#include "cache.h"
+#include "tag.h"
#include "commit.h"
+#include "tree.h"
+#include "blob.h"
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)
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) {
unsigned char now[20], next[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 (nth_packed_object_sha1(p, first+1, next) ||
+ !match_sha(len, match, next)) {
+ /* unique within this pack */
+ if (!found) {
+ memcpy(found_sha1, now, 20);
+ found++;
+ }
+ else if (memcmp(found_sha1, now, 20)) {
+ found = 2;
+ break;
+ }
+ }
+ else {
+ /* not even unique within this pack */
+ found = 2;
+ break;
}
}
}
}
+ if (found == 1)
+ memcpy(sha1, found_sha1, 20);
+ return found;
+}
+
+#define SHORT_NAME_NOT_FOUND (-1)
+#define SHORT_NAME_AMBIGUOUS (-2)
+
+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 SHORT_NAME_NOT_FOUND;
+ if (1 < has_unpacked || 1 < has_packed)
+ return SHORT_NAME_AMBIGUOUS;
+ 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 -2;
+ 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 quietly)
{
- int i;
+ int i, status;
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')
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;
+
+ status = find_unique_short_object(i, canonical, res, sha1);
+ if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
+ return error("short SHA1 %.*s is ambiguous.", len, canonical);
+ return status;
}
-static int get_sha1_file(const char *path, unsigned char *result)
+const char *find_unique_abbrev(const unsigned char *sha1, int len)
{
- char buffer[60];
- int fd = open(path, O_RDONLY);
- int len;
+ int status;
+ static char hex[41];
+ memcpy(hex, sha1_to_hex(sha1), 40);
+ while (len < 40) {
+ unsigned char sha1_ret[20];
+ status = get_short_sha1(hex, len, sha1_ret, 1);
+ if (!status) {
+ hex[len] = 0;
+ return hex;
+ }
+ if (status != SHORT_NAME_AMBIGUOUS)
+ return NULL;
+ len++;
+ }
+ return NULL;
+}
- if (fd < 0)
- return -1;
- len = read(fd, buffer, sizeof(buffer));
- close(fd);
- if (len < 40)
- return -1;
- return get_sha1_hex(buffer, result);
+static int ambiguous_path(const char *path)
+{
+ int slash = 1;
+
+ for (;;) {
+ switch (*path++) {
+ case '\0':
+ break;
+ case '/':
+ if (slash)
+ break;
+ slash = 1;
+ continue;
+ case '.':
+ continue;
+ default:
+ slash = 0;
+ continue;
+ }
+ return slash;
+ }
}
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
"refs",
"refs/tags",
"refs/heads",
- "refs/snap",
NULL
};
const char **p;
+ int found = 0;
- if (!get_sha1_hex(str, sha1))
+ if (len == 40 && !get_sha1_hex(str, sha1))
return 0;
+ /* Accept only unambiguous ref paths. */
+ if (ambiguous_path(str))
+ return -1;
+
for (p = prefix; *p; p++) {
char *pathname = git_path("%s/%.*s", *p, len, str);
- if (!get_sha1_file(pathname, sha1))
- return 0;
+ if (!read_ref(pathname, sha1)) {
+ /* Must be unique; i.e. when heads/foo and
+ * tags/foo are both present, reject "foo".
+ * Note that read_ref() eventually calls
+ * get_sha1_hex() which can smudge initial
+ * part of the buffer even if what is read
+ * is found to be invalid halfway.
+ */
+ if (1 < found++)
+ return -1;
+ }
}
-
+ if (found == 1)
+ return 0;
return -1;
}
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 peel_onion(const char *name, int len, unsigned char *sha1)
+{
+ unsigned char outer[20];
+ const char *sp;
+ const char *type_string = NULL;
+ struct object *o;
+
+ /*
+ * "ref^{type}" dereferences ref repeatedly until you cannot
+ * dereference anymore, or you get an object of given type,
+ * whichever comes first. "ref^{}" means just dereference
+ * tags until you get a non-tag. "ref^0" is a shorthand for
+ * "ref^{commit}". "commit^{tree}" could be used to find the
+ * top-level tree of the given commit.
+ */
+ if (len < 4 || name[len-1] != '}')
+ return -1;
+
+ for (sp = name + len - 1; name <= sp; sp--) {
+ int ch = *sp;
+ if (ch == '{' && name < sp && sp[-1] == '^')
+ break;
+ }
+ if (sp <= name)
+ return -1;
+
+ sp++; /* beginning of type name, or closing brace for empty */
+ if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
+ type_string = commit_type;
+ else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
+ type_string = tree_type;
+ else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
+ type_string = blob_type;
+ else if (sp[0] == '}')
+ type_string = NULL;
+ else
+ return -1;
+
+ if (get_sha1_1(name, sp - name - 2, outer))
+ return -1;
+
+ o = parse_object(outer);
+ if (!o)
+ return -1;
+ if (!type_string) {
+ o = deref_tag(o, name, sp - name - 2);
+ if (!o || (!o->parsed && !parse_object(o->sha1)))
+ return -1;
+ memcpy(sha1, o->sha1, 20);
+ }
+ else {
+ /* At this point, the syntax look correct, so
+ * if we do not get the needed object, we should
+ * barf.
+ */
+
+ while (1) {
+ if (!o || (!o->parsed && !parse_object(o->sha1)))
+ return -1;
+ if (o->type == type_string) {
+ memcpy(sha1, o->sha1, 20);
+ return 0;
+ }
+ if (o->type == tag_type)
+ o = ((struct tag*) o)->tagged;
+ else if (o->type == commit_type)
+ o = &(((struct commit *) o)->tree->object);
+ else
+ return error("%.*s: expected %s type, but the object dereferences to %s type",
+ len, name, type_string,
+ o->type);
+ if (!o->parsed)
+ parse_object(o->sha1);
+ }
+ }
+ 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] == '^' &&
} else
parent = -1;
- if (0 <= parent) {
- ret = get_parent(name, len, sha1, parent);
- if (!ret)
- return 0;
- else if(parent>0)
- return ret;
+ 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 = peel_onion(name, len, sha1);
+ if (!ret)
+ return 0;
+
ret = get_sha1_basic(name, len, sha1);
if (!ret)
return 0;
- return get_short_sha1(name, sha1);
+ return get_short_sha1(name, len, sha1, 0);
}
/*
*/
int get_sha1(const char *name, unsigned char *sha1)
{
+ prepare_alt_odb();
return get_sha1_1(name, strlen(name), sha1);
}