diff options
Diffstat (limited to 'fitz/stm_read.c')
| -rw-r--r-- | fitz/stm_read.c | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/fitz/stm_read.c b/fitz/stm_read.c new file mode 100644 index 00000000..e0a6e8a1 --- /dev/null +++ b/fitz/stm_read.c @@ -0,0 +1,313 @@ +/* + * 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 ; +} + |