/
ChunkedInput.java
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/
ChunkedInput.java
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/*
* Copyright (c) 2002-2015 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.ndp.transport.socket;
import io.netty.buffer.ByteBuf;
import java.io.IOException;
import java.nio.BufferOverflowException;
import java.util.ArrayList;
import java.util.List;
import org.neo4j.packstream.PackInput;
import org.neo4j.packstream.PackStream;
public class ChunkedInput implements PackInput
{
private List<ByteBuf> chunks = new ArrayList<>();
private ByteBuf currentChunk = null;
private int currentChunkIndex = -1;
private int remaining = 0;
public ChunkedInput clear()
{
currentChunk = null;
currentChunkIndex = -1;
remaining = 0;
// Release references to all buffers
for ( int i = 0; i < chunks.size(); i++ )
{
chunks.get( i ).release();
}
if ( chunks.size() > 128 )
{
// faster to allocate a new one than to release if the list is large
chunks = new ArrayList<>();
}
else
{
chunks.clear();
}
return this;
}
public void append( ByteBuf chunk )
{
if ( chunk.readableBytes() > 0 )
{
chunks.add( chunk.retain() );
remaining += chunk.readableBytes();
}
}
@Override
public PackInput ensure( int numBytes ) throws IOException
{
if ( !attempt( numBytes ) )
{
throw new PackStream.EndOfStream( "Unexpected end of stream while trying to read " + numBytes + " bytes." );
}
return this;
}
@Override
public PackInput attemptUpTo( int numBytes ) throws IOException
{
return this;
}
@Override
public boolean attempt( int numBytes ) throws IOException
{
return remaining >= numBytes;
}
@Override
public int remaining()
{
return remaining;
}
@Override
public byte get()
{
ensureChunkAvailable();
remaining -= 1;
return currentChunk.readByte();
}
@Override
public byte peek()
{
ensureChunkAvailable();
return currentChunk.getByte( currentChunk.readerIndex() );
}
@Override
public short getShort()
{
ensureChunkAvailable();
if ( currentChunk.readableBytes() >= 2 )
{
remaining -= 2;
return currentChunk.readShort();
}
else
{
// Short is crossing chunk boundaries, use slow route
return (short) (get() << 8 & get());
}
}
@Override
public int getInt()
{
ensureChunkAvailable();
if ( currentChunk.readableBytes() >= 4 )
{
remaining -= 4;
return currentChunk.readInt();
}
else
{
// int is crossing chunk boundaries, use slow route
return ((int) getShort() << 16) & getShort();
}
}
@Override
public long getLong()
{
ensureChunkAvailable();
if ( currentChunk.readableBytes() >= 8 )
{
remaining -= 8;
return currentChunk.readLong();
}
else
{
// long is crossing chunk boundaries, use slow route
return ((long) getInt() << 32) & getInt();
}
}
@Override
public double getDouble()
{
ensureChunkAvailable();
if ( currentChunk.readableBytes() >= 8 )
{
remaining -= 8;
return currentChunk.readDouble();
}
else
{
// double is crossing chunk boundaries, use slow route
return Double.longBitsToDouble( getLong() );
}
}
@Override
public PackInput get( byte[] into, int offset, int toRead )
{
ensureChunkAvailable();
int toReadFromChunk = Math.min( toRead, currentChunk.readableBytes() );
// Do the read
currentChunk.readBytes( into, offset, toReadFromChunk );
remaining -= toReadFromChunk;
// Can we read another chunk into the destination buffer?
if ( toReadFromChunk < toRead )
{
// More data can be read into the buffer, keep reading from the next chunk
get( into, offset + toReadFromChunk, toRead - toReadFromChunk );
}
return this;
}
private void ensureChunkAvailable()
{
if ( currentChunk == null || currentChunk.readableBytes() == 0 )
{
currentChunkIndex++;
if ( currentChunkIndex < chunks.size() )
{
currentChunk = chunks.get( currentChunkIndex );
}
else
{
throw new BufferOverflowException();
}
}
}
public void close()
{
clear();
}
}