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 (buf->eof)
return fz_okay;
fz_rewindbuffer(buf);
if (buf->ep - buf->wp == 0)
fz_growbuffer(buf);
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)
fz_rewindbuffer(buf);
else
fz_growbuffer(buf);
}
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");
}
}
fz_error *
fz_processpipeline(fz_filter *filter, fz_buffer *in, fz_buffer *out)
{
fz_pipeline *p = (fz_pipeline*)filter;
fz_error *e;
if (p->buffer->eof)
goto tail;
if (p->tailneedsin && p->head->produced)
goto tail;
head:
e = fz_process(p->head, in, p->buffer);
if (e == fz_ioneedin)
return fz_ioneedin;
else if (e == fz_ioneedout)
{
if (p->tailneedsin && !p->head->produced)
{
fz_error *be = nil;
if (p->buffer->rp > p->buffer->bp)
be = fz_rewindbuffer(p->buffer);
else
be = fz_growbuffer(p->buffer);
if (be)
return be;
goto head;
}
goto tail;
}
else if (e == fz_iodone)
goto tail;
else
return e;
tail:
e = fz_process(p->tail, p->buffer, out);
if (e == fz_ioneedin)
{
if (p->buffer->eof)
return fz_throw("ioerror: premature eof in pipeline");
p->tailneedsin = 1;
goto head;
}
else if (e == fz_ioneedout)
{
p->tailneedsin = 0;
return fz_ioneedout;
}
else if (e == fz_iodone)
return fz_iodone;
else
return e;
}
