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/*
* Copyright (C) 2007-2013 Xagasoft, All rights reserved.
*
* This file is part of the libgats library and is released under the
* terms of the license contained in the file LICENSE.
*/
package com.xagasoft.gats;
import java.io.OutputStream;
import java.io.InputStream;
/**
* Represents a simple java long value. This does not handle arbitrary
* precision integer values, a class to handle that is forthcoming.
*/
public class GatsInteger extends GatsObject
{
private long iValue = 0;
public GatsInteger()
{
}
public GatsInteger( long iValue )
{
this.iValue = iValue;
}
public long getValue()
{
return iValue;
}
public void setValue( long iValue )
{
this.iValue = iValue;
}
public String toString()
{
return "" + iValue;
}
public int getType()
{
return GatsObject.INTEGER;
};
void read( InputStream is, char cType ) throws java.io.IOException
{
iValue = readPackedInt( is );
}
void write( OutputStream os ) throws java.io.IOException
{
os.write( (int)'i' );
writePackedInt( os, iValue );
}
/**
* This is a general helper function used by several parts of the Gats
* system.
* It reads a "packed integer" from the given input stream, and returns the
* value.
* Possible TODO: have this return a Number, and construct either a Long
* or BigInteger when appropriate.
*/
public static long readPackedInt( InputStream is ) throws java.io.IOException
{
int b;
long rOut = 0;
boolean bNeg;
b = is.read();
bNeg = (b&0x40) == 0x40;
rOut |= b&0x3F;
int c = 0;
while( (b&0x80) == 0x80 )
{
b = is.read();
rOut |= (long)(b&0x7F) << (6+7*(c++));
}
if( bNeg )
return -rOut;
return rOut;
}
/**
* This is a general helper function used by several parts of the Gats
* system.
* It writes a "packed integer" to the given output stream.
*/
public static void writePackedInt( OutputStream os, long iIn ) throws java.io.IOException
{
int b;
if( iIn < 0 )
{
iIn = -iIn;
b = (int)(iIn&0x3F);
if( iIn > b )
b |= 0x80 | 0x40;
else
b |= 0x40;
}
else
{
b = (int)(iIn&0x3F);
if( iIn > b )
b |= 0x80;
}
os.write( b );
iIn = iIn >> 6;
while( iIn > 0 )
{
b = (int)(iIn&0x7F);
if( iIn > b )
b |= 0x80;
os.write( b );
iIn = iIn >> 7;
}
}
};
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