base64stream.cpp revision c4ec17e94f2b6bbbe14d6da2fd361543735a6aeb
/*
* Base64-enabled input and output streams
*
* This class allows easy encoding and decoding
* of Base64 data with a stream interface, hiding
* the implementation from the user.
*
* http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/idl-definitions.html
*
* Authors:
* Bob Jamison
*
* Copyright (C) 2006 Bob Jamison
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "base64stream.h"
namespace Inkscape
{
namespace IO
{
//#########################################################################
//# B A S E 6 4 I N P U T S T R E A M
//#########################################################################
static int base64decode[] =
{
/*00*/ -1, -1, -1, -1, -1, -1, -1, -1,
/*08*/ -1, -1, -1, -1, -1, -1, -1, -1,
/*10*/ -1, -1, -1, -1, -1, -1, -1, -1,
/*18*/ -1, -1, -1, -1, -1, -1, -1, -1,
/*20*/ -1, -1, -1, -1, -1, -1, -1, -1,
/*28*/ -1, -1, -1, 62, -1, -1, -1, 63,
/*30*/ 52, 53, 54, 55, 56, 57, 58, 59,
/*38*/ 60, 61, -1, -1, -1, -1, -1, -1,
/*40*/ -1, 0, 1, 2, 3, 4, 5, 6,
/*48*/ 7, 8, 9, 10, 11, 12, 13, 14,
/*50*/ 15, 16, 17, 18, 19, 20, 21, 22,
/*58*/ 23, 24, 25, -1, -1, -1, -1, -1,
/*60*/ -1, 26, 27, 28, 29, 30, 31, 32,
/*68*/ 33, 34, 35, 36, 37, 38, 39, 40,
/*70*/ 41, 42, 43, 44, 45, 46, 47, 48,
/*78*/ 49, 50, 51, -1, -1, -1, -1, -1
};
/**
*
*/
Base64InputStream::Base64InputStream(InputStream &sourceStream)
: BasicInputStream(sourceStream),
outCount(0),
padCount(0),
done(false)
{
for (int k=0;k<3;k++)
{
outBytes[k]=0;
}
}
/**
*
*/
Base64InputStream::~Base64InputStream()
{
close();
}
/**
* Returns the number of bytes that can be read (or skipped over) from
* this input stream without blocking by the next caller of a method for
* this input stream.
*/
int Base64InputStream::available()
{
if (closed )
return 0;
int len = source.available() * 2 / 3;
return len;
}
/**
* Closes this input stream and releases any system resources
* associated with the stream.
*/
void Base64InputStream::close()
{
if (closed)
return;
source.close();
closed = true;
}
/**
* Reads the next byte of data from the input stream. -1 if EOF
*/
int Base64InputStream::get()
{
if (closed)
return -1;
if (outCount - padCount > 0)
{
return outBytes[3-(outCount--)];
}
if (done)
return -1;
int inBytes[4];
int inCount = 0;
while (inCount < 4)
{
int ch = source.get();
if (ch < 0)
{
while (inCount < 4) //pad if needed
{
inBytes[inCount++] = 0;
padCount++;
}
done = true;
break;
}
if (isspace(ch)) //ascii whitespace
{
//nothing
}
else if (ch == '=') //padding
{
inBytes[inCount++] = 0;
padCount++;
}
else
{
int byteVal = base64decode[ch & 0x7f];
//printf("char:%c %d\n", ch, byteVal);
if (byteVal < 0)
{
//Bad lookup value
}
inBytes[inCount++] = byteVal;
}
}
outBytes[0] = ((inBytes[0]<<2) & 0xfc) | ((inBytes[1]>>4) & 0x03);
outBytes[1] = ((inBytes[1]<<4) & 0xf0) | ((inBytes[2]>>2) & 0x0f);
outBytes[2] = ((inBytes[2]<<6) & 0xc0) | ((inBytes[3] ) & 0x3f);
outCount = 3;
//try again
if (outCount - padCount > 0)
{
return outBytes[3-(outCount--)];
}
return -1;
}
//#########################################################################
//# B A S E 6 4 O U T P U T S T R E A M
//#########################################################################
static char const *base64encode =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/**
*
*/
Base64OutputStream::Base64OutputStream(OutputStream &destinationStream)
: BasicOutputStream(destinationStream)
{
column = 0;
columnWidth = 72;
outBuf = 0L;
bitCount = 0;
}
/**
*
*/
Base64OutputStream::~Base64OutputStream()
{
close();
}
/**
* Closes this output stream and releases any system resources
* associated with this stream.
*/
void Base64OutputStream::close()
{
if (closed)
return;
//get any last bytes (1 or 2) out of the buffer
if (bitCount == 16)
{
outBuf <<= 2; //pad to make 18 bits
int indx = (int)((outBuf & 0x0003f000L) >> 12);
int obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x00000fc0L) >> 6);
obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x0000003fL) );
obyte = (int)base64encode[indx & 63];
putCh(obyte);
putCh('=');
}
else if (bitCount == 8)
{
outBuf <<= 4; //pad to make 12 bits
int indx = (int)((outBuf & 0x00000fc0L) >> 6);
int obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x0000003fL) );
obyte = (int)base64encode[indx & 63];
putCh(obyte);
putCh('=');
putCh('=');
}
if (columnWidth > 0) //if <=0, no newlines
destination.put('\n');
destination.close();
closed = true;
}
/**
* Flushes this output stream and forces any buffered output
* bytes to be written out.
*/
void Base64OutputStream::flush()
{
if (closed)
return;
//dont flush here. do it on close()
destination.flush();
}
/**
* Private. Put a char to the output stream, checking for line length
*/
void Base64OutputStream::putCh(int ch)
{
destination.put(ch);
column++;
if (columnWidth > 0 && column >= columnWidth)
{
destination.put('\n');
column = 0;
}
}
/**
* Writes the specified byte to this output stream.
*/
void Base64OutputStream::put(gunichar ch)
{
if (closed)
{
//probably throw an exception here
return;
}
outBuf <<= 8;
outBuf |= (ch & 0xff);
bitCount += 8;
if (bitCount >= 24)
{
int indx = (int)((outBuf & 0x00fc0000L) >> 18);
int obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x0003f000L) >> 12);
obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x00000fc0L) >> 6);
obyte = (int)base64encode[indx & 63];
putCh(obyte);
indx = (int)((outBuf & 0x0000003fL) );
obyte = (int)base64encode[indx & 63];
putCh(obyte);
bitCount = 0;
outBuf = 0L;
}
}
} // namespace IO
} // namespace Inkscape
//#########################################################################
//# E N D O F F I L E
//#########################################################################