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/*
* Input streams.
*/
#include "fitz-base.h"
#include "fitz-stream.h"
fz_error *
fz_readimp(fz_stream *stm)
{
fz_buffer *buf = stm->buffer;
fz_error *error;
fz_error *reason;
int produced;
int n;
if (stm->dead)
return fz_throw("assert: read from dead stream");
if (stm->mode != FZ_SREAD)
return fz_throw("assert: read from writing stream");
if (buf->eof)
return fz_okay;
error = fz_rewindbuffer(buf);
if (error)
{
stm->dead = 1;
return fz_rethrow(error, "cannot rewind output buffer");
}
if (buf->ep - buf->wp == 0)
{
error = fz_growbuffer(buf);
if (error)
{
stm->dead = 1;
return fz_rethrow(error, "cannot grow output buffer");
}
}
switch (stm->kind)
{
case FZ_SFILE:
n = read(stm->file, buf->wp, buf->ep - buf->wp);
if (n == -1)
{
stm->dead = 1;
return fz_throw("syserr: read: %s", strerror(errno));
}
if (n == 0)
buf->eof = 1;
buf->wp += n;
return fz_okay;
case FZ_SFILTER:
produced = 0;
while (1)
{
reason = fz_process(stm->filter, stm->chain->buffer, buf);
if (stm->filter->produced)
produced = 1;
if (reason == fz_ioneedin)
{
error = fz_readimp(stm->chain);
if (error)
{
stm->dead = 1;
return fz_rethrow(error, "cannot read from input stream");
}
}
else if (reason == fz_ioneedout)
{
if (produced)
return 0;
if (buf->rp > buf->bp)
{
error = fz_rewindbuffer(buf);
if (error)
{
stm->dead = 1;
return fz_rethrow(error, "cannot rewind buffer");
}
}
else
{
error = fz_growbuffer(buf);
if (error)
{
stm->dead = 1;
return fz_rethrow(error, "cannot grow buffer");
}
}
}
else if (reason == fz_iodone)
{
return fz_okay;
}
else
{
stm->dead = 1;
return fz_rethrow(reason, "cannot process filter");
}
}
case FZ_SBUFFER:
return fz_okay;
default:
return fz_throw("assert: unknown stream type");
}
}
int
fz_rtell(fz_stream *stm)
{
fz_buffer *buf = stm->buffer;
int t;
if (stm->dead)
return EOF;
if (stm->mode != FZ_SREAD)
return EOF;
switch (stm->kind)
{
case FZ_SFILE:
t = lseek(stm->file, 0, 1);
if (t < 0)
{
fz_warn("syserr: lseek: %s", strerror(errno));
stm->dead = 1;
return EOF;
}
return t - (buf->wp - buf->rp);
case FZ_SFILTER:
return stm->filter->count - (buf->wp - buf->rp);
case FZ_SBUFFER:
return buf->rp - buf->bp;
default:
return EOF;
}
}
fz_error *
fz_rseek(fz_stream *stm, int offset, int whence)
{
fz_error *error;
fz_buffer *buf = stm->buffer;
int t, c;
if (stm->dead)
return fz_throw("assert: seek in dead stream");
if (stm->mode != FZ_SREAD)
return fz_throw("assert: read operation on writing stream");
if (whence == 1)
{
int cur = fz_rtell(stm);
if (cur < 0)
return fz_throw("cannot tell current position");
offset = cur + offset;
whence = 0;
}
buf->eof = 0;
switch (stm->kind)
{
case FZ_SFILE:
t = lseek(stm->file, offset, whence);
if (t < 0)
{
stm->dead = 1;
return fz_throw("syserr: lseek: %s", strerror(errno));
}
buf->rp = buf->bp;
buf->wp = buf->bp;
return fz_okay;
case FZ_SFILTER:
if (whence == 0)
{
if (offset < fz_rtell(stm))
{
stm->dead = 1;
return fz_throw("assert: seek backwards in filter");
}
while (fz_rtell(stm) < offset)
{
c = fz_readbyte(stm);
if (c == EOF)
{
error = fz_readerror(stm);
if (error)
return fz_rethrow(error, "cannot seek forward in filter");
break;
}
}
return fz_okay;
}
stm->dead = 1;
return fz_throw("assert: relative seek in filter");
case FZ_SBUFFER:
if (whence == 0)
buf->rp = CLAMP(buf->bp + offset, buf->bp, buf->ep);
else
buf->rp = CLAMP(buf->ep + offset, buf->bp, buf->ep);
return fz_okay;
default:
return fz_throw("unknown stream type");
}
}
fz_error *
fz_read(int *np, fz_stream *stm, unsigned char *mem, int n)
{
fz_error *error;
fz_buffer *buf = stm->buffer;
int i = 0;
while (i < n)
{
while (buf->rp < buf->wp && i < n)
mem[i++] = *buf->rp++;
if (buf->rp == buf->wp)
{
if (buf->eof)
{
*np = i;
return fz_okay;
}
error = fz_readimp(stm);
if (error)
return fz_rethrow(error, "cannot produce data");
}
}
*np = i;
return fz_okay;
}
fz_error *
fz_readerror(fz_stream *stm)
{
fz_error *error;
if (stm->error)
{
error = stm->error;
stm->error = fz_okay;
return fz_rethrow(error, "delayed read error");
}
return fz_okay;
}
int
fz_readbytex(fz_stream *stm)
{
fz_buffer *buf = stm->buffer;
if (buf->rp == buf->wp)
{
if (!buf->eof && !stm->error)
{
fz_error *error = fz_readimp(stm);
if (error)
stm->error = fz_rethrow(error, "cannot read data");
}
}
return buf->rp < buf->wp ? *buf->rp++ : EOF ;
}
int
fz_peekbytex(fz_stream *stm)
{
fz_buffer *buf = stm->buffer;
if (buf->rp == buf->wp)
{
if (!buf->eof && !stm->error)
{
fz_error *error = fz_readimp(stm);
if (error)
stm->error = fz_rethrow(error, "cannot read data");
}
}
return buf->rp < buf->wp ? *buf->rp : EOF ;
}
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