diff options
author | tamasmeszaros <meszaros.q@gmail.com> | 2019-03-18 18:00:21 +0300 |
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committer | tamasmeszaros <meszaros.q@gmail.com> | 2019-03-18 18:00:21 +0300 |
commit | 865120d805b94673d05675d7ce164327520d9439 (patch) | |
tree | b66fca83faa6fe796e539f1f1dbcbe1ef0025949 /src/png/zlib/gzread.c | |
parent | cd2cccec5f2ff20fa06b8f66472656671032c616 (diff) |
Exporting png images with minz deflate implementation.
Getting rid of zlib and libpng dependencies
Diffstat (limited to 'src/png/zlib/gzread.c')
-rw-r--r-- | src/png/zlib/gzread.c | 654 |
1 files changed, 0 insertions, 654 deletions
diff --git a/src/png/zlib/gzread.c b/src/png/zlib/gzread.c deleted file mode 100644 index 956b91ea7..000000000 --- a/src/png/zlib/gzread.c +++ /dev/null @@ -1,654 +0,0 @@ -/* gzread.c -- zlib functions for reading gzip files - * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013, 2016 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - */ - -#include "gzguts.h" - -/* Local functions */ -local int gz_load OF((gz_statep, unsigned char *, unsigned, unsigned *)); -local int gz_avail OF((gz_statep)); -local int gz_look OF((gz_statep)); -local int gz_decomp OF((gz_statep)); -local int gz_fetch OF((gz_statep)); -local int gz_skip OF((gz_statep, z_off64_t)); -local z_size_t gz_read OF((gz_statep, voidp, z_size_t)); - -/* Use read() to load a buffer -- return -1 on error, otherwise 0. Read from - state->fd, and update state->eof, state->err, and state->msg as appropriate. - This function needs to loop on read(), since read() is not guaranteed to - read the number of bytes requested, depending on the type of descriptor. */ -local int gz_load(state, buf, len, have) - gz_statep state; - unsigned char *buf; - unsigned len; - unsigned *have; -{ - int ret; - unsigned get, max = ((unsigned)-1 >> 2) + 1; - - *have = 0; - do { - get = len - *have; - if (get > max) - get = max; - ret = read(state->fd, buf + *have, get); - if (ret <= 0) - break; - *have += (unsigned)ret; - } while (*have < len); - if (ret < 0) { - gz_error(state, Z_ERRNO, zstrerror()); - return -1; - } - if (ret == 0) - state->eof = 1; - return 0; -} - -/* Load up input buffer and set eof flag if last data loaded -- return -1 on - error, 0 otherwise. Note that the eof flag is set when the end of the input - file is reached, even though there may be unused data in the buffer. Once - that data has been used, no more attempts will be made to read the file. - If strm->avail_in != 0, then the current data is moved to the beginning of - the input buffer, and then the remainder of the buffer is loaded with the - available data from the input file. */ -local int gz_avail(state) - gz_statep state; -{ - unsigned got; - z_streamp strm = &(state->strm); - - if (state->err != Z_OK && state->err != Z_BUF_ERROR) - return -1; - if (state->eof == 0) { - if (strm->avail_in) { /* copy what's there to the start */ - unsigned char *p = state->in; - unsigned const char *q = strm->next_in; - unsigned n = strm->avail_in; - do { - *p++ = *q++; - } while (--n); - } - if (gz_load(state, state->in + strm->avail_in, - state->size - strm->avail_in, &got) == -1) - return -1; - strm->avail_in += got; - strm->next_in = state->in; - } - return 0; -} - -/* Look for gzip header, set up for inflate or copy. state->x.have must be 0. - 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 COPY - if there is no gzip header and direct copying will be performed, or it will - be set to GZIP for decompression. 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 will be initialized. - gz_look() will return 0 on success or -1 on failure. */ -local int gz_look(state) - gz_statep state; -{ - z_streamp strm = &(state->strm); - - /* allocate read buffers and inflate memory */ - if (state->size == 0) { - /* allocate buffers */ - state->in = (unsigned char *)malloc(state->want); - state->out = (unsigned char *)malloc(state->want << 1); - if (state->in == NULL || state->out == NULL) { - free(state->out); - free(state->in); - gz_error(state, Z_MEM_ERROR, "out of memory"); - return -1; - } - state->size = state->want; - - /* allocate inflate memory */ - state->strm.zalloc = Z_NULL; - state->strm.zfree = Z_NULL; - state->strm.opaque = Z_NULL; - state->strm.avail_in = 0; - state->strm.next_in = Z_NULL; - if (inflateInit2(&(state->strm), 15 + 16) != Z_OK) { /* gunzip */ - free(state->out); - free(state->in); - state->size = 0; - gz_error(state, Z_MEM_ERROR, "out of memory"); - return -1; - } - } - - /* get at least the magic bytes in the input buffer */ - if (strm->avail_in < 2) { - if (gz_avail(state) == -1) - return -1; - if (strm->avail_in == 0) - return 0; - } - - /* look for gzip magic bytes -- if there, do gzip decoding (note: there is - a logical dilemma here when considering the case of a partially written - gzip file, to wit, if a single 31 byte is written, then we cannot tell - whether this is a single-byte file, or just a partially written gzip - file -- for here we assume that if a gzip file is being written, then - the header will be written in a single operation, so that reading a - single byte is sufficient indication that it is not a gzip file) */ - if (strm->avail_in > 1 && - strm->next_in[0] == 31 && strm->next_in[1] == 139) { - inflateReset(strm); - state->how = GZIP; - state->direct = 0; - return 0; - } - - /* no gzip header -- if we were decoding gzip before, then this is trailing - garbage. Ignore the trailing garbage and finish. */ - if (state->direct == 0) { - strm->avail_in = 0; - state->eof = 1; - state->x.have = 0; - return 0; - } - - /* doing raw i/o, copy any leftover input to output -- this assumes that - the output buffer is larger than the input buffer, which also assures - space for gzungetc() */ - state->x.next = state->out; - if (strm->avail_in) { - memcpy(state->x.next, strm->next_in, strm->avail_in); - state->x.have = strm->avail_in; - strm->avail_in = 0; - } - state->how = COPY; - state->direct = 1; - return 0; -} - -/* Decompress from input to the provided next_out and avail_out in the state. - On return, state->x.have and state->x.next point to the just decompressed - data. If the gzip stream completes, state->how is reset to LOOK to look for - the next gzip stream or raw data, once state->x.have is depleted. Returns 0 - on success, -1 on failure. */ -local int gz_decomp(state) - gz_statep state; -{ - int ret = Z_OK; - unsigned had; - z_streamp strm = &(state->strm); - - /* fill output buffer up to end of deflate stream */ - had = strm->avail_out; - do { - /* get more input for inflate() */ - if (strm->avail_in == 0 && gz_avail(state) == -1) - return -1; - if (strm->avail_in == 0) { - gz_error(state, Z_BUF_ERROR, "unexpected end of file"); - break; - } - - /* decompress and handle errors */ - ret = inflate(strm, Z_NO_FLUSH); - if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) { - gz_error(state, Z_STREAM_ERROR, - "internal error: inflate stream corrupt"); - return -1; - } - if (ret == Z_MEM_ERROR) { - gz_error(state, Z_MEM_ERROR, "out of memory"); - return -1; - } - if (ret == Z_DATA_ERROR) { /* deflate stream invalid */ - gz_error(state, Z_DATA_ERROR, - strm->msg == NULL ? "compressed data error" : strm->msg); - return -1; - } - } while (strm->avail_out && ret != Z_STREAM_END); - - /* update available output */ - state->x.have = had - strm->avail_out; - state->x.next = strm->next_out - state->x.have; - - /* if the gzip stream completed successfully, look for another */ - if (ret == Z_STREAM_END) - state->how = LOOK; - - /* good decompression */ - return 0; -} - -/* Fetch data and put it in the output buffer. Assumes state->x.have is 0. - Data is either copied from the input file or decompressed from the input - file depending on state->how. If state->how is LOOK, then a gzip header is - looked for to determine whether to copy or decompress. Returns -1 on error, - otherwise 0. gz_fetch() will leave state->how as COPY or GZIP unless the - end of the input file has been reached and all data has been processed. */ -local int gz_fetch(state) - gz_statep state; -{ - z_streamp strm = &(state->strm); - - do { - switch(state->how) { - case LOOK: /* -> LOOK, COPY (only if never GZIP), or GZIP */ - if (gz_look(state) == -1) - return -1; - if (state->how == LOOK) - return 0; - break; - case COPY: /* -> COPY */ - if (gz_load(state, state->out, state->size << 1, &(state->x.have)) - == -1) - return -1; - state->x.next = state->out; - return 0; - case GZIP: /* -> GZIP or LOOK (if end of gzip stream) */ - strm->avail_out = state->size << 1; - strm->next_out = state->out; - if (gz_decomp(state) == -1) - return -1; - } - } while (state->x.have == 0 && (!state->eof || strm->avail_in)); - return 0; -} - -/* Skip len uncompressed bytes of output. Return -1 on error, 0 on success. */ -local int gz_skip(state, len) - gz_statep state; - z_off64_t len; -{ - unsigned n; - - /* skip over len bytes or reach end-of-file, whichever comes first */ - while (len) - /* skip over whatever is in output buffer */ - if (state->x.have) { - n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > len ? - (unsigned)len : state->x.have; - state->x.have -= n; - state->x.next += n; - state->x.pos += n; - len -= n; - } - - /* output buffer empty -- return if we're at the end of the input */ - else if (state->eof && state->strm.avail_in == 0) - break; - - /* need more data to skip -- load up output buffer */ - else { - /* get more output, looking for header if required */ - if (gz_fetch(state) == -1) - return -1; - } - return 0; -} - -/* Read len bytes into buf from file, or less than len up to the end of the - input. Return the number of bytes read. If zero is returned, either the - end of file was reached, or there was an error. state->err must be - consulted in that case to determine which. */ -local z_size_t gz_read(state, buf, len) - gz_statep state; - voidp buf; - z_size_t len; -{ - z_size_t got; - unsigned n; - - /* if len is zero, avoid unnecessary operations */ - if (len == 0) - return 0; - - /* process a skip request */ - if (state->seek) { - state->seek = 0; - if (gz_skip(state, state->skip) == -1) - return 0; - } - - /* get len bytes to buf, or less than len if at the end */ - got = 0; - do { - /* set n to the maximum amount of len that fits in an unsigned int */ - n = -1; - if (n > len) - n = len; - - /* first just try copying data from the output buffer */ - if (state->x.have) { - if (state->x.have < n) - n = state->x.have; - memcpy(buf, state->x.next, n); - state->x.next += n; - state->x.have -= n; - } - - /* output buffer empty -- return if we're at the end of the input */ - else if (state->eof && state->strm.avail_in == 0) { - state->past = 1; /* tried to read past end */ - break; - } - - /* need output data -- for small len or new stream load up our output - buffer */ - else if (state->how == LOOK || n < (state->size << 1)) { - /* get more output, looking for header if required */ - if (gz_fetch(state) == -1) - return 0; - continue; /* no progress yet -- go back to copy above */ - /* the copy above assures that we will leave with space in the - output buffer, allowing at least one gzungetc() to succeed */ - } - - /* large len -- read directly into user buffer */ - else if (state->how == COPY) { /* read directly */ - if (gz_load(state, (unsigned char *)buf, n, &n) == -1) - return 0; - } - - /* large len -- decompress directly into user buffer */ - else { /* state->how == GZIP */ - state->strm.avail_out = n; - state->strm.next_out = (unsigned char *)buf; - if (gz_decomp(state) == -1) - return 0; - n = state->x.have; - state->x.have = 0; - } - - /* update progress */ - len -= n; - buf = (char *)buf + n; - got += n; - state->x.pos += n; - } while (len); - - /* return number of bytes read into user buffer */ - return got; -} - -/* -- see zlib.h -- */ -int ZEXPORT gzread(file, buf, len) - gzFile file; - voidp buf; - unsigned len; -{ - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return -1; - state = (gz_statep)file; - - /* check that we're reading and that there's no (serious) error */ - if (state->mode != GZ_READ || - (state->err != Z_OK && state->err != Z_BUF_ERROR)) - return -1; - - /* since an int is returned, make sure len fits in one, otherwise return - with an error (this avoids a flaw in the interface) */ - if ((int)len < 0) { - gz_error(state, Z_STREAM_ERROR, "request does not fit in an int"); - return -1; - } - - /* read len or fewer bytes to buf */ - len = gz_read(state, buf, len); - - /* check for an error */ - if (len == 0 && state->err != Z_OK && state->err != Z_BUF_ERROR) - return -1; - - /* return the number of bytes read (this is assured to fit in an int) */ - return (int)len; -} - -/* -- see zlib.h -- */ -z_size_t ZEXPORT gzfread(buf, size, nitems, file) - voidp buf; - z_size_t size; - z_size_t nitems; - gzFile file; -{ - z_size_t len; - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return 0; - state = (gz_statep)file; - - /* check that we're reading and that there's no (serious) error */ - if (state->mode != GZ_READ || - (state->err != Z_OK && state->err != Z_BUF_ERROR)) - return 0; - - /* compute bytes to read -- error on overflow */ - len = nitems * size; - if (size && len / size != nitems) { - gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t"); - return 0; - } - - /* read len or fewer bytes to buf, return the number of full items read */ - return len ? gz_read(state, buf, len) / size : 0; -} - -/* -- see zlib.h -- */ -#ifdef Z_PREFIX_SET -# undef z_gzgetc -#else -# undef gzgetc -#endif -int ZEXPORT gzgetc(file) - gzFile file; -{ - int ret; - unsigned char buf[1]; - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return -1; - state = (gz_statep)file; - - /* check that we're reading and that there's no (serious) error */ - if (state->mode != GZ_READ || - (state->err != Z_OK && state->err != Z_BUF_ERROR)) - return -1; - - /* try output buffer (no need to check for skip request) */ - if (state->x.have) { - state->x.have--; - state->x.pos++; - return *(state->x.next)++; - } - - /* nothing there -- try gz_read() */ - ret = gz_read(state, buf, 1); - return ret < 1 ? -1 : buf[0]; -} - -int ZEXPORT gzgetc_(file) -gzFile file; -{ - return gzgetc(file); -} - -/* -- see zlib.h -- */ -int ZEXPORT gzungetc(c, file) - int c; - gzFile file; -{ - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return -1; - state = (gz_statep)file; - - /* check that we're reading and that there's no (serious) error */ - if (state->mode != GZ_READ || - (state->err != Z_OK && state->err != Z_BUF_ERROR)) - return -1; - - /* process a skip request */ - if (state->seek) { - state->seek = 0; - if (gz_skip(state, state->skip) == -1) - return -1; - } - - /* can't push EOF */ - if (c < 0) - return -1; - - /* if output buffer empty, put byte at end (allows more pushing) */ - if (state->x.have == 0) { - state->x.have = 1; - state->x.next = state->out + (state->size << 1) - 1; - state->x.next[0] = (unsigned char)c; - state->x.pos--; - state->past = 0; - return c; - } - - /* if no room, give up (must have already done a gzungetc()) */ - if (state->x.have == (state->size << 1)) { - gz_error(state, Z_DATA_ERROR, "out of room to push characters"); - return -1; - } - - /* slide output data if needed and insert byte before existing data */ - if (state->x.next == state->out) { - unsigned char *src = state->out + state->x.have; - unsigned char *dest = state->out + (state->size << 1); - while (src > state->out) - *--dest = *--src; - state->x.next = dest; - } - state->x.have++; - state->x.next--; - state->x.next[0] = (unsigned char)c; - state->x.pos--; - state->past = 0; - return c; -} - -/* -- see zlib.h -- */ -char * ZEXPORT gzgets(file, buf, len) - gzFile file; - char *buf; - int len; -{ - unsigned left, n; - char *str; - unsigned char *eol; - gz_statep state; - - /* check parameters and get internal structure */ - if (file == NULL || buf == NULL || len < 1) - return NULL; - state = (gz_statep)file; - - /* check that we're reading and that there's no (serious) error */ - if (state->mode != GZ_READ || - (state->err != Z_OK && state->err != Z_BUF_ERROR)) - return NULL; - - /* process a skip request */ - if (state->seek) { - state->seek = 0; - if (gz_skip(state, state->skip) == -1) - return NULL; - } - - /* copy output bytes up to new line or len - 1, whichever comes first -- - append a terminating zero to the string (we don't check for a zero in - the contents, let the user worry about that) */ - str = buf; - left = (unsigned)len - 1; - if (left) do { - /* assure that something is in the output buffer */ - if (state->x.have == 0 && gz_fetch(state) == -1) - return NULL; /* error */ - if (state->x.have == 0) { /* end of file */ - state->past = 1; /* read past end */ - break; /* return what we have */ - } - - /* look for end-of-line in current output buffer */ - n = state->x.have > left ? left : state->x.have; - eol = (unsigned char *)memchr(state->x.next, '\n', n); - if (eol != NULL) - n = (unsigned)(eol - state->x.next) + 1; - - /* copy through end-of-line, or remainder if not found */ - memcpy(buf, state->x.next, n); - state->x.have -= n; - state->x.next += n; - state->x.pos += n; - left -= n; - buf += n; - } while (left && eol == NULL); - - /* return terminated string, or if nothing, end of file */ - if (buf == str) - return NULL; - buf[0] = 0; - return str; -} - -/* -- see zlib.h -- */ -int ZEXPORT gzdirect(file) - gzFile file; -{ - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return 0; - state = (gz_statep)file; - - /* 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->mode == GZ_READ && state->how == LOOK && state->x.have == 0) - (void)gz_look(state); - - /* return 1 if transparent, 0 if processing a gzip stream */ - return state->direct; -} - -/* -- see zlib.h -- */ -int ZEXPORT gzclose_r(file) - gzFile file; -{ - int ret, err; - gz_statep state; - - /* get internal structure */ - if (file == NULL) - return Z_STREAM_ERROR; - state = (gz_statep)file; - - /* check that we're reading */ - if (state->mode != GZ_READ) - return Z_STREAM_ERROR; - - /* free memory and close file */ - if (state->size) { - inflateEnd(&(state->strm)); - free(state->out); - free(state->in); - } - err = state->err == Z_BUF_ERROR ? Z_BUF_ERROR : Z_OK; - gz_error(state, Z_OK, NULL); - free(state->path); - ret = close(state->fd); - free(state); - return ret ? Z_ERRNO : err; -} |