CacheDataOutput.java

/**
 * (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.controlprogram.caching;

import java.io.DataOutput;
import java.io.IOException;


import com.ibm.bi.dml.runtime.matrix.data.MatrixBlockDataOutput;
import com.ibm.bi.dml.runtime.matrix.data.SparseRow;

/**
 * Customer DataOutput to serialize directly into the given byte array.
 * 
 * 
 */
public class CacheDataOutput implements DataOutput, MatrixBlockDataOutput 
{
	
	protected byte[] _buff;
	protected int _bufflen;
	protected int _count;

	public CacheDataOutput( byte[] mem ) 
	{		
		_buff = mem;
		_bufflen = _buff.length;
		_count = 0;
	}
	
	@Override
	public void write(int b) 
    	throws IOException 
    {
		_buff[_count++] = (byte)b;
    }

    @Override
	public void write(byte[] b) 
		throws IOException 
	{
		System.arraycopy(b, 0, _buff, _count, b.length);
		_count += b.length;
	}
    
    @Override
	public void write(byte[] b, int off, int len) 
    	throws IOException 
    {
		System.arraycopy(b, off, _buff, _count, len);
		_count += len;
    }
	
	@Override
	public void writeBoolean(boolean v) 
		throws IOException 
	{
		_buff[_count++] = (byte)( v ? 1 : 0 );
	}


	@Override
	public void writeInt(int v) 
		throws IOException 
	{
		intToBa(v, _buff, _count);
		_count += 4;
	}
	
	@Override
	public void writeDouble(double v) 
		throws IOException 
	{
		long tmp = Double.doubleToRawLongBits(v);		
		longToBa(tmp, _buff, _count);
		_count += 8;
	}

	@Override
	public void writeByte(int v) throws IOException {
		_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 writeLong(long v) throws IOException {
		longToBa(v,  _buff, _count);
		_count += 8;
	}

	@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
	{
		//original buffer offset
		int off = _count;
		
		//serialize entire array into buffer
		for( int i=0; i<len; i++ )
		{
		    long tmp = Double.doubleToRawLongBits(varr[i]);
		    longToBa(tmp, _buff, off+i*8);
		}
		
		//update buffer offset
		_count = off + len*8;
	}
	
	@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[] aix = arow.getIndexContainer();
				double[] avals = arow.getValueContainer();
				
				writeInt( alen );

				for( int j=0; j<alen; j++ )
				{
					intToBa(aix[j], _buff, _count);
					long tmp2 = Double.doubleToRawLongBits(avals[j]);
					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);
	}
}