Re: [PATCH 17/16] http-push: refactor parsing of remote object names
On Thu, Jun 19, 2014 at 05:58:10PM -0400, Jeff King wrote:
> It's still a little more magical than I would like, but I think this is
> the best we can do while still building on get_sha1_hex. Parsing it
> left-to-right would be better, but we would essentially end up
> reimplementing get_sha1_hex.
Just for fun, that would look something like this (on top):
diff --git a/http-push.c b/http-push.c
index c5c95e8..2425c61 100644
--- a/http-push.c
+++ b/http-push.c
@@ -1016,20 +1016,34 @@ static void remote_ls(const char *path, int flags,
void (*userFunc)(struct remote_ls_ctx *ls),
void *userData);
+static inline int parse_one_hex(unsigned char **to, const char **from)
+{
+ unsigned int val;
+
+ /* avoid reading past end-of-string for from[1] */
+ if (!(*from)[0])
+ return -1;
+ val = (hexval((*from)[0]) << 4) | hexval((*from)[1]);
+ if (val & ~0xff)
+ return -1;
+ *(*to)++ = val;
+ (*from) += 2;
+ return 0;
+}
+
/* extract hex from sharded "xx/x{40}" filename */
static int get_sha1_hex_from_objpath(const char *path, unsigned char *sha1)
{
- char hex[40];
+ int i;
- if (strlen(path) != 41)
+ if (parse_one_hex(&sha1, &path) < 0)
return -1;
-
- memcpy(hex, path, 2);
- path += 2;
- path++; /* skip '/' */
- memcpy(hex, path, 38);
-
- return get_sha1_hex(hex, sha1);
+ if (*path++ != '/')
+ return -1;
+ for (i = 1; i < 20; i++)
+ if (parse_one_hex(&sha1, &path) < 0)
+ return -1;
+ return 0;
}
static void process_ls_object(struct remote_ls_ctx *ls)
In theory we could factor parse_one_hex to share with get_sha1_hex, but
I am hesitant to touch get_sha1_hex, as it is used in a lot of tight
loops.
-Peff
Jeff King <peff@peff.net>