From 61e2a70ff26f83f761fa36e0cc16996878d8dd59 Mon Sep 17 00:00:00 2001 From: "brian m. carlson" Date: Sat, 22 Feb 2020 20:17:29 +0000 Subject: [PATCH] hex: add functions to parse hex object IDs in any algorithm There are some places where we need to parse a hex object ID in any algorithm without knowing beforehand which algorithm is in use. An example is when parsing fast-import marks. Add a get_oid_hex_any to parse an object ID and return the algorithm it belongs to, and additionally add parse_oid_hex_any which is the equivalent change for parse_oid_hex. If the object is not parseable, we return GIT_HASH_UNKNOWN. Signed-off-by: brian m. carlson Signed-off-by: Junio C Hamano --- cache.h | 10 ++++++++++ hex.c | 22 ++++++++++++++++++++++ 2 files changed, 32 insertions(+) diff --git a/cache.h b/cache.h index 4c9c21a11d..158d7ccfd8 100644 --- a/cache.h +++ b/cache.h @@ -1523,6 +1523,16 @@ int parse_oid_hex(const char *hex, struct object_id *oid, const char **end); int parse_oid_hex_algop(const char *hex, struct object_id *oid, const char **end, const struct git_hash_algo *algo); + +/* + * These functions work like get_oid_hex and parse_oid_hex, but they will parse + * a hex value for any algorithm. The algorithm is detected based on the length + * and the algorithm in use is returned. If this is not a hex object ID in any + * algorithm, returns GIT_HASH_UNKNOWN. + */ +int get_oid_hex_any(const char *hex, struct object_id *oid); +int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end); + /* * This reads short-hand syntax that not only evaluates to a commit * object name, but also can act as if the end user spelled the name diff --git a/hex.c b/hex.c index 10e24dc2e4..da51e64929 100644 --- a/hex.c +++ b/hex.c @@ -72,6 +72,20 @@ int get_oid_hex_algop(const char *hex, struct object_id *oid, return get_hash_hex_algop(hex, oid->hash, algop); } +/* + * NOTE: This function relies on hash algorithms being in order from shortest + * length to longest length. + */ +int get_oid_hex_any(const char *hex, struct object_id *oid) +{ + int i; + for (i = GIT_HASH_NALGOS - 1; i > 0; i--) { + if (!get_hash_hex_algop(hex, oid->hash, &hash_algos[i])) + return i; + } + return GIT_HASH_UNKNOWN; +} + int get_oid_hex(const char *hex, struct object_id *oid) { return get_oid_hex_algop(hex, oid, the_hash_algo); @@ -87,6 +101,14 @@ int parse_oid_hex_algop(const char *hex, struct object_id *oid, return ret; } +int parse_oid_hex_any(const char *hex, struct object_id *oid, const char **end) +{ + int ret = get_oid_hex_any(hex, oid); + if (ret) + *end = hex + hash_algos[ret].hexsz; + return ret; +} + int parse_oid_hex(const char *hex, struct object_id *oid, const char **end) { return parse_oid_hex_algop(hex, oid, end, the_hash_algo);