diff options
Diffstat (limited to 'sha1_name.c')
| -rw-r--r-- | sha1_name.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/sha1_name.c b/sha1_name.c index 3b647fd7cf..beb7ab588b 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -15,6 +15,7 @@ typedef int (*disambiguate_hint_fn)(const unsigned char *, void *); struct disambiguate_state { int len; /* length of prefix in hex chars */ + unsigned int nrobjects; char hex_pfx[GIT_SHA1_HEXSZ + 1]; unsigned char bin_pfx[GIT_SHA1_RAWSZ]; @@ -118,6 +119,14 @@ static void find_short_object_filename(struct disambiguate_state *ds) if (strlen(de->d_name) != 38) continue; + + /* + * We only look at the one subdirectory, and we assume + * each subdirectory is roughly similar, so each + * object we find probably has 255 other objects in + * the other fan-out directories. + */ + ds->nrobjects += 256; if (memcmp(de->d_name, ds->hex_pfx + 2, ds->len - 2)) continue; memcpy(hex + 2, de->d_name, 38); @@ -151,6 +160,7 @@ static void unique_in_pack(struct packed_git *p, open_pack_index(p); num = p->num_objects; + ds->nrobjects += num; last = num; while (first < last) { uint32_t mid = (first + last) / 2; @@ -380,6 +390,9 @@ static int show_ambiguous_object(const unsigned char *sha1, void *data) return 0; } +/* start from our historical default before the automatic abbreviation */ +static int default_automatic_abbrev = FALLBACK_DEFAULT_ABBREV; + static int get_short_sha1(const char *name, int len, unsigned char *sha1, unsigned flags) { @@ -426,6 +439,14 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1, for_each_abbrev(ds.hex_pfx, show_ambiguous_object, &ds); } + if (len < 16 && !status && (flags & GET_SHA1_AUTOMATIC)) { + unsigned int expect_collision = 1 << (len * 2); + if (ds.nrobjects > expect_collision) { + default_automatic_abbrev = len+1; + return SHORT_NAME_AMBIGUOUS; + } + } + return status; } @@ -458,14 +479,19 @@ int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data) int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len) { int status, exists; + int flags = GET_SHA1_QUIETLY; + if (len < 0) { + flags |= GET_SHA1_AUTOMATIC; + len = default_automatic_abbrev; + } sha1_to_hex_r(hex, sha1); if (len == 40 || !len) return 40; exists = has_sha1_file(sha1); while (len < 40) { unsigned char sha1_ret[20]; - status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY); + status = get_short_sha1(hex, len, sha1_ret, flags); if (exists ? !status : status == SHORT_NAME_NOT_FOUND) { |