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-rw-r--r--zlib/gzread.c602
1 files changed, 602 insertions, 0 deletions
diff --git a/zlib/gzread.c b/zlib/gzread.c
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--- /dev/null
+++ b/zlib/gzread.c
@@ -0,0 +1,602 @@
+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004-2017 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "gzguts.h"
+
+/* 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(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(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(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;
+ 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(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(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(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(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 = (unsigned)-1;
+ if (n > len)
+ n = (unsigned)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(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 = (unsigned)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(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(gzFile file) {
+ 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() */
+ return (int)gz_read(state, buf, 1) < 1 ? -1 : buf[0];
+}
+
+int ZEXPORT gzgetc_(gzFile file) {
+ return gzgetc(file);
+}
+
+/* -- see zlib.h -- */
+int ZEXPORT gzungetc(int c, gzFile file) {
+ gz_statep state;
+
+ /* get internal structure */
+ if (file == NULL)
+ return -1;
+ state = (gz_statep)file;
+
+ /* in case this was just opened, set up the input buffer */
+ if (state->mode == GZ_READ && state->how == LOOK && state->x.have == 0)
+ (void)gz_look(state);
+
+ /* 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(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(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(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;
+}
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