diff options
| -rw-r--r-- | sha1_name.c | 172 |
1 files changed, 112 insertions, 60 deletions
diff --git a/sha1_name.c b/sha1_name.c index db8ac83a12..2e2dbb8664 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -9,11 +9,67 @@ static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *); -static int find_short_object_filename(int len, const char *hex_pfx, unsigned char *sha1) +typedef int (*disambiguate_hint_fn)(const unsigned char *, void *); + +struct disambiguate_state { + disambiguate_hint_fn fn; + void *cb_data; + unsigned char candidate[20]; + unsigned candidate_exists:1; + unsigned candidate_checked:1; + unsigned candidate_ok:1; + unsigned disambiguate_fn_used:1; + unsigned ambiguous:1; +}; + +static void update_candidates(struct disambiguate_state *ds, const unsigned char *current) +{ + if (!ds->candidate_exists) { + /* this is the first candidate */ + hashcpy(ds->candidate, current); + ds->candidate_exists = 1; + return; + } else if (!hashcmp(ds->candidate, current)) { + /* the same as what we already have seen */ + return; + } + + if (!ds->fn) { + /* cannot disambiguate between ds->candidate and current */ + ds->ambiguous = 1; + return; + } + + if (!ds->candidate_checked) { + ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data); + ds->disambiguate_fn_used = 1; + ds->candidate_checked = 1; + } + + if (!ds->candidate_ok) { + /* discard the candidate; we know it does not satisify fn */ + hashcpy(ds->candidate, current); + ds->candidate_checked = 0; + return; + } + + /* if we reach this point, we know ds->candidate satisfies fn */ + if (ds->fn(current, ds->cb_data)) { + /* + * if both current and candidate satisfy fn, we cannot + * disambiguate. + */ + ds->candidate_ok = 0; + ds->ambiguous = 1; + } + + /* otherwise, current can be discarded and candidate is still good */ +} + +static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds) { struct alternate_object_database *alt; char hex[40]; - int found = 0; static struct alternate_object_database *fakeent; if (!fakeent) { @@ -35,32 +91,27 @@ static int find_short_object_filename(int len, const char *hex_pfx, unsigned cha fakeent->next = alt_odb_list; sprintf(hex, "%.2s", hex_pfx); - for (alt = fakeent; alt && found < 2; alt = alt->next) { + for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) { struct dirent *de; DIR *dir; sprintf(alt->name, "%.2s/", hex_pfx); dir = opendir(alt->base); if (!dir) continue; - while ((de = readdir(dir)) != NULL) { + + while (!ds->ambiguous && (de = readdir(dir)) != NULL) { + unsigned char sha1[20]; + if (strlen(de->d_name) != 38) continue; if (memcmp(de->d_name, hex_pfx + 2, len - 2)) continue; - if (!found) { - memcpy(hex + 2, de->d_name, 38); - found++; - } - else if (memcmp(hex + 2, de->d_name, 38)) { - found = 2; - break; - } + memcpy(hex + 2, de->d_name, 38); + if (!get_sha1_hex(hex, sha1)) + update_candidates(ds, sha1); } closedir(dir); } - if (found == 1) - return get_sha1_hex(hex, sha1) == 0; - return found; } static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b) @@ -78,11 +129,10 @@ static int match_sha(unsigned len, const unsigned char *a, const unsigned char * return 1; } -static int unique_in_pack(int len, +static void unique_in_pack(int len, const unsigned char *bin_pfx, - struct packed_git *p, - const unsigned char **found_sha1, - int seen_so_far) + struct packed_git *p, + struct disambiguate_state *ds) { uint32_t num, last, i, first = 0; const unsigned char *current = NULL; @@ -113,63 +163,58 @@ static int unique_in_pack(int len, * with an object name that could match "bin_pfx". See if we have * 0, 1 or more objects that actually match(es). */ - for (i = first; i < num; i++) { - current = nth_packed_object_sha1(p, first); + for (i = first; i < num && !ds->ambiguous; i++) { + current = nth_packed_object_sha1(p, i); if (!match_sha(len, bin_pfx, current)) break; - - /* current matches */ - if (!seen_so_far) { - *found_sha1 = current; - seen_so_far++; - } else if (seen_so_far) { - /* is it the same as the one previously found elsewhere? */ - if (hashcmp(*found_sha1, current)) - return 2; /* definitely not unique */ - } + update_candidates(ds, current); } - return seen_so_far; } -static int find_short_packed_object(int len, const unsigned char *bin_pfx, unsigned char *sha1) +static void find_short_packed_object(int len, const unsigned char *bin_pfx, + struct disambiguate_state *ds) { struct packed_git *p; - const unsigned char *found_sha1 = NULL; - int found = 0; prepare_packed_git(); - for (p = packed_git; p && found < 2; p = p->next) - found = unique_in_pack(len, bin_pfx, p, &found_sha1, found); - - if (found == 1) - hashcpy(sha1, found_sha1); - return found; + for (p = packed_git; p && !ds->ambiguous; p = p->next) + unique_in_pack(len, bin_pfx, p, ds); } #define SHORT_NAME_NOT_FOUND (-1) #define SHORT_NAME_AMBIGUOUS (-2) -static int find_unique_short_object(int len, char *hex_pfx, - unsigned char *bin_pfx, unsigned char *sha1) +static int finish_object_disambiguation(struct disambiguate_state *ds, + unsigned char *sha1) { - int has_unpacked, has_packed; - unsigned char unpacked_sha1[20], packed_sha1[20]; + if (ds->ambiguous) + return SHORT_NAME_AMBIGUOUS; - prepare_alt_odb(); - has_unpacked = find_short_object_filename(len, hex_pfx, unpacked_sha1); - has_packed = find_short_packed_object(len, bin_pfx, packed_sha1); - if (!has_unpacked && !has_packed) + if (!ds->candidate_exists) return SHORT_NAME_NOT_FOUND; - if (1 < has_unpacked || 1 < has_packed) - return SHORT_NAME_AMBIGUOUS; - if (has_unpacked != has_packed) { - hashcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1)); - return 0; - } - /* Both have unique ones -- do they match? */ - if (hashcmp(packed_sha1, unpacked_sha1)) - return SHORT_NAME_AMBIGUOUS; - hashcpy(sha1, packed_sha1); + + if (!ds->candidate_checked) + /* + * If this is the only candidate, there is no point + * calling the disambiguation hint callback. + * + * On the other hand, if the current candidate + * replaced an earlier candidate that did _not_ pass + * the disambiguation hint callback, then we do have + * more than one objects that match the short name + * given, so we should make sure this one matches; + * otherwise, if we discovered this one and the one + * that we previously discarded in the reverse order, + * we would end up showing different results in the + * same repository! + */ + ds->candidate_ok = (!ds->disambiguate_fn_used || + ds->fn(ds->candidate, ds->cb_data)); + + if (!ds->candidate_ok) + return SHORT_NAME_NOT_FOUND; + + hashcpy(sha1, ds->candidate); return 0; } @@ -179,6 +224,7 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1, int i, status; char hex_pfx[40]; unsigned char bin_pfx[20]; + struct disambiguate_state ds; if (len < MINIMUM_ABBREV || len > 40) return -1; @@ -203,7 +249,13 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1, bin_pfx[i >> 1] |= val; } - status = find_unique_short_object(i, hex_pfx, bin_pfx, sha1); + prepare_alt_odb(); + + memset(&ds, 0, sizeof(ds)); + find_short_object_filename(len, hex_pfx, &ds); + find_short_packed_object(len, bin_pfx, &ds); + status = finish_object_disambiguation(&ds, sha1); + if (!quietly && (status == SHORT_NAME_AMBIGUOUS)) return error("short SHA1 %.*s is ambiguous.", len, hex_pfx); return status; |