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) {
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)
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;
* 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))
+
+ 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_AMBIGUOUS;
- hashcpy(sha1, packed_sha1);
+
+ hashcpy(sha1, ds->candidate);
return 0;
}
+static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
+{
+ int kind = sha1_object_info(sha1, NULL);
+ return kind == OBJ_COMMIT;
+}
+
static int get_short_sha1(const char *name, int len, unsigned char *sha1,
- int quietly)
+ unsigned flags)
{
int i, status;
char hex_pfx[40];
unsigned char bin_pfx[20];
+ struct disambiguate_state ds;
+ int quietly = !!(flags & GET_SHA1_QUIETLY);
if (len < MINIMUM_ABBREV || len > 40)
return -1;
bin_pfx[i >> 1] |= val;
}
- status = find_unique_short_object(i, hex_pfx, bin_pfx, sha1);
+ prepare_alt_odb();
+
+ memset(&ds, 0, sizeof(ds));
+ if (flags & GET_SHA1_COMMIT)
+ ds.fn = disambiguate_commit_only;
+
+ 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;
return hex;
while (len < 40) {
unsigned char sha1_ret[20];
- status = get_short_sha1(hex, len, sha1_ret, 1);
+ status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
if (exists
? !status
: status == SHORT_NAME_NOT_FOUND) {
static int get_describe_name(const char *name, int len, unsigned char *sha1)
{
const char *cp;
+ unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
for (cp = name + len - 1; name + 2 <= cp; cp--) {
char ch = *cp;
if (ch == 'g' && cp[-1] == '-') {
cp++;
len -= cp - name;
- return get_short_sha1(cp, len, sha1, 1);
+ return get_short_sha1(cp, len, sha1, flags);
}
}
}