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authorPierre Habouzit <madcoder@debian.org>2007-09-27 12:58:23 +0200
committerJunio C Hamano <gitster@pobox.com>2007-09-29 02:13:33 -0700
commitb315c5c08139c0d3c1e4867a305334e29da01d07 (patch)
treefd4b122c7dd87e06a642a191b678b426d35e5a5b /strbuf.c
parent690b61f5f13db05aa4ad0efc422bd01aef3c1367 (diff)
downloadgit-b315c5c08139c0d3c1e4867a305334e29da01d07.tar.gz
strbuf change: be sure ->buf is never ever NULL.
For that purpose, the ->buf is always initialized with a char * buf living in the strbuf module. It is made a char * so that we can sloppily accept things that perform: sb->buf[0] = '\0', and because you can't pass "" as an initializer for ->buf without making gcc unhappy for very good reasons. strbuf_init/_detach/_grow have been fixed to trust ->alloc and not ->buf anymore. as a consequence strbuf_detach is _mandatory_ to detach a buffer, copying ->buf isn't an option anymore, if ->buf is going to escape from the scope, and eventually be free'd. API changes: * strbuf_setlen now always works, so just make strbuf_reset a convenience macro. * strbuf_detatch takes a size_t* optional argument (meaning it can be NULL) to copy the buffer's len, as it was needed for this refactor to make the code more readable, and working like the callers. Signed-off-by: Pierre Habouzit <madcoder@debian.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'strbuf.c')
-rw-r--r--strbuf.c30
1 files changed, 19 insertions, 11 deletions
diff --git a/strbuf.c b/strbuf.c
index d1e338bfb6..0e431daa61 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,27 +1,33 @@
#include "cache.h"
+/*
+ * Used as the default ->buf value, so that people can always assume
+ * buf is non NULL and ->buf is NUL terminated even for a freshly
+ * initialized strbuf.
+ */
+char strbuf_slopbuf[1];
+
void strbuf_init(struct strbuf *sb, size_t hint)
{
- memset(sb, 0, sizeof(*sb));
+ sb->alloc = sb->len = 0;
+ sb->buf = strbuf_slopbuf;
if (hint)
strbuf_grow(sb, hint);
}
void strbuf_release(struct strbuf *sb)
{
- free(sb->buf);
- memset(sb, 0, sizeof(*sb));
-}
-
-void strbuf_reset(struct strbuf *sb)
-{
- if (sb->len)
- strbuf_setlen(sb, 0);
+ if (sb->alloc) {
+ free(sb->buf);
+ strbuf_init(sb, 0);
+ }
}
-char *strbuf_detach(struct strbuf *sb)
+char *strbuf_detach(struct strbuf *sb, size_t *sz)
{
- char *res = sb->buf;
+ char *res = sb->alloc ? sb->buf : NULL;
+ if (sz)
+ *sz = sb->len;
strbuf_init(sb, 0);
return res;
}
@@ -40,6 +46,8 @@ void strbuf_grow(struct strbuf *sb, size_t extra)
{
if (sb->len + extra + 1 <= sb->len)
die("you want to use way too much memory");
+ if (!sb->alloc)
+ sb->buf = NULL;
ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
}