diff options
Diffstat (limited to 'sha1_name.c')
| -rw-r--r-- | sha1_name.c | 717 |
1 files changed, 717 insertions, 0 deletions
diff --git a/sha1_name.c b/sha1_name.c new file mode 100644 index 0000000000..2d727d54dc --- /dev/null +++ b/sha1_name.c @@ -0,0 +1,717 @@ +#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; + const unsigned char *found_sha1 = NULL; + int found = 0; + + prepare_packed_git(); + for (p = packed_git; p && found < 2; p = p->next) { + uint32_t num, last; + uint32_t first = 0; + open_pack_index(p); + num = p->num_objects; + last = num; + while (first < last) { + uint32_t mid = (first + last) / 2; + const unsigned char *now; + int cmp; + + now = nth_packed_object_sha1(p, mid); + cmp = hashcmp(match, now); + if (!cmp) { + first = mid; + break; + } + if (cmp > 0) { + first = mid+1; + continue; + } + last = mid; + } + if (first < num) { + const unsigned char *now, *next; + now = nth_packed_object_sha1(p, first); + if (match_sha(len, match, now)) { + next = nth_packed_object_sha1(p, first+1); + if (!next|| !match_sha(len, match, next)) { + /* unique within this pack */ + if (!found) { + found_sha1 = now; + found++; + } + else if (hashcmp(found_sha1, now)) { + found = 2; + break; + } + } + else { + /* not even unique within this pack */ + found = 2; + break; + } + } + } + } + if (found == 1) + hashcpy(sha1, found_sha1); + 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]; + + prepare_alt_odb(); + 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) { + 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); + 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 || len > 40) + return -1; + hashclr(res); + 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 = is_null_sha1(sha1); + memcpy(hex, sha1_to_hex(sha1), 40); + if (len == 40 || !len) + 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 const char *ref_fmt[] = { + "%.*s", + "refs/%.*s", + "refs/tags/%.*s", + "refs/heads/%.*s", + "refs/remotes/%.*s", + "refs/remotes/%.*s/HEAD", + NULL +}; + +int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) +{ + const char **p, *r; + int refs_found = 0; + + *ref = NULL; + for (p = ref_fmt; *p; p++) { + unsigned char sha1_from_ref[20]; + unsigned char *this_result; + + this_result = refs_found ? sha1_from_ref : sha1; + r = resolve_ref(mkpath(*p, len, str), this_result, 1, NULL); + if (r) { + if (!refs_found++) + *ref = xstrdup(r); + if (!warn_ambiguous_refs) + break; + } + } + return refs_found; +} + +int dwim_log(const char *str, int len, unsigned char *sha1, char **log) +{ + const char **p; + int logs_found = 0; + + *log = NULL; + for (p = ref_fmt; *p; p++) { + struct stat st; + unsigned char hash[20]; + char path[PATH_MAX]; + const char *ref, *it; + + strcpy(path, mkpath(*p, len, str)); + ref = resolve_ref(path, hash, 0, NULL); + if (!ref) + continue; + if (!stat(git_path("logs/%s", path), &st) && + S_ISREG(st.st_mode)) + it = path; + else if (strcmp(ref, path) && + !stat(git_path("logs/%s", ref), &st) && + S_ISREG(st.st_mode)) + it = ref; + else + continue; + if (!logs_found++) { + *log = xstrdup(it); + hashcpy(sha1, hash); + } + if (!warn_ambiguous_refs) + break; + } + return logs_found; +} + +static int get_sha1_basic(const char *str, int len, unsigned char *sha1) +{ + static const char *warning = "warning: refname '%.*s' is ambiguous.\n"; + char *real_ref = NULL; + int refs_found = 0; + int at, reflog_len; + + if (len == 40 && !get_sha1_hex(str, sha1)) + return 0; + + /* basic@{time or number} format to query ref-log */ + reflog_len = at = 0; + if (str[len-1] == '}') { + for (at = 0; at < len - 1; at++) { + if (str[at] == '@' && str[at+1] == '{') { + reflog_len = (len-1) - (at+2); + len = at; + break; + } + } + } + + /* Accept only unambiguous ref paths. */ + if (len && ambiguous_path(str, len)) + return -1; + + if (!len && reflog_len) { + /* allow "@{...}" to mean the current branch reflog */ + refs_found = dwim_ref("HEAD", 4, sha1, &real_ref); + } else if (reflog_len) + refs_found = dwim_log(str, len, sha1, &real_ref); + else + refs_found = dwim_ref(str, len, sha1, &real_ref); + + if (!refs_found) + return -1; + + if (warn_ambiguous_refs && refs_found > 1) + fprintf(stderr, warning, len, str); + + if (reflog_len) { + int nth, i; + unsigned long at_time; + unsigned long co_time; + int co_tz, co_cnt; + + /* Is it asking for N-th entry, or approxidate? */ + for (i = nth = 0; 0 <= nth && i < reflog_len; i++) { + char ch = str[at+2+i]; + if ('0' <= ch && ch <= '9') + nth = nth * 10 + ch - '0'; + else + nth = -1; + } + if (0 <= nth) + at_time = 0; + else + at_time = approxidate(str + at + 2); + if (read_ref_at(real_ref, at_time, nth, sha1, NULL, + &co_time, &co_tz, &co_cnt)) { + if (at_time) + fprintf(stderr, + "warning: Log for '%.*s' only goes " + "back to %s.\n", len, str, + show_date(co_time, co_tz, DATE_RFC2822)); + else + fprintf(stderr, + "warning: Log for '%.*s' only has " + "%d entries.\n", len, str, co_cnt); + } + } + + free(real_ref); + 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) { + hashcpy(result, commit->object.sha1); + return 0; + } + p = commit->parents; + while (p) { + if (!--idx) { + hashcpy(result, p->item->object.sha1); + 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; + hashcpy(sha1, commit->parents->item->object.sha1); + } + hashcpy(result, sha1); + return 0; +} + +static int peel_onion(const char *name, int len, unsigned char *sha1) +{ + unsigned char outer[20]; + const char *sp; + unsigned int expected_type = 0; + 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] == '}') + expected_type = OBJ_COMMIT; + else if (!strncmp(tree_type, sp, 4) && sp[4] == '}') + expected_type = OBJ_TREE; + else if (!strncmp(blob_type, sp, 4) && sp[4] == '}') + expected_type = OBJ_BLOB; + else if (sp[0] == '}') + expected_type = OBJ_NONE; + else + return -1; + + if (get_sha1_1(name, sp - name - 2, outer)) + return -1; + + o = parse_object(outer); + if (!o) + return -1; + if (!expected_type) { + o = deref_tag(o, name, sp - name - 2); + if (!o || (!o->parsed && !parse_object(o->sha1))) + return -1; + hashcpy(sha1, o->sha1); + } + 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 == expected_type) { + hashcpy(sha1, o->sha1); + return 0; + } + if (o->type == OBJ_TAG) + o = ((struct tag*) o)->tagged; + else if (o->type == OBJ_COMMIT) + o = &(((struct commit *) o)->tree->object); + else + return error("%.*s: expected %s type, but the object dereferences to %s type", + len, name, typename(expected_type), + typename(o->type)); + if (!o->parsed) + parse_object(o->sha1); + } + } + return 0; +} + +static int get_describe_name(const char *name, int len, unsigned char *sha1) +{ + const char *cp; + + for (cp = name + len - 1; name + 2 <= cp; cp--) { + char ch = *cp; + if (hexval(ch) & ~0377) { + /* We must be looking at g in "SOMETHING-g" + * for it to be describe output. + */ + if (ch == 'g' && cp[-1] == '-') { + cp++; + len -= cp - name; + return get_short_sha1(cp, len, sha1, 1); + } + } + } + return -1; +} + +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; + + /* It could be describe output that is "SOMETHING-gXXXX" */ + ret = get_describe_name(name, len, sha1); + if (!ret) + return 0; + + return get_short_sha1(name, len, sha1, 0); +} + +static int handle_one_ref(const char *path, + const unsigned char *sha1, int flag, void *cb_data) +{ + struct commit_list **list = cb_data; + struct object *object = parse_object(sha1); + if (!object) + return 0; + if (object->type == OBJ_TAG) + object = deref_tag(object, path, strlen(path)); + if (object->type != OBJ_COMMIT) + return 0; + insert_by_date((struct commit *)object, list); + return 0; +} + +/* + * This interprets names like ':/Initial revision of "git"' by searching + * through history and returning the first commit whose message starts + * with the given string. + * + * For future extension, ':/!' is reserved. If you want to match a message + * beginning with a '!', you have to repeat the exclamation mark. + */ + +#define ONELINE_SEEN (1u<<20) +static int get_sha1_oneline(const char *prefix, unsigned char *sha1) +{ + struct commit_list *list = NULL, *backup = NULL, *l; + int retval = -1; + + if (prefix[0] == '!') { + if (prefix[1] != '!') + die ("Invalid search pattern: %s", prefix); + prefix++; + } + if (!save_commit_buffer) + return error("Could not expand oneline-name."); + for_each_ref(handle_one_ref, &list); + for (l = list; l; l = l->next) + commit_list_insert(l->item, &backup); + while (list) { + char *p; + struct commit *commit; + + commit = pop_most_recent_commit(&list, ONELINE_SEEN); + parse_object(commit->object.sha1); + if (!commit->buffer || !(p = strstr(commit->buffer, "\n\n"))) + continue; + if (!prefixcmp(p + 2, prefix)) { + hashcpy(sha1, commit->object.sha1); + retval = 0; + break; + } + } + free_commit_list(list); + for (l = backup; l; l = l->next) + clear_commit_marks(l->item, ONELINE_SEEN); + return retval; +} + +/* + * 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) +{ + unsigned unused; + return get_sha1_with_mode(name, sha1, &unused); +} + +int get_sha1_with_mode(const char *name, unsigned char *sha1, unsigned *mode) +{ + int ret, bracket_depth; + int namelen = strlen(name); + const char *cp; + + *mode = S_IFINVALID; + 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 > 2 && name[1] == '/') + return get_sha1_oneline(name + 2, sha1); + 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(); + 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) { + hashcpy(sha1, ce->sha1); + *mode = ntohl(ce->ce_mode); + 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, + mode); + } + return ret; +} |