From 85d9219a62c23c3ff58b42a63b65390526b89b6b Mon Sep 17 00:00:00 2001 From: David Bremner Date: Sat, 29 Mar 2014 14:53:17 -0300 Subject: util: add gz_readline The idea is to provide a more or less drop in replacement for readline to read from zlib/gzip streams. Take the opportunity to replace malloc with talloc. --- util/zlib-extra.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 util/zlib-extra.c (limited to 'util/zlib-extra.c') diff --git a/util/zlib-extra.c b/util/zlib-extra.c new file mode 100644 index 00000000..2e704457 --- /dev/null +++ b/util/zlib-extra.c @@ -0,0 +1,85 @@ +/* zlib-extra.c - Extra or enhanced routines for compressed I/O. + * + * Copyright (c) 2014 David Bremner + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see http://www.gnu.org/licenses/ . + * + * Author: David Bremner + */ + +#include "zlib-extra.h" +#include +#include +#include + +/* mimic POSIX/glibc getline, but on a zlib gzFile stream, and using talloc */ +util_status_t +gz_getline (void *talloc_ctx, char **bufptr, ssize_t *bytes_read, gzFile stream) +{ + char *buf = *bufptr; + unsigned int len; + size_t offset = 0; + + if (buf) { + len = talloc_array_length (buf); + } else { + /* same as getdelim from gnulib */ + len = 120; + buf = talloc_array (talloc_ctx, char, len); + if (buf == NULL) + return UTIL_OUT_OF_MEMORY; + } + + while (1) { + if (! gzgets (stream, buf + offset, len - offset)) { + /* Null indicates EOF or error */ + int zlib_status = 0; + (void) gzerror (stream, &zlib_status); + switch (zlib_status) { + case Z_OK: + /* no data read before EOF */ + if (offset == 0) + return UTIL_EOF; + else + goto SUCCESS; + case Z_ERRNO: + return UTIL_ERRNO; + default: + return UTIL_GZERROR; + } + } + + offset += strlen (buf + offset); + + if (buf[offset - 1] == '\n') + goto SUCCESS; + + len *= 2; + buf = talloc_realloc (talloc_ctx, buf, char, len); + if (buf == NULL) + return UTIL_OUT_OF_MEMORY; + } + SUCCESS: + *bufptr = buf; + *bytes_read = offset; + return UTIL_SUCCESS; +} + +const char *gz_error_string (util_status_t status, gzFile file) +{ + if (status == UTIL_GZERROR) + return gzerror (file, NULL); + else + return util_error_string (status); +} -- cgit v1.2.3