From 77bc4f8944c0e1a1fd4689eddbcead6e93bef58a Mon Sep 17 00:00:00 2001 From: Mark Adler Date: Sun, 4 Dec 2016 18:29:43 -0800 Subject: [PATCH] Add gzfwrite(), duplicating the interface of fwrite(). --- gzwrite.c | 138 ++++++++++++++++++++++++++++++++++++++---------------- zlib.h | 14 ++++++ 2 files changed, 112 insertions(+), 40 deletions(-) diff --git a/gzwrite.c b/gzwrite.c index eb73d9c..2420514 100644 --- a/gzwrite.c +++ b/gzwrite.c @@ -9,6 +9,7 @@ local int gz_init OF((gz_statep)); local int gz_comp OF((gz_statep, int)); local int gz_zero OF((gz_statep, z_off64_t)); +local z_size_t gz_write OF((gz_statep, voidpc, z_size_t)); /* Initialize state for writing a gzip file. Mark initialization by setting state->size to non-zero. Return -1 on a memory allocation failure, or 0 on @@ -170,32 +171,14 @@ local int gz_zero(state, len) return 0; } -/* -- see zlib.h -- */ -int ZEXPORT gzwrite(file, buf, len) - gzFile file; +/* Write len bytes from buf to file. Return the number of bytes written. If + the returned value is less than len, then there was an error. */ +local z_size_t gz_write(state, buf, len) + gz_statep state; voidpc buf; - unsigned len; + z_size_t len; { - unsigned put = len; - gz_statep state; - z_streamp strm; - - /* get internal structure */ - if (file == NULL) - return 0; - state = (gz_statep)file; - strm = &(state->strm); - - /* check that we're writing and that there's no error */ - if (state->mode != GZ_WRITE || state->err != Z_OK) - return 0; - - /* 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_DATA_ERROR, "requested length does not fit in int"); - return 0; - } + z_size_t put = len; /* if len is zero, avoid unnecessary operations */ if (len == 0) @@ -218,14 +201,15 @@ int ZEXPORT gzwrite(file, buf, len) do { unsigned have, copy; - if (strm->avail_in == 0) - strm->next_in = state->in; - have = (unsigned)((strm->next_in + strm->avail_in) - state->in); + if (state->strm.avail_in == 0) + state->strm.next_in = state->in; + have = (unsigned)((state->strm.next_in + state->strm.avail_in) - + state->in); copy = state->size - have; if (copy > len) copy = len; memcpy(state->in + have, buf, copy); - strm->avail_in += copy; + state->strm.avail_in += copy; state->x.pos += copy; buf = (const char *)buf + copy; len -= copy; @@ -235,19 +219,83 @@ int ZEXPORT gzwrite(file, buf, len) } else { /* consume whatever's left in the input buffer */ - if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1) + if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1) return 0; /* directly compress user buffer to file */ - strm->avail_in = len; - strm->next_in = (z_const Bytef *)buf; - state->x.pos += len; - if (gz_comp(state, Z_NO_FLUSH) == -1) - return 0; + state->strm.next_in = (z_const Bytef *)buf; + do { + unsigned n = -1; + if (n > len) + n = len; + state->strm.avail_in = n; + state->x.pos += n; + if (gz_comp(state, Z_NO_FLUSH) == -1) + return 0; + len -= n; + } while (len); + } + + /* input was all buffered or compressed */ + return put; +} + +/* -- see zlib.h -- */ +int ZEXPORT gzwrite(file, buf, len) + gzFile file; + voidpc buf; + unsigned len; +{ + gz_statep state; + + /* get internal structure */ + if (file == NULL) + return 0; + state = (gz_statep)file; + + /* check that we're writing and that there's no error */ + if (state->mode != GZ_WRITE || state->err != Z_OK) + return 0; + + /* 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_DATA_ERROR, "requested length does not fit in int"); + return 0; + } + + /* write len bytes from buf (the return value will fit in an int) */ + return (int)gz_write(state, buf, len); +} + +/* -- see zlib.h -- */ +z_size_t ZEXPORT gzfwrite(buf, size, nitems, file) + voidpc 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 writing and that there's no error */ + if (state->mode != GZ_WRITE || state->err != Z_OK) + 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; } - /* input was all buffered or compressed (put will fit in int) */ - return (int)put; + /* write len bytes to buf, return the number of full items written */ + return len ? gz_write(state, buf, len) / size : 0; } /* -- see zlib.h -- */ @@ -293,7 +341,7 @@ int ZEXPORT gzputc(file, c) /* no room in buffer or not initialized, use gz_write() */ buf[0] = (unsigned char)c; - if (gzwrite(file, buf, 1) != 1) + if (gz_write(state, buf, 1) != 1) return -1; return c & 0xff; } @@ -304,11 +352,21 @@ int ZEXPORT gzputs(file, str) const char *str; { int ret; - unsigned len; + z_size_t len; + gz_statep state; + + /* get internal structure */ + if (file == NULL) + return -1; + state = (gz_statep)file; + + /* check that we're writing and that there's no error */ + if (state->mode != GZ_WRITE || state->err != Z_OK) + return -1; /* write string */ - len = (unsigned)strlen(str); - ret = gzwrite(file, str, len); + len = strlen(str); + ret = gz_write(state, str, len); return ret == 0 && len != 0 ? -1 : ret; } diff --git a/zlib.h b/zlib.h index ff4469d..053e6e2 100644 --- a/zlib.h +++ b/zlib.h @@ -1427,6 +1427,20 @@ ZEXTERN int ZEXPORT gzwrite OF((gzFile file, error. */ +ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size, + z_size_t nitems, gzFile file)); +/* + gzfwrite() writes nitems items of size size from buf to file, duplicating + the interface of stdio's fwrite(), with size_t request and return types. If + the library defines size_t, then z_size_t is identical to size_t. If not, + then z_size_t is an unsigned integer type that can contain a pointer. + + gzfwrite() returns the number of full items written of size size, or zero + if there was an error. If the multiplication of size and nitems overflows, + i.e. the product does not fit in a z_size_t, then nothing is written, zero + is returned, and the error state is set to Z_STREAM_ERROR. +*/ + ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); /* Converts, formats, and writes the arguments to the compressed file under -- 2.44.0