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-rw-r--r--archived/ptlibzippy/gzread.c669
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diff --git a/archived/ptlibzippy/gzread.c b/archived/ptlibzippy/gzread.c
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index 0000000000..b35d4e2718
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+++ b/archived/ptlibzippy/gzread.c
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+/* gzread.c -- zlib functions for reading gzip files
+ * Copyright (C) 2004-2026 Mark Adler
+ * Copyright (C) 2026 Project Tick
+ * For conditions of distribution and use, see copyright notice in ptlibzippy.h
+ */
+
+#include "ptzippyguts.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. It
+ also needs to loop to manage the fact that read() returns an int. If the
+ descriptor is non-blocking and read() returns with no data in order to avoid
+ blocking, then gz_load() will return 0 if some data has been read, or -1 if
+ no data has been read. Either way, state->again is set true to indicate a
+ non-blocking event. If errno is non-zero on return, then there was an error
+ signaled from read(). *have is set to the number of bytes read. */
+local int gz_load(gz_statep state, unsigned char *buf, unsigned len,
+ unsigned *have) {
+ int ret;
+ unsigned get, max = ((unsigned)-1 >> 2) + 1;
+
+ state->again = 0;
+ errno = 0;
+ *have = 0;
+ do {
+ get = len - *have;
+ if (get > max)
+ get = max;
+ ret = (int)read(state->fd, buf + *have, get);
+ if (ret <= 0)
+ break;
+ *have += (unsigned)ret;
+ } while (*have < len);
+ if (ret < 0) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK) {
+ state->again = 1;
+ if (*have != 0)
+ return 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;
+
+ if (q != p) {
+ 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;
+ }
+ }
+
+ /* if transparent reading is disabled, which would only be at the start, or
+ if we're looking for a gzip member after the first one, which is not at
+ the start, then proceed directly to look for a gzip member next */
+ if (state->direct == -1 || state->junk == 0) {
+ inflateReset(strm);
+ state->how = GZIP;
+ state->junk = state->junk != -1;
+ state->direct = 0;
+ return 0;
+ }
+
+ /* otherwise we're at the start with auto-detect -- we check to see if the
+ first four bytes could be gzip header in order to decide whether or not
+ this will be a transparent read */
+
+ /* load any header bytes into the input buffer -- if the input is empty,
+ then it's not an error as this is a transparent read of zero bytes */
+ if (gz_avail(state) == -1)
+ return -1;
+ if (strm->avail_in == 0 || (state->again && strm->avail_in < 4))
+ /* if non-blocking input stalled before getting four bytes, then
+ return and wait until a later call has accumulated enough */
+ return 0;
+
+ /* see if this is (likely) gzip input -- if the first four bytes are
+ consistent with a gzip header, then go look for the first gzip member,
+ otherwise proceed to copy the input transparently */
+ if (strm->avail_in > 3 &&
+ strm->next_in[0] == 31 && strm->next_in[1] == 139 &&
+ strm->next_in[2] == 8 && strm->next_in[3] < 32) {
+ inflateReset(strm);
+ state->how = GZIP;
+ state->junk = 1;
+ state->direct = 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;
+ 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. If EOF is reached when looking for more input to
+ complete the gzip member, then an unexpected end of file error is raised.
+ If there is no more input, but state->again is true, then EOF has not been
+ reached, and no error is raised. */
+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) {
+ ret = state->err;
+ break;
+ }
+ if (strm->avail_in == 0) {
+ if (!state->again)
+ gz_error(state, Z_BUF_ERROR, "unexpected end of file");
+ break;
+ }
+
+ /* decompress and handle errors */
+ ret = inflate(strm, Z_NO_FLUSH);
+ if (strm->avail_out < had)
+ /* any decompressed data marks this as a real gzip stream */
+ state->junk = 0;
+ if (ret == Z_STREAM_ERROR || ret == Z_NEED_DICT) {
+ gz_error(state, Z_STREAM_ERROR,
+ "internal error: inflate stream corrupt");
+ break;
+ }
+ if (ret == Z_MEM_ERROR) {
+ gz_error(state, Z_MEM_ERROR, "out of memory");
+ break;
+ }
+ if (ret == Z_DATA_ERROR) { /* deflate stream invalid */
+ if (state->junk == 1) { /* trailing garbage is ok */
+ strm->avail_in = 0;
+ state->eof = 1;
+ state->how = LOOK;
+ ret = Z_OK;
+ break;
+ }
+ gz_error(state, Z_DATA_ERROR,
+ strm->msg == NULL ? "compressed data error" : strm->msg);
+ break;
+ }
+ } 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->junk = 0;
+ state->how = LOOK;
+ return 0;
+ }
+
+ /* return decompression status */
+ return ret != Z_OK ? -1 : 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;
+ break;
+ default:
+ gz_error(state, Z_STREAM_ERROR, "state corrupt");
+ return -1;
+ }
+ } while (state->x.have == 0 && (!state->eof || strm->avail_in));
+ return 0;
+}
+
+/* Skip state->skip (> 0) uncompressed bytes of output. Return -1 on error, 0
+ on success. */
+local int gz_skip(gz_statep state) {
+ unsigned n;
+
+ /* skip over len bytes or reach end-of-file, whichever comes first */
+ do {
+ /* skip over whatever is in output buffer */
+ if (state->x.have) {
+ n = GT_OFF(state->x.have) ||
+ (z_off64_t)state->x.have > state->skip ?
+ (unsigned)state->skip : state->x.have;
+ state->x.have -= n;
+ state->x.next += n;
+ state->x.pos += n;
+ state->skip -= 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;
+ }
+ } while (state->skip);
+ 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. If there was an error, but some uncompressed
+ bytes were read before the error, then that count is returned. The error is
+ still recorded, and so is deferred until the next call. */
+local z_size_t gz_read(gz_statep state, voidp buf, z_size_t len) {
+ z_size_t got;
+ unsigned n;
+ int err;
+
+ /* if len is zero, avoid unnecessary operations */
+ if (len == 0)
+ return 0;
+
+ /* process a skip request */
+ if (state->skip && gz_skip(state) == -1)
+ return 0;
+
+ /* get len bytes to buf, or less than len if at the end */
+ got = 0;
+ err = 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;
+ if (state->err != Z_OK)
+ /* caught deferred error from gz_fetch() */
+ err = -1;
+ }
+
+ /* output buffer empty -- return if we're at the end of the input */
+ else if (state->eof && state->strm.avail_in == 0)
+ break;
+
+ /* need output data -- for small len or new stream load up our output
+ buffer, so that gzgetc() can be fast */
+ else if (state->how == LOOK || n < (state->size << 1)) {
+ /* get more output, looking for header if required */
+ if (gz_fetch(state) == -1 && state->x.have == 0)
+ /* if state->x.have != 0, error will be caught after copy */
+ err = -1;
+ 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 */
+ err = gz_load(state, (unsigned char *)buf, n, &n);
+
+ /* large len -- decompress directly into user buffer */
+ else { /* state->how == GZIP */
+ state->strm.avail_out = n;
+ state->strm.next_out = (unsigned char *)buf;
+ err = gz_decomp(state);
+ n = state->x.have;
+ state->x.have = 0;
+ }
+
+ /* update progress */
+ len -= n;
+ buf = (char *)buf + n;
+ got += n;
+ state->x.pos += n;
+ } while (len && !err);
+
+ /* note read past eof */
+ if (len && state->eof)
+ state->past = 1;
+
+ /* return number of bytes read into user buffer */
+ return got;
+}
+
+/* -- see ptlibzippy.h -- */
+int ZEXPORT gzread(gzFile file, voidp buf, unsigned len) {
+ gz_statep state;
+
+ /* get internal structure and check that it's for reading */
+ if (file == NULL)
+ return -1;
+ state = (gz_statep)file;
+ if (state->mode != GZ_READ)
+ return -1;
+
+ /* check that there was no (serious) error */
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)
+ return -1;
+ gz_error(state, Z_OK, NULL);
+
+ /* 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) {
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR)
+ return -1;
+ if (state->again) {
+ /* non-blocking input stalled after some input was read, but no
+ uncompressed bytes were produced -- let the application know
+ this isn't EOF */
+ gz_error(state, Z_ERRNO, zstrerror());
+ return -1;
+ }
+ }
+
+ /* return the number of bytes read */
+ return (int)len;
+}
+
+/* -- see ptlibzippy.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 and check that it's for reading */
+ if (file == NULL)
+ return 0;
+ state = (gz_statep)file;
+ if (state->mode != GZ_READ)
+ return 0;
+
+ /* check that there was no (serious) error */
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)
+ return 0;
+ gz_error(state, Z_OK, NULL);
+
+ /* 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 ptlibzippy.h -- */
+#ifdef PT_PREFIX_SET
+# undef pt_gzgetc
+#else
+# undef gzgetc
+#endif
+int ZEXPORT gzgetc(gzFile file) {
+ unsigned char buf[1];
+ gz_statep state;
+
+ /* get internal structure and check that it's for reading */
+ if (file == NULL)
+ return -1;
+ state = (gz_statep)file;
+ if (state->mode != GZ_READ)
+ return -1;
+
+ /* check that there was no (serious) error */
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)
+ return -1;
+ gz_error(state, Z_OK, NULL);
+
+ /* 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 gz_read(state, buf, 1) < 1 ? -1 : buf[0];
+}
+
+int ZEXPORT gzgetc_(gzFile file) {
+ return gzgetc(file);
+}
+
+/* -- see ptlibzippy.h -- */
+int ZEXPORT gzungetc(int c, gzFile file) {
+ gz_statep state;
+
+ /* get internal structure and check that it's for reading */
+ if (file == NULL)
+ return -1;
+ state = (gz_statep)file;
+ if (state->mode != GZ_READ)
+ return -1;
+
+ /* in case this was just opened, set up the input buffer */
+ if (state->how == LOOK && state->x.have == 0)
+ (void)gz_look(state);
+
+ /* check that there was no (serious) error */
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)
+ return -1;
+ gz_error(state, Z_OK, NULL);
+
+ /* process a skip request */
+ if (state->skip && gz_skip(state) == -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 ptlibzippy.h -- */
+char * ZEXPORT gzgets(gzFile file, char *buf, int len) {
+ unsigned left, n;
+ char *str;
+ unsigned char *eol;
+ gz_statep state;
+
+ /* check parameters, get internal structure, and check that it's for
+ reading */
+ if (file == NULL || buf == NULL || len < 1)
+ return NULL;
+ state = (gz_statep)file;
+ if (state->mode != GZ_READ)
+ return NULL;
+
+ /* check that there was no (serious) error */
+ if (state->err != Z_OK && state->err != Z_BUF_ERROR && !state->again)
+ return NULL;
+ gz_error(state, Z_OK, NULL);
+
+ /* process a skip request */
+ if (state->skip && gz_skip(state) == -1)
+ return NULL;
+
+ /* copy output up to a new line, len-1 bytes, or there is no more output,
+ whichever comes first */
+ 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)
+ break; /* 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);
+
+ /* append a terminating zero to the string (we don't check for a zero in
+ the contents, let the user worry about that) -- return the terminated
+ string, or if nothing was read, NULL */
+ if (buf == str)
+ return NULL;
+ buf[0] = 0;
+ return str;
+}
+
+/* -- see ptlibzippy.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 == 1;
+}
+
+/* -- see ptlibzippy.h -- */
+int ZEXPORT gzclose_r(gzFile file) {
+ int ret, err;
+ gz_statep state;
+
+ /* get internal structure and check that it's for reading */
+ if (file == NULL)
+ return Z_STREAM_ERROR;
+ state = (gz_statep)file;
+ 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;
+}
generated by cgit 0.0.5-2-1-g0f52 (git 2.46.0) at 2026-04-05 19:40:33 +0000