mchapman/zlib
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

zlib 1.2.3.7

Browse Source
This commit is contained in:
Mark Adler
2011-09-09 23:27:08 -07:00
parent dc5a43ebfa
commit 7df877eccd
28 changed files with 745 additions and 553 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
gzread.c
View File

@@ -92,15 +92,16 @@ local int gz_next4(state, ret)
/* Look for gzip header, set up for inflate or copy. state->have must be zero.
If this is the first time in, allocate required memory. state->how will be
left unchanged if there is no more input data available, will be set to 1 if
there is no gzip header and direct copying will be performed, or it will be
set to 2 for decompression, and the gzip header will be skipped so that the
next available input data is the raw deflate stream. If direct copying,
then leftover input data from the input buffer will be copied to the output
buffer. In that case, all further file reads will be directly to either the
output buffer or a user buffer. If decompressing, the inflate state and the
check value will be initialized. gz_head() will return 0 on success or -1
on failure. Failures may include read errors or gzip header errors. */
left unchanged if there is no more input data available, will be set to COPY
if there is no gzip header and direct copying will be performed, or it will
be set to GZIP for decompression, and the gzip header will be skipped so
that the next available input data is the raw deflate stream. If direct
copying, then leftover input data from the input buffer will be copied to
the output buffer. In that case, all further file reads will be directly to
either the output buffer or a user buffer. If decompressing, the inflate
state and the check value will be initialized. gz_head() will return 0 on
success or -1 on failure. Failures may include read errors or gzip header
errors. */
local int gz_head(state)
gz_statep state;
{
@@ -196,7 +197,8 @@ local int gz_head(state)
/* set up for decompression */
inflateReset(strm);
strm->adler = crc32(0L, Z_NULL, 0);
state->how = 2;
state->how = GZIP;
state->direct = 0;
return 0;
}
else {
@@ -216,7 +218,8 @@ local int gz_head(state)
state->have += strm->avail_in;
strm->avail_in = 0;
}
state->how = 1;
state->how = COPY;
state->direct = 1;
return 0;
}
@@ -224,7 +227,7 @@ local int gz_head(state)
If the end of the compressed data is reached, then verify the gzip trailer
check value and length (modulo 2^32). state->have and state->next are set
to point to the just decompressed data, and the crc is updated. If the
trailer is verified, state->how is reset to zero to look for the next gzip
trailer is verified, state->how is reset to LOOK to look for the next gzip
stream or raw data, once state->have is depleted. Returns 0 on success, -1
on failure. Failures may include invalid compressed data or a failed gzip
trailer verification. */
@@ -284,7 +287,8 @@ local int gz_decomp(state)
gz_error(state, Z_DATA_ERROR, "incorrect length check");
return -1;
}
state->how = 0; /* ready for next stream, once have is 0 */
state->how = LOOK; /* ready for next stream, once have is 0 (leave
state->direct unchanged to remember how) */
}
/* good decompression */
@@ -293,28 +297,28 @@ local int gz_decomp(state)
/* Make data and put in the output buffer. Assumes that state->have == 0.
Data is either copied from the input file or decompressed from the input
file depending on state->how. If state->how is zero, then a gzip header is
file depending on state->how. If state->how is LOOK, then a gzip header is
looked for (and skipped if found) to determine wither to copy or decompress.
Returns -1 on error, otherwise 0. gz_make() will leave state->have non-zero
unless the end of the input file has been reached and all data has been
processed. */
Returns -1 on error, otherwise 0. gz_make() will leave state->have as COPY
or GZIP unless the end of the input file has been reached and all data has
been processed. */
local int gz_make(state)
gz_statep state;
{
z_streamp strm = &(state->strm);
if (state->how == 0) { /* look for gzip header */
if (state->how == LOOK) { /* look for gzip header */
if (gz_head(state) == -1)
return -1;
if (state->have) /* got some data from gz_head() */
return 0;
}
if (state->how == 1) { /* straight copy */
if (state->how == COPY) { /* straight copy */
if (gz_load(state, state->out, state->size << 1, &(state->have)) == -1)
return -1;
state->next = state->out;
}
else if (state->how == 2) { /* decompress */
else if (state->how == GZIP) { /* decompress */
strm->avail_out = state->size << 1;
strm->next_out = state->out;
if (gz_decomp(state) == -1)
@@ -409,7 +413,7 @@ int ZEXPORT gzread(file, buf, len)
/* need output data -- for small len or new stream load up our output
buffer */
else if (state->how == 0 || len < (state->size << 1)) {
else if (state->how == LOOK || len < (state->size << 1)) {
/* get more output, looking for header if required */
if (gz_make(state) == -1)
return -1;
@@ -419,13 +423,13 @@ int ZEXPORT gzread(file, buf, len)
}
/* large len -- read directly into user buffer */
else if (state->how == 1) { /* read directly */
else if (state->how == COPY) { /* read directly */
if (gz_load(state, buf, len, &n) == -1)
return -1;
}
/* large len -- decompress directly into user buffer */
else { /* state->how == 2 */
else { /* state->how == GZIP */
strm->avail_out = len;
strm->next_out = buf;
if (gz_decomp(state) == -1)
@@ -614,14 +618,20 @@ int ZEXPORT gzdirect(file)
if (state->mode != GZ_READ)
return 0;
/* return true if reading without decompression */
return state->how == 1;
/* if the state is not known, but we can find out, then do so (this is
mainly for right after a gzopen() or gzdopen()) */
if (state->how == LOOK && state->have == 0)
(void)gz_head(state);
/* return 1 if reading direct, 0 if decompressing a gzip stream */
return state->direct;
}
/* -- see zlib.h -- */
int ZEXPORT gzclose_r(file)
gzFile file;
{
int ret;
gz_statep state;
/* get internal structure */
@@ -640,9 +650,9 @@ int ZEXPORT gzclose_r(file)
free(state->in);
}
gz_error(state, Z_OK, NULL);
close(state->fd);
ret = close(state->fd);
free(state);
return Z_OK;
return ret ? Z_ERRNO : Z_OK;
}
#endif /* !OLD_GZIO */