X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_name.c;h=8920de1c45ce0a094fbc0b5ea2ca744ef27c6393;hb=df8baa42fe4eeb5a021ac262caf601f44d2a5746;hp=df3ba2d43f14d9dbcc805a639c3f413f60c2e26a;hpb=3f81fc82743ccd4fd7157f1f1db41605eb018fb9;p=git.git

diff --git a/sha1_name.c b/sha1_name.c
index df3ba2d4..8920de1c 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -3,31 +3,49 @@
 
 static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
 {
-	static char dirname[PATH_MAX];
+	struct alternate_object_database *alt;
 	char hex[40];
-	DIR *dir;
-	int found;
+	int found = 0;
+	static struct alternate_object_database *fakeent;
+
+	if (!fakeent) {
+		const char *objdir = get_object_directory();
+		int objdir_len = strlen(objdir);
+		int entlen = objdir_len + 43;
+		fakeent = xmalloc(sizeof(*fakeent) + entlen);
+		memcpy(fakeent->base, objdir, objdir_len);
+		fakeent->name = fakeent->base + objdir_len + 1;
+		fakeent->name[-1] = '/';
+	}
+	fakeent->next = alt_odb_list;
 
-	snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
-	dir = opendir(dirname);
 	sprintf(hex, "%.2s", name);
-	found = 0;
-	if (dir) {
+	for (alt = fakeent; alt && found < 2; alt = alt->next) {
 		struct dirent *de;
+		DIR *dir;
+		sprintf(alt->name, "%.2s/", name);
+		dir = opendir(alt->base);
+		if (!dir)
+			continue;
 		while ((de = readdir(dir)) != NULL) {
 			if (strlen(de->d_name) != 38)
 				continue;
-			if (memcmp(de->d_name, name + 2, len-2))
+			if (memcmp(de->d_name, name + 2, len - 2))
 				continue;
-			memcpy(hex + 2, de->d_name, 38);
-			if (++found > 1)
+			if (!found) {
+				memcpy(hex + 2, de->d_name, 38);
+				found++;
+			}
+			else if (memcmp(hex + 2, de->d_name, 38)) {
+				found = 2;
 				break;
+			}
 		}
 		closedir(dir);
 	}
 	if (found == 1)
 		return get_sha1_hex(hex, sha1) == 0;
-	return 0;
+	return found;
 }
 
 static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
@@ -48,9 +66,11 @@ static int match_sha(unsigned len, const unsigned char *a, const unsigned char *
 static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
 {
 	struct packed_git *p;
+	unsigned char found_sha1[20];
+	int found = 0;
 
 	prepare_packed_git();
-	for (p = packed_git; p; p = p->next) {
+	for (p = packed_git; p && found < 2; p = p->next) {
 		unsigned num = num_packed_objects(p);
 		unsigned first = 0, last = num;
 		while (first < last) {
@@ -71,32 +91,61 @@ static int find_short_packed_object(int len, const unsigned char *match, unsigne
 			last = mid;
 		}
 		if (first < num) {
-			unsigned char now[20], next[20];
+			unsigned char now[20];
 			nth_packed_object_sha1(p, first, now);
 			if (match_sha(len, match, now)) {
-				if (nth_packed_object_sha1(p, first+1, next) || !match_sha(len, match, next)) {
-					memcpy(sha1, now, 20);
-					return 1;
+				if (!found) {
+					memcpy(found_sha1, now, 20);
+					found++;
+				}
+				else if (memcmp(found_sha1, now, 20)) {
+					found = 2;
+					break;
 				}
 			}
 		}
 	}
+	if (found == 1)
+		memcpy(sha1, found_sha1, 20);
+	return found;
+}
+
+static int find_unique_short_object(int len, char *canonical,
+				    unsigned char *res, unsigned char *sha1)
+{
+	int has_unpacked, has_packed;
+	unsigned char unpacked_sha1[20], packed_sha1[20];
+
+	has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
+	has_packed = find_short_packed_object(len, res, packed_sha1);
+	if (!has_unpacked && !has_packed)
+		return -1;
+	if (1 < has_unpacked || 1 < has_packed)
+		return -1;
+	if (has_unpacked != has_packed) {
+		memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
+		return 0;
+	}
+	/* Both have unique ones -- do they match? */
+	if (memcmp(packed_sha1, unpacked_sha1, 20))
+		return error("short SHA1 %.*s is ambiguous.", len, canonical);
+	memcpy(sha1, packed_sha1, 20);
 	return 0;
 }
 
-static int get_short_sha1(const char *name, unsigned char *sha1)
+static int get_short_sha1(const char *name, int len, unsigned char *sha1)
 {
 	int i;
 	char canonical[40];
 	unsigned char res[20];
 
+	if (len < 4)
+		return -1;
 	memset(res, 0, 20);
 	memset(canonical, 'x', 40);
-	for (i = 0;;i++) {
+	for (i = 0; i < len ;i++) {
 		unsigned char c = name[i];
 		unsigned char val;
-		if (!c || i > 40)
-			break;
 		if (c >= '0' && c <= '9')
 			val = c - '0';
 		else if (c >= 'a' && c <= 'f')
@@ -112,28 +161,8 @@ static int get_short_sha1(const char *name, unsigned char *sha1)
 			val <<= 4;
 		res[i >> 1] |= val;
 	}
-	if (i < 4)
-		return -1;
-	if (find_short_object_filename(i, canonical, sha1))
-		return 0;
-	if (find_short_packed_object(i, res, sha1))
-		return 0;
-	return -1;
-}
-
-static int get_sha1_file(const char *path, unsigned char *result)
-{
-	char buffer[60];
-	int fd = open(path, O_RDONLY);
-	int len;
 
-	if (fd < 0)
-		return -1;
-	len = read(fd, buffer, sizeof(buffer));
-	close(fd);
-	if (len < 40)
-		return -1;
-	return get_sha1_hex(buffer, result);
+	return find_unique_short_object(i, canonical, res, sha1);
 }
 
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
@@ -143,17 +172,16 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 		"refs",
 		"refs/tags",
 		"refs/heads",
-		"refs/snap",
 		NULL
 	};
 	const char **p;
 
-	if (!get_sha1_hex(str, sha1))
+	if (len == 40 && !get_sha1_hex(str, sha1))
 		return 0;
 
 	for (p = prefix; *p; p++) {
 		char *pathname = git_path("%s/%.*s", *p, len, str);
-		if (!get_sha1_file(pathname, sha1))
+		if (!read_ref(pathname, sha1))
 			return 0;
 	}
 
@@ -192,9 +220,29 @@ static int get_parent(const char *name, int len,
 	return -1;
 }
 
+static int get_nth_ancestor(const char *name, int len,
+			    unsigned char *result, int generation)
+{
+	unsigned char sha1[20];
+	int ret = get_sha1_1(name, len, sha1);
+	if (ret)
+		return ret;
+
+	while (generation--) {
+		struct commit *commit = lookup_commit_reference(sha1);
+
+		if (!commit || parse_commit(commit) || !commit->parents)
+			return -1;
+		memcpy(sha1, commit->parents->item->object.sha1, 20);
+	}
+	memcpy(result, sha1, 20);
+	return 0;
+}
+
 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 {
 	int parent, ret;
+	const char *cp;
 
 	/* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
 	if (len > 2 && name[len-2] == '^' &&
@@ -202,20 +250,40 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 		parent = name[len-1] - '0';
 		len -= 2;
 	}
-	else if (len > 1 && name[len-1] == '^')
+	else if (len > 1 && name[len-1] == '^') {
 		parent = 1;
-	else
+		len--;
+	} else
 		parent = -1;
 
-	if (0 <= parent) {
-		ret = get_parent(name, len-1, sha1, parent);
-		if (!ret)
-			return 0;
+	if (parent >= 0)
+		return get_parent(name, len, sha1, parent);
+
+	/* "name~3" is "name^^^",
+	 * "name~12" is "name^^^^^^^^^^^^", and
+	 * "name~" and "name~0" are name -- not "name^0"!
+	 */
+	parent = 0;
+	for (cp = name + len - 1; name <= cp; cp--) {
+		int ch = *cp;
+		if ('0' <= ch && ch <= '9')
+			continue;
+		if (ch != '~')
+			parent = -1;
+		break;
 	}
+	if (!parent && *cp == '~') {
+		int len1 = cp - name;
+		cp++;
+		while (cp < name + len)
+			parent = parent * 10 + *cp++ - '0';
+		return get_nth_ancestor(name, len1, sha1, parent);
+	}
+
 	ret = get_sha1_basic(name, len, sha1);
 	if (!ret)
 		return 0;
-	return get_short_sha1(name, sha1);
+	return get_short_sha1(name, len, sha1);
 }
 
 /*
@@ -224,5 +292,6 @@ static int get_sha1_1(const char *name, int len, unsigned char *sha1)
  */
 int get_sha1(const char *name, unsigned char *sha1)
 {
+	prepare_alt_odb();
 	return get_sha1_1(name, strlen(name), sha1);
 }