuffer#order(ByteOrder)
*/
public abstract ByteBuffer order(ByteOrder bo);
/**
* @see java.nio.ByteBuffer#getChar()
*/
public abstract char getChar();
/**
* @see java.nio.ByteBuffer#putChar(char)
*/
public abstract ByteBuffer putChar(char value);
/**
* @see java.nio.ByteBuffer#getChar(int)
*/
public abstract char getChar(int index);
/**
* @see java.nio.ByteBuffer#putChar(int, char)
*/
public abstract ByteBuffer putChar(int index, char value);
/**
* @see java.nio.ByteBuffer#asCharBuffer()
*/
public abstract CharBuffer asCharBuffer();
/**
* @see java.nio.ByteBuffer#getShort()
*/
public abstract short getShort();
/**
* Reads two bytes unsigned integer.
*/
public int getUnsignedShort() {
return getShort() & 0xffff;
}
/**
* @see java.nio.ByteBuffer#putShort(short)
*/
public abstract ByteBuffer putShort(short value);
/**
* @see java.nio.ByteBuffer#getShort()
*/
public abstract short getShort(int index);
/**
* Reads two bytes unsigned integer.
*/
public int getUnsignedShort(int index) {
return getShort(index) & 0xffff;
}
/**
* @see java.nio.ByteBuffer#putShort(int, short)
*/
public abstract ByteBuffer putShort(int index, short value);
/**
* @see java.nio.ByteBuffer#asShortBuffer()
*/
public abstract ShortBuffer asShortBuffer();
/**
* @see java.nio.ByteBuffer#getInt()
*/
public abstract int getInt();
/**
* Reads four bytes unsigned integer.
*/
public long getUnsignedInt() {
return getInt() & 0xffffffffL;
}
/**
* @see java.nio.ByteBuffer#putInt(int)
*/
public abstract ByteBuffer putInt(int value);
/**
* @see java.nio.ByteBuffer#getInt(int)
*/
public abstract int getInt(int index);
/**
* Reads four bytes unsigned integer.
*/
public long getUnsignedInt(int index) {
return getInt(index) & 0xffffffffL;
}
/**
* @see java.nio.ByteBuffer#putInt(int, int)
*/
public abstract ByteBuffer putInt(int index, int value);
/**
* @see java.nio.ByteBuffer#asIntBuffer()
*/
public abstract IntBuffer asIntBuffer();
/**
* @see java.nio.ByteBuffer#getLong()
*/
public abstract long getLong();
/**
* @see java.nio.ByteBuffer#putLong(int, long)
*/
public abstract ByteBuffer putLong(long value);
/**
* @see java.nio.ByteBuffer#getLong(int)
*/
public abstract long getLong(int index);
/**
* @see java.nio.ByteBuffer#putLong(int, long)
*/
public abstract ByteBuffer putLong(int index, long value);
/**
* @see java.nio.ByteBuffer#asLongBuffer()
*/
public abstract LongBuffer asLongBuffer();
/**
* @see java.nio.ByteBuffer#getFloat()
*/
public abstract float getFloat();
/**
* @see java.nio.ByteBuffer#putFloat(float)
*/
public abstract ByteBuffer putFloat(float value);
/**
* @see java.nio.ByteBuffer#getFloat(int)
*/
public abstract float getFloat(int index);
/**
* @see java.nio.ByteBuffer#putFloat(int, float)
*/
public abstract ByteBuffer putFloat(int index, float value);
/**
* @see java.nio.ByteBuffer#asFloatBuffer()
*/
public abstract FloatBuffer asFloatBuffer();
/**
* @see java.nio.ByteBuffer#getDouble()
*/
public abstract double getDouble();
/**
* @see java.nio.ByteBuffer#putDouble(double)
*/
public abstract ByteBuffer putDouble(double value);
/**
* @see java.nio.ByteBuffer#getDouble(int)
*/
public abstract double getDouble(int index);
/**
* @see java.nio.ByteBuffer#putDouble(int, double)
*/
public abstract ByteBuffer putDouble(int index, double value);
/**
* @see java.nio.ByteBuffer#asDoubleBuffer()
*/
public abstract DoubleBuffer asDoubleBuffer();
/**
* Returns an {@link InputStream} that reads the data from this buffer.
* {@link InputStream#read()} returns <tt>-1</tt> if the buffer position
* reaches to the limit.
*/
public InputStream asInputStream() {
return new InputStream() {
public int available() {
return ByteBuffer.this.remaining();
}
public synchronized void mark(int readlimit) {
ByteBuffer.this.mark();
}
public boolean markSupported() {
return true;
}
public int read() {
if (ByteBuffer.this.hasRemaining()) {
return ByteBuffer.this.get() & 0xff;
} else {
return -1;
}
}
public int read(byte[] b, int off, int len) {
int remaining = ByteBuffer.this.remaining();
if (remaining > 0) {
int readBytes = Math.min(remaining, len);
ByteBuffer.this.get(b, off, readBytes);
return readBytes;
} else {
return -1;
}
}
public synchronized void reset() {
ByteBuffer.this.reset();
}
public long skip(long n) {
int bytes;
if (n > Integer.MAX_VALUE) {
bytes = ByteBuffer.this.remaining();
} else {
bytes = Math.min(ByteBuffer.this.remaining(), (int) n);
}
ByteBuffer.this.skip(bytes);
return bytes;
}
};
}
/**
* Returns an {@link OutputStream} that appends the data into this buffer.
* Please note that the {@link OutputStream#write(int)} will throw a
* {@link BufferOverflowException} instead of an {@link IOException}
* in case of buffer overflow. Please set <tt>autoExpand</tt> property by
* calling {@link #setAutoExpand(boolean)} to prevent the unexpected runtime
* exception.
*/
public OutputStream asOutputStream() {
return new OutputStream() {
public void write(byte[] b, int off, int len) {
ByteBuffer.this.put(b, off, len);
}
public void write(int b) {
ByteBuffer.this.put((byte) b);
}
};
}
/**
* Returns hexdump of this buffer.
*/
public String getHexDump() {
return ByteBufferHexDumper.getHexdump(this);
}
////////////////////////////////
// String getters and putters //
////////////////////////////////
/**
* Reads a <code>NUL</code>-terminated string from this buffer using the
* specified <code>decoder</code> and returns it. This method reads
* until the limit of this buffer if no <tt>NUL</tt> is found.
*/
public String getString(CharsetDecoder decoder)
throws CharacterCodingException {
if (!hasRemaining()) {
return "";
}
boolean utf16 = decoder.charset().name().startsWith("UTF-16");
int oldPos = position();
int oldLimit = limit();
int end;
if (!utf16) {
while (hasRemaining()) {
if (get() == 0) {
break;
}
}
end = position();
if (end == oldLimit && get(end - 1) != 0) {
limit(end);
} else {
limit(end - 1);
}
} else {
while (remaining() >= 2) {
boolean highZero = (get() == 0);
boolean lowZero = (get() == 0);
if (highZero && lowZero) {
break;
}
}
end = position();
if (end == oldLimit || end == oldLimit - 1) {
limit(end);
} else {
limit(end - 2);
}
}
position(oldPos);
if (!hasRemaining()) {
limit(oldLimit);
position(end);
return "";
}
decoder.reset();
int expectedLength = (int) (remaining() * decoder.averageCharsPerByte()) + 1;
CharBuffer out = CharBuffer.allocate(expectedLength);
for (;;) {
CoderResult cr;
if (hasRemaining()) {
cr = decoder.decode(buf(), out, true);
} else {
cr = decoder.flush(out);
}
if (cr.isUnderflow()) {
break;
}
if (cr.isOverflow()) {
CharBuffer o = CharBuffer.allocate(out.capacity()
+ expectedLength);
out.flip();
o.put(out);
out = o;
continue;
}
if (cr.isError()) {
// Revert the buffer back to the previous state.
limit(oldLimit);
position(oldPos);
cr.throwException();
}
}
limit(oldLimit);
position(end);
return out.flip().toString();
}
/**
* Reads a <code>NUL</code>-terminated string from this buffer using the
* specified <code>decoder</code> and returns it.
*
* @param fieldSize the maximum number of bytes to read
*/
public String getString(int fieldSize, CharsetDecoder decoder)
throws CharacterCodingException {
checkFieldSize(fieldSize);
if (fieldSize == 0) {
return "";
}
if (!hasRemaining()) {
return "";
}
boolean utf16 = decoder.charset().name().startsWith("UTF-16");
if (utf16 && ((fieldSize & 1) != 0)) {
throw new IllegalArgumentException("fieldSize is not even.");
}
int oldPos = position();
int oldLimit = limit();
int end = position() + fieldSize;
if (oldLimit < end) {
throw new BufferUnderflowException();
}
int i;
if (!utf16) {
for (i = 0; i < fieldSize; i++) {
if (get() == 0) {
break;
}
}
if (i == fieldSize) {
limit(end);
} else {
limit(position() - 1);
}
} else {
for (i = 0; i < fieldSize; i += 2) {
boolean highZero = (get() == 0);
boolean lowZero = (get() == 0);
if (highZero && lowZero) {
break;
}
}
if (i == fieldSize) {
limit(end);
} else {
limit(position() - 2);
}
}
position(oldPos);
if (!hasRemaining()) {
limit(oldLimit);
position(end);
return "";
}
decoder.reset();
int expectedLength = (int) (remaining() * decoder.averageCharsPerByte()) + 1;
CharBuffer out = CharBuffer.allocate(expectedLength);
for (;;) {
CoderResult cr;
if (hasRemaining()) {
cr = decoder.decode(buf(), out, true);
} else {
cr = decoder.flush(out);
}
if (cr.isUnderflow()) {
break;
}
if (cr.isOverflow()) {
CharBuffer o = CharBuffer.allocate(out.capacity()
+ expectedLength);
out.flip();
o.put(out);
out = o;
continue;
}
if (cr.isError()) {
// Revert the buffer back to the previous state.
limit(oldLimit);
position(oldPos);
cr.throwException();
}
}
limit(oldLimit);
position(end);
return out.flip().toString();
}
/**
* Writes the content of <code>in</code> into this buffer using the
* specified <code>encoder</code>. This method doesn't terminate
* string with <tt>NUL</tt>. You have to do it by yourself.
*
* @throws BufferOverflowException if the specified string doesn't fit
*/
public ByteBuffer putString(CharSequence val, CharsetEncoder encoder)
throws CharacterCodingException {
if (val.length() == 0) {
return this;
}
CharBuffer in = CharBuffer.wrap(val);
encoder.reset();
int expandedState = 0;
for (;;) {
CoderResult cr;
if (in.hasRemaining()) {
cr = encoder.encode(in, buf(), true);
} else {
cr = encoder.flush(buf());
}
if (cr.isUnderflow()) {
break;
}
if (cr.isOverflow()) {
if (isAutoExpand()) {
switch (expandedState) {
case 0:
autoExpand((int) Math.ceil(in.remaining()
* encoder.averageBytesPerChar()));
expandedState++;
break;
case 1:
autoExpand((int) Math.ceil(in.remaining()
* encoder.maxBytesPerChar()));
expandedState++;
break;
default:
throw new RuntimeException("Expanded by "
+ (int) Math.ceil(in.remaining()
* encoder.maxBytesPerChar())
+ " but that wasn't enough for '" + val + "'");
}
continue;
}
} else {
expandedState = 0;
}
cr.throwException();
}
return this;
}
/**
* Writes the content of <code>in</code> into this buffer as a
* <code>NUL</code>-terminated string using the specified
* <code>encoder</code>.
* <p>
* If the charset name of the encoder is UTF-16, you cannot specify
* odd <code>fieldSize</code>, and this method will append two
* <code>NUL</code>s as a terminator.
* <p>
* Please note that this method doesn't terminate with <code>NUL</code>
* if the input string is longer than <tt>fieldSize</tt>.
*
* @param fieldSize the maximum number of bytes to write
*/
public ByteBuffer putString(CharSequence val, int fieldSize,
CharsetEncoder encoder) throws CharacterCodingException {
checkFieldSize(fieldSize);
if (fieldSize == 0)
return this;
autoExpand(fieldSize);
boolean utf16 = encoder.charset().name().startsWith("UTF-16");
if (utf16 && ((fieldSize & 1) != 0)) {
throw new IllegalArgumentException("fieldSize is not even.");
}
int oldLimit = limit();
int end = position() + fieldSize;
if (oldLimit < end) {
throw new BufferOverflowException();
}
if (val.length() == 0) {
if (!utf16) {
put((byte) 0x00);
} else {
put((byte) 0x00);
put((byte) 0x00);
}
position(end);
return this;
}
CharBuffer in = CharBuffer.wrap(val);
limit(end);
encoder.reset();
for (;;) {
CoderResult cr;
if (in.hasRemaining()) {
cr = encoder.encode(in, buf(), true);
} else {
cr = encoder.flush(buf());
}
if (cr.isUnderflow() || cr.isOverflow()) {
break;
}
cr.throwException();
}
limit(oldLimit);
if (position() < end) {
if (!utf16) {
put((byte) 0x00);
} else {
put((byte) 0x00);
put((byte) 0x00);
}
}
position(end);
return this;
}
/**
* Reads a string which has a 16-bit length field before the actual
* encoded string, using the specified <code>decoder</code> and returns it.
* This method is a shortcut for <tt>getPrefixedString(2, decoder)</tt>.
*/
public String getPrefixedString(CharsetDecoder decoder)
throws CharacterCodingException {
return getPrefixedString(2, decoder);
}
/**
* Reads a string which has a length field before the actual
* encoded string, using the specified <code>decoder</code> and returns it.
*
* @param prefixLength the length of the length field (1, 2, or 4)
*/
public String getPrefixedString(int prefixLength, CharsetDecoder decoder)
throws CharacterCodingException {
if (!prefixedDataAvailable(prefixLength)) {
throw new BufferUnderflowException();
}
int fieldSize = 0;
switch (prefixLength) {
case 1:
fieldSize = getUnsigned();
break;
case 2:
fieldSize = getUnsignedShort();
break;
case 4:
fieldSize = getInt();
break;
}
if (fieldSize == 0) {
return "";
}
boolean utf16 = decoder.charset().name().startsWith("UTF-16");
if (utf16 && ((fieldSize & 1) != 0)) {
throw new BufferDataException(
"fieldSize is not even for a UTF-16 string.");
}
int oldLimit = limit();
int end = position() + fieldSize;
if (oldLimit < end) {
throw new BufferUnderflowException();
}
limit(end);
decoder.reset();
int expectedLength = (int) (remaining() * decoder.averageCharsPerByte()) + 1;
CharBuffer out = CharBuffer.allocate(expectedLength);
for (;;) {
CoderResult cr;
if (hasRemaining()) {
cr = decoder.decode(buf(), out, true);
} else {
cr = decoder.flush(out);
}
if (cr.isUnderflow()) {
break;
}
if (cr.isOverflow()) {
CharBuffer o = CharBuffer.allocate(out.capacity()
+ expectedLength);
out.flip();
o.put(out);
out = o;
continue;
}
cr.throwException();
}
limit(oldLimit);
position(end);
return out.flip().toString();
}
/**
* Writes the content of <code>in</code> into this buffer as a
* string which has a 16-bit length field before the actual
* encoded string, using the specified <code>encoder</code>.
* This method is a shortcut for <tt>putPrefixedString(in, 2, 0, encoder)</tt>.
*
* @throws BufferOverflowException if the specified string doesn't fit
*/
public ByteBuffer putPrefixedString(CharSequence in, CharsetEncoder encoder)
throws CharacterCodingException {
return putPrefixedString(in, 2, 0, encoder);
}
/**
* Writes the content of <code>in</code> into this buffer as a
* string which has a 16-bit length field before the actual
* encoded string, using the specified <code>encoder</code>.
* This method is a shortcut for <tt>putPrefixedString(in, prefixLength, 0, encoder)</tt>.
*
* @param prefixLength the length of the length field (1, 2, or 4)
*
* @throws BufferOverflowException if the specified string doesn't fit
*/
public ByteBuffer putPrefixedString(CharSequence in, int prefixLength,
CharsetEncoder encoder) throws CharacterCodingException {
return putPrefixedString(in, prefixLength, 0, encoder);
}
/**
* Writes the content of <code>in</code> into this buffer as a
* string which has a 16-bit length field before the actual
* encoded string, using the specified <code>encoder</code>.
* This method is a shortcut for <tt>putPrefixedString(in, prefixLength, padding, ( byte ) 0, encoder)</tt>.
*
* @param prefixLength the length of the length field (1, 2, or 4)
* @param padding the number of padded <tt>NUL</tt>s (1 (or 0), 2, or 4)
*
* @throws BufferOverflowException if the specified string doesn't fit
*/
public ByteBuffer putPrefixedString(CharSequence in, int prefixLength,
int padding, CharsetEncoder encoder)
throws CharacterCodingException {
return putPrefixedString(in, prefixLength, padding, (byte) 0, encoder);
}
/**
* Writes the content of <code>in</code> into this buffer as a
* string which has a 16-bit length field before the actual
* encoded string, using the specified <code>encoder</code>.
*
* @param prefixLength the length of the length field (1, 2, or 4)
* @param padding the number of padded bytes (1 (or 0), 2, or 4)
* @param padValue the value of padded bytes
*
* @throws BufferOverflowException if the specified string doesn't fit
*/
public ByteBuffer putPrefixedString(CharSequence val, int prefixLength,
int padding, byte padValue, CharsetEncoder encoder)
throws CharacterCodingException {
int maxLength;
switch (prefixLength) {
case 1:
maxLength = 255;
break;
case 2:
maxLength = 65535;
break;
case 4:
maxLength = Integer.MAX_VALUE;
break;
default:
throw new IllegalArgumentException("prefixLength: " + prefixLength);
}
if (val.length() > maxLength) {
throw new IllegalArgumentException(
"The specified string is too long.");
}
if (val.length() == 0) {
switch (prefixLength) {
case 1:
put((byte) 0);
break;
case 2:
putShort((short) 0);
break;
case 4:
putInt(0);
break;
}
return this;
}
int padMask;
switch (padding) {
case 0:
case 1:
padMask = 0;
break;
case 2:
padMask = 1;
break;
case 4:
padMask = 3;
break;
default:
throw new IllegalArgumentException("padding: " + padding);
}
CharBuffer in = CharBuffer.wrap(val);
int expectedLength = (int) (in.remaining() * encoder
.averageBytesPerChar()) + 1;
skip(prefixLength); // make a room for the length field
int oldPos = position();
encoder.reset();
for (;;) {
CoderResult cr;
if (in.hasRemaining()) {
cr = encoder.encode(in, buf(), true);
} else {
cr = encoder.flush(buf());
}
if (position() - oldPos > maxLength) {
throw new IllegalArgumentException(
"The specified string is too long.");
}
if (cr.isUnderflow()) {
break;
}
if (cr.isOverflow() && isAutoExpand()) {
autoExpand(expectedLength);
continue;
}
cr.throwException();
}
// Write the length field
fill(padValue, padding - ((position() - oldPos) & padMask));
int length = position() - oldPos;
switch (prefixLength) {
case 1:
put(oldPos - 1, (byte) length);
break;
case 2:
putShort(oldPos - 2, (short) length);
break;
case 4:
putInt(oldPos - 4, length);
break;
}
return this;
}
/**
* Reads a Java object from the buffer using the context {@link ClassLoader}
* of the current thread.
*/
public Object getObject() throws ClassNotFoundException {
return getObject(Thread.currentThread().getContextClassLoader());
}
/**
* Reads a Java object from the buffer using the specified <tt>classLoader</tt>.
*/
public Object getObject(final ClassLoader classLoader)
throws ClassNotFoundException {
if (!prefixedDataAvailable(4)) {
throw new BufferUnderflowException();
}
int length = getInt();
if (length <= 4) {
throw new BufferDataException(
"Object length should be greater than 4: " + length);
}
int oldLimit = limit();
limit(position() + length);
try {
ObjectInputStream in = new ObjectInputStream(asInputStream()) {
protected ObjectStreamClass readClassDescriptor()
throws IOException, ClassNotFoundException {
int type = read();
if (type < 0) {
throw new EOFException();
}
switch (type) {
case 0: // Primitive types
return super.readClassDescriptor();
case 1: // Non-primitive types
String className = readUTF();
Class clazz =
Class.forName(className, true, classLoader);
return ObjectStreamClass.lookup(clazz);
default:
throw new StreamCorruptedException(
"Unexpected class descriptor type: " + type);
}
}
};
return in.readObject();
} catch (IOException e) {
throw new BufferDataException(e);
} finally {
limit(oldLimit);
}
}
/**
* Writes the specified Java object to the buffer.
*/
public ByteBuffer putObject(Object o) {
int oldPos = position();
skip(4); // Make a room for the length field.
try {
ObjectOutputStream out = new ObjectOutputStream(asOutputStream()) {
protected void writeClassDescriptor(ObjectStreamClass desc)
throws IOException {
String className = desc.getName();
if (primitiveTypeNames.contains(className)) {
write(0);
super.writeClassDescriptor(desc);
} else {
write(1);
writeUTF(desc.getName());
}
}
};
out.writeObject(o);
out.flush();
} catch (IOException e) {
throw new BufferDataException(e);
}
// Fill the length field
int newPos = position();
position(oldPos);
putInt(newPos - oldPos - 4);
position(newPos);
return this;
}
/**
* Returns <tt>true</tt> if this buffer contains a data which has a data
* length as a prefix and the buffer has remaining data as enough as
* specified in the data length field. This method is identical with
* <tt>prefixedDataAvailable( prefixLength, Integer.MAX_VALUE )</tt>.
* Please not that using this method can allow DoS (Denial of Service)
* attack in case the remote peer sends too big data length value.
* It is recommended to use {@link #prefixedDataAvailable(int, int)}
* instead.
*
* @param prefixLength the length of the prefix field (1, 2, or 4)
*
* @throws IllegalArgumentException if prefixLength is wrong
* @throws BufferDataException if data length is negative
*/
public boolean prefixedDataAvailable(int prefixLength) {
return prefixedDataAvailable(prefixLength, Integer.MAX_VALUE);
}
/**
* Returns <tt>true</tt> if this buffer contains a data which has a data
* length as a prefix and the buffer has remaining data as enough as
* specified in the data length field.
*
* @param prefixLength the length of the prefix field (1, 2, or 4)
* @param maxDataLength the allowed maximum of the read data length
*
* @throws IllegalArgumentException if prefixLength is wrong
* @throws BufferDataException if data length is negative or greater then <tt>maxDataLength</tt>
*/
public boolean prefixedDataAvailable(int prefixLength, int maxDataLength) {
if (remaining() < prefixLength) {
return false;
}
int dataLength;
switch (prefixLength) {
case 1:
dataLength = getUnsigned(position());
break;
case 2:
dataLength = getUnsignedShort(position());
break;
case 4:
dataLength = getInt(position());
break;
default:
throw new IllegalArgumentException("prefixLength: " + prefixLength);
}
if (dataLength < 0 || dataLength > maxDataLength) {
throw new BufferDataException("dataLength: " + dataLength);
}
return remaining() - prefixLength >= dataLength;
}
//////////////////////////
// Skip or fill methods //
//////////////////////////
/**
* Forwards the position of this buffer as the specified <code>size</code>
* bytes.
*/
public ByteBuffer skip(int size) {
autoExpand(size);
return position(position() + size);
}
/**
* Fills this buffer with the specified value.
* This method moves buffer position forward.
*/
public ByteBuffer fill(byte value, int size) {
autoExpand(size);
int q = size >>> 3;
int r = size & 7;
if (q > 0) {
int intValue = value | (value << 8) | (value << 16) | (value << 24);
long longValue = intValue;
longValue <<= 32;
longValue |= intValue;
for (int i = q; i > 0; i--) {
putLong(longValue);
}
}
q = r >>> 2;
r = r & 3;
if (q > 0) {
int intValue = value | (value << 8) | (value << 16) | (value << 24);
putInt(intValue);
}
q = r >> 1;
r = r & 1;
if (q > 0) {
short shortValue = (short) (value | (value << 8));
putShort(shortValue);
}
if (r > 0) {
put(value);
}
return this;
}
/**
* Fills this buffer with the specified value.
* This method does not change buffer position.
*/
public ByteBuffer fillAndReset(byte value, int size) {
autoExpand(size);
int pos = position();
try {
fill(value, size);
} finally {
position(pos);
}
return this;
}
/**
* Fills this buffer with <code>NUL (0x00)</code>.
* This method moves buffer position forward.
*/
public ByteBuffer fill(int size) {
autoExpand(size);
int q = size >>> 3;
int r = size & 7;
for (int i = q; i > 0; i--) {
putLong(0L);
}
q = r >>> 2;
r = r & 3;
if (q > 0) {
putInt(0);
}
q = r >> 1;
r = r & 1;
if (q > 0) {
putShort((short) 0);
}
if (r > 0) {
put((byte) 0);
}
return this;
}
/**
* Fills this buffer with <code>NUL (0x00)</code>.
* This method does not change buffer position.
*/
public ByteBuffer fillAndReset(int size) {
autoExpand(size);
int pos = position();
try {
fill(size);
} finally {
position(pos);
}
return this;
}
/**
* This method forwards the call to {@link #expand(int)} only when
* <tt>autoExpand</tt> property is <tt>true</tt>.
*/
protected ByteBuffer autoExpand(int expectedRemaining) {
if (isAutoExpand()) {
expand(expectedRemaining);
}
return this;
}
/**
* This method forwards the call to {@link #expand(int)} only when
* <tt>autoExpand</tt> property is <tt>true</tt>.
*/
protected ByteBuffer autoExpand(int pos, int expectedRemaining) {
if (isAutoExpand()) {
expand(pos, expectedRemaining);
}
return this;
}
private static void checkFieldSize(int fieldSize) {
if (fieldSize < 0) {
throw new IllegalArgumentException("fieldSize cannot be negative: "
+ fieldSize);
}
}
}