/**
* (C) Copyright IBM Corp. 2010, 2015
*
* Licensed 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 com.ibm.bi.dml.runtime.util;
import java.io.DataOutput;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import com.ibm.bi.dml.runtime.matrix.data.MatrixBlockDataOutput;
import com.ibm.bi.dml.runtime.matrix.data.SparseRow;
/**
* This buffered output stream is essentially a merged version of
* BufferedOutputStream and DataOutputStream, wrt SystemML requirements.
*
* Micro-benchmarks showed a 25% performance improvement for local write binary block
* due to the following advantages:
* - 1) unsynchronized buffered output stream (not required in SystemML since single writer)
* - 2) single output buffer (avoid two-level buffers of individual streams)
* - 3) specific support for writing double arrays in a blockwise fashion
*
*/
public class FastBufferedDataOutputStream extends FilterOutputStream implements DataOutput, MatrixBlockDataOutput
{
protected byte[] _buff;
protected int _bufflen;
protected int _count;
public FastBufferedDataOutputStream(OutputStream out)
{
this(out, 8192);
}
public FastBufferedDataOutputStream(OutputStream out, int size)
{
super(out);
if(size <= 0)
throw new IllegalArgumentException("Buffer size <= 0.");
if( size%8 != 0 )
throw new IllegalArgumentException("Buffer size not a multiple of 8.");
_buff = new byte[size];
_bufflen = size;
}
@Override
public void write(int b)
throws IOException
{
if (_count >= _bufflen) {
flushBuffer();
}
_buff[_count++] = (byte)b;
}
@Override
public void write(byte[] b, int off, int len)
throws IOException
{
if (len >= _bufflen) {
flushBuffer();
out.write(b, off, len);
return;
}
if (len > _bufflen - _count) {
flushBuffer();
}
System.arraycopy(b, off, _buff, _count, len);
_count += len;
}
@Override
public void flush()
throws IOException
{
flushBuffer();
out.flush();
}
private void flushBuffer()
throws IOException
{
if(_count > 0)
{
out.write(_buff, 0, _count);
_count = 0;
}
}
@Override
public void close()
throws IOException
{
super.close();
}
/////////////////////////////
// DataOutput Implementation
/////////////////////////////
@Override
public void writeBoolean(boolean v)
throws IOException
{
if (_count >= _bufflen) {
flushBuffer();
}
_buff[_count++] = (byte)(v ? 1 : 0);
}
@Override
public void writeInt(int v)
throws IOException
{
if (_count+4 > _bufflen) {
flushBuffer();
}
intToBa(v, _buff, _count);
_count += 4;
}
@Override
public void writeLong(long v)
throws IOException
{
if (_count+8 > _bufflen) {
flushBuffer();
}
longToBa(v, _buff, _count);
_count += 8;
}
@Override
public void writeDouble(double v)
throws IOException
{
if (_count+8 > _bufflen) {
flushBuffer();
}
long tmp = Double.doubleToRawLongBits(v);
longToBa(tmp, _buff, _count);
_count += 8;
}
@Override
public void writeByte(int v) throws IOException {
if (_count+1 > _bufflen) {
flushBuffer();
}
_buff[_count++] = (byte) v;
}
@Override
public void writeBytes(String s) throws IOException {
throw new IOException("Not supported.");
}
@Override
public void writeChar(int v) throws IOException {
throw new IOException("Not supported.");
}
@Override
public void writeChars(String s) throws IOException {
throw new IOException("Not supported.");
}
@Override
public void writeFloat(float v) throws IOException {
throw new IOException("Not supported.");
}
@Override
public void writeShort(int v) throws IOException {
throw new IOException("Not supported.");
}
@Override
public void writeUTF(String s) throws IOException {
throw new IOException("Not supported.");
}
///////////////////////////////////////////////
// Implementation of MatrixBlockDSMDataOutput
///////////////////////////////////////////////
@Override
public void writeDoubleArray(int len, double[] varr)
throws IOException
{
//initial flush
flushBuffer();
//write matrix block-wise to underlying stream
//(increase i in awareness of len to prevent int overflow)
int blen = _bufflen/8;
for( int i=0; i<len; i+=Math.min(len-i, blen) )
{
//write values of current block
int lblen = Math.min(len-i, blen);
for( int j=0; j<lblen; j++ )
{
long tmp = Double.doubleToRawLongBits(varr[i+j]);
longToBa(tmp, _buff, _count);
_count += 8;
}
//flush buffer for current block
flushBuffer(); //based on count
}
}
@Override
public void writeSparseRows(int rlen, SparseRow[] rows)
throws IOException
{
int lrlen = Math.min(rows.length, rlen);
//process existing rows
for( int i=0; i<lrlen; i++ )
{
SparseRow arow = rows[i];
if( arow!=null && !arow.isEmpty() )
{
int alen = arow.size();
int alen2 = alen*12;
int[] aix = arow.getIndexContainer();
double[] avals = arow.getValueContainer();
writeInt( alen );
if( alen2 < _bufflen )
{
if (_count+alen2 > _bufflen)
flushBuffer();
for( int j=0; j<alen; j++ )
{
long tmp2 = Double.doubleToRawLongBits(avals[j]);
intToBa(aix[j], _buff, _count);
longToBa(tmp2, _buff, _count+4);
_count += 12;
}
}
else
{
//row does not fit in buffer
for( int j=0; j<alen; j++ )
{
if (_count+12 > _bufflen)
flushBuffer();
long tmp2 = Double.doubleToRawLongBits(avals[j]);
intToBa(aix[j], _buff, _count);
longToBa(tmp2, _buff, _count+4);
_count += 12;
}
}
}
else
writeInt( 0 );
}
//process remaining empty rows
for( int i=lrlen; i<rlen; i++ )
writeInt( 0 );
}
/**
*
* @param val
* @param ba
* @param off
*/
private static void intToBa( final int val, byte[] ba, final int off )
{
//shift and mask out 4 bytes
ba[ off+0 ] = (byte)((val >>> 24) & 0xFF);
ba[ off+1 ] = (byte)((val >>> 16) & 0xFF);
ba[ off+2 ] = (byte)((val >>> 8) & 0xFF);
ba[ off+3 ] = (byte)((val >>> 0) & 0xFF);
}
/**
*
* @param val
* @param ba
* @param off
*/
private static void longToBa( final long val, byte[] ba, final int off )
{
//shift and mask out 8 bytes
ba[ off+0 ] = (byte)((val >>> 56) & 0xFF);
ba[ off+1 ] = (byte)((val >>> 48) & 0xFF);
ba[ off+2 ] = (byte)((val >>> 40) & 0xFF);
ba[ off+3 ] = (byte)((val >>> 32) & 0xFF);
ba[ off+4 ] = (byte)((val >>> 24) & 0xFF);
ba[ off+5 ] = (byte)((val >>> 16) & 0xFF);
ba[ off+6 ] = (byte)((val >>> 8) & 0xFF);
ba[ off+7 ] = (byte)((val >>> 0) & 0xFF);
}
}