Re: [PATCH 2/3] http-push: use hex_to_bytes()
- From
René Scharfe <l.s.r@web.de>
- Date
- Nov 4, 2017, 09:05 UTC
- Message-ID
- <abf7c219-880b-790f-78ef-18c7cdd54ad6@web.de>
- In-Reply-To
- <20171101221541.6dwezd4t4hweuis2@sigill.intra.peff.net>
Am 01.11.2017 um 23:15 schrieb Jeff King:
Show 12 quoted lines
> On Wed, Nov 01, 2017 at 10:59:49PM +0100, René Scharfe wrote: > >>> The hex_to_bytes() function requires that the caller make sure they have >>> the right number of bytes. But for many callers, I think they'd want to >>> say "parse this oid, which might be truncated; I can't tell what the >>> length is supposed to be". >> >> I'm confused by the word "many". After this series there are three >> callers of hex_to_bytes() and I don't expect that number to grow. > > I meant only that most callers that parse oids, both in-file and not, > would want to stop knowing about the length ahead of time.
That's a good idea.
> I'm not sure we know 100% > yet what "new"-style hashes will look like, nor how their loose-object > filenames would look.
So it's too early to implement a solution, but here's how a patch for reducing dependency on hash lengths could look like today:
--- cache.h | 2 ++ hex.c | 13 +++++++++++++ http-push.c | 7 +++---- notes.c | 6 +----- sha1_file.c | 4 +--- 5 files changed, 20 insertions(+), 12 deletions(-)
diff --git a/cache.h b/cache.h index f06bfbaf32..acd3804c21 100644 --- a/cache.h +++ b/cache.h @@ -1317,6 +1317,8 @@ extern int set_disambiguate_hint_config(const char *var, const char *value); extern int get_sha1_hex(const char *hex, unsigned char *sha1); extern int get_oid_hex(const char *hex, struct object_id *sha1); +extern int get_oid_hex_tail(const char *hex, struct object_id *oid, size_t offset); + /* * Read `len` pairs of hexadecimal digits from `hex` and write the * values to `binary` as `len` bytes. Return 0 on success, or -1 if diff --git a/hex.c b/hex.c index 8df2d63728..3e6abe4d5e 100644 --- a/hex.c +++ b/hex.c @@ -47,6 +47,19 @@ int hex_to_bytes(unsigned char *binary, const char *hex, size_t len) return 0; } +int get_oid_hex_tail(const char *hex, struct object_id *oid, size_t offset) +{ + for (; offset < GIT_SHA1_RAWSZ; offset++, hex += 2) { + int val = hex2chr(hex); + if (val < 0) + return -1; + oid->hash[offset] = val; + } + if (*hex) + return -1; + return 0; +} + int get_sha1_hex(const char *hex, unsigned char *sha1) { int i; diff --git a/http-push.c b/http-push.c index 14435ab65d..a5512616b9 100644 --- a/http-push.c +++ b/http-push.c @@ -1007,18 +1007,17 @@ static void remote_ls(const char *path, int flags, void (*userFunc)(struct remote_ls_ctx *ls), void *userData); -/* extract hex from sharded "xx/x{38}" filename */ +/* extract hex from sharded "xx/x{N}" filename */ static int get_oid_hex_from_objpath(const char *path, struct object_id *oid) { - if (strlen(path) != GIT_SHA1_HEXSZ + 1) + if (strnlen(path, 3) < 3) return -1; - if (hex_to_bytes(oid->hash, path, 1)) return -1; path += 2; path++; /* skip '/' */ - return hex_to_bytes(oid->hash + 1, path, GIT_SHA1_RAWSZ - 1); + return get_oid_hex_tail(path, oid, 1); } static void process_ls_object(struct remote_ls_ctx *ls) diff --git a/notes.c b/notes.c index 04f8c8613c..ff6ce57022 100644 --- a/notes.c +++ b/notes.c @@ -410,17 +410,13 @@ static void load_subtree(struct notes_tree *t, struct leaf_node *subtree, struct leaf_node *l; size_t path_len = strlen(entry.path); - if (path_len == 2 * (GIT_SHA1_RAWSZ - prefix_len)) { + if (!get_oid_hex_tail(entry.path, &object_oid, prefix_len)) { /* This is potentially the remainder of the SHA-1 */ if (!S_ISREG(entry.mode)) /* notes must be blobs */ goto handle_non_note; - if (hex_to_bytes(object_oid.hash + prefix_len, entry.path, - GIT_SHA1_RAWSZ - prefix_len)) - goto handle_non_note; /* entry.path is not a SHA1 */ - type = PTR_TYPE_NOTE; } else if (path_len == 2) { /* This is potentially an internal node */ diff --git a/sha1_file.c b/sha1_file.c index a3c32d91d1..0486696b0b 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1911,9 +1911,7 @@ int for_each_file_in_obj_subdir(unsigned int subdir_nr, strbuf_setlen(path, baselen); strbuf_addf(path, "/%s", de->d_name); - if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2 && - !hex_to_bytes(oid.hash + 1, de->d_name, - GIT_SHA1_RAWSZ - 1)) { + if (!get_oid_hex_tail(de->d_name, &oid, 1)) { if (obj_cb) { r = obj_cb(&oid, path->buf, data); if (r)
-- 2.15.0