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-rw-r--r--sha1_name.c546
1 files changed, 546 insertions, 0 deletions
diff --git a/sha1_name.c b/sha1_name.c
new file mode 100644
index 0000000000..fbbde1cf7d
--- /dev/null
+++ b/sha1_name.c
@@ -0,0 +1,546 @@
+#include "cache.h"
+#include "tag.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+#include "tree-walk.h"
+#include "refs.h"
+
+static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
+{
+ struct alternate_object_database *alt;
+ char hex[40];
+ 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;
+
+ sprintf(hex, "%.2s", name);
+ 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))
+ continue;
+ 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 found;
+}
+
+static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
+{
+ do {
+ if (*a != *b)
+ return 0;
+ a++;
+ b++;
+ len -= 2;
+ } while (len > 1);
+ if (len)
+ if ((*a ^ *b) & 0xf0)
+ return 0;
+ return 1;
+}
+
+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 && found < 2; p = p->next) {
+ unsigned num = num_packed_objects(p);
+ unsigned first = 0, last = num;
+ while (first < last) {
+ unsigned mid = (first + last) / 2;
+ unsigned char now[20];
+ int cmp;
+
+ nth_packed_object_sha1(p, mid, now);
+ cmp = memcmp(match, now, 20);
+ if (!cmp) {
+ first = mid;
+ break;
+ }
+ if (cmp > 0) {
+ first = mid+1;
+ continue;
+ }
+ last = mid;
+ }
+ if (first < num) {
+ 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)) {
+ /* 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 SHORT_NAME_AMBIGUOUS;
+ memcpy(sha1, packed_sha1, 20);
+ return 0;
+}
+
+static int get_short_sha1(const char *name, int len, unsigned char *sha1,
+ int quietly)
+{
+ int i, status;
+ char canonical[40];
+ unsigned char res[20];
+
+ if (len < MINIMUM_ABBREV)
+ return -1;
+ memset(res, 0, 20);
+ memset(canonical, 'x', 40);
+ for (i = 0; i < len ;i++) {
+ unsigned char c = name[i];
+ unsigned char val;
+ if (c >= '0' && c <= '9')
+ val = c - '0';
+ else if (c >= 'a' && c <= 'f')
+ val = c - 'a' + 10;
+ else if (c >= 'A' && c <='F') {
+ val = c - 'A' + 10;
+ c -= 'A' - 'a';
+ }
+ else
+ return -1;
+ canonical[i] = c;
+ if (!(i & 1))
+ val <<= 4;
+ res[i >> 1] |= val;
+ }
+
+ 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;
+}
+
+const char *find_unique_abbrev(const unsigned char *sha1, int len)
+{
+ int status, is_null;
+ static char hex[41];
+
+ is_null = !memcmp(sha1, null_sha1, 20);
+ memcpy(hex, sha1_to_hex(sha1), 40);
+ if (len == 40)
+ return hex;
+ while (len < 40) {
+ unsigned char sha1_ret[20];
+ status = get_short_sha1(hex, len, sha1_ret, 1);
+ if (!status ||
+ (is_null && status != SHORT_NAME_AMBIGUOUS)) {
+ hex[len] = 0;
+ return hex;
+ }
+ if (status != SHORT_NAME_AMBIGUOUS)
+ return NULL;
+ len++;
+ }
+ return NULL;
+}
+
+static int ambiguous_path(const char *path, int len)
+{
+ int slash = 1;
+ int cnt;
+
+ for (cnt = 0; cnt < len; cnt++) {
+ switch (*path++) {
+ case '\0':
+ break;
+ case '/':
+ if (slash)
+ break;
+ slash = 1;
+ continue;
+ case '.':
+ continue;
+ default:
+ slash = 0;
+ continue;
+ }
+ break;
+ }
+ return slash;
+}
+
+static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
+{
+ static const char *fmt[] = {
+ "%.*s",
+ "refs/%.*s",
+ "refs/tags/%.*s",
+ "refs/heads/%.*s",
+ "refs/remotes/%.*s",
+ "refs/remotes/%.*s/HEAD",
+ NULL
+ };
+ static const char *warning = "warning: refname '%.*s' is ambiguous.\n";
+ const char **p, *pathname;
+ char *real_path = NULL;
+ int refs_found = 0, am;
+ unsigned long at_time = (unsigned long)-1;
+ unsigned char *this_result;
+ unsigned char sha1_from_ref[20];
+
+ if (len == 40 && !get_sha1_hex(str, sha1))
+ return 0;
+
+ /* At a given period of time? "@{2 hours ago}" */
+ for (am = 1; am < len - 1; am++) {
+ if (str[am] == '@' && str[am+1] == '{' && str[len-1] == '}') {
+ int date_len = len - am - 3;
+ char *date_spec = xmalloc(date_len + 1);
+ strncpy(date_spec, str + am + 2, date_len);
+ date_spec[date_len] = 0;
+ at_time = approxidate(date_spec);
+ free(date_spec);
+ len = am;
+ break;
+ }
+ }
+
+ /* Accept only unambiguous ref paths. */
+ if (ambiguous_path(str, len))
+ return -1;
+
+ for (p = fmt; *p; p++) {
+ this_result = refs_found ? sha1_from_ref : sha1;
+ pathname = resolve_ref(git_path(*p, len, str), this_result, 1);
+ if (pathname) {
+ if (!refs_found++)
+ real_path = strdup(pathname);
+ if (!warn_ambiguous_refs)
+ break;
+ }
+ }
+
+ if (!refs_found)
+ return -1;
+
+ if (warn_ambiguous_refs && refs_found > 1)
+ fprintf(stderr, warning, len, str);
+
+ if (at_time != (unsigned long)-1) {
+ read_ref_at(
+ real_path + strlen(git_path(".")) - 1,
+ at_time,
+ sha1);
+ }
+
+ free(real_path);
+ return 0;
+}
+
+static int get_sha1_1(const char *name, int len, unsigned char *sha1);
+
+static int get_parent(const char *name, int len,
+ unsigned char *result, int idx)
+{
+ unsigned char sha1[20];
+ int ret = get_sha1_1(name, len, sha1);
+ struct commit *commit;
+ struct commit_list *p;
+
+ if (ret)
+ return ret;
+ commit = lookup_commit_reference(sha1);
+ if (!commit)
+ return -1;
+ if (parse_commit(commit))
+ return -1;
+ if (!idx) {
+ memcpy(result, commit->object.sha1, 20);
+ return 0;
+ }
+ p = commit->parents;
+ while (p) {
+ if (!--idx) {
+ memcpy(result, p->item->object.sha1, 20);
+ return 0;
+ }
+ p = p->next;
+ }
+ 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 ret, has_suffix;
+ const char *cp;
+
+ /* "name~3" is "name^^^",
+ * "name~" and "name~0" are name -- not "name^0"!
+ * "name^" is not "name^0"; it is "name^1".
+ */
+ has_suffix = 0;
+ for (cp = name + len - 1; name <= cp; cp--) {
+ int ch = *cp;
+ if ('0' <= ch && ch <= '9')
+ continue;
+ if (ch == '~' || ch == '^')
+ has_suffix = ch;
+ break;
+ }
+
+ if (has_suffix) {
+ int num = 0;
+ int len1 = cp - name;
+ cp++;
+ while (cp < name + len)
+ num = num * 10 + *cp++ - '0';
+ if (has_suffix == '^') {
+ if (!num && len1 == len - 1)
+ num = 1;
+ return get_parent(name, len1, sha1, num);
+ }
+ /* else if (has_suffix == '~') -- goes without saying */
+ return get_nth_ancestor(name, len1, sha1, num);
+ }
+
+ 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, len, sha1, 0);
+}
+
+/*
+ * This is like "get_sha1_basic()", except it allows "sha1 expressions",
+ * notably "xyz^" for "parent of xyz"
+ */
+int get_sha1(const char *name, unsigned char *sha1)
+{
+ int ret, bracket_depth;
+ unsigned unused;
+ int namelen = strlen(name);
+ const char *cp;
+
+ prepare_alt_odb();
+ ret = get_sha1_1(name, namelen, sha1);
+ if (!ret)
+ return ret;
+ /* sha1:path --> object name of path in ent sha1
+ * :path -> object name of path in index
+ * :[0-3]:path -> object name of path in index at stage
+ */
+ if (name[0] == ':') {
+ int stage = 0;
+ struct cache_entry *ce;
+ int pos;
+ if (namelen < 3 ||
+ name[2] != ':' ||
+ name[1] < '0' || '3' < name[1])
+ cp = name + 1;
+ else {
+ stage = name[1] - '0';
+ cp = name + 3;
+ }
+ namelen = namelen - (cp - name);
+ if (!active_cache)
+ read_cache();
+ if (active_nr < 0)
+ return -1;
+ pos = cache_name_pos(cp, namelen);
+ if (pos < 0)
+ pos = -pos - 1;
+ while (pos < active_nr) {
+ ce = active_cache[pos];
+ if (ce_namelen(ce) != namelen ||
+ memcmp(ce->name, cp, namelen))
+ break;
+ if (ce_stage(ce) == stage) {
+ memcpy(sha1, ce->sha1, 20);
+ return 0;
+ }
+ pos++;
+ }
+ return -1;
+ }
+ for (cp = name, bracket_depth = 0; *cp; cp++) {
+ if (*cp == '{')
+ bracket_depth++;
+ else if (bracket_depth && *cp == '}')
+ bracket_depth--;
+ else if (!bracket_depth && *cp == ':')
+ break;
+ }
+ if (*cp == ':') {
+ unsigned char tree_sha1[20];
+ if (!get_sha1_1(name, cp-name, tree_sha1))
+ return get_tree_entry(tree_sha1, cp+1, sha1,
+ &unused);
+ }
+ return ret;
+}
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-17 22:52:33 +0000