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apache / mina / 6c067a9ba100f21ceed50226adf275793d352ea7 / . / core / src / main / java / org / apache / mina / common / ByteBuffer.java
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/*
* 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.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.OutputStream;
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 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 $Rev$, $Date$
* @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 ) );
}
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
{
String className = readUTF();
Class clazz = Class.forName( className, true, classLoader );
return ObjectStreamClass.lookup( clazz );
}
};
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
{
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 );
}
}
}