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Diffstat (limited to 'zlib-1.2.5/gzread.c')
| -rw-r--r-- | zlib-1.2.5/gzread.c | 653 |
1 files changed, 0 insertions, 653 deletions
diff --git a/zlib-1.2.5/gzread.c b/zlib-1.2.5/gzread.c deleted file mode 100644 index 548201ab0..000000000 --- a/zlib-1.2.5/gzread.c +++ /dev/null @@ -1,653 +0,0 @@ -/* gzread.c -- zlib functions for reading gzip files - * Copyright (C) 2004, 2005, 2010 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_next4 OF((gz_statep, unsigned long *)); -local int gz_head OF((gz_statep)); -local int gz_decomp OF((gz_statep)); -local int gz_make OF((gz_statep)); -local int gz_skip OF((gz_statep, z_off64_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; - - *have = 0; - do { - ret = read(state->fd, buf + *have, len - *have); - if (ret <= 0) - break; - *have += 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. - gz_avail() assumes that strm->avail_in == 0. */ -local int gz_avail(state) - gz_statep state; -{ - z_streamp strm = &(state->strm); - - if (state->err != Z_OK) - return -1; - if (state->eof == 0) { - if (gz_load(state, state->in, state->size, - (unsigned *)&(strm->avail_in)) == -1) - return -1; - strm->next_in = state->in; - } - return 0; -} - -/* Get next byte from input, or -1 if end or error. */ -#define NEXT() ((strm->avail_in == 0 && gz_avail(state) == -1) ? -1 : \ - (strm->avail_in == 0 ? -1 : \ - (strm->avail_in--, *(strm->next_in)++))) - -/* Get a four-byte little-endian integer and return 0 on success and the value - in *ret. Otherwise -1 is returned and *ret is not modified. */ -local int gz_next4(state, ret) - gz_statep state; - unsigned long *ret; -{ - int ch; - unsigned long val; - z_streamp strm = &(state->strm); - - val = NEXT(); - val += (unsigned)NEXT() << 8; - val += (unsigned long)NEXT() << 16; - ch = NEXT(); - if (ch == -1) - return -1; - val += (unsigned long)ch << 24; - *ret = val; - return 0; -} - -/* 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 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; -{ - z_streamp strm = &(state->strm); - int flags; - unsigned len; - - /* allocate read buffers and inflate memory */ - if (state->size == 0) { - /* allocate buffers */ - state->in = malloc(state->want); - state->out = malloc(state->want << 1); - if (state->in == NULL || state->out == NULL) { - if (state->out != NULL) - free(state->out); - if (state->in != NULL) - 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) != Z_OK) { /* raw inflate */ - free(state->out); - free(state->in); - state->size = 0; - gz_error(state, Z_MEM_ERROR, "out of memory"); - return -1; - } - } - - /* get some data in the input buffer */ - if (strm->avail_in == 0) { - if (gz_avail(state) == -1) - return -1; - if (strm->avail_in == 0) - return 0; - } - - /* look for the gzip magic header bytes 31 and 139 */ - if (strm->next_in[0] == 31) { - strm->avail_in--; - strm->next_in++; - if (strm->avail_in == 0 && gz_avail(state) == -1) - return -1; - if (strm->avail_in && strm->next_in[0] == 139) { - /* we have a gzip header, woo hoo! */ - strm->avail_in--; - strm->next_in++; - - /* skip rest of header */ - if (NEXT() != 8) { /* compression method */ - gz_error(state, Z_DATA_ERROR, "unknown compression method"); - return -1; - } - flags = NEXT(); - if (flags & 0xe0) { /* reserved flag bits */ - gz_error(state, Z_DATA_ERROR, "unknown header flags set"); - return -1; - } - NEXT(); /* modification time */ - NEXT(); - NEXT(); - NEXT(); - NEXT(); /* extra flags */ - NEXT(); /* operating system */ - if (flags & 4) { /* extra field */ - len = (unsigned)NEXT(); - len += (unsigned)NEXT() << 8; - while (len--) - if (NEXT() < 0) - break; - } - if (flags & 8) /* file name */ - while (NEXT() > 0) - ; - if (flags & 16) /* comment */ - while (NEXT() > 0) - ; - if (flags & 2) { /* header crc */ - NEXT(); - NEXT(); - } - /* an unexpected end of file is not checked for here -- it will be - noticed on the first request for uncompressed data */ - - /* set up for decompression */ - inflateReset(strm); - strm->adler = crc32(0L, Z_NULL, 0); - state->how = GZIP; - state->direct = 0; - return 0; - } - else { - /* not a gzip file -- save first byte (31) and fall to raw i/o */ - state->out[0] = 31; - state->have = 1; - } - } - - /* doing raw i/o, save start of raw data for seeking, 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->raw = state->pos; - state->next = state->out; - if (strm->avail_in) { - memcpy(state->next + state->have, strm->next_in, strm->avail_in); - state->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. - 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 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. */ -local int gz_decomp(state) - gz_statep state; -{ - int ret; - unsigned had; - unsigned long crc, len; - 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_DATA_ERROR, "unexpected end of file"); - return -1; - } - - /* 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 and crc check value */ - state->have = had - strm->avail_out; - state->next = strm->next_out - state->have; - strm->adler = crc32(strm->adler, state->next, state->have); - - /* check gzip trailer if at end of deflate stream */ - if (ret == Z_STREAM_END) { - if (gz_next4(state, &crc) == -1 || gz_next4(state, &len) == -1) { - gz_error(state, Z_DATA_ERROR, "unexpected end of file"); - return -1; - } - if (crc != strm->adler) { - gz_error(state, Z_DATA_ERROR, "incorrect data check"); - return -1; - } - if (len != (strm->total_out & 0xffffffffL)) { - gz_error(state, Z_DATA_ERROR, "incorrect length check"); - return -1; - } - state->how = LOOK; /* ready for next stream, once have is 0 (leave - state->direct unchanged to remember how) */ - } - - /* good decompression */ - return 0; -} - -/* 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 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 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 == 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 == 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 == GZIP) { /* decompress */ - strm->avail_out = state->size << 1; - strm->next_out = state->out; - if (gz_decomp(state) == -1) - return -1; - } - 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->have) { - n = GT_OFF(state->have) || (z_off64_t)state->have > len ? - (unsigned)len : state->have; - state->have -= n; - state->next += n; - state->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_make(state) == -1) - return -1; - } - return 0; -} - -/* -- see zlib.h -- */ -int ZEXPORT gzread(file, buf, len) - gzFile file; - voidp buf; - unsigned len; -{ - unsigned got, n; - gz_statep state; - z_streamp strm; - - /* get internal structure */ - if (file == NULL) - return -1; - state = (gz_statep)file; - strm = &(state->strm); - - /* check that we're reading and that there's no error */ - if (state->mode != GZ_READ || state->err != Z_OK) - return -1; - - /* since an int is returned, make sure len fits in one, otherwise return - with an error (this avoids the flaw in the interface) */ - if ((int)len < 0) { - gz_error(state, Z_BUF_ERROR, "requested length does not fit in int"); - return -1; - } - - /* 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 -1; - } - - /* get len bytes to buf, or less than len if at the end */ - got = 0; - do { - /* first just try copying data from the output buffer */ - if (state->have) { - n = state->have > len ? len : state->have; - memcpy(buf, state->next, n); - state->next += n; - state->have -= n; - } - - /* output buffer empty -- return if we're at the end of the input */ - else if (state->eof && strm->avail_in == 0) - break; - - /* need output data -- for small len or new stream load up our output - buffer */ - else if (state->how == LOOK || len < (state->size << 1)) { - /* get more output, looking for header if required */ - if (gz_make(state) == -1) - return -1; - continue; /* no progress yet -- go back to memcpy() 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, buf, len, &n) == -1) - return -1; - } - - /* large len -- decompress directly into user buffer */ - else { /* state->how == GZIP */ - strm->avail_out = len; - strm->next_out = buf; - if (gz_decomp(state) == -1) - return -1; - n = state->have; - state->have = 0; - } - - /* update progress */ - len -= n; - buf = (char *)buf + n; - got += n; - state->pos += n; - } while (len); - - /* return number of bytes read into user buffer (will fit in int) */ - return (int)got; -} - -/* -- see zlib.h -- */ -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 error */ - if (state->mode != GZ_READ || state->err != Z_OK) - return -1; - - /* try output buffer (no need to check for skip request) */ - if (state->have) { - state->have--; - state->pos++; - return *(state->next)++; - } - - /* nothing there -- try gzread() */ - ret = gzread(file, buf, 1); - return ret < 1 ? -1 : buf[0]; -} - -/* -- 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 error */ - if (state->mode != GZ_READ || state->err != Z_OK) - 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->have == 0) { - state->have = 1; - state->next = state->out + (state->size << 1) - 1; - state->next[0] = c; - state->pos--; - return c; - } - - /* if no room, give up (must have already done a gzungetc()) */ - if (state->have == (state->size << 1)) { - gz_error(state, Z_BUF_ERROR, "out of room to push characters"); - return -1; - } - - /* slide output data if needed and insert byte before existing data */ - if (state->next == state->out) { - unsigned char *src = state->out + state->have; - unsigned char *dest = state->out + (state->size << 1); - while (src > state->out) - *--dest = *--src; - state->next = dest; - } - state->have++; - state->next--; - state->next[0] = c; - state->pos--; - 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 error */ - if (state->mode != GZ_READ || state->err != Z_OK) - 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->have == 0) { - if (gz_make(state) == -1) - return NULL; /* error */ - if (state->have == 0) { /* end of file */ - if (buf == str) /* got bupkus */ - return NULL; - break; /* got something -- return it */ - } - } - - /* look for end-of-line in current output buffer */ - n = state->have > left ? left : state->have; - eol = memchr(state->next, '\n', n); - if (eol != NULL) - n = (unsigned)(eol - state->next) + 1; - - /* copy through end-of-line, or remainder if not found */ - memcpy(buf, state->next, n); - state->have -= n; - state->next += n; - state->pos += n; - left -= n; - buf += n; - } while (left && eol == NULL); - - /* found end-of-line or out of space -- terminate string and return it */ - 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; - - /* check that we're reading */ - if (state->mode != GZ_READ) - return 0; - - /* 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 */ - 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); - } - gz_error(state, Z_OK, NULL); - free(state->path); - ret = close(state->fd); - free(state); - return ret ? Z_ERRNO : Z_OK; -} |