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mirror of https://github.com/qpdf/qpdf.git synced 2024-11-01 03:12:29 +00:00
qpdf/libqpdf/Pl_ASCII85Decoder.cc
Jay Berkenbilt 5d4cad9c02 ABI change: fix use of off_t, size_t, and integer types
Significantly improve the code's use of off_t for file offsets, size_t
for memory sizes, and integer types in cases where there has to be
compatibility with external interfaces.  Rework sections of the code
that would have prevented qpdf from working on files larger than 2 (or
maybe 4) GB in size.
2012-06-20 15:20:26 -04:00

132 lines
2.1 KiB
C++

#include <qpdf/Pl_ASCII85Decoder.hh>
#include <qpdf/QTC.hh>
#include <stdexcept>
#include <string.h>
Pl_ASCII85Decoder::Pl_ASCII85Decoder(char const* identifier, Pipeline* next) :
Pipeline(identifier, next),
pos(0),
eod(0)
{
memset(this->inbuf, 117, 5);
}
Pl_ASCII85Decoder::~Pl_ASCII85Decoder()
{
}
void
Pl_ASCII85Decoder::write(unsigned char* buf, size_t len)
{
if (eod > 1)
{
return;
}
for (size_t i = 0; i < len; ++i)
{
if (eod > 1)
{
break;
}
else if (eod == 1)
{
if (buf[i] == '>')
{
flush();
eod = 2;
}
else
{
throw std::runtime_error(
"broken end-of-data sequence in base 85 data");
}
}
else
{
switch (buf[i])
{
case ' ':
case '\f':
case '\v':
case '\t':
case '\r':
case '\n':
QTC::TC("libtests", "Pl_ASCII85Decoder ignore space");
// ignore whitespace
break;
case '~':
eod = 1;
break;
case 'z':
if (pos != 0)
{
throw std::runtime_error(
"unexpected z during base 85 decode");
}
else
{
QTC::TC("libtests", "Pl_ASCII85Decoder read z");
getNext()->write((unsigned char*)"\000\000\000\000", 4);
}
break;
default:
if ((buf[i] < 33) || (buf[i] > 117))
{
throw std::runtime_error(
"character out of range during base 85 decode");
}
else
{
this->inbuf[this->pos++] = buf[i];
if (pos == 5)
{
flush();
}
}
break;
}
}
}
}
void
Pl_ASCII85Decoder::flush()
{
if (this->pos == 0)
{
QTC::TC("libtests", "Pl_ASCII85Decoder no-op flush");
return;
}
unsigned long lval = 0;
for (int i = 0; i < 5; ++i)
{
lval *= 85;
lval += (this->inbuf[i] - 33);
}
unsigned char outbuf[4];
memset(outbuf, 0, 4);
for (int i = 3; i >= 0; --i)
{
outbuf[i] = lval & 0xff;
lval >>= 8;
}
QTC::TC("libtests", "Pl_ASCII85Decoder partial flush",
(this->pos == 5) ? 0 : 1);
getNext()->write(outbuf, this->pos - 1);
this->pos = 0;
memset(this->inbuf, 117, 5);
}
void
Pl_ASCII85Decoder::finish()
{
flush();
getNext()->finish();
}