1#include "cache.h" 2#include "lockfile.h" 3#include "refs.h" 4#include "object.h" 5#include "tag.h" 6#include "dir.h" 7#include "string-list.h" 8 9/* 10 * How to handle various characters in refnames: 11 * 0: An acceptable character for refs 12 * 1: End-of-component 13 * 2: ., look for a preceding . to reject .. in refs 14 * 3: {, look for a preceding @ to reject @{ in refs 15 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 16 */ 17static unsigned char refname_disposition[256] = { 18 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 19 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 20 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1, 21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0, 24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 26}; 27 28/* 29 * Used as a flag to ref_transaction_delete when a loose ref is being 30 * pruned. 31 */ 32#define REF_ISPRUNING 0x0100 33/* 34 * Try to read one refname component from the front of refname. 35 * Return the length of the component found, or -1 if the component is 36 * not legal. It is legal if it is something reasonable to have under 37 * ".git/refs/"; We do not like it if: 38 * 39 * - any path component of it begins with ".", or 40 * - it has double dots "..", or 41 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 42 * - it ends with a "/". 43 * - it ends with ".lock" 44 * - it contains a "\" (backslash) 45 */ 46static int check_refname_component(const char *refname, int flags) 47{ 48 const char *cp; 49 char last = '\0'; 50 51 for (cp = refname; ; cp++) { 52 int ch = *cp & 255; 53 unsigned char disp = refname_disposition[ch]; 54 switch (disp) { 55 case 1: 56 goto out; 57 case 2: 58 if (last == '.') 59 return -1; /* Refname contains "..". */ 60 break; 61 case 3: 62 if (last == '@') 63 return -1; /* Refname contains "@{". */ 64 break; 65 case 4: 66 return -1; 67 } 68 last = ch; 69 } 70out: 71 if (cp == refname) 72 return 0; /* Component has zero length. */ 73 if (refname[0] == '.') 74 return -1; /* Component starts with '.'. */ 75 if (cp - refname >= LOCK_SUFFIX_LEN && 76 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 77 return -1; /* Refname ends with ".lock". */ 78 return cp - refname; 79} 80 81int check_refname_format(const char *refname, int flags) 82{ 83 int component_len, component_count = 0; 84 85 if (!strcmp(refname, "@")) 86 /* Refname is a single character '@'. */ 87 return -1; 88 89 while (1) { 90 /* We are at the start of a path component. */ 91 component_len = check_refname_component(refname, flags); 92 if (component_len <= 0) { 93 if ((flags & REFNAME_REFSPEC_PATTERN) && 94 refname[0] == '*' && 95 (refname[1] == '\0' || refname[1] == '/')) { 96 /* Accept one wildcard as a full refname component. */ 97 flags &= ~REFNAME_REFSPEC_PATTERN; 98 component_len = 1; 99 } else { 100 return -1; 101 } 102 } 103 component_count++; 104 if (refname[component_len] == '\0') 105 break; 106 /* Skip to next component. */ 107 refname += component_len + 1; 108 } 109 110 if (refname[component_len - 1] == '.') 111 return -1; /* Refname ends with '.'. */ 112 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) 113 return -1; /* Refname has only one component. */ 114 return 0; 115} 116 117struct ref_entry; 118 119/* 120 * Information used (along with the information in ref_entry) to 121 * describe a single cached reference. This data structure only 122 * occurs embedded in a union in struct ref_entry, and only when 123 * (ref_entry->flag & REF_DIR) is zero. 124 */ 125struct ref_value { 126 /* 127 * The name of the object to which this reference resolves 128 * (which may be a tag object). If REF_ISBROKEN, this is 129 * null. If REF_ISSYMREF, then this is the name of the object 130 * referred to by the last reference in the symlink chain. 131 */ 132 unsigned char sha1[20]; 133 134 /* 135 * If REF_KNOWS_PEELED, then this field holds the peeled value 136 * of this reference, or null if the reference is known not to 137 * be peelable. See the documentation for peel_ref() for an 138 * exact definition of "peelable". 139 */ 140 unsigned char peeled[20]; 141}; 142 143struct ref_cache; 144 145/* 146 * Information used (along with the information in ref_entry) to 147 * describe a level in the hierarchy of references. This data 148 * structure only occurs embedded in a union in struct ref_entry, and 149 * only when (ref_entry.flag & REF_DIR) is set. In that case, 150 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 151 * in the directory have already been read: 152 * 153 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 154 * or packed references, already read. 155 * 156 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 157 * references that hasn't been read yet (nor has any of its 158 * subdirectories). 159 * 160 * Entries within a directory are stored within a growable array of 161 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 162 * sorted are sorted by their component name in strcmp() order and the 163 * remaining entries are unsorted. 164 * 165 * Loose references are read lazily, one directory at a time. When a 166 * directory of loose references is read, then all of the references 167 * in that directory are stored, and REF_INCOMPLETE stubs are created 168 * for any subdirectories, but the subdirectories themselves are not 169 * read. The reading is triggered by get_ref_dir(). 170 */ 171struct ref_dir { 172 int nr, alloc; 173 174 /* 175 * Entries with index 0 <= i < sorted are sorted by name. New 176 * entries are appended to the list unsorted, and are sorted 177 * only when required; thus we avoid the need to sort the list 178 * after the addition of every reference. 179 */ 180 int sorted; 181 182 /* A pointer to the ref_cache that contains this ref_dir. */ 183 struct ref_cache *ref_cache; 184 185 struct ref_entry **entries; 186}; 187 188/* 189 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 190 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 191 * public values; see refs.h. 192 */ 193 194/* 195 * The field ref_entry->u.value.peeled of this value entry contains 196 * the correct peeled value for the reference, which might be 197 * null_sha1 if the reference is not a tag or if it is broken. 198 */ 199#define REF_KNOWS_PEELED 0x10 200 201/* ref_entry represents a directory of references */ 202#define REF_DIR 0x20 203 204/* 205 * Entry has not yet been read from disk (used only for REF_DIR 206 * entries representing loose references) 207 */ 208#define REF_INCOMPLETE 0x40 209 210/* 211 * A ref_entry represents either a reference or a "subdirectory" of 212 * references. 213 * 214 * Each directory in the reference namespace is represented by a 215 * ref_entry with (flags & REF_DIR) set and containing a subdir member 216 * that holds the entries in that directory that have been read so 217 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 218 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 219 * used for loose reference directories. 220 * 221 * References are represented by a ref_entry with (flags & REF_DIR) 222 * unset and a value member that describes the reference's value. The 223 * flag member is at the ref_entry level, but it is also needed to 224 * interpret the contents of the value field (in other words, a 225 * ref_value object is not very much use without the enclosing 226 * ref_entry). 227 * 228 * Reference names cannot end with slash and directories' names are 229 * always stored with a trailing slash (except for the top-level 230 * directory, which is always denoted by ""). This has two nice 231 * consequences: (1) when the entries in each subdir are sorted 232 * lexicographically by name (as they usually are), the references in 233 * a whole tree can be generated in lexicographic order by traversing 234 * the tree in left-to-right, depth-first order; (2) the names of 235 * references and subdirectories cannot conflict, and therefore the 236 * presence of an empty subdirectory does not block the creation of a 237 * similarly-named reference. (The fact that reference names with the 238 * same leading components can conflict *with each other* is a 239 * separate issue that is regulated by is_refname_available().) 240 * 241 * Please note that the name field contains the fully-qualified 242 * reference (or subdirectory) name. Space could be saved by only 243 * storing the relative names. But that would require the full names 244 * to be generated on the fly when iterating in do_for_each_ref(), and 245 * would break callback functions, who have always been able to assume 246 * that the name strings that they are passed will not be freed during 247 * the iteration. 248 */ 249struct ref_entry { 250 unsigned char flag; /* ISSYMREF? ISPACKED? */ 251 union { 252 struct ref_value value; /* if not (flags&REF_DIR) */ 253 struct ref_dir subdir; /* if (flags&REF_DIR) */ 254 } u; 255 /* 256 * The full name of the reference (e.g., "refs/heads/master") 257 * or the full name of the directory with a trailing slash 258 * (e.g., "refs/heads/"): 259 */ 260 char name[FLEX_ARRAY]; 261}; 262 263static void read_loose_refs(const char *dirname, struct ref_dir *dir); 264 265static struct ref_dir *get_ref_dir(struct ref_entry *entry) 266{ 267 struct ref_dir *dir; 268 assert(entry->flag & REF_DIR); 269 dir = &entry->u.subdir; 270 if (entry->flag & REF_INCOMPLETE) { 271 read_loose_refs(entry->name, dir); 272 entry->flag &= ~REF_INCOMPLETE; 273 } 274 return dir; 275} 276 277/* 278 * Check if a refname is safe. 279 * For refs that start with "refs/" we consider it safe as long they do 280 * not try to resolve to outside of refs/. 281 * 282 * For all other refs we only consider them safe iff they only contain 283 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like 284 * "config"). 285 */ 286static int refname_is_safe(const char *refname) 287{ 288 if (starts_with(refname, "refs/")) { 289 char *buf; 290 int result; 291 292 buf = xmalloc(strlen(refname) + 1); 293 /* 294 * Does the refname try to escape refs/? 295 * For example: refs/foo/../bar is safe but refs/foo/../../bar 296 * is not. 297 */ 298 result = !normalize_path_copy(buf, refname + strlen("refs/")); 299 free(buf); 300 return result; 301 } 302 while (*refname) { 303 if (!isupper(*refname) && *refname != '_') 304 return 0; 305 refname++; 306 } 307 return 1; 308} 309 310static struct ref_entry *create_ref_entry(const char *refname, 311 const unsigned char *sha1, int flag, 312 int check_name) 313{ 314 int len; 315 struct ref_entry *ref; 316 317 if (check_name && 318 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 319 die("Reference has invalid format: '%s'", refname); 320 if (!check_name && !refname_is_safe(refname)) 321 die("Reference has invalid name: '%s'", refname); 322 len = strlen(refname) + 1; 323 ref = xmalloc(sizeof(struct ref_entry) + len); 324 hashcpy(ref->u.value.sha1, sha1); 325 hashclr(ref->u.value.peeled); 326 memcpy(ref->name, refname, len); 327 ref->flag = flag; 328 return ref; 329} 330 331static void clear_ref_dir(struct ref_dir *dir); 332 333static void free_ref_entry(struct ref_entry *entry) 334{ 335 if (entry->flag & REF_DIR) { 336 /* 337 * Do not use get_ref_dir() here, as that might 338 * trigger the reading of loose refs. 339 */ 340 clear_ref_dir(&entry->u.subdir); 341 } 342 free(entry); 343} 344 345/* 346 * Add a ref_entry to the end of dir (unsorted). Entry is always 347 * stored directly in dir; no recursion into subdirectories is 348 * done. 349 */ 350static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 351{ 352 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 353 dir->entries[dir->nr++] = entry; 354 /* optimize for the case that entries are added in order */ 355 if (dir->nr == 1 || 356 (dir->nr == dir->sorted + 1 && 357 strcmp(dir->entries[dir->nr - 2]->name, 358 dir->entries[dir->nr - 1]->name) < 0)) 359 dir->sorted = dir->nr; 360} 361 362/* 363 * Clear and free all entries in dir, recursively. 364 */ 365static void clear_ref_dir(struct ref_dir *dir) 366{ 367 int i; 368 for (i = 0; i < dir->nr; i++) 369 free_ref_entry(dir->entries[i]); 370 free(dir->entries); 371 dir->sorted = dir->nr = dir->alloc = 0; 372 dir->entries = NULL; 373} 374 375/* 376 * Create a struct ref_entry object for the specified dirname. 377 * dirname is the name of the directory with a trailing slash (e.g., 378 * "refs/heads/") or "" for the top-level directory. 379 */ 380static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 381 const char *dirname, size_t len, 382 int incomplete) 383{ 384 struct ref_entry *direntry; 385 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); 386 memcpy(direntry->name, dirname, len); 387 direntry->name[len] = '\0'; 388 direntry->u.subdir.ref_cache = ref_cache; 389 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 390 return direntry; 391} 392 393static int ref_entry_cmp(const void *a, const void *b) 394{ 395 struct ref_entry *one = *(struct ref_entry **)a; 396 struct ref_entry *two = *(struct ref_entry **)b; 397 return strcmp(one->name, two->name); 398} 399 400static void sort_ref_dir(struct ref_dir *dir); 401 402struct string_slice { 403 size_t len; 404 const char *str; 405}; 406 407static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 408{ 409 const struct string_slice *key = key_; 410 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 411 int cmp = strncmp(key->str, ent->name, key->len); 412 if (cmp) 413 return cmp; 414 return '\0' - (unsigned char)ent->name[key->len]; 415} 416 417/* 418 * Return the index of the entry with the given refname from the 419 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 420 * no such entry is found. dir must already be complete. 421 */ 422static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 423{ 424 struct ref_entry **r; 425 struct string_slice key; 426 427 if (refname == NULL || !dir->nr) 428 return -1; 429 430 sort_ref_dir(dir); 431 key.len = len; 432 key.str = refname; 433 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 434 ref_entry_cmp_sslice); 435 436 if (r == NULL) 437 return -1; 438 439 return r - dir->entries; 440} 441 442/* 443 * Search for a directory entry directly within dir (without 444 * recursing). Sort dir if necessary. subdirname must be a directory 445 * name (i.e., end in '/'). If mkdir is set, then create the 446 * directory if it is missing; otherwise, return NULL if the desired 447 * directory cannot be found. dir must already be complete. 448 */ 449static struct ref_dir *search_for_subdir(struct ref_dir *dir, 450 const char *subdirname, size_t len, 451 int mkdir) 452{ 453 int entry_index = search_ref_dir(dir, subdirname, len); 454 struct ref_entry *entry; 455 if (entry_index == -1) { 456 if (!mkdir) 457 return NULL; 458 /* 459 * Since dir is complete, the absence of a subdir 460 * means that the subdir really doesn't exist; 461 * therefore, create an empty record for it but mark 462 * the record complete. 463 */ 464 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 465 add_entry_to_dir(dir, entry); 466 } else { 467 entry = dir->entries[entry_index]; 468 } 469 return get_ref_dir(entry); 470} 471 472/* 473 * If refname is a reference name, find the ref_dir within the dir 474 * tree that should hold refname. If refname is a directory name 475 * (i.e., ends in '/'), then return that ref_dir itself. dir must 476 * represent the top-level directory and must already be complete. 477 * Sort ref_dirs and recurse into subdirectories as necessary. If 478 * mkdir is set, then create any missing directories; otherwise, 479 * return NULL if the desired directory cannot be found. 480 */ 481static struct ref_dir *find_containing_dir(struct ref_dir *dir, 482 const char *refname, int mkdir) 483{ 484 const char *slash; 485 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 486 size_t dirnamelen = slash - refname + 1; 487 struct ref_dir *subdir; 488 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 489 if (!subdir) { 490 dir = NULL; 491 break; 492 } 493 dir = subdir; 494 } 495 496 return dir; 497} 498 499/* 500 * Find the value entry with the given name in dir, sorting ref_dirs 501 * and recursing into subdirectories as necessary. If the name is not 502 * found or it corresponds to a directory entry, return NULL. 503 */ 504static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 505{ 506 int entry_index; 507 struct ref_entry *entry; 508 dir = find_containing_dir(dir, refname, 0); 509 if (!dir) 510 return NULL; 511 entry_index = search_ref_dir(dir, refname, strlen(refname)); 512 if (entry_index == -1) 513 return NULL; 514 entry = dir->entries[entry_index]; 515 return (entry->flag & REF_DIR) ? NULL : entry; 516} 517 518/* 519 * Remove the entry with the given name from dir, recursing into 520 * subdirectories as necessary. If refname is the name of a directory 521 * (i.e., ends with '/'), then remove the directory and its contents. 522 * If the removal was successful, return the number of entries 523 * remaining in the directory entry that contained the deleted entry. 524 * If the name was not found, return -1. Please note that this 525 * function only deletes the entry from the cache; it does not delete 526 * it from the filesystem or ensure that other cache entries (which 527 * might be symbolic references to the removed entry) are updated. 528 * Nor does it remove any containing dir entries that might be made 529 * empty by the removal. dir must represent the top-level directory 530 * and must already be complete. 531 */ 532static int remove_entry(struct ref_dir *dir, const char *refname) 533{ 534 int refname_len = strlen(refname); 535 int entry_index; 536 struct ref_entry *entry; 537 int is_dir = refname[refname_len - 1] == '/'; 538 if (is_dir) { 539 /* 540 * refname represents a reference directory. Remove 541 * the trailing slash; otherwise we will get the 542 * directory *representing* refname rather than the 543 * one *containing* it. 544 */ 545 char *dirname = xmemdupz(refname, refname_len - 1); 546 dir = find_containing_dir(dir, dirname, 0); 547 free(dirname); 548 } else { 549 dir = find_containing_dir(dir, refname, 0); 550 } 551 if (!dir) 552 return -1; 553 entry_index = search_ref_dir(dir, refname, refname_len); 554 if (entry_index == -1) 555 return -1; 556 entry = dir->entries[entry_index]; 557 558 memmove(&dir->entries[entry_index], 559 &dir->entries[entry_index + 1], 560 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 561 ); 562 dir->nr--; 563 if (dir->sorted > entry_index) 564 dir->sorted--; 565 free_ref_entry(entry); 566 return dir->nr; 567} 568 569/* 570 * Add a ref_entry to the ref_dir (unsorted), recursing into 571 * subdirectories as necessary. dir must represent the top-level 572 * directory. Return 0 on success. 573 */ 574static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 575{ 576 dir = find_containing_dir(dir, ref->name, 1); 577 if (!dir) 578 return -1; 579 add_entry_to_dir(dir, ref); 580 return 0; 581} 582 583/* 584 * Emit a warning and return true iff ref1 and ref2 have the same name 585 * and the same sha1. Die if they have the same name but different 586 * sha1s. 587 */ 588static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 589{ 590 if (strcmp(ref1->name, ref2->name)) 591 return 0; 592 593 /* Duplicate name; make sure that they don't conflict: */ 594 595 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 596 /* This is impossible by construction */ 597 die("Reference directory conflict: %s", ref1->name); 598 599 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 600 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 601 602 warning("Duplicated ref: %s", ref1->name); 603 return 1; 604} 605 606/* 607 * Sort the entries in dir non-recursively (if they are not already 608 * sorted) and remove any duplicate entries. 609 */ 610static void sort_ref_dir(struct ref_dir *dir) 611{ 612 int i, j; 613 struct ref_entry *last = NULL; 614 615 /* 616 * This check also prevents passing a zero-length array to qsort(), 617 * which is a problem on some platforms. 618 */ 619 if (dir->sorted == dir->nr) 620 return; 621 622 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 623 624 /* Remove any duplicates: */ 625 for (i = 0, j = 0; j < dir->nr; j++) { 626 struct ref_entry *entry = dir->entries[j]; 627 if (last && is_dup_ref(last, entry)) 628 free_ref_entry(entry); 629 else 630 last = dir->entries[i++] = entry; 631 } 632 dir->sorted = dir->nr = i; 633} 634 635/* Include broken references in a do_for_each_ref*() iteration: */ 636#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 637 638/* 639 * Return true iff the reference described by entry can be resolved to 640 * an object in the database. Emit a warning if the referred-to 641 * object does not exist. 642 */ 643static int ref_resolves_to_object(struct ref_entry *entry) 644{ 645 if (entry->flag & REF_ISBROKEN) 646 return 0; 647 if (!has_sha1_file(entry->u.value.sha1)) { 648 error("%s does not point to a valid object!", entry->name); 649 return 0; 650 } 651 return 1; 652} 653 654/* 655 * current_ref is a performance hack: when iterating over references 656 * using the for_each_ref*() functions, current_ref is set to the 657 * current reference's entry before calling the callback function. If 658 * the callback function calls peel_ref(), then peel_ref() first 659 * checks whether the reference to be peeled is the current reference 660 * (it usually is) and if so, returns that reference's peeled version 661 * if it is available. This avoids a refname lookup in a common case. 662 */ 663static struct ref_entry *current_ref; 664 665typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 666 667struct ref_entry_cb { 668 const char *base; 669 int trim; 670 int flags; 671 each_ref_fn *fn; 672 void *cb_data; 673}; 674 675/* 676 * Handle one reference in a do_for_each_ref*()-style iteration, 677 * calling an each_ref_fn for each entry. 678 */ 679static int do_one_ref(struct ref_entry *entry, void *cb_data) 680{ 681 struct ref_entry_cb *data = cb_data; 682 struct ref_entry *old_current_ref; 683 int retval; 684 685 if (!starts_with(entry->name, data->base)) 686 return 0; 687 688 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 689 !ref_resolves_to_object(entry)) 690 return 0; 691 692 /* Store the old value, in case this is a recursive call: */ 693 old_current_ref = current_ref; 694 current_ref = entry; 695 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 696 entry->flag, data->cb_data); 697 current_ref = old_current_ref; 698 return retval; 699} 700 701/* 702 * Call fn for each reference in dir that has index in the range 703 * offset <= index < dir->nr. Recurse into subdirectories that are in 704 * that index range, sorting them before iterating. This function 705 * does not sort dir itself; it should be sorted beforehand. fn is 706 * called for all references, including broken ones. 707 */ 708static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 709 each_ref_entry_fn fn, void *cb_data) 710{ 711 int i; 712 assert(dir->sorted == dir->nr); 713 for (i = offset; i < dir->nr; i++) { 714 struct ref_entry *entry = dir->entries[i]; 715 int retval; 716 if (entry->flag & REF_DIR) { 717 struct ref_dir *subdir = get_ref_dir(entry); 718 sort_ref_dir(subdir); 719 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 720 } else { 721 retval = fn(entry, cb_data); 722 } 723 if (retval) 724 return retval; 725 } 726 return 0; 727} 728 729/* 730 * Call fn for each reference in the union of dir1 and dir2, in order 731 * by refname. Recurse into subdirectories. If a value entry appears 732 * in both dir1 and dir2, then only process the version that is in 733 * dir2. The input dirs must already be sorted, but subdirs will be 734 * sorted as needed. fn is called for all references, including 735 * broken ones. 736 */ 737static int do_for_each_entry_in_dirs(struct ref_dir *dir1, 738 struct ref_dir *dir2, 739 each_ref_entry_fn fn, void *cb_data) 740{ 741 int retval; 742 int i1 = 0, i2 = 0; 743 744 assert(dir1->sorted == dir1->nr); 745 assert(dir2->sorted == dir2->nr); 746 while (1) { 747 struct ref_entry *e1, *e2; 748 int cmp; 749 if (i1 == dir1->nr) { 750 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 751 } 752 if (i2 == dir2->nr) { 753 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 754 } 755 e1 = dir1->entries[i1]; 756 e2 = dir2->entries[i2]; 757 cmp = strcmp(e1->name, e2->name); 758 if (cmp == 0) { 759 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 760 /* Both are directories; descend them in parallel. */ 761 struct ref_dir *subdir1 = get_ref_dir(e1); 762 struct ref_dir *subdir2 = get_ref_dir(e2); 763 sort_ref_dir(subdir1); 764 sort_ref_dir(subdir2); 765 retval = do_for_each_entry_in_dirs( 766 subdir1, subdir2, fn, cb_data); 767 i1++; 768 i2++; 769 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 770 /* Both are references; ignore the one from dir1. */ 771 retval = fn(e2, cb_data); 772 i1++; 773 i2++; 774 } else { 775 die("conflict between reference and directory: %s", 776 e1->name); 777 } 778 } else { 779 struct ref_entry *e; 780 if (cmp < 0) { 781 e = e1; 782 i1++; 783 } else { 784 e = e2; 785 i2++; 786 } 787 if (e->flag & REF_DIR) { 788 struct ref_dir *subdir = get_ref_dir(e); 789 sort_ref_dir(subdir); 790 retval = do_for_each_entry_in_dir( 791 subdir, 0, fn, cb_data); 792 } else { 793 retval = fn(e, cb_data); 794 } 795 } 796 if (retval) 797 return retval; 798 } 799} 800 801/* 802 * Load all of the refs from the dir into our in-memory cache. The hard work 803 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 804 * through all of the sub-directories. We do not even need to care about 805 * sorting, as traversal order does not matter to us. 806 */ 807static void prime_ref_dir(struct ref_dir *dir) 808{ 809 int i; 810 for (i = 0; i < dir->nr; i++) { 811 struct ref_entry *entry = dir->entries[i]; 812 if (entry->flag & REF_DIR) 813 prime_ref_dir(get_ref_dir(entry)); 814 } 815} 816 817static int entry_matches(struct ref_entry *entry, const struct string_list *list) 818{ 819 return list && string_list_has_string(list, entry->name); 820} 821 822struct nonmatching_ref_data { 823 const struct string_list *skip; 824 struct ref_entry *found; 825}; 826 827static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) 828{ 829 struct nonmatching_ref_data *data = vdata; 830 831 if (entry_matches(entry, data->skip)) 832 return 0; 833 834 data->found = entry; 835 return 1; 836} 837 838static void report_refname_conflict(struct ref_entry *entry, 839 const char *refname) 840{ 841 error("'%s' exists; cannot create '%s'", entry->name, refname); 842} 843 844/* 845 * Return true iff a reference named refname could be created without 846 * conflicting with the name of an existing reference in dir. If 847 * skip is non-NULL, ignore potential conflicts with refs in skip 848 * (e.g., because they are scheduled for deletion in the same 849 * operation). 850 * 851 * Two reference names conflict if one of them exactly matches the 852 * leading components of the other; e.g., "foo/bar" conflicts with 853 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 854 * "foo/barbados". 855 * 856 * skip must be sorted. 857 */ 858static int is_refname_available(const char *refname, 859 const struct string_list *skip, 860 struct ref_dir *dir) 861{ 862 const char *slash; 863 size_t len; 864 int pos; 865 char *dirname; 866 867 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 868 /* 869 * We are still at a leading dir of the refname; we are 870 * looking for a conflict with a leaf entry. 871 * 872 * If we find one, we still must make sure it is 873 * not in "skip". 874 */ 875 pos = search_ref_dir(dir, refname, slash - refname); 876 if (pos >= 0) { 877 struct ref_entry *entry = dir->entries[pos]; 878 if (entry_matches(entry, skip)) 879 return 1; 880 report_refname_conflict(entry, refname); 881 return 0; 882 } 883 884 885 /* 886 * Otherwise, we can try to continue our search with 887 * the next component; if we come up empty, we know 888 * there is nothing under this whole prefix. 889 */ 890 pos = search_ref_dir(dir, refname, slash + 1 - refname); 891 if (pos < 0) 892 return 1; 893 894 dir = get_ref_dir(dir->entries[pos]); 895 } 896 897 /* 898 * We are at the leaf of our refname; we want to 899 * make sure there are no directories which match it. 900 */ 901 len = strlen(refname); 902 dirname = xmallocz(len + 1); 903 sprintf(dirname, "%s/", refname); 904 pos = search_ref_dir(dir, dirname, len + 1); 905 free(dirname); 906 907 if (pos >= 0) { 908 /* 909 * We found a directory named "refname". It is a 910 * problem iff it contains any ref that is not 911 * in "skip". 912 */ 913 struct ref_entry *entry = dir->entries[pos]; 914 struct ref_dir *dir = get_ref_dir(entry); 915 struct nonmatching_ref_data data; 916 917 data.skip = skip; 918 sort_ref_dir(dir); 919 if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) 920 return 1; 921 922 report_refname_conflict(data.found, refname); 923 return 0; 924 } 925 926 /* 927 * There is no point in searching for another leaf 928 * node which matches it; such an entry would be the 929 * ref we are looking for, not a conflict. 930 */ 931 return 1; 932} 933 934struct packed_ref_cache { 935 struct ref_entry *root; 936 937 /* 938 * Count of references to the data structure in this instance, 939 * including the pointer from ref_cache::packed if any. The 940 * data will not be freed as long as the reference count is 941 * nonzero. 942 */ 943 unsigned int referrers; 944 945 /* 946 * Iff the packed-refs file associated with this instance is 947 * currently locked for writing, this points at the associated 948 * lock (which is owned by somebody else). The referrer count 949 * is also incremented when the file is locked and decremented 950 * when it is unlocked. 951 */ 952 struct lock_file *lock; 953 954 /* The metadata from when this packed-refs cache was read */ 955 struct stat_validity validity; 956}; 957 958/* 959 * Future: need to be in "struct repository" 960 * when doing a full libification. 961 */ 962static struct ref_cache { 963 struct ref_cache *next; 964 struct ref_entry *loose; 965 struct packed_ref_cache *packed; 966 /* 967 * The submodule name, or "" for the main repo. We allocate 968 * length 1 rather than FLEX_ARRAY so that the main ref_cache 969 * is initialized correctly. 970 */ 971 char name[1]; 972} ref_cache, *submodule_ref_caches; 973 974/* Lock used for the main packed-refs file: */ 975static struct lock_file packlock; 976 977/* 978 * Increment the reference count of *packed_refs. 979 */ 980static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 981{ 982 packed_refs->referrers++; 983} 984 985/* 986 * Decrease the reference count of *packed_refs. If it goes to zero, 987 * free *packed_refs and return true; otherwise return false. 988 */ 989static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 990{ 991 if (!--packed_refs->referrers) { 992 free_ref_entry(packed_refs->root); 993 stat_validity_clear(&packed_refs->validity); 994 free(packed_refs); 995 return 1; 996 } else { 997 return 0; 998 } 999}10001001static void clear_packed_ref_cache(struct ref_cache *refs)1002{1003 if (refs->packed) {1004 struct packed_ref_cache *packed_refs = refs->packed;10051006 if (packed_refs->lock)1007 die("internal error: packed-ref cache cleared while locked");1008 refs->packed = NULL;1009 release_packed_ref_cache(packed_refs);1010 }1011}10121013static void clear_loose_ref_cache(struct ref_cache *refs)1014{1015 if (refs->loose) {1016 free_ref_entry(refs->loose);1017 refs->loose = NULL;1018 }1019}10201021static struct ref_cache *create_ref_cache(const char *submodule)1022{1023 int len;1024 struct ref_cache *refs;1025 if (!submodule)1026 submodule = "";1027 len = strlen(submodule) + 1;1028 refs = xcalloc(1, sizeof(struct ref_cache) + len);1029 memcpy(refs->name, submodule, len);1030 return refs;1031}10321033/*1034 * Return a pointer to a ref_cache for the specified submodule. For1035 * the main repository, use submodule==NULL. The returned structure1036 * will be allocated and initialized but not necessarily populated; it1037 * should not be freed.1038 */1039static struct ref_cache *get_ref_cache(const char *submodule)1040{1041 struct ref_cache *refs;10421043 if (!submodule || !*submodule)1044 return &ref_cache;10451046 for (refs = submodule_ref_caches; refs; refs = refs->next)1047 if (!strcmp(submodule, refs->name))1048 return refs;10491050 refs = create_ref_cache(submodule);1051 refs->next = submodule_ref_caches;1052 submodule_ref_caches = refs;1053 return refs;1054}10551056/* The length of a peeled reference line in packed-refs, including EOL: */1057#define PEELED_LINE_LENGTH 4210581059/*1060 * The packed-refs header line that we write out. Perhaps other1061 * traits will be added later. The trailing space is required.1062 */1063static const char PACKED_REFS_HEADER[] =1064 "# pack-refs with: peeled fully-peeled \n";10651066/*1067 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1068 * Return a pointer to the refname within the line (null-terminated),1069 * or NULL if there was a problem.1070 */1071static const char *parse_ref_line(char *line, unsigned char *sha1)1072{1073 /*1074 * 42: the answer to everything.1075 *1076 * In this case, it happens to be the answer to1077 * 40 (length of sha1 hex representation)1078 * +1 (space in between hex and name)1079 * +1 (newline at the end of the line)1080 */1081 int len = strlen(line) - 42;10821083 if (len <= 0)1084 return NULL;1085 if (get_sha1_hex(line, sha1) < 0)1086 return NULL;1087 if (!isspace(line[40]))1088 return NULL;1089 line += 41;1090 if (isspace(*line))1091 return NULL;1092 if (line[len] != '\n')1093 return NULL;1094 line[len] = 0;10951096 return line;1097}10981099/*1100 * Read f, which is a packed-refs file, into dir.1101 *1102 * A comment line of the form "# pack-refs with: " may contain zero or1103 * more traits. We interpret the traits as follows:1104 *1105 * No traits:1106 *1107 * Probably no references are peeled. But if the file contains a1108 * peeled value for a reference, we will use it.1109 *1110 * peeled:1111 *1112 * References under "refs/tags/", if they *can* be peeled, *are*1113 * peeled in this file. References outside of "refs/tags/" are1114 * probably not peeled even if they could have been, but if we find1115 * a peeled value for such a reference we will use it.1116 *1117 * fully-peeled:1118 *1119 * All references in the file that can be peeled are peeled.1120 * Inversely (and this is more important), any references in the1121 * file for which no peeled value is recorded is not peelable. This1122 * trait should typically be written alongside "peeled" for1123 * compatibility with older clients, but we do not require it1124 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1125 */1126static void read_packed_refs(FILE *f, struct ref_dir *dir)1127{1128 struct ref_entry *last = NULL;1129 char refline[PATH_MAX];1130 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11311132 while (fgets(refline, sizeof(refline), f)) {1133 unsigned char sha1[20];1134 const char *refname;1135 static const char header[] = "# pack-refs with:";11361137 if (!strncmp(refline, header, sizeof(header)-1)) {1138 const char *traits = refline + sizeof(header) - 1;1139 if (strstr(traits, " fully-peeled "))1140 peeled = PEELED_FULLY;1141 else if (strstr(traits, " peeled "))1142 peeled = PEELED_TAGS;1143 /* perhaps other traits later as well */1144 continue;1145 }11461147 refname = parse_ref_line(refline, sha1);1148 if (refname) {1149 int flag = REF_ISPACKED;11501151 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1152 hashclr(sha1);1153 flag |= REF_BAD_NAME | REF_ISBROKEN;1154 }1155 last = create_ref_entry(refname, sha1, flag, 0);1156 if (peeled == PEELED_FULLY ||1157 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1158 last->flag |= REF_KNOWS_PEELED;1159 add_ref(dir, last);1160 continue;1161 }1162 if (last &&1163 refline[0] == '^' &&1164 strlen(refline) == PEELED_LINE_LENGTH &&1165 refline[PEELED_LINE_LENGTH - 1] == '\n' &&1166 !get_sha1_hex(refline + 1, sha1)) {1167 hashcpy(last->u.value.peeled, sha1);1168 /*1169 * Regardless of what the file header said,1170 * we definitely know the value of *this*1171 * reference:1172 */1173 last->flag |= REF_KNOWS_PEELED;1174 }1175 }1176}11771178/*1179 * Get the packed_ref_cache for the specified ref_cache, creating it1180 * if necessary.1181 */1182static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1183{1184 const char *packed_refs_file;11851186 if (*refs->name)1187 packed_refs_file = git_path_submodule(refs->name, "packed-refs");1188 else1189 packed_refs_file = git_path("packed-refs");11901191 if (refs->packed &&1192 !stat_validity_check(&refs->packed->validity, packed_refs_file))1193 clear_packed_ref_cache(refs);11941195 if (!refs->packed) {1196 FILE *f;11971198 refs->packed = xcalloc(1, sizeof(*refs->packed));1199 acquire_packed_ref_cache(refs->packed);1200 refs->packed->root = create_dir_entry(refs, "", 0, 0);1201 f = fopen(packed_refs_file, "r");1202 if (f) {1203 stat_validity_update(&refs->packed->validity, fileno(f));1204 read_packed_refs(f, get_ref_dir(refs->packed->root));1205 fclose(f);1206 }1207 }1208 return refs->packed;1209}12101211static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1212{1213 return get_ref_dir(packed_ref_cache->root);1214}12151216static struct ref_dir *get_packed_refs(struct ref_cache *refs)1217{1218 return get_packed_ref_dir(get_packed_ref_cache(refs));1219}12201221void add_packed_ref(const char *refname, const unsigned char *sha1)1222{1223 struct packed_ref_cache *packed_ref_cache =1224 get_packed_ref_cache(&ref_cache);12251226 if (!packed_ref_cache->lock)1227 die("internal error: packed refs not locked");1228 add_ref(get_packed_ref_dir(packed_ref_cache),1229 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1230}12311232/*1233 * Read the loose references from the namespace dirname into dir1234 * (without recursing). dirname must end with '/'. dir must be the1235 * directory entry corresponding to dirname.1236 */1237static void read_loose_refs(const char *dirname, struct ref_dir *dir)1238{1239 struct ref_cache *refs = dir->ref_cache;1240 DIR *d;1241 const char *path;1242 struct dirent *de;1243 int dirnamelen = strlen(dirname);1244 struct strbuf refname;12451246 if (*refs->name)1247 path = git_path_submodule(refs->name, "%s", dirname);1248 else1249 path = git_path("%s", dirname);12501251 d = opendir(path);1252 if (!d)1253 return;12541255 strbuf_init(&refname, dirnamelen + 257);1256 strbuf_add(&refname, dirname, dirnamelen);12571258 while ((de = readdir(d)) != NULL) {1259 unsigned char sha1[20];1260 struct stat st;1261 int flag;1262 const char *refdir;12631264 if (de->d_name[0] == '.')1265 continue;1266 if (ends_with(de->d_name, ".lock"))1267 continue;1268 strbuf_addstr(&refname, de->d_name);1269 refdir = *refs->name1270 ? git_path_submodule(refs->name, "%s", refname.buf)1271 : git_path("%s", refname.buf);1272 if (stat(refdir, &st) < 0) {1273 ; /* silently ignore */1274 } else if (S_ISDIR(st.st_mode)) {1275 strbuf_addch(&refname, '/');1276 add_entry_to_dir(dir,1277 create_dir_entry(refs, refname.buf,1278 refname.len, 1));1279 } else {1280 if (*refs->name) {1281 hashclr(sha1);1282 flag = 0;1283 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {1284 hashclr(sha1);1285 flag |= REF_ISBROKEN;1286 }1287 } else if (read_ref_full(refname.buf,1288 RESOLVE_REF_READING,1289 sha1, &flag)) {1290 hashclr(sha1);1291 flag |= REF_ISBROKEN;1292 }1293 if (check_refname_format(refname.buf,1294 REFNAME_ALLOW_ONELEVEL)) {1295 hashclr(sha1);1296 flag |= REF_BAD_NAME | REF_ISBROKEN;1297 }1298 add_entry_to_dir(dir,1299 create_ref_entry(refname.buf, sha1, flag, 0));1300 }1301 strbuf_setlen(&refname, dirnamelen);1302 }1303 strbuf_release(&refname);1304 closedir(d);1305}13061307static struct ref_dir *get_loose_refs(struct ref_cache *refs)1308{1309 if (!refs->loose) {1310 /*1311 * Mark the top-level directory complete because we1312 * are about to read the only subdirectory that can1313 * hold references:1314 */1315 refs->loose = create_dir_entry(refs, "", 0, 0);1316 /*1317 * Create an incomplete entry for "refs/":1318 */1319 add_entry_to_dir(get_ref_dir(refs->loose),1320 create_dir_entry(refs, "refs/", 5, 1));1321 }1322 return get_ref_dir(refs->loose);1323}13241325/* We allow "recursive" symbolic refs. Only within reason, though */1326#define MAXDEPTH 51327#define MAXREFLEN (1024)13281329/*1330 * Called by resolve_gitlink_ref_recursive() after it failed to read1331 * from the loose refs in ref_cache refs. Find <refname> in the1332 * packed-refs file for the submodule.1333 */1334static int resolve_gitlink_packed_ref(struct ref_cache *refs,1335 const char *refname, unsigned char *sha1)1336{1337 struct ref_entry *ref;1338 struct ref_dir *dir = get_packed_refs(refs);13391340 ref = find_ref(dir, refname);1341 if (ref == NULL)1342 return -1;13431344 hashcpy(sha1, ref->u.value.sha1);1345 return 0;1346}13471348static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1349 const char *refname, unsigned char *sha1,1350 int recursion)1351{1352 int fd, len;1353 char buffer[128], *p;1354 char *path;13551356 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)1357 return -1;1358 path = *refs->name1359 ? git_path_submodule(refs->name, "%s", refname)1360 : git_path("%s", refname);1361 fd = open(path, O_RDONLY);1362 if (fd < 0)1363 return resolve_gitlink_packed_ref(refs, refname, sha1);13641365 len = read(fd, buffer, sizeof(buffer)-1);1366 close(fd);1367 if (len < 0)1368 return -1;1369 while (len && isspace(buffer[len-1]))1370 len--;1371 buffer[len] = 0;13721373 /* Was it a detached head or an old-fashioned symlink? */1374 if (!get_sha1_hex(buffer, sha1))1375 return 0;13761377 /* Symref? */1378 if (strncmp(buffer, "ref:", 4))1379 return -1;1380 p = buffer + 4;1381 while (isspace(*p))1382 p++;13831384 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1385}13861387int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1388{1389 int len = strlen(path), retval;1390 char *submodule;1391 struct ref_cache *refs;13921393 while (len && path[len-1] == '/')1394 len--;1395 if (!len)1396 return -1;1397 submodule = xstrndup(path, len);1398 refs = get_ref_cache(submodule);1399 free(submodule);14001401 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1402 return retval;1403}14041405/*1406 * Return the ref_entry for the given refname from the packed1407 * references. If it does not exist, return NULL.1408 */1409static struct ref_entry *get_packed_ref(const char *refname)1410{1411 return find_ref(get_packed_refs(&ref_cache), refname);1412}14131414/*1415 * A loose ref file doesn't exist; check for a packed ref. The1416 * options are forwarded from resolve_safe_unsafe().1417 */1418static int resolve_missing_loose_ref(const char *refname,1419 int resolve_flags,1420 unsigned char *sha1,1421 int *flags)1422{1423 struct ref_entry *entry;14241425 /*1426 * The loose reference file does not exist; check for a packed1427 * reference.1428 */1429 entry = get_packed_ref(refname);1430 if (entry) {1431 hashcpy(sha1, entry->u.value.sha1);1432 if (flags)1433 *flags |= REF_ISPACKED;1434 return 0;1435 }1436 /* The reference is not a packed reference, either. */1437 if (resolve_flags & RESOLVE_REF_READING) {1438 errno = ENOENT;1439 return -1;1440 } else {1441 hashclr(sha1);1442 return 0;1443 }1444}14451446/* This function needs to return a meaningful errno on failure */1447const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1448{1449 int depth = MAXDEPTH;1450 ssize_t len;1451 char buffer[256];1452 static char refname_buffer[256];1453 int bad_name = 0;14541455 if (flags)1456 *flags = 0;14571458 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1459 if (flags)1460 *flags |= REF_BAD_NAME;14611462 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1463 !refname_is_safe(refname)) {1464 errno = EINVAL;1465 return NULL;1466 }1467 /*1468 * dwim_ref() uses REF_ISBROKEN to distinguish between1469 * missing refs and refs that were present but invalid,1470 * to complain about the latter to stderr.1471 *1472 * We don't know whether the ref exists, so don't set1473 * REF_ISBROKEN yet.1474 */1475 bad_name = 1;1476 }1477 for (;;) {1478 char path[PATH_MAX];1479 struct stat st;1480 char *buf;1481 int fd;14821483 if (--depth < 0) {1484 errno = ELOOP;1485 return NULL;1486 }14871488 git_snpath(path, sizeof(path), "%s", refname);14891490 /*1491 * We might have to loop back here to avoid a race1492 * condition: first we lstat() the file, then we try1493 * to read it as a link or as a file. But if somebody1494 * changes the type of the file (file <-> directory1495 * <-> symlink) between the lstat() and reading, then1496 * we don't want to report that as an error but rather1497 * try again starting with the lstat().1498 */1499 stat_ref:1500 if (lstat(path, &st) < 0) {1501 if (errno != ENOENT)1502 return NULL;1503 if (resolve_missing_loose_ref(refname, resolve_flags,1504 sha1, flags))1505 return NULL;1506 if (bad_name) {1507 hashclr(sha1);1508 if (flags)1509 *flags |= REF_ISBROKEN;1510 }1511 return refname;1512 }15131514 /* Follow "normalized" - ie "refs/.." symlinks by hand */1515 if (S_ISLNK(st.st_mode)) {1516 len = readlink(path, buffer, sizeof(buffer)-1);1517 if (len < 0) {1518 if (errno == ENOENT || errno == EINVAL)1519 /* inconsistent with lstat; retry */1520 goto stat_ref;1521 else1522 return NULL;1523 }1524 buffer[len] = 0;1525 if (starts_with(buffer, "refs/") &&1526 !check_refname_format(buffer, 0)) {1527 strcpy(refname_buffer, buffer);1528 refname = refname_buffer;1529 if (flags)1530 *flags |= REF_ISSYMREF;1531 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1532 hashclr(sha1);1533 return refname;1534 }1535 continue;1536 }1537 }15381539 /* Is it a directory? */1540 if (S_ISDIR(st.st_mode)) {1541 errno = EISDIR;1542 return NULL;1543 }15441545 /*1546 * Anything else, just open it and try to use it as1547 * a ref1548 */1549 fd = open(path, O_RDONLY);1550 if (fd < 0) {1551 if (errno == ENOENT)1552 /* inconsistent with lstat; retry */1553 goto stat_ref;1554 else1555 return NULL;1556 }1557 len = read_in_full(fd, buffer, sizeof(buffer)-1);1558 if (len < 0) {1559 int save_errno = errno;1560 close(fd);1561 errno = save_errno;1562 return NULL;1563 }1564 close(fd);1565 while (len && isspace(buffer[len-1]))1566 len--;1567 buffer[len] = '\0';15681569 /*1570 * Is it a symbolic ref?1571 */1572 if (!starts_with(buffer, "ref:")) {1573 /*1574 * Please note that FETCH_HEAD has a second1575 * line containing other data.1576 */1577 if (get_sha1_hex(buffer, sha1) ||1578 (buffer[40] != '\0' && !isspace(buffer[40]))) {1579 if (flags)1580 *flags |= REF_ISBROKEN;1581 errno = EINVAL;1582 return NULL;1583 }1584 if (bad_name) {1585 hashclr(sha1);1586 if (flags)1587 *flags |= REF_ISBROKEN;1588 }1589 return refname;1590 }1591 if (flags)1592 *flags |= REF_ISSYMREF;1593 buf = buffer + 4;1594 while (isspace(*buf))1595 buf++;1596 refname = strcpy(refname_buffer, buf);1597 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1598 hashclr(sha1);1599 return refname;1600 }1601 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1602 if (flags)1603 *flags |= REF_ISBROKEN;16041605 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1606 !refname_is_safe(buf)) {1607 errno = EINVAL;1608 return NULL;1609 }1610 bad_name = 1;1611 }1612 }1613}16141615char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)1616{1617 const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags);1618 return ret ? xstrdup(ret) : NULL;1619}16201621/* The argument to filter_refs */1622struct ref_filter {1623 const char *pattern;1624 each_ref_fn *fn;1625 void *cb_data;1626};16271628int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1629{1630 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1631 return 0;1632 return -1;1633}16341635int read_ref(const char *refname, unsigned char *sha1)1636{1637 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1638}16391640int ref_exists(const char *refname)1641{1642 unsigned char sha1[20];1643 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1644}16451646static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1647 void *data)1648{1649 struct ref_filter *filter = (struct ref_filter *)data;1650 if (wildmatch(filter->pattern, refname, 0, NULL))1651 return 0;1652 return filter->fn(refname, sha1, flags, filter->cb_data);1653}16541655enum peel_status {1656 /* object was peeled successfully: */1657 PEEL_PEELED = 0,16581659 /*1660 * object cannot be peeled because the named object (or an1661 * object referred to by a tag in the peel chain), does not1662 * exist.1663 */1664 PEEL_INVALID = -1,16651666 /* object cannot be peeled because it is not a tag: */1667 PEEL_NON_TAG = -2,16681669 /* ref_entry contains no peeled value because it is a symref: */1670 PEEL_IS_SYMREF = -3,16711672 /*1673 * ref_entry cannot be peeled because it is broken (i.e., the1674 * symbolic reference cannot even be resolved to an object1675 * name):1676 */1677 PEEL_BROKEN = -41678};16791680/*1681 * Peel the named object; i.e., if the object is a tag, resolve the1682 * tag recursively until a non-tag is found. If successful, store the1683 * result to sha1 and return PEEL_PEELED. If the object is not a tag1684 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1685 * and leave sha1 unchanged.1686 */1687static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1688{1689 struct object *o = lookup_unknown_object(name);16901691 if (o->type == OBJ_NONE) {1692 int type = sha1_object_info(name, NULL);1693 if (type < 0 || !object_as_type(o, type, 0))1694 return PEEL_INVALID;1695 }16961697 if (o->type != OBJ_TAG)1698 return PEEL_NON_TAG;16991700 o = deref_tag_noverify(o);1701 if (!o)1702 return PEEL_INVALID;17031704 hashcpy(sha1, o->sha1);1705 return PEEL_PEELED;1706}17071708/*1709 * Peel the entry (if possible) and return its new peel_status. If1710 * repeel is true, re-peel the entry even if there is an old peeled1711 * value that is already stored in it.1712 *1713 * It is OK to call this function with a packed reference entry that1714 * might be stale and might even refer to an object that has since1715 * been garbage-collected. In such a case, if the entry has1716 * REF_KNOWS_PEELED then leave the status unchanged and return1717 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1718 */1719static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1720{1721 enum peel_status status;17221723 if (entry->flag & REF_KNOWS_PEELED) {1724 if (repeel) {1725 entry->flag &= ~REF_KNOWS_PEELED;1726 hashclr(entry->u.value.peeled);1727 } else {1728 return is_null_sha1(entry->u.value.peeled) ?1729 PEEL_NON_TAG : PEEL_PEELED;1730 }1731 }1732 if (entry->flag & REF_ISBROKEN)1733 return PEEL_BROKEN;1734 if (entry->flag & REF_ISSYMREF)1735 return PEEL_IS_SYMREF;17361737 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1738 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1739 entry->flag |= REF_KNOWS_PEELED;1740 return status;1741}17421743int peel_ref(const char *refname, unsigned char *sha1)1744{1745 int flag;1746 unsigned char base[20];17471748 if (current_ref && (current_ref->name == refname1749 || !strcmp(current_ref->name, refname))) {1750 if (peel_entry(current_ref, 0))1751 return -1;1752 hashcpy(sha1, current_ref->u.value.peeled);1753 return 0;1754 }17551756 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1757 return -1;17581759 /*1760 * If the reference is packed, read its ref_entry from the1761 * cache in the hope that we already know its peeled value.1762 * We only try this optimization on packed references because1763 * (a) forcing the filling of the loose reference cache could1764 * be expensive and (b) loose references anyway usually do not1765 * have REF_KNOWS_PEELED.1766 */1767 if (flag & REF_ISPACKED) {1768 struct ref_entry *r = get_packed_ref(refname);1769 if (r) {1770 if (peel_entry(r, 0))1771 return -1;1772 hashcpy(sha1, r->u.value.peeled);1773 return 0;1774 }1775 }17761777 return peel_object(base, sha1);1778}17791780struct warn_if_dangling_data {1781 FILE *fp;1782 const char *refname;1783 const struct string_list *refnames;1784 const char *msg_fmt;1785};17861787static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1788 int flags, void *cb_data)1789{1790 struct warn_if_dangling_data *d = cb_data;1791 const char *resolves_to;1792 unsigned char junk[20];17931794 if (!(flags & REF_ISSYMREF))1795 return 0;17961797 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);1798 if (!resolves_to1799 || (d->refname1800 ? strcmp(resolves_to, d->refname)1801 : !string_list_has_string(d->refnames, resolves_to))) {1802 return 0;1803 }18041805 fprintf(d->fp, d->msg_fmt, refname);1806 fputc('\n', d->fp);1807 return 0;1808}18091810void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1811{1812 struct warn_if_dangling_data data;18131814 data.fp = fp;1815 data.refname = refname;1816 data.refnames = NULL;1817 data.msg_fmt = msg_fmt;1818 for_each_rawref(warn_if_dangling_symref, &data);1819}18201821void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)1822{1823 struct warn_if_dangling_data data;18241825 data.fp = fp;1826 data.refname = NULL;1827 data.refnames = refnames;1828 data.msg_fmt = msg_fmt;1829 for_each_rawref(warn_if_dangling_symref, &data);1830}18311832/*1833 * Call fn for each reference in the specified ref_cache, omitting1834 * references not in the containing_dir of base. fn is called for all1835 * references, including broken ones. If fn ever returns a non-zero1836 * value, stop the iteration and return that value; otherwise, return1837 * 0.1838 */1839static int do_for_each_entry(struct ref_cache *refs, const char *base,1840 each_ref_entry_fn fn, void *cb_data)1841{1842 struct packed_ref_cache *packed_ref_cache;1843 struct ref_dir *loose_dir;1844 struct ref_dir *packed_dir;1845 int retval = 0;18461847 /*1848 * We must make sure that all loose refs are read before accessing the1849 * packed-refs file; this avoids a race condition in which loose refs1850 * are migrated to the packed-refs file by a simultaneous process, but1851 * our in-memory view is from before the migration. get_packed_ref_cache()1852 * takes care of making sure our view is up to date with what is on1853 * disk.1854 */1855 loose_dir = get_loose_refs(refs);1856 if (base && *base) {1857 loose_dir = find_containing_dir(loose_dir, base, 0);1858 }1859 if (loose_dir)1860 prime_ref_dir(loose_dir);18611862 packed_ref_cache = get_packed_ref_cache(refs);1863 acquire_packed_ref_cache(packed_ref_cache);1864 packed_dir = get_packed_ref_dir(packed_ref_cache);1865 if (base && *base) {1866 packed_dir = find_containing_dir(packed_dir, base, 0);1867 }18681869 if (packed_dir && loose_dir) {1870 sort_ref_dir(packed_dir);1871 sort_ref_dir(loose_dir);1872 retval = do_for_each_entry_in_dirs(1873 packed_dir, loose_dir, fn, cb_data);1874 } else if (packed_dir) {1875 sort_ref_dir(packed_dir);1876 retval = do_for_each_entry_in_dir(1877 packed_dir, 0, fn, cb_data);1878 } else if (loose_dir) {1879 sort_ref_dir(loose_dir);1880 retval = do_for_each_entry_in_dir(1881 loose_dir, 0, fn, cb_data);1882 }18831884 release_packed_ref_cache(packed_ref_cache);1885 return retval;1886}18871888/*1889 * Call fn for each reference in the specified ref_cache for which the1890 * refname begins with base. If trim is non-zero, then trim that many1891 * characters off the beginning of each refname before passing the1892 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1893 * broken references in the iteration. If fn ever returns a non-zero1894 * value, stop the iteration and return that value; otherwise, return1895 * 0.1896 */1897static int do_for_each_ref(struct ref_cache *refs, const char *base,1898 each_ref_fn fn, int trim, int flags, void *cb_data)1899{1900 struct ref_entry_cb data;1901 data.base = base;1902 data.trim = trim;1903 data.flags = flags;1904 data.fn = fn;1905 data.cb_data = cb_data;19061907 return do_for_each_entry(refs, base, do_one_ref, &data);1908}19091910static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1911{1912 unsigned char sha1[20];1913 int flag;19141915 if (submodule) {1916 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1917 return fn("HEAD", sha1, 0, cb_data);19181919 return 0;1920 }19211922 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1923 return fn("HEAD", sha1, flag, cb_data);19241925 return 0;1926}19271928int head_ref(each_ref_fn fn, void *cb_data)1929{1930 return do_head_ref(NULL, fn, cb_data);1931}19321933int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1934{1935 return do_head_ref(submodule, fn, cb_data);1936}19371938int for_each_ref(each_ref_fn fn, void *cb_data)1939{1940 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);1941}19421943int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1944{1945 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);1946}19471948int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1949{1950 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);1951}19521953int for_each_ref_in_submodule(const char *submodule, const char *prefix,1954 each_ref_fn fn, void *cb_data)1955{1956 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);1957}19581959int for_each_tag_ref(each_ref_fn fn, void *cb_data)1960{1961 return for_each_ref_in("refs/tags/", fn, cb_data);1962}19631964int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1965{1966 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1967}19681969int for_each_branch_ref(each_ref_fn fn, void *cb_data)1970{1971 return for_each_ref_in("refs/heads/", fn, cb_data);1972}19731974int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1975{1976 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1977}19781979int for_each_remote_ref(each_ref_fn fn, void *cb_data)1980{1981 return for_each_ref_in("refs/remotes/", fn, cb_data);1982}19831984int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1985{1986 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1987}19881989int for_each_replace_ref(each_ref_fn fn, void *cb_data)1990{1991 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);1992}19931994int head_ref_namespaced(each_ref_fn fn, void *cb_data)1995{1996 struct strbuf buf = STRBUF_INIT;1997 int ret = 0;1998 unsigned char sha1[20];1999 int flag;20002001 strbuf_addf(&buf, "%sHEAD", get_git_namespace());2002 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))2003 ret = fn(buf.buf, sha1, flag, cb_data);2004 strbuf_release(&buf);20052006 return ret;2007}20082009int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)2010{2011 struct strbuf buf = STRBUF_INIT;2012 int ret;2013 strbuf_addf(&buf, "%srefs/", get_git_namespace());2014 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);2015 strbuf_release(&buf);2016 return ret;2017}20182019int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,2020 const char *prefix, void *cb_data)2021{2022 struct strbuf real_pattern = STRBUF_INIT;2023 struct ref_filter filter;2024 int ret;20252026 if (!prefix && !starts_with(pattern, "refs/"))2027 strbuf_addstr(&real_pattern, "refs/");2028 else if (prefix)2029 strbuf_addstr(&real_pattern, prefix);2030 strbuf_addstr(&real_pattern, pattern);20312032 if (!has_glob_specials(pattern)) {2033 /* Append implied '/' '*' if not present. */2034 if (real_pattern.buf[real_pattern.len - 1] != '/')2035 strbuf_addch(&real_pattern, '/');2036 /* No need to check for '*', there is none. */2037 strbuf_addch(&real_pattern, '*');2038 }20392040 filter.pattern = real_pattern.buf;2041 filter.fn = fn;2042 filter.cb_data = cb_data;2043 ret = for_each_ref(filter_refs, &filter);20442045 strbuf_release(&real_pattern);2046 return ret;2047}20482049int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)2050{2051 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);2052}20532054int for_each_rawref(each_ref_fn fn, void *cb_data)2055{2056 return do_for_each_ref(&ref_cache, "", fn, 0,2057 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2058}20592060const char *prettify_refname(const char *name)2061{2062 return name + (2063 starts_with(name, "refs/heads/") ? 11 :2064 starts_with(name, "refs/tags/") ? 10 :2065 starts_with(name, "refs/remotes/") ? 13 :2066 0);2067}20682069static const char *ref_rev_parse_rules[] = {2070 "%.*s",2071 "refs/%.*s",2072 "refs/tags/%.*s",2073 "refs/heads/%.*s",2074 "refs/remotes/%.*s",2075 "refs/remotes/%.*s/HEAD",2076 NULL2077};20782079int refname_match(const char *abbrev_name, const char *full_name)2080{2081 const char **p;2082 const int abbrev_name_len = strlen(abbrev_name);20832084 for (p = ref_rev_parse_rules; *p; p++) {2085 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {2086 return 1;2087 }2088 }20892090 return 0;2091}20922093/* This function should make sure errno is meaningful on error */2094static struct ref_lock *verify_lock(struct ref_lock *lock,2095 const unsigned char *old_sha1, int mustexist)2096{2097 if (read_ref_full(lock->ref_name,2098 mustexist ? RESOLVE_REF_READING : 0,2099 lock->old_sha1, NULL)) {2100 int save_errno = errno;2101 error("Can't verify ref %s", lock->ref_name);2102 unlock_ref(lock);2103 errno = save_errno;2104 return NULL;2105 }2106 if (hashcmp(lock->old_sha1, old_sha1)) {2107 error("Ref %s is at %s but expected %s", lock->ref_name,2108 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));2109 unlock_ref(lock);2110 errno = EBUSY;2111 return NULL;2112 }2113 return lock;2114}21152116static int remove_empty_directories(const char *file)2117{2118 /* we want to create a file but there is a directory there;2119 * if that is an empty directory (or a directory that contains2120 * only empty directories), remove them.2121 */2122 struct strbuf path;2123 int result, save_errno;21242125 strbuf_init(&path, 20);2126 strbuf_addstr(&path, file);21272128 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2129 save_errno = errno;21302131 strbuf_release(&path);2132 errno = save_errno;21332134 return result;2135}21362137/*2138 * *string and *len will only be substituted, and *string returned (for2139 * later free()ing) if the string passed in is a magic short-hand form2140 * to name a branch.2141 */2142static char *substitute_branch_name(const char **string, int *len)2143{2144 struct strbuf buf = STRBUF_INIT;2145 int ret = interpret_branch_name(*string, *len, &buf);21462147 if (ret == *len) {2148 size_t size;2149 *string = strbuf_detach(&buf, &size);2150 *len = size;2151 return (char *)*string;2152 }21532154 return NULL;2155}21562157int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)2158{2159 char *last_branch = substitute_branch_name(&str, &len);2160 const char **p, *r;2161 int refs_found = 0;21622163 *ref = NULL;2164 for (p = ref_rev_parse_rules; *p; p++) {2165 char fullref[PATH_MAX];2166 unsigned char sha1_from_ref[20];2167 unsigned char *this_result;2168 int flag;21692170 this_result = refs_found ? sha1_from_ref : sha1;2171 mksnpath(fullref, sizeof(fullref), *p, len, str);2172 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2173 this_result, &flag);2174 if (r) {2175 if (!refs_found++)2176 *ref = xstrdup(r);2177 if (!warn_ambiguous_refs)2178 break;2179 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {2180 warning("ignoring dangling symref %s.", fullref);2181 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {2182 warning("ignoring broken ref %s.", fullref);2183 }2184 }2185 free(last_branch);2186 return refs_found;2187}21882189int dwim_log(const char *str, int len, unsigned char *sha1, char **log)2190{2191 char *last_branch = substitute_branch_name(&str, &len);2192 const char **p;2193 int logs_found = 0;21942195 *log = NULL;2196 for (p = ref_rev_parse_rules; *p; p++) {2197 unsigned char hash[20];2198 char path[PATH_MAX];2199 const char *ref, *it;22002201 mksnpath(path, sizeof(path), *p, len, str);2202 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,2203 hash, NULL);2204 if (!ref)2205 continue;2206 if (reflog_exists(path))2207 it = path;2208 else if (strcmp(ref, path) && reflog_exists(ref))2209 it = ref;2210 else2211 continue;2212 if (!logs_found++) {2213 *log = xstrdup(it);2214 hashcpy(sha1, hash);2215 }2216 if (!warn_ambiguous_refs)2217 break;2218 }2219 free(last_branch);2220 return logs_found;2221}22222223/*2224 * Locks a ref returning the lock on success and NULL on failure.2225 * On failure errno is set to something meaningful.2226 */2227static struct ref_lock *lock_ref_sha1_basic(const char *refname,2228 const unsigned char *old_sha1,2229 const struct string_list *skip,2230 int flags, int *type_p)2231{2232 char *ref_file;2233 const char *orig_refname = refname;2234 struct ref_lock *lock;2235 int last_errno = 0;2236 int type, lflags;2237 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2238 int resolve_flags = 0;2239 int missing = 0;2240 int attempts_remaining = 3;22412242 lock = xcalloc(1, sizeof(struct ref_lock));2243 lock->lock_fd = -1;22442245 if (mustexist)2246 resolve_flags |= RESOLVE_REF_READING;2247 if (flags & REF_DELETING) {2248 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;2249 if (flags & REF_NODEREF)2250 resolve_flags |= RESOLVE_REF_NO_RECURSE;2251 }22522253 refname = resolve_ref_unsafe(refname, resolve_flags,2254 lock->old_sha1, &type);2255 if (!refname && errno == EISDIR) {2256 /* we are trying to lock foo but we used to2257 * have foo/bar which now does not exist;2258 * it is normal for the empty directory 'foo'2259 * to remain.2260 */2261 ref_file = git_path("%s", orig_refname);2262 if (remove_empty_directories(ref_file)) {2263 last_errno = errno;2264 error("there are still refs under '%s'", orig_refname);2265 goto error_return;2266 }2267 refname = resolve_ref_unsafe(orig_refname, resolve_flags,2268 lock->old_sha1, &type);2269 }2270 if (type_p)2271 *type_p = type;2272 if (!refname) {2273 last_errno = errno;2274 error("unable to resolve reference %s: %s",2275 orig_refname, strerror(errno));2276 goto error_return;2277 }2278 missing = is_null_sha1(lock->old_sha1);2279 /* When the ref did not exist and we are creating it,2280 * make sure there is no existing ref that is packed2281 * whose name begins with our refname, nor a ref whose2282 * name is a proper prefix of our refname.2283 */2284 if (missing &&2285 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {2286 last_errno = ENOTDIR;2287 goto error_return;2288 }22892290 lock->lk = xcalloc(1, sizeof(struct lock_file));22912292 lflags = 0;2293 if (flags & REF_NODEREF) {2294 refname = orig_refname;2295 lflags |= LOCK_NO_DEREF;2296 }2297 lock->ref_name = xstrdup(refname);2298 lock->orig_ref_name = xstrdup(orig_refname);2299 ref_file = git_path("%s", refname);2300 if (missing)2301 lock->force_write = 1;2302 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))2303 lock->force_write = 1;23042305 retry:2306 switch (safe_create_leading_directories(ref_file)) {2307 case SCLD_OK:2308 break; /* success */2309 case SCLD_VANISHED:2310 if (--attempts_remaining > 0)2311 goto retry;2312 /* fall through */2313 default:2314 last_errno = errno;2315 error("unable to create directory for %s", ref_file);2316 goto error_return;2317 }23182319 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);2320 if (lock->lock_fd < 0) {2321 if (errno == ENOENT && --attempts_remaining > 0)2322 /*2323 * Maybe somebody just deleted one of the2324 * directories leading to ref_file. Try2325 * again:2326 */2327 goto retry;2328 else2329 unable_to_lock_die(ref_file, errno);2330 }2331 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;23322333 error_return:2334 unlock_ref(lock);2335 errno = last_errno;2336 return NULL;2337}23382339struct ref_lock *lock_any_ref_for_update(const char *refname,2340 const unsigned char *old_sha1,2341 int flags, int *type_p)2342{2343 return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);2344}23452346/*2347 * Write an entry to the packed-refs file for the specified refname.2348 * If peeled is non-NULL, write it as the entry's peeled value.2349 */2350static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2351 unsigned char *peeled)2352{2353 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2354 if (peeled)2355 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2356}23572358/*2359 * An each_ref_entry_fn that writes the entry to a packed-refs file.2360 */2361static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2362{2363 enum peel_status peel_status = peel_entry(entry, 0);23642365 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2366 error("internal error: %s is not a valid packed reference!",2367 entry->name);2368 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2369 peel_status == PEEL_PEELED ?2370 entry->u.value.peeled : NULL);2371 return 0;2372}23732374/* This should return a meaningful errno on failure */2375int lock_packed_refs(int flags)2376{2377 struct packed_ref_cache *packed_ref_cache;23782379 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)2380 return -1;2381 /*2382 * Get the current packed-refs while holding the lock. If the2383 * packed-refs file has been modified since we last read it,2384 * this will automatically invalidate the cache and re-read2385 * the packed-refs file.2386 */2387 packed_ref_cache = get_packed_ref_cache(&ref_cache);2388 packed_ref_cache->lock = &packlock;2389 /* Increment the reference count to prevent it from being freed: */2390 acquire_packed_ref_cache(packed_ref_cache);2391 return 0;2392}23932394/*2395 * Commit the packed refs changes.2396 * On error we must make sure that errno contains a meaningful value.2397 */2398int commit_packed_refs(void)2399{2400 struct packed_ref_cache *packed_ref_cache =2401 get_packed_ref_cache(&ref_cache);2402 int error = 0;2403 int save_errno = 0;2404 FILE *out;24052406 if (!packed_ref_cache->lock)2407 die("internal error: packed-refs not locked");24082409 out = fdopen_lock_file(packed_ref_cache->lock, "w");2410 if (!out)2411 die_errno("unable to fdopen packed-refs descriptor");24122413 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2414 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2415 0, write_packed_entry_fn, out);24162417 if (commit_lock_file(packed_ref_cache->lock)) {2418 save_errno = errno;2419 error = -1;2420 }2421 packed_ref_cache->lock = NULL;2422 release_packed_ref_cache(packed_ref_cache);2423 errno = save_errno;2424 return error;2425}24262427void rollback_packed_refs(void)2428{2429 struct packed_ref_cache *packed_ref_cache =2430 get_packed_ref_cache(&ref_cache);24312432 if (!packed_ref_cache->lock)2433 die("internal error: packed-refs not locked");2434 rollback_lock_file(packed_ref_cache->lock);2435 packed_ref_cache->lock = NULL;2436 release_packed_ref_cache(packed_ref_cache);2437 clear_packed_ref_cache(&ref_cache);2438}24392440struct ref_to_prune {2441 struct ref_to_prune *next;2442 unsigned char sha1[20];2443 char name[FLEX_ARRAY];2444};24452446struct pack_refs_cb_data {2447 unsigned int flags;2448 struct ref_dir *packed_refs;2449 struct ref_to_prune *ref_to_prune;2450};24512452/*2453 * An each_ref_entry_fn that is run over loose references only. If2454 * the loose reference can be packed, add an entry in the packed ref2455 * cache. If the reference should be pruned, also add it to2456 * ref_to_prune in the pack_refs_cb_data.2457 */2458static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2459{2460 struct pack_refs_cb_data *cb = cb_data;2461 enum peel_status peel_status;2462 struct ref_entry *packed_entry;2463 int is_tag_ref = starts_with(entry->name, "refs/tags/");24642465 /* ALWAYS pack tags */2466 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2467 return 0;24682469 /* Do not pack symbolic or broken refs: */2470 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2471 return 0;24722473 /* Add a packed ref cache entry equivalent to the loose entry. */2474 peel_status = peel_entry(entry, 1);2475 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2476 die("internal error peeling reference %s (%s)",2477 entry->name, sha1_to_hex(entry->u.value.sha1));2478 packed_entry = find_ref(cb->packed_refs, entry->name);2479 if (packed_entry) {2480 /* Overwrite existing packed entry with info from loose entry */2481 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2482 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2483 } else {2484 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,2485 REF_ISPACKED | REF_KNOWS_PEELED, 0);2486 add_ref(cb->packed_refs, packed_entry);2487 }2488 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);24892490 /* Schedule the loose reference for pruning if requested. */2491 if ((cb->flags & PACK_REFS_PRUNE)) {2492 int namelen = strlen(entry->name) + 1;2493 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2494 hashcpy(n->sha1, entry->u.value.sha1);2495 strcpy(n->name, entry->name);2496 n->next = cb->ref_to_prune;2497 cb->ref_to_prune = n;2498 }2499 return 0;2500}25012502/*2503 * Remove empty parents, but spare refs/ and immediate subdirs.2504 * Note: munges *name.2505 */2506static void try_remove_empty_parents(char *name)2507{2508 char *p, *q;2509 int i;2510 p = name;2511 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2512 while (*p && *p != '/')2513 p++;2514 /* tolerate duplicate slashes; see check_refname_format() */2515 while (*p == '/')2516 p++;2517 }2518 for (q = p; *q; q++)2519 ;2520 while (1) {2521 while (q > p && *q != '/')2522 q--;2523 while (q > p && *(q-1) == '/')2524 q--;2525 if (q == p)2526 break;2527 *q = '\0';2528 if (rmdir(git_path("%s", name)))2529 break;2530 }2531}25322533/* make sure nobody touched the ref, and unlink */2534static void prune_ref(struct ref_to_prune *r)2535{2536 struct ref_transaction *transaction;2537 struct strbuf err = STRBUF_INIT;25382539 if (check_refname_format(r->name, 0))2540 return;25412542 transaction = ref_transaction_begin(&err);2543 if (!transaction ||2544 ref_transaction_delete(transaction, r->name, r->sha1,2545 REF_ISPRUNING, 1, NULL, &err) ||2546 ref_transaction_commit(transaction, &err)) {2547 ref_transaction_free(transaction);2548 error("%s", err.buf);2549 strbuf_release(&err);2550 return;2551 }2552 ref_transaction_free(transaction);2553 strbuf_release(&err);2554 try_remove_empty_parents(r->name);2555}25562557static void prune_refs(struct ref_to_prune *r)2558{2559 while (r) {2560 prune_ref(r);2561 r = r->next;2562 }2563}25642565int pack_refs(unsigned int flags)2566{2567 struct pack_refs_cb_data cbdata;25682569 memset(&cbdata, 0, sizeof(cbdata));2570 cbdata.flags = flags;25712572 lock_packed_refs(LOCK_DIE_ON_ERROR);2573 cbdata.packed_refs = get_packed_refs(&ref_cache);25742575 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2576 pack_if_possible_fn, &cbdata);25772578 if (commit_packed_refs())2579 die_errno("unable to overwrite old ref-pack file");25802581 prune_refs(cbdata.ref_to_prune);2582 return 0;2583}25842585/*2586 * If entry is no longer needed in packed-refs, add it to the string2587 * list pointed to by cb_data. Reasons for deleting entries:2588 *2589 * - Entry is broken.2590 * - Entry is overridden by a loose ref.2591 * - Entry does not point at a valid object.2592 *2593 * In the first and third cases, also emit an error message because these2594 * are indications of repository corruption.2595 */2596static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)2597{2598 struct string_list *refs_to_delete = cb_data;25992600 if (entry->flag & REF_ISBROKEN) {2601 /* This shouldn't happen to packed refs. */2602 error("%s is broken!", entry->name);2603 string_list_append(refs_to_delete, entry->name);2604 return 0;2605 }2606 if (!has_sha1_file(entry->u.value.sha1)) {2607 unsigned char sha1[20];2608 int flags;26092610 if (read_ref_full(entry->name, 0, sha1, &flags))2611 /* We should at least have found the packed ref. */2612 die("Internal error");2613 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2614 /*2615 * This packed reference is overridden by a2616 * loose reference, so it is OK that its value2617 * is no longer valid; for example, it might2618 * refer to an object that has been garbage2619 * collected. For this purpose we don't even2620 * care whether the loose reference itself is2621 * invalid, broken, symbolic, etc. Silently2622 * remove the packed reference.2623 */2624 string_list_append(refs_to_delete, entry->name);2625 return 0;2626 }2627 /*2628 * There is no overriding loose reference, so the fact2629 * that this reference doesn't refer to a valid object2630 * indicates some kind of repository corruption.2631 * Report the problem, then omit the reference from2632 * the output.2633 */2634 error("%s does not point to a valid object!", entry->name);2635 string_list_append(refs_to_delete, entry->name);2636 return 0;2637 }26382639 return 0;2640}26412642int repack_without_refs(const char **refnames, int n, struct strbuf *err)2643{2644 struct ref_dir *packed;2645 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2646 struct string_list_item *ref_to_delete;2647 int i, ret, removed = 0;26482649 /* Look for a packed ref */2650 for (i = 0; i < n; i++)2651 if (get_packed_ref(refnames[i]))2652 break;26532654 /* Avoid locking if we have nothing to do */2655 if (i == n)2656 return 0; /* no refname exists in packed refs */26572658 if (lock_packed_refs(0)) {2659 if (err) {2660 unable_to_lock_message(git_path("packed-refs"), errno,2661 err);2662 return -1;2663 }2664 unable_to_lock_error(git_path("packed-refs"), errno);2665 return error("cannot delete '%s' from packed refs", refnames[i]);2666 }2667 packed = get_packed_refs(&ref_cache);26682669 /* Remove refnames from the cache */2670 for (i = 0; i < n; i++)2671 if (remove_entry(packed, refnames[i]) != -1)2672 removed = 1;2673 if (!removed) {2674 /*2675 * All packed entries disappeared while we were2676 * acquiring the lock.2677 */2678 rollback_packed_refs();2679 return 0;2680 }26812682 /* Remove any other accumulated cruft */2683 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);2684 for_each_string_list_item(ref_to_delete, &refs_to_delete) {2685 if (remove_entry(packed, ref_to_delete->string) == -1)2686 die("internal error");2687 }26882689 /* Write what remains */2690 ret = commit_packed_refs();2691 if (ret && err)2692 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2693 strerror(errno));2694 return ret;2695}26962697static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2698{2699 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2700 /*2701 * loose. The loose file name is the same as the2702 * lockfile name, minus ".lock":2703 */2704 char *loose_filename = get_locked_file_path(lock->lk);2705 int res = unlink_or_msg(loose_filename, err);2706 free(loose_filename);2707 if (res)2708 return 1;2709 }2710 return 0;2711}27122713int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2714{2715 struct ref_transaction *transaction;2716 struct strbuf err = STRBUF_INIT;27172718 transaction = ref_transaction_begin(&err);2719 if (!transaction ||2720 ref_transaction_delete(transaction, refname, sha1, delopt,2721 sha1 && !is_null_sha1(sha1), NULL, &err) ||2722 ref_transaction_commit(transaction, &err)) {2723 error("%s", err.buf);2724 ref_transaction_free(transaction);2725 strbuf_release(&err);2726 return 1;2727 }2728 ref_transaction_free(transaction);2729 strbuf_release(&err);2730 return 0;2731}27322733/*2734 * People using contrib's git-new-workdir have .git/logs/refs ->2735 * /some/other/path/.git/logs/refs, and that may live on another device.2736 *2737 * IOW, to avoid cross device rename errors, the temporary renamed log must2738 * live into logs/refs.2739 */2740#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"27412742static int rename_tmp_log(const char *newrefname)2743{2744 int attempts_remaining = 4;27452746 retry:2747 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {2748 case SCLD_OK:2749 break; /* success */2750 case SCLD_VANISHED:2751 if (--attempts_remaining > 0)2752 goto retry;2753 /* fall through */2754 default:2755 error("unable to create directory for %s", newrefname);2756 return -1;2757 }27582759 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2760 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2761 /*2762 * rename(a, b) when b is an existing2763 * directory ought to result in ISDIR, but2764 * Solaris 5.8 gives ENOTDIR. Sheesh.2765 */2766 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2767 error("Directory not empty: logs/%s", newrefname);2768 return -1;2769 }2770 goto retry;2771 } else if (errno == ENOENT && --attempts_remaining > 0) {2772 /*2773 * Maybe another process just deleted one of2774 * the directories in the path to newrefname.2775 * Try again from the beginning.2776 */2777 goto retry;2778 } else {2779 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2780 newrefname, strerror(errno));2781 return -1;2782 }2783 }2784 return 0;2785}27862787static int rename_ref_available(const char *oldname, const char *newname)2788{2789 struct string_list skip = STRING_LIST_INIT_NODUP;2790 int ret;27912792 string_list_insert(&skip, oldname);2793 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))2794 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));2795 string_list_clear(&skip, 0);2796 return ret;2797}27982799static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,2800 const char *logmsg);28012802int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2803{2804 unsigned char sha1[20], orig_sha1[20];2805 int flag = 0, logmoved = 0;2806 struct ref_lock *lock;2807 struct stat loginfo;2808 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2809 const char *symref = NULL;28102811 if (log && S_ISLNK(loginfo.st_mode))2812 return error("reflog for %s is a symlink", oldrefname);28132814 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2815 orig_sha1, &flag);2816 if (flag & REF_ISSYMREF)2817 return error("refname %s is a symbolic ref, renaming it is not supported",2818 oldrefname);2819 if (!symref)2820 return error("refname %s not found", oldrefname);28212822 if (!rename_ref_available(oldrefname, newrefname))2823 return 1;28242825 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2826 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2827 oldrefname, strerror(errno));28282829 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2830 error("unable to delete old %s", oldrefname);2831 goto rollback;2832 }28332834 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2835 delete_ref(newrefname, sha1, REF_NODEREF)) {2836 if (errno==EISDIR) {2837 if (remove_empty_directories(git_path("%s", newrefname))) {2838 error("Directory not empty: %s", newrefname);2839 goto rollback;2840 }2841 } else {2842 error("unable to delete existing %s", newrefname);2843 goto rollback;2844 }2845 }28462847 if (log && rename_tmp_log(newrefname))2848 goto rollback;28492850 logmoved = log;28512852 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);2853 if (!lock) {2854 error("unable to lock %s for update", newrefname);2855 goto rollback;2856 }2857 lock->force_write = 1;2858 hashcpy(lock->old_sha1, orig_sha1);2859 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2860 error("unable to write current sha1 into %s", newrefname);2861 goto rollback;2862 }28632864 return 0;28652866 rollback:2867 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);2868 if (!lock) {2869 error("unable to lock %s for rollback", oldrefname);2870 goto rollbacklog;2871 }28722873 lock->force_write = 1;2874 flag = log_all_ref_updates;2875 log_all_ref_updates = 0;2876 if (write_ref_sha1(lock, orig_sha1, NULL))2877 error("unable to write current sha1 into %s", oldrefname);2878 log_all_ref_updates = flag;28792880 rollbacklog:2881 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2882 error("unable to restore logfile %s from %s: %s",2883 oldrefname, newrefname, strerror(errno));2884 if (!logmoved && log &&2885 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2886 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2887 oldrefname, strerror(errno));28882889 return 1;2890}28912892int close_ref(struct ref_lock *lock)2893{2894 if (close_lock_file(lock->lk))2895 return -1;2896 lock->lock_fd = -1;2897 return 0;2898}28992900int commit_ref(struct ref_lock *lock)2901{2902 if (commit_lock_file(lock->lk))2903 return -1;2904 lock->lock_fd = -1;2905 return 0;2906}29072908void unlock_ref(struct ref_lock *lock)2909{2910 /* Do not free lock->lk -- atexit() still looks at them */2911 if (lock->lk)2912 rollback_lock_file(lock->lk);2913 free(lock->ref_name);2914 free(lock->orig_ref_name);2915 free(lock);2916}29172918/*2919 * copy the reflog message msg to buf, which has been allocated sufficiently2920 * large, while cleaning up the whitespaces. Especially, convert LF to space,2921 * because reflog file is one line per entry.2922 */2923static int copy_msg(char *buf, const char *msg)2924{2925 char *cp = buf;2926 char c;2927 int wasspace = 1;29282929 *cp++ = '\t';2930 while ((c = *msg++)) {2931 if (wasspace && isspace(c))2932 continue;2933 wasspace = isspace(c);2934 if (wasspace)2935 c = ' ';2936 *cp++ = c;2937 }2938 while (buf < cp && isspace(cp[-1]))2939 cp--;2940 *cp++ = '\n';2941 return cp - buf;2942}29432944/* This function must set a meaningful errno on failure */2945int log_ref_setup(const char *refname, char *logfile, int bufsize)2946{2947 int logfd, oflags = O_APPEND | O_WRONLY;29482949 git_snpath(logfile, bufsize, "logs/%s", refname);2950 if (log_all_ref_updates &&2951 (starts_with(refname, "refs/heads/") ||2952 starts_with(refname, "refs/remotes/") ||2953 starts_with(refname, "refs/notes/") ||2954 !strcmp(refname, "HEAD"))) {2955 if (safe_create_leading_directories(logfile) < 0) {2956 int save_errno = errno;2957 error("unable to create directory for %s", logfile);2958 errno = save_errno;2959 return -1;2960 }2961 oflags |= O_CREAT;2962 }29632964 logfd = open(logfile, oflags, 0666);2965 if (logfd < 0) {2966 if (!(oflags & O_CREAT) && errno == ENOENT)2967 return 0;29682969 if ((oflags & O_CREAT) && errno == EISDIR) {2970 if (remove_empty_directories(logfile)) {2971 int save_errno = errno;2972 error("There are still logs under '%s'",2973 logfile);2974 errno = save_errno;2975 return -1;2976 }2977 logfd = open(logfile, oflags, 0666);2978 }29792980 if (logfd < 0) {2981 int save_errno = errno;2982 error("Unable to append to %s: %s", logfile,2983 strerror(errno));2984 errno = save_errno;2985 return -1;2986 }2987 }29882989 adjust_shared_perm(logfile);2990 close(logfd);2991 return 0;2992}29932994static int log_ref_write(const char *refname, const unsigned char *old_sha1,2995 const unsigned char *new_sha1, const char *msg)2996{2997 int logfd, result, written, oflags = O_APPEND | O_WRONLY;2998 unsigned maxlen, len;2999 int msglen;3000 char log_file[PATH_MAX];3001 char *logrec;3002 const char *committer;30033004 if (log_all_ref_updates < 0)3005 log_all_ref_updates = !is_bare_repository();30063007 result = log_ref_setup(refname, log_file, sizeof(log_file));3008 if (result)3009 return result;30103011 logfd = open(log_file, oflags);3012 if (logfd < 0)3013 return 0;3014 msglen = msg ? strlen(msg) : 0;3015 committer = git_committer_info(0);3016 maxlen = strlen(committer) + msglen + 100;3017 logrec = xmalloc(maxlen);3018 len = sprintf(logrec, "%s %s %s\n",3019 sha1_to_hex(old_sha1),3020 sha1_to_hex(new_sha1),3021 committer);3022 if (msglen)3023 len += copy_msg(logrec + len - 1, msg) - 1;3024 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;3025 free(logrec);3026 if (written != len) {3027 int save_errno = errno;3028 close(logfd);3029 error("Unable to append to %s", log_file);3030 errno = save_errno;3031 return -1;3032 }3033 if (close(logfd)) {3034 int save_errno = errno;3035 error("Unable to append to %s", log_file);3036 errno = save_errno;3037 return -1;3038 }3039 return 0;3040}30413042int is_branch(const char *refname)3043{3044 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");3045}30463047/*3048 * Write sha1 into the ref specified by the lock. Make sure that errno3049 * is sane on error.3050 */3051static int write_ref_sha1(struct ref_lock *lock,3052 const unsigned char *sha1, const char *logmsg)3053{3054 static char term = '\n';3055 struct object *o;30563057 if (!lock) {3058 errno = EINVAL;3059 return -1;3060 }3061 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3062 unlock_ref(lock);3063 return 0;3064 }3065 o = parse_object(sha1);3066 if (!o) {3067 error("Trying to write ref %s with nonexistent object %s",3068 lock->ref_name, sha1_to_hex(sha1));3069 unlock_ref(lock);3070 errno = EINVAL;3071 return -1;3072 }3073 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {3074 error("Trying to write non-commit object %s to branch %s",3075 sha1_to_hex(sha1), lock->ref_name);3076 unlock_ref(lock);3077 errno = EINVAL;3078 return -1;3079 }3080 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||3081 write_in_full(lock->lock_fd, &term, 1) != 1 ||3082 close_ref(lock) < 0) {3083 int save_errno = errno;3084 error("Couldn't write %s", lock->lk->filename.buf);3085 unlock_ref(lock);3086 errno = save_errno;3087 return -1;3088 }3089 clear_loose_ref_cache(&ref_cache);3090 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||3091 (strcmp(lock->ref_name, lock->orig_ref_name) &&3092 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {3093 unlock_ref(lock);3094 return -1;3095 }3096 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {3097 /*3098 * Special hack: If a branch is updated directly and HEAD3099 * points to it (may happen on the remote side of a push3100 * for example) then logically the HEAD reflog should be3101 * updated too.3102 * A generic solution implies reverse symref information,3103 * but finding all symrefs pointing to the given branch3104 * would be rather costly for this rare event (the direct3105 * update of a branch) to be worth it. So let's cheat and3106 * check with HEAD only which should cover 99% of all usage3107 * scenarios (even 100% of the default ones).3108 */3109 unsigned char head_sha1[20];3110 int head_flag;3111 const char *head_ref;3112 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3113 head_sha1, &head_flag);3114 if (head_ref && (head_flag & REF_ISSYMREF) &&3115 !strcmp(head_ref, lock->ref_name))3116 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3117 }3118 if (commit_ref(lock)) {3119 error("Couldn't set %s", lock->ref_name);3120 unlock_ref(lock);3121 return -1;3122 }3123 unlock_ref(lock);3124 return 0;3125}31263127int create_symref(const char *ref_target, const char *refs_heads_master,3128 const char *logmsg)3129{3130 const char *lockpath;3131 char ref[1000];3132 int fd, len, written;3133 char *git_HEAD = git_pathdup("%s", ref_target);3134 unsigned char old_sha1[20], new_sha1[20];31353136 if (logmsg && read_ref(ref_target, old_sha1))3137 hashclr(old_sha1);31383139 if (safe_create_leading_directories(git_HEAD) < 0)3140 return error("unable to create directory for %s", git_HEAD);31413142#ifndef NO_SYMLINK_HEAD3143 if (prefer_symlink_refs) {3144 unlink(git_HEAD);3145 if (!symlink(refs_heads_master, git_HEAD))3146 goto done;3147 fprintf(stderr, "no symlink - falling back to symbolic ref\n");3148 }3149#endif31503151 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);3152 if (sizeof(ref) <= len) {3153 error("refname too long: %s", refs_heads_master);3154 goto error_free_return;3155 }3156 lockpath = mkpath("%s.lock", git_HEAD);3157 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);3158 if (fd < 0) {3159 error("Unable to open %s for writing", lockpath);3160 goto error_free_return;3161 }3162 written = write_in_full(fd, ref, len);3163 if (close(fd) != 0 || written != len) {3164 error("Unable to write to %s", lockpath);3165 goto error_unlink_return;3166 }3167 if (rename(lockpath, git_HEAD) < 0) {3168 error("Unable to create %s", git_HEAD);3169 goto error_unlink_return;3170 }3171 if (adjust_shared_perm(git_HEAD)) {3172 error("Unable to fix permissions on %s", lockpath);3173 error_unlink_return:3174 unlink_or_warn(lockpath);3175 error_free_return:3176 free(git_HEAD);3177 return -1;3178 }31793180#ifndef NO_SYMLINK_HEAD3181 done:3182#endif3183 if (logmsg && !read_ref(refs_heads_master, new_sha1))3184 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31853186 free(git_HEAD);3187 return 0;3188}31893190struct read_ref_at_cb {3191 const char *refname;3192 unsigned long at_time;3193 int cnt;3194 int reccnt;3195 unsigned char *sha1;3196 int found_it;31973198 unsigned char osha1[20];3199 unsigned char nsha1[20];3200 int tz;3201 unsigned long date;3202 char **msg;3203 unsigned long *cutoff_time;3204 int *cutoff_tz;3205 int *cutoff_cnt;3206};32073208static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,3209 const char *email, unsigned long timestamp, int tz,3210 const char *message, void *cb_data)3211{3212 struct read_ref_at_cb *cb = cb_data;32133214 cb->reccnt++;3215 cb->tz = tz;3216 cb->date = timestamp;32173218 if (timestamp <= cb->at_time || cb->cnt == 0) {3219 if (cb->msg)3220 *cb->msg = xstrdup(message);3221 if (cb->cutoff_time)3222 *cb->cutoff_time = timestamp;3223 if (cb->cutoff_tz)3224 *cb->cutoff_tz = tz;3225 if (cb->cutoff_cnt)3226 *cb->cutoff_cnt = cb->reccnt - 1;3227 /*3228 * we have not yet updated cb->[n|o]sha1 so they still3229 * hold the values for the previous record.3230 */3231 if (!is_null_sha1(cb->osha1)) {3232 hashcpy(cb->sha1, nsha1);3233 if (hashcmp(cb->osha1, nsha1))3234 warning("Log for ref %s has gap after %s.",3235 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));3236 }3237 else if (cb->date == cb->at_time)3238 hashcpy(cb->sha1, nsha1);3239 else if (hashcmp(nsha1, cb->sha1))3240 warning("Log for ref %s unexpectedly ended on %s.",3241 cb->refname, show_date(cb->date, cb->tz,3242 DATE_RFC2822));3243 hashcpy(cb->osha1, osha1);3244 hashcpy(cb->nsha1, nsha1);3245 cb->found_it = 1;3246 return 1;3247 }3248 hashcpy(cb->osha1, osha1);3249 hashcpy(cb->nsha1, nsha1);3250 if (cb->cnt > 0)3251 cb->cnt--;3252 return 0;3253}32543255static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,3256 const char *email, unsigned long timestamp,3257 int tz, const char *message, void *cb_data)3258{3259 struct read_ref_at_cb *cb = cb_data;32603261 if (cb->msg)3262 *cb->msg = xstrdup(message);3263 if (cb->cutoff_time)3264 *cb->cutoff_time = timestamp;3265 if (cb->cutoff_tz)3266 *cb->cutoff_tz = tz;3267 if (cb->cutoff_cnt)3268 *cb->cutoff_cnt = cb->reccnt;3269 hashcpy(cb->sha1, osha1);3270 if (is_null_sha1(cb->sha1))3271 hashcpy(cb->sha1, nsha1);3272 /* We just want the first entry */3273 return 1;3274}32753276int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,3277 unsigned char *sha1, char **msg,3278 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)3279{3280 struct read_ref_at_cb cb;32813282 memset(&cb, 0, sizeof(cb));3283 cb.refname = refname;3284 cb.at_time = at_time;3285 cb.cnt = cnt;3286 cb.msg = msg;3287 cb.cutoff_time = cutoff_time;3288 cb.cutoff_tz = cutoff_tz;3289 cb.cutoff_cnt = cutoff_cnt;3290 cb.sha1 = sha1;32913292 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);32933294 if (!cb.reccnt) {3295 if (flags & GET_SHA1_QUIETLY)3296 exit(128);3297 else3298 die("Log for %s is empty.", refname);3299 }3300 if (cb.found_it)3301 return 0;33023303 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33043305 return 1;3306}33073308int reflog_exists(const char *refname)3309{3310 struct stat st;33113312 return !lstat(git_path("logs/%s", refname), &st) &&3313 S_ISREG(st.st_mode);3314}33153316int delete_reflog(const char *refname)3317{3318 return remove_path(git_path("logs/%s", refname));3319}33203321static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3322{3323 unsigned char osha1[20], nsha1[20];3324 char *email_end, *message;3325 unsigned long timestamp;3326 int tz;33273328 /* old SP new SP name <email> SP time TAB msg LF */3329 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3330 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3331 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3332 !(email_end = strchr(sb->buf + 82, '>')) ||3333 email_end[1] != ' ' ||3334 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3335 !message || message[0] != ' ' ||3336 (message[1] != '+' && message[1] != '-') ||3337 !isdigit(message[2]) || !isdigit(message[3]) ||3338 !isdigit(message[4]) || !isdigit(message[5]))3339 return 0; /* corrupt? */3340 email_end[1] = '\0';3341 tz = strtol(message + 1, NULL, 10);3342 if (message[6] != '\t')3343 message += 6;3344 else3345 message += 7;3346 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3347}33483349static char *find_beginning_of_line(char *bob, char *scan)3350{3351 while (bob < scan && *(--scan) != '\n')3352 ; /* keep scanning backwards */3353 /*3354 * Return either beginning of the buffer, or LF at the end of3355 * the previous line.3356 */3357 return scan;3358}33593360int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3361{3362 struct strbuf sb = STRBUF_INIT;3363 FILE *logfp;3364 long pos;3365 int ret = 0, at_tail = 1;33663367 logfp = fopen(git_path("logs/%s", refname), "r");3368 if (!logfp)3369 return -1;33703371 /* Jump to the end */3372 if (fseek(logfp, 0, SEEK_END) < 0)3373 return error("cannot seek back reflog for %s: %s",3374 refname, strerror(errno));3375 pos = ftell(logfp);3376 while (!ret && 0 < pos) {3377 int cnt;3378 size_t nread;3379 char buf[BUFSIZ];3380 char *endp, *scanp;33813382 /* Fill next block from the end */3383 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3384 if (fseek(logfp, pos - cnt, SEEK_SET))3385 return error("cannot seek back reflog for %s: %s",3386 refname, strerror(errno));3387 nread = fread(buf, cnt, 1, logfp);3388 if (nread != 1)3389 return error("cannot read %d bytes from reflog for %s: %s",3390 cnt, refname, strerror(errno));3391 pos -= cnt;33923393 scanp = endp = buf + cnt;3394 if (at_tail && scanp[-1] == '\n')3395 /* Looking at the final LF at the end of the file */3396 scanp--;3397 at_tail = 0;33983399 while (buf < scanp) {3400 /*3401 * terminating LF of the previous line, or the beginning3402 * of the buffer.3403 */3404 char *bp;34053406 bp = find_beginning_of_line(buf, scanp);34073408 if (*bp != '\n') {3409 strbuf_splice(&sb, 0, 0, buf, endp - buf);3410 if (pos)3411 break; /* need to fill another block */3412 scanp = buf - 1; /* leave loop */3413 } else {3414 /*3415 * (bp + 1) thru endp is the beginning of the3416 * current line we have in sb3417 */3418 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3419 scanp = bp;3420 endp = bp + 1;3421 }3422 ret = show_one_reflog_ent(&sb, fn, cb_data);3423 strbuf_reset(&sb);3424 if (ret)3425 break;3426 }34273428 }3429 if (!ret && sb.len)3430 ret = show_one_reflog_ent(&sb, fn, cb_data);34313432 fclose(logfp);3433 strbuf_release(&sb);3434 return ret;3435}34363437int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3438{3439 FILE *logfp;3440 struct strbuf sb = STRBUF_INIT;3441 int ret = 0;34423443 logfp = fopen(git_path("logs/%s", refname), "r");3444 if (!logfp)3445 return -1;34463447 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3448 ret = show_one_reflog_ent(&sb, fn, cb_data);3449 fclose(logfp);3450 strbuf_release(&sb);3451 return ret;3452}3453/*3454 * Call fn for each reflog in the namespace indicated by name. name3455 * must be empty or end with '/'. Name will be used as a scratch3456 * space, but its contents will be restored before return.3457 */3458static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3459{3460 DIR *d = opendir(git_path("logs/%s", name->buf));3461 int retval = 0;3462 struct dirent *de;3463 int oldlen = name->len;34643465 if (!d)3466 return name->len ? errno : 0;34673468 while ((de = readdir(d)) != NULL) {3469 struct stat st;34703471 if (de->d_name[0] == '.')3472 continue;3473 if (ends_with(de->d_name, ".lock"))3474 continue;3475 strbuf_addstr(name, de->d_name);3476 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3477 ; /* silently ignore */3478 } else {3479 if (S_ISDIR(st.st_mode)) {3480 strbuf_addch(name, '/');3481 retval = do_for_each_reflog(name, fn, cb_data);3482 } else {3483 unsigned char sha1[20];3484 if (read_ref_full(name->buf, 0, sha1, NULL))3485 retval = error("bad ref for %s", name->buf);3486 else3487 retval = fn(name->buf, sha1, 0, cb_data);3488 }3489 if (retval)3490 break;3491 }3492 strbuf_setlen(name, oldlen);3493 }3494 closedir(d);3495 return retval;3496}34973498int for_each_reflog(each_ref_fn fn, void *cb_data)3499{3500 int retval;3501 struct strbuf name;3502 strbuf_init(&name, PATH_MAX);3503 retval = do_for_each_reflog(&name, fn, cb_data);3504 strbuf_release(&name);3505 return retval;3506}35073508/**3509 * Information needed for a single ref update. Set new_sha1 to the3510 * new value or to zero to delete the ref. To check the old value3511 * while locking the ref, set have_old to 1 and set old_sha1 to the3512 * value or to zero to ensure the ref does not exist before update.3513 */3514struct ref_update {3515 unsigned char new_sha1[20];3516 unsigned char old_sha1[20];3517 int flags; /* REF_NODEREF? */3518 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */3519 struct ref_lock *lock;3520 int type;3521 char *msg;3522 const char refname[FLEX_ARRAY];3523};35243525/*3526 * Transaction states.3527 * OPEN: The transaction is in a valid state and can accept new updates.3528 * An OPEN transaction can be committed.3529 * CLOSED: A closed transaction is no longer active and no other operations3530 * than free can be used on it in this state.3531 * A transaction can either become closed by successfully committing3532 * an active transaction or if there is a failure while building3533 * the transaction thus rendering it failed/inactive.3534 */3535enum ref_transaction_state {3536 REF_TRANSACTION_OPEN = 0,3537 REF_TRANSACTION_CLOSED = 13538};35393540/*3541 * Data structure for holding a reference transaction, which can3542 * consist of checks and updates to multiple references, carried out3543 * as atomically as possible. This structure is opaque to callers.3544 */3545struct ref_transaction {3546 struct ref_update **updates;3547 size_t alloc;3548 size_t nr;3549 enum ref_transaction_state state;3550};35513552struct ref_transaction *ref_transaction_begin(struct strbuf *err)3553{3554 return xcalloc(1, sizeof(struct ref_transaction));3555}35563557void ref_transaction_free(struct ref_transaction *transaction)3558{3559 int i;35603561 if (!transaction)3562 return;35633564 for (i = 0; i < transaction->nr; i++) {3565 free(transaction->updates[i]->msg);3566 free(transaction->updates[i]);3567 }3568 free(transaction->updates);3569 free(transaction);3570}35713572static struct ref_update *add_update(struct ref_transaction *transaction,3573 const char *refname)3574{3575 size_t len = strlen(refname);3576 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);35773578 strcpy((char *)update->refname, refname);3579 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);3580 transaction->updates[transaction->nr++] = update;3581 return update;3582}35833584int ref_transaction_update(struct ref_transaction *transaction,3585 const char *refname,3586 const unsigned char *new_sha1,3587 const unsigned char *old_sha1,3588 int flags, int have_old, const char *msg,3589 struct strbuf *err)3590{3591 struct ref_update *update;35923593 if (transaction->state != REF_TRANSACTION_OPEN)3594 die("BUG: update called for transaction that is not open");35953596 if (have_old && !old_sha1)3597 die("BUG: have_old is true but old_sha1 is NULL");35983599 if (!is_null_sha1(new_sha1) &&3600 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3601 strbuf_addf(err, "refusing to update ref with bad name %s",3602 refname);3603 return -1;3604 }36053606 update = add_update(transaction, refname);3607 hashcpy(update->new_sha1, new_sha1);3608 update->flags = flags;3609 update->have_old = have_old;3610 if (have_old)3611 hashcpy(update->old_sha1, old_sha1);3612 if (msg)3613 update->msg = xstrdup(msg);3614 return 0;3615}36163617int ref_transaction_create(struct ref_transaction *transaction,3618 const char *refname,3619 const unsigned char *new_sha1,3620 int flags, const char *msg,3621 struct strbuf *err)3622{3623 struct ref_update *update;36243625 if (transaction->state != REF_TRANSACTION_OPEN)3626 die("BUG: create called for transaction that is not open");36273628 if (!new_sha1 || is_null_sha1(new_sha1))3629 die("BUG: create ref with null new_sha1");36303631 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3632 strbuf_addf(err, "refusing to create ref with bad name %s",3633 refname);3634 return -1;3635 }36363637 update = add_update(transaction, refname);36383639 hashcpy(update->new_sha1, new_sha1);3640 hashclr(update->old_sha1);3641 update->flags = flags;3642 update->have_old = 1;3643 if (msg)3644 update->msg = xstrdup(msg);3645 return 0;3646}36473648int ref_transaction_delete(struct ref_transaction *transaction,3649 const char *refname,3650 const unsigned char *old_sha1,3651 int flags, int have_old, const char *msg,3652 struct strbuf *err)3653{3654 struct ref_update *update;36553656 if (transaction->state != REF_TRANSACTION_OPEN)3657 die("BUG: delete called for transaction that is not open");36583659 if (have_old && !old_sha1)3660 die("BUG: have_old is true but old_sha1 is NULL");36613662 update = add_update(transaction, refname);3663 update->flags = flags;3664 update->have_old = have_old;3665 if (have_old) {3666 assert(!is_null_sha1(old_sha1));3667 hashcpy(update->old_sha1, old_sha1);3668 }3669 if (msg)3670 update->msg = xstrdup(msg);3671 return 0;3672}36733674int update_ref(const char *action, const char *refname,3675 const unsigned char *sha1, const unsigned char *oldval,3676 int flags, enum action_on_err onerr)3677{3678 struct ref_transaction *t;3679 struct strbuf err = STRBUF_INIT;36803681 t = ref_transaction_begin(&err);3682 if (!t ||3683 ref_transaction_update(t, refname, sha1, oldval, flags,3684 !!oldval, action, &err) ||3685 ref_transaction_commit(t, &err)) {3686 const char *str = "update_ref failed for ref '%s': %s";36873688 ref_transaction_free(t);3689 switch (onerr) {3690 case UPDATE_REFS_MSG_ON_ERR:3691 error(str, refname, err.buf);3692 break;3693 case UPDATE_REFS_DIE_ON_ERR:3694 die(str, refname, err.buf);3695 break;3696 case UPDATE_REFS_QUIET_ON_ERR:3697 break;3698 }3699 strbuf_release(&err);3700 return 1;3701 }3702 strbuf_release(&err);3703 ref_transaction_free(t);3704 return 0;3705}37063707static int ref_update_compare(const void *r1, const void *r2)3708{3709 const struct ref_update * const *u1 = r1;3710 const struct ref_update * const *u2 = r2;3711 return strcmp((*u1)->refname, (*u2)->refname);3712}37133714static int ref_update_reject_duplicates(struct ref_update **updates, int n,3715 struct strbuf *err)3716{3717 int i;3718 for (i = 1; i < n; i++)3719 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {3720 const char *str =3721 "Multiple updates for ref '%s' not allowed.";3722 if (err)3723 strbuf_addf(err, str, updates[i]->refname);37243725 return 1;3726 }3727 return 0;3728}37293730int ref_transaction_commit(struct ref_transaction *transaction,3731 struct strbuf *err)3732{3733 int ret = 0, delnum = 0, i;3734 const char **delnames;3735 int n = transaction->nr;3736 struct ref_update **updates = transaction->updates;37373738 if (transaction->state != REF_TRANSACTION_OPEN)3739 die("BUG: commit called for transaction that is not open");37403741 if (!n) {3742 transaction->state = REF_TRANSACTION_CLOSED;3743 return 0;3744 }37453746 /* Allocate work space */3747 delnames = xmalloc(sizeof(*delnames) * n);37483749 /* Copy, sort, and reject duplicate refs */3750 qsort(updates, n, sizeof(*updates), ref_update_compare);3751 if (ref_update_reject_duplicates(updates, n, err)) {3752 ret = TRANSACTION_GENERIC_ERROR;3753 goto cleanup;3754 }37553756 /* Acquire all locks while verifying old values */3757 for (i = 0; i < n; i++) {3758 struct ref_update *update = updates[i];3759 int flags = update->flags;37603761 if (is_null_sha1(update->new_sha1))3762 flags |= REF_DELETING;3763 update->lock = lock_ref_sha1_basic(update->refname,3764 (update->have_old ?3765 update->old_sha1 :3766 NULL),3767 NULL,3768 flags,3769 &update->type);3770 if (!update->lock) {3771 ret = (errno == ENOTDIR)3772 ? TRANSACTION_NAME_CONFLICT3773 : TRANSACTION_GENERIC_ERROR;3774 if (err)3775 strbuf_addf(err, "Cannot lock the ref '%s'.",3776 update->refname);3777 goto cleanup;3778 }3779 }37803781 /* Perform updates first so live commits remain referenced */3782 for (i = 0; i < n; i++) {3783 struct ref_update *update = updates[i];37843785 if (!is_null_sha1(update->new_sha1)) {3786 if (write_ref_sha1(update->lock, update->new_sha1,3787 update->msg)) {3788 update->lock = NULL; /* freed by write_ref_sha1 */3789 if (err)3790 strbuf_addf(err, "Cannot update the ref '%s'.",3791 update->refname);3792 ret = TRANSACTION_GENERIC_ERROR;3793 goto cleanup;3794 }3795 update->lock = NULL; /* freed by write_ref_sha1 */3796 }3797 }37983799 /* Perform deletes now that updates are safely completed */3800 for (i = 0; i < n; i++) {3801 struct ref_update *update = updates[i];38023803 if (update->lock) {3804 if (delete_ref_loose(update->lock, update->type, err))3805 ret = TRANSACTION_GENERIC_ERROR;38063807 if (!(update->flags & REF_ISPRUNING))3808 delnames[delnum++] = update->lock->ref_name;3809 }3810 }38113812 if (repack_without_refs(delnames, delnum, err))3813 ret = TRANSACTION_GENERIC_ERROR;3814 for (i = 0; i < delnum; i++)3815 unlink_or_warn(git_path("logs/%s", delnames[i]));3816 clear_loose_ref_cache(&ref_cache);38173818cleanup:3819 transaction->state = REF_TRANSACTION_CLOSED;38203821 for (i = 0; i < n; i++)3822 if (updates[i]->lock)3823 unlock_ref(updates[i]->lock);3824 free(delnames);3825 return ret;3826}38273828char *shorten_unambiguous_ref(const char *refname, int strict)3829{3830 int i;3831 static char **scanf_fmts;3832 static int nr_rules;3833 char *short_name;38343835 if (!nr_rules) {3836 /*3837 * Pre-generate scanf formats from ref_rev_parse_rules[].3838 * Generate a format suitable for scanf from a3839 * ref_rev_parse_rules rule by interpolating "%s" at the3840 * location of the "%.*s".3841 */3842 size_t total_len = 0;3843 size_t offset = 0;38443845 /* the rule list is NULL terminated, count them first */3846 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)3847 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3848 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;38493850 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);38513852 offset = 0;3853 for (i = 0; i < nr_rules; i++) {3854 assert(offset < total_len);3855 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;3856 offset += snprintf(scanf_fmts[i], total_len - offset,3857 ref_rev_parse_rules[i], 2, "%s") + 1;3858 }3859 }38603861 /* bail out if there are no rules */3862 if (!nr_rules)3863 return xstrdup(refname);38643865 /* buffer for scanf result, at most refname must fit */3866 short_name = xstrdup(refname);38673868 /* skip first rule, it will always match */3869 for (i = nr_rules - 1; i > 0 ; --i) {3870 int j;3871 int rules_to_fail = i;3872 int short_name_len;38733874 if (1 != sscanf(refname, scanf_fmts[i], short_name))3875 continue;38763877 short_name_len = strlen(short_name);38783879 /*3880 * in strict mode, all (except the matched one) rules3881 * must fail to resolve to a valid non-ambiguous ref3882 */3883 if (strict)3884 rules_to_fail = nr_rules;38853886 /*3887 * check if the short name resolves to a valid ref,3888 * but use only rules prior to the matched one3889 */3890 for (j = 0; j < rules_to_fail; j++) {3891 const char *rule = ref_rev_parse_rules[j];3892 char refname[PATH_MAX];38933894 /* skip matched rule */3895 if (i == j)3896 continue;38973898 /*3899 * the short name is ambiguous, if it resolves3900 * (with this previous rule) to a valid ref3901 * read_ref() returns 0 on success3902 */3903 mksnpath(refname, sizeof(refname),3904 rule, short_name_len, short_name);3905 if (ref_exists(refname))3906 break;3907 }39083909 /*3910 * short name is non-ambiguous if all previous rules3911 * haven't resolved to a valid ref3912 */3913 if (j == rules_to_fail)3914 return short_name;3915 }39163917 free(short_name);3918 return xstrdup(refname);3919}39203921static struct string_list *hide_refs;39223923int parse_hide_refs_config(const char *var, const char *value, const char *section)3924{3925 if (!strcmp("transfer.hiderefs", var) ||3926 /* NEEDSWORK: use parse_config_key() once both are merged */3927 (starts_with(var, section) && var[strlen(section)] == '.' &&3928 !strcmp(var + strlen(section), ".hiderefs"))) {3929 char *ref;3930 int len;39313932 if (!value)3933 return config_error_nonbool(var);3934 ref = xstrdup(value);3935 len = strlen(ref);3936 while (len && ref[len - 1] == '/')3937 ref[--len] = '\0';3938 if (!hide_refs) {3939 hide_refs = xcalloc(1, sizeof(*hide_refs));3940 hide_refs->strdup_strings = 1;3941 }3942 string_list_append(hide_refs, ref);3943 }3944 return 0;3945}39463947int ref_is_hidden(const char *refname)3948{3949 struct string_list_item *item;39503951 if (!hide_refs)3952 return 0;3953 for_each_string_list_item(item, hide_refs) {3954 int len;3955 if (!starts_with(refname, item->string))3956 continue;3957 len = strlen(item->string);3958 if (!refname[len] || refname[len] == '/')3959 return 1;3960 }3961 return 0;3962}