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389 lines
8.6 KiB
389 lines
8.6 KiB
#include "cache.h" |
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#include "tag.h" |
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#include "commit.h" |
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#include "tree.h" |
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#include "blob.h" |
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|
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static int find_short_object_filename(int len, const char *name, unsigned char *sha1) |
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{ |
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struct alternate_object_database *alt; |
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char hex[40]; |
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int found = 0; |
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static struct alternate_object_database *fakeent; |
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|
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if (!fakeent) { |
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const char *objdir = get_object_directory(); |
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int objdir_len = strlen(objdir); |
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int entlen = objdir_len + 43; |
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fakeent = xmalloc(sizeof(*fakeent) + entlen); |
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memcpy(fakeent->base, objdir, objdir_len); |
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fakeent->name = fakeent->base + objdir_len + 1; |
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fakeent->name[-1] = '/'; |
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} |
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fakeent->next = alt_odb_list; |
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|
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sprintf(hex, "%.2s", name); |
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for (alt = fakeent; alt && found < 2; alt = alt->next) { |
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struct dirent *de; |
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DIR *dir; |
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sprintf(alt->name, "%.2s/", name); |
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dir = opendir(alt->base); |
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if (!dir) |
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continue; |
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while ((de = readdir(dir)) != NULL) { |
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if (strlen(de->d_name) != 38) |
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continue; |
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if (memcmp(de->d_name, name + 2, len - 2)) |
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continue; |
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if (!found) { |
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memcpy(hex + 2, de->d_name, 38); |
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found++; |
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} |
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else if (memcmp(hex + 2, de->d_name, 38)) { |
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found = 2; |
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break; |
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} |
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} |
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closedir(dir); |
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} |
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if (found == 1) |
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return get_sha1_hex(hex, sha1) == 0; |
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return found; |
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} |
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static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b) |
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{ |
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do { |
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if (*a != *b) |
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return 0; |
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a++; |
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b++; |
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len -= 2; |
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} while (len > 1); |
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if (len) |
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if ((*a ^ *b) & 0xf0) |
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return 0; |
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return 1; |
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} |
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static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1) |
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{ |
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struct packed_git *p; |
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unsigned char found_sha1[20]; |
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int found = 0; |
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prepare_packed_git(); |
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for (p = packed_git; p && found < 2; p = p->next) { |
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unsigned num = num_packed_objects(p); |
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unsigned first = 0, last = num; |
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while (first < last) { |
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unsigned mid = (first + last) / 2; |
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unsigned char now[20]; |
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int cmp; |
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nth_packed_object_sha1(p, mid, now); |
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cmp = memcmp(match, now, 20); |
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if (!cmp) { |
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first = mid; |
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break; |
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} |
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if (cmp > 0) { |
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first = mid+1; |
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continue; |
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} |
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last = mid; |
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} |
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if (first < num) { |
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unsigned char now[20], next[20]; |
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nth_packed_object_sha1(p, first, now); |
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if (match_sha(len, match, now)) { |
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if (nth_packed_object_sha1(p, first+1, next) || |
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!match_sha(len, match, next)) { |
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/* unique within this pack */ |
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if (!found) { |
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memcpy(found_sha1, now, 20); |
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found++; |
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} |
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else if (memcmp(found_sha1, now, 20)) { |
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found = 2; |
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break; |
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} |
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} |
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else { |
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/* not even unique within this pack */ |
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found = 2; |
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break; |
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} |
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} |
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} |
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} |
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if (found == 1) |
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memcpy(sha1, found_sha1, 20); |
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return found; |
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} |
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static int find_unique_short_object(int len, char *canonical, |
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unsigned char *res, unsigned char *sha1) |
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{ |
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int has_unpacked, has_packed; |
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unsigned char unpacked_sha1[20], packed_sha1[20]; |
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has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1); |
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has_packed = find_short_packed_object(len, res, packed_sha1); |
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if (!has_unpacked && !has_packed) |
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return -1; |
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if (1 < has_unpacked || 1 < has_packed) |
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return error("short SHA1 %.*s is ambiguous.", len, canonical); |
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if (has_unpacked != has_packed) { |
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memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20); |
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return 0; |
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} |
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/* Both have unique ones -- do they match? */ |
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if (memcmp(packed_sha1, unpacked_sha1, 20)) |
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return error("short SHA1 %.*s is ambiguous.", len, canonical); |
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memcpy(sha1, packed_sha1, 20); |
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return 0; |
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} |
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static int get_short_sha1(const char *name, int len, unsigned char *sha1) |
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{ |
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int i; |
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char canonical[40]; |
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unsigned char res[20]; |
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if (len < 4) |
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return -1; |
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memset(res, 0, 20); |
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memset(canonical, 'x', 40); |
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for (i = 0; i < len ;i++) { |
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unsigned char c = name[i]; |
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unsigned char val; |
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if (c >= '0' && c <= '9') |
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val = c - '0'; |
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else if (c >= 'a' && c <= 'f') |
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val = c - 'a' + 10; |
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else if (c >= 'A' && c <='F') { |
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val = c - 'A' + 10; |
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c -= 'A' - 'a'; |
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} |
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else |
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return -1; |
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canonical[i] = c; |
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if (!(i & 1)) |
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val <<= 4; |
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res[i >> 1] |= val; |
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} |
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return find_unique_short_object(i, canonical, res, sha1); |
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} |
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static int get_sha1_basic(const char *str, int len, unsigned char *sha1) |
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{ |
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static const char *prefix[] = { |
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"", |
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"refs", |
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"refs/tags", |
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"refs/heads", |
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NULL |
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}; |
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const char **p; |
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if (len == 40 && !get_sha1_hex(str, sha1)) |
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return 0; |
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for (p = prefix; *p; p++) { |
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char *pathname = git_path("%s/%.*s", *p, len, str); |
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if (!read_ref(pathname, sha1)) |
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return 0; |
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} |
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return -1; |
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} |
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static int get_sha1_1(const char *name, int len, unsigned char *sha1); |
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static int get_parent(const char *name, int len, |
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unsigned char *result, int idx) |
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{ |
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unsigned char sha1[20]; |
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int ret = get_sha1_1(name, len, sha1); |
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struct commit *commit; |
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struct commit_list *p; |
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if (ret) |
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return ret; |
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commit = lookup_commit_reference(sha1); |
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if (!commit) |
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return -1; |
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if (parse_commit(commit)) |
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return -1; |
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if (!idx) { |
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memcpy(result, commit->object.sha1, 20); |
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return 0; |
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} |
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p = commit->parents; |
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while (p) { |
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if (!--idx) { |
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memcpy(result, p->item->object.sha1, 20); |
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return 0; |
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} |
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p = p->next; |
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} |
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return -1; |
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} |
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static int get_nth_ancestor(const char *name, int len, |
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unsigned char *result, int generation) |
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{ |
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unsigned char sha1[20]; |
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int ret = get_sha1_1(name, len, sha1); |
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if (ret) |
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return ret; |
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while (generation--) { |
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struct commit *commit = lookup_commit_reference(sha1); |
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if (!commit || parse_commit(commit) || !commit->parents) |
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return -1; |
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memcpy(sha1, commit->parents->item->object.sha1, 20); |
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} |
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memcpy(result, sha1, 20); |
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return 0; |
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} |
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static int peel_onion(const char *name, int len, unsigned char *sha1) |
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{ |
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unsigned char outer[20]; |
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const char *sp; |
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const char *type_string = NULL; |
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struct object *o; |
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/* |
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* "ref^{type}" dereferences ref repeatedly until you cannot |
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* dereference anymore, or you get an object of given type, |
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* whichever comes first. "ref^{}" means just dereference |
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* tags until you get a non-tag. "ref^0" is a shorthand for |
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* "ref^{commit}". "commit^{tree}" could be used to find the |
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* top-level tree of the given commit. |
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*/ |
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if (len < 4 || name[len-1] != '}') |
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return -1; |
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for (sp = name + len - 1; name <= sp; sp--) { |
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int ch = *sp; |
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if (ch == '{' && name < sp && sp[-1] == '^') |
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break; |
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} |
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if (sp <= name) |
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return -1; |
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sp++; /* beginning of type name, or closing brace for empty */ |
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if (!strncmp(commit_type, sp, 6) && sp[6] == '}') |
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type_string = commit_type; |
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else if (!strncmp(tree_type, sp, 4) && sp[4] == '}') |
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type_string = tree_type; |
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else if (!strncmp(blob_type, sp, 4) && sp[4] == '}') |
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type_string = blob_type; |
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else if (sp[0] == '}') |
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type_string = NULL; |
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else |
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return -1; |
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if (get_sha1_1(name, sp - name - 2, outer)) |
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return -1; |
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o = parse_object(outer); |
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if (!o) |
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return -1; |
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if (!type_string) { |
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o = deref_tag(o); |
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memcpy(sha1, o->sha1, 20); |
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} |
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else { |
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/* At this point, the syntax look correct, so |
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* if we do not get the needed object, we should |
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* barf. |
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*/ |
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while (1) { |
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if (!o) |
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return -1; |
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if (o->type == type_string) { |
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memcpy(sha1, o->sha1, 20); |
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return 0; |
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} |
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if (o->type == tag_type) |
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o = ((struct tag*) o)->tagged; |
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else if (o->type == commit_type) |
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o = &(((struct commit *) o)->tree->object); |
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else |
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return error("%.*s: expected %s type, but the object dereferences to %s type", |
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len, name, type_string, |
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o->type); |
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if (!o->parsed) |
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parse_object(o->sha1); |
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} |
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} |
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return 0; |
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} |
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static int get_sha1_1(const char *name, int len, unsigned char *sha1) |
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{ |
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int parent, ret; |
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const char *cp; |
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/* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */ |
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if (len > 2 && name[len-2] == '^' && |
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name[len-1] >= '0' && name[len-1] <= '9') { |
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parent = name[len-1] - '0'; |
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len -= 2; |
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} |
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else if (len > 1 && name[len-1] == '^') { |
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parent = 1; |
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len--; |
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} else |
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parent = -1; |
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if (parent >= 0) |
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return get_parent(name, len, sha1, parent); |
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/* "name~3" is "name^^^", |
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* "name~12" is "name^^^^^^^^^^^^", and |
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* "name~" and "name~0" are name -- not "name^0"! |
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*/ |
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parent = 0; |
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for (cp = name + len - 1; name <= cp; cp--) { |
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int ch = *cp; |
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if ('0' <= ch && ch <= '9') |
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continue; |
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if (ch != '~') |
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parent = -1; |
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break; |
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} |
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if (!parent && *cp == '~') { |
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int len1 = cp - name; |
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cp++; |
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while (cp < name + len) |
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parent = parent * 10 + *cp++ - '0'; |
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return get_nth_ancestor(name, len1, sha1, parent); |
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} |
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ret = peel_onion(name, len, sha1); |
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if (!ret) |
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return 0; |
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ret = get_sha1_basic(name, len, sha1); |
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if (!ret) |
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return 0; |
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return get_short_sha1(name, len, sha1); |
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} |
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/* |
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* This is like "get_sha1_basic()", except it allows "sha1 expressions", |
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* notably "xyz^" for "parent of xyz" |
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*/ |
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int get_sha1(const char *name, unsigned char *sha1) |
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{ |
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prepare_alt_odb(); |
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return get_sha1_1(name, strlen(name), sha1); |
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}
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