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/Makefile.local | 2 +-
util/util.h | 12 +++++++++
util/zlib-extra.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++
util/zlib-extra.h | 11 ++++++++
4 files changed, 100 insertions(+), 1 deletion(-)
create mode 100644 util/util.h
create mode 100644 util/zlib-extra.c
create mode 100644 util/zlib-extra.h
diff --git a/util/Makefile.local b/util/Makefile.local
index 29c0ce6..e2a5b65 100644
--- a/util/Makefile.local
+++ b/util/Makefile.local
@@ -4,7 +4,7 @@ dir := util
extra_cflags += -I$(srcdir)/$(dir)
libutil_c_srcs := $(dir)/xutil.c $(dir)/error_util.c $(dir)/hex-escape.c \
- $(dir)/string-util.c $(dir)/talloc-extra.c
+ $(dir)/string-util.c $(dir)/talloc-extra.c $(dir)/zlib-extra.c
libutil_modules := $(libutil_c_srcs:.c=.o)
diff --git a/util/util.h b/util/util.h
new file mode 100644
index 0000000..8663cfc
--- /dev/null
+++ b/util/util.h
@@ -0,0 +1,12 @@
+#ifndef _UTIL_H
+#define _UTIL_H
+
+typedef enum util_status {
+ UTIL_SUCCESS = 0,
+ UTIL_ERROR = 1,
+ UTIL_OUT_OF_MEMORY,
+ UTIL_EOF,
+ UTIL_FILE,
+} util_status_t;
+
+#endif
diff --git a/util/zlib-extra.c b/util/zlib-extra.c
new file mode 100644
index 0000000..cb1eba0
--- /dev/null
+++ b/util/zlib-extra.c
@@ -0,0 +1,76 @@
+/* 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 <david at tethera.net>
+ */
+
+#include "zlib-extra.h"
+#include <talloc.h>
+#include <stdio.h>
+#include <string.h>
+
+/* mimic POSIX/glibc getline, but on a zlib gzFile stream, and using talloc */
+util_status_t
+gz_getline (void *talloc_ctx, char **bufptr, size_t *bufsiz, ssize_t
*bytes_read,
+ gzFile stream)
+{
+ size_t len = *bufsiz;
+ char *buf = *bufptr;
+ size_t offset = 0;
+
+ if (len == 0 || buf == NULL) {
+ /* same as getdelim from gnulib */
+ len = 120;
+ buf = talloc_size (talloc_ctx, len);
+ if (buf == NULL)
+ return UTIL_OUT_OF_MEMORY;
+ }
+
+ while (1) {
+ if (! gzgets (stream, buf + offset, len - offset)) {
+ int zlib_status = 0;
+ (void) gzerror (stream, &zlib_status);
+ switch (zlib_status) {
+ case Z_OK:
+ /* follow getline behaviour */
+ *bytes_read = -1;
+ return UTIL_EOF;
+ break;
+ case Z_ERRNO:
+ return UTIL_FILE;
+ break;
+ default:
+ return UTIL_ERROR;
+ }
+ }
+
+ offset += strlen (buf + offset);
+
+ if ( buf[offset - 1] == '\n' )
+ break;
+
+ len *= 2;
+ buf = talloc_realloc (talloc_ctx, buf, char, len);
+ if (buf == NULL)
+ return UTIL_OUT_OF_MEMORY;
+ }
+
+ *bufptr = buf;
+ *bufsiz = len;
+ *bytes_read = offset;
+ return UTIL_SUCCESS;
+}
diff --git a/util/zlib-extra.h b/util/zlib-extra.h
new file mode 100644
index 0000000..ed46ac1
--- /dev/null
+++ b/util/zlib-extra.h
@@ -0,0 +1,11 @@
+#ifndef _ZLIB_EXTRA_H
+#define _ZLIB_EXTRA_H
+
+#include <zlib.h>
+#include "util.h"
+/* Like getline, but read from a gzFile. Allocation is with talloc */
+util_status_t
+gz_getline (void *ctx, char **lineptr, size_t *line_size, ssize_t *bytes_read,
+ gzFile stream);
+
+#endif
--
1.9.0
