sha1_to_hex() usage cleanup

Somebody on the #git channel complained that the sha1_to_hex() thing uses
a static buffer which caused an error message to show the same hex output
twice instead of showing two different ones.

That's pretty easily rectified by making it uses a simple LRU of a few
buffers, which also allows some other users (that were aware of the buffer
re-use) to be written in a more straightforward manner.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff.c b/diff.c
index 6762fce..c845c87 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -1018,14 +1018,12 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
        }
 
        if (memcmp(one->sha1, two->sha1, 20)) {
-               char one_sha1[41];
                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
-               memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
 
                len += snprintf(msg + len, sizeof(msg) - len,
                                "index %.*s..%.*s",
-                               abbrev, one_sha1, abbrev,
-                               sha1_to_hex(two->sha1));
+                               abbrev, sha1_to_hex(one->sha1),
+                               abbrev, sha1_to_hex(two->sha1));
                if (one->mode == two->mode)
                        len += snprintf(msg + len, sizeof(msg) - len,
                                        " %06o", one->mode);

diff --git a/merge-tree.c b/merge-tree.c
index 50528d5..cc7b5bd 100644 (file)
--- a/merge-tree.c
+++ b/merge-tree.c
@@ -24,16 +24,14 @@ static const char *sha1_to_hex_zero(const unsigned char *sha1)
 
 static void resolve(const char *base, struct name_entry *branch1, struct name_entry *result)
 {
-       char branch1_sha1[50];
-
        /* If it's already branch1, don't bother showing it */
        if (!branch1)
                return;
-       memcpy(branch1_sha1, sha1_to_hex_zero(branch1->sha1), 41);
 
        printf("0 %06o->%06o %s->%s %s%s\n",
                branch1->mode, result->mode,
-               branch1_sha1, sha1_to_hex_zero(result->sha1),
+               sha1_to_hex_zero(branch1->sha1),
+               sha1_to_hex_zero(result->sha1),
                base, result->path);
 }
 

diff --git a/sha1_file.c b/sha1_file.c
index f2d33af..5464828 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -108,9 +108,10 @@ int safe_create_leading_directories(char *path)
 
 char * sha1_to_hex(const unsigned char *sha1)
 {
-       static char buffer[50];
+       static int bufno;
+       static char hexbuffer[4][50];
        static const char hex[] = "0123456789abcdef";
-       char *buf = buffer;
+       char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
        int i;
 
        for (i = 0; i < 20; i++) {