object-name: extract function to parse object ID prefixes

Extract the logic that parses an object ID prefix into a new function.
This function will be used by a second callsite in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/object-name.c b/object-name.c
index ff0de06ff9bd874c9006067cbe37b1a7928f67a9..fd1b010ab3b35ceb33fa8df670b6e7bc405c02b0 100644 (file)
--- a/object-name.c
+++ b/object-name.c
@@ -270,41 +270,57 @@ int set_disambiguate_hint_config(const char *var, const char *value)
        return error("unknown hint type for '%s': %s", var, value);
 }
 
+static int parse_oid_prefix(const char *name, int len,
+                           const struct git_hash_algo *algo,
+                           char *hex_out,
+                           struct object_id *oid_out)
+{
+       for (int i = 0; i < len; i++) {
+               unsigned char c = name[i];
+               unsigned char val;
+               if (c >= '0' && c <= '9') {
+                       val = c - '0';
+               } else if (c >= 'a' && c <= 'f') {
+                       val = c - 'a' + 10;
+               } else if (c >= 'A' && c <='F') {
+                       val = c - 'A' + 10;
+                       c -= 'A' - 'a';
+               } else {
+                       return -1;
+               }
+
+               if (hex_out)
+                       hex_out[i] = c;
+               if (oid_out) {
+                       if (!(i & 1))
+                               val <<= 4;
+                       oid_out->hash[i >> 1] |= val;
+               }
+       }
+
+       if (hex_out)
+               hex_out[len] = '\0';
+       if (oid_out)
+               oid_out->algo = algo ? hash_algo_by_ptr(algo) : GIT_HASH_UNKNOWN;
+
+       return 0;
+}
+
 static int init_object_disambiguation(struct repository *r,
                                      const char *name, int len,
                                      const struct git_hash_algo *algo,
                                      struct disambiguate_state *ds)
 {
-       int i;
-
        if (len < MINIMUM_ABBREV || len > GIT_MAX_HEXSZ)
                return -1;
 
        memset(ds, 0, sizeof(*ds));
 
-       for (i = 0; i < len ;i++) {
-               unsigned char c = name[i];
-               unsigned char val;
-               if (c >= '0' && c <= '9')
-                       val = c - '0';
-               else if (c >= 'a' && c <= 'f')
-                       val = c - 'a' + 10;
-               else if (c >= 'A' && c <='F') {
-                       val = c - 'A' + 10;
-                       c -= 'A' - 'a';
-               }
-               else
-                       return -1;
-               ds->hex_pfx[i] = c;
-               if (!(i & 1))
-                       val <<= 4;
-               ds->bin_pfx.hash[i >> 1] |= val;
-       }
+       if (parse_oid_prefix(name, len, algo, ds->hex_pfx, &ds->bin_pfx) < 0)
+               return -1;
 
        ds->len = len;
-       ds->hex_pfx[len] = '\0';
        ds->repo = r;
-       ds->bin_pfx.algo = algo ? hash_algo_by_ptr(algo) : GIT_HASH_UNKNOWN;
        odb_prepare_alternates(r->objects);
        return 0;
 }