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 if (!(flags & REFNAME_DOT_COMPONENT)) 75 return -1; /* Component starts with '.'. */ 76 /* 77 * Even if leading dots are allowed, don't allow "." 78 * as a component (".." is prevented by a rule above). 79 */ 80 if (refname[1] == '\0') 81 return -1; /* Component equals ".". */ 82 } 83 if (cp - refname >= LOCK_SUFFIX_LEN && 84 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 85 return -1; /* Refname ends with ".lock". */ 86 return cp - refname; 87} 88 89int check_refname_format(const char *refname, int flags) 90{ 91 int component_len, component_count = 0; 92 93 if (!strcmp(refname, "@")) 94 /* Refname is a single character '@'. */ 95 return -1; 96 97 while (1) { 98 /* We are at the start of a path component. */ 99 component_len = check_refname_component(refname, flags); 100 if (component_len <= 0) { 101 if ((flags & REFNAME_REFSPEC_PATTERN) && 102 refname[0] == '*' && 103 (refname[1] == '\0' || refname[1] == '/')) { 104 /* Accept one wildcard as a full refname component. */ 105 flags &= ~REFNAME_REFSPEC_PATTERN; 106 component_len = 1; 107 } else { 108 return -1; 109 } 110 } 111 component_count++; 112 if (refname[component_len] == '\0') 113 break; 114 /* Skip to next component. */ 115 refname += component_len + 1; 116 } 117 118 if (refname[component_len - 1] == '.') 119 return -1; /* Refname ends with '.'. */ 120 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) 121 return -1; /* Refname has only one component. */ 122 return 0; 123} 124 125struct ref_entry; 126 127/* 128 * Information used (along with the information in ref_entry) to 129 * describe a single cached reference. This data structure only 130 * occurs embedded in a union in struct ref_entry, and only when 131 * (ref_entry->flag & REF_DIR) is zero. 132 */ 133struct ref_value { 134 /* 135 * The name of the object to which this reference resolves 136 * (which may be a tag object). If REF_ISBROKEN, this is 137 * null. If REF_ISSYMREF, then this is the name of the object 138 * referred to by the last reference in the symlink chain. 139 */ 140 unsigned char sha1[20]; 141 142 /* 143 * If REF_KNOWS_PEELED, then this field holds the peeled value 144 * of this reference, or null if the reference is known not to 145 * be peelable. See the documentation for peel_ref() for an 146 * exact definition of "peelable". 147 */ 148 unsigned char peeled[20]; 149}; 150 151struct ref_cache; 152 153/* 154 * Information used (along with the information in ref_entry) to 155 * describe a level in the hierarchy of references. This data 156 * structure only occurs embedded in a union in struct ref_entry, and 157 * only when (ref_entry.flag & REF_DIR) is set. In that case, 158 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 159 * in the directory have already been read: 160 * 161 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 162 * or packed references, already read. 163 * 164 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 165 * references that hasn't been read yet (nor has any of its 166 * subdirectories). 167 * 168 * Entries within a directory are stored within a growable array of 169 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 170 * sorted are sorted by their component name in strcmp() order and the 171 * remaining entries are unsorted. 172 * 173 * Loose references are read lazily, one directory at a time. When a 174 * directory of loose references is read, then all of the references 175 * in that directory are stored, and REF_INCOMPLETE stubs are created 176 * for any subdirectories, but the subdirectories themselves are not 177 * read. The reading is triggered by get_ref_dir(). 178 */ 179struct ref_dir { 180 int nr, alloc; 181 182 /* 183 * Entries with index 0 <= i < sorted are sorted by name. New 184 * entries are appended to the list unsorted, and are sorted 185 * only when required; thus we avoid the need to sort the list 186 * after the addition of every reference. 187 */ 188 int sorted; 189 190 /* A pointer to the ref_cache that contains this ref_dir. */ 191 struct ref_cache *ref_cache; 192 193 struct ref_entry **entries; 194}; 195 196/* 197 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 198 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 199 * refs.h. 200 */ 201 202/* 203 * The field ref_entry->u.value.peeled of this value entry contains 204 * the correct peeled value for the reference, which might be 205 * null_sha1 if the reference is not a tag or if it is broken. 206 */ 207#define REF_KNOWS_PEELED 0x08 208 209/* ref_entry represents a directory of references */ 210#define REF_DIR 0x10 211 212/* 213 * Entry has not yet been read from disk (used only for REF_DIR 214 * entries representing loose references) 215 */ 216#define REF_INCOMPLETE 0x20 217 218/* 219 * A ref_entry represents either a reference or a "subdirectory" of 220 * references. 221 * 222 * Each directory in the reference namespace is represented by a 223 * ref_entry with (flags & REF_DIR) set and containing a subdir member 224 * that holds the entries in that directory that have been read so 225 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 226 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 227 * used for loose reference directories. 228 * 229 * References are represented by a ref_entry with (flags & REF_DIR) 230 * unset and a value member that describes the reference's value. The 231 * flag member is at the ref_entry level, but it is also needed to 232 * interpret the contents of the value field (in other words, a 233 * ref_value object is not very much use without the enclosing 234 * ref_entry). 235 * 236 * Reference names cannot end with slash and directories' names are 237 * always stored with a trailing slash (except for the top-level 238 * directory, which is always denoted by ""). This has two nice 239 * consequences: (1) when the entries in each subdir are sorted 240 * lexicographically by name (as they usually are), the references in 241 * a whole tree can be generated in lexicographic order by traversing 242 * the tree in left-to-right, depth-first order; (2) the names of 243 * references and subdirectories cannot conflict, and therefore the 244 * presence of an empty subdirectory does not block the creation of a 245 * similarly-named reference. (The fact that reference names with the 246 * same leading components can conflict *with each other* is a 247 * separate issue that is regulated by is_refname_available().) 248 * 249 * Please note that the name field contains the fully-qualified 250 * reference (or subdirectory) name. Space could be saved by only 251 * storing the relative names. But that would require the full names 252 * to be generated on the fly when iterating in do_for_each_ref(), and 253 * would break callback functions, who have always been able to assume 254 * that the name strings that they are passed will not be freed during 255 * the iteration. 256 */ 257struct ref_entry { 258 unsigned char flag; /* ISSYMREF? ISPACKED? */ 259 union { 260 struct ref_value value; /* if not (flags&REF_DIR) */ 261 struct ref_dir subdir; /* if (flags&REF_DIR) */ 262 } u; 263 /* 264 * The full name of the reference (e.g., "refs/heads/master") 265 * or the full name of the directory with a trailing slash 266 * (e.g., "refs/heads/"): 267 */ 268 char name[FLEX_ARRAY]; 269}; 270 271static void read_loose_refs(const char *dirname, struct ref_dir *dir); 272 273static struct ref_dir *get_ref_dir(struct ref_entry *entry) 274{ 275 struct ref_dir *dir; 276 assert(entry->flag & REF_DIR); 277 dir = &entry->u.subdir; 278 if (entry->flag & REF_INCOMPLETE) { 279 read_loose_refs(entry->name, dir); 280 entry->flag &= ~REF_INCOMPLETE; 281 } 282 return dir; 283} 284 285static struct ref_entry *create_ref_entry(const char *refname, 286 const unsigned char *sha1, int flag, 287 int check_name) 288{ 289 int len; 290 struct ref_entry *ref; 291 292 if (check_name && 293 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 294 die("Reference has invalid format: '%s'", refname); 295 len = strlen(refname) + 1; 296 ref = xmalloc(sizeof(struct ref_entry) + len); 297 hashcpy(ref->u.value.sha1, sha1); 298 hashclr(ref->u.value.peeled); 299 memcpy(ref->name, refname, len); 300 ref->flag = flag; 301 return ref; 302} 303 304static void clear_ref_dir(struct ref_dir *dir); 305 306static void free_ref_entry(struct ref_entry *entry) 307{ 308 if (entry->flag & REF_DIR) { 309 /* 310 * Do not use get_ref_dir() here, as that might 311 * trigger the reading of loose refs. 312 */ 313 clear_ref_dir(&entry->u.subdir); 314 } 315 free(entry); 316} 317 318/* 319 * Add a ref_entry to the end of dir (unsorted). Entry is always 320 * stored directly in dir; no recursion into subdirectories is 321 * done. 322 */ 323static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 324{ 325 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 326 dir->entries[dir->nr++] = entry; 327 /* optimize for the case that entries are added in order */ 328 if (dir->nr == 1 || 329 (dir->nr == dir->sorted + 1 && 330 strcmp(dir->entries[dir->nr - 2]->name, 331 dir->entries[dir->nr - 1]->name) < 0)) 332 dir->sorted = dir->nr; 333} 334 335/* 336 * Clear and free all entries in dir, recursively. 337 */ 338static void clear_ref_dir(struct ref_dir *dir) 339{ 340 int i; 341 for (i = 0; i < dir->nr; i++) 342 free_ref_entry(dir->entries[i]); 343 free(dir->entries); 344 dir->sorted = dir->nr = dir->alloc = 0; 345 dir->entries = NULL; 346} 347 348/* 349 * Create a struct ref_entry object for the specified dirname. 350 * dirname is the name of the directory with a trailing slash (e.g., 351 * "refs/heads/") or "" for the top-level directory. 352 */ 353static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 354 const char *dirname, size_t len, 355 int incomplete) 356{ 357 struct ref_entry *direntry; 358 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); 359 memcpy(direntry->name, dirname, len); 360 direntry->name[len] = '\0'; 361 direntry->u.subdir.ref_cache = ref_cache; 362 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 363 return direntry; 364} 365 366static int ref_entry_cmp(const void *a, const void *b) 367{ 368 struct ref_entry *one = *(struct ref_entry **)a; 369 struct ref_entry *two = *(struct ref_entry **)b; 370 return strcmp(one->name, two->name); 371} 372 373static void sort_ref_dir(struct ref_dir *dir); 374 375struct string_slice { 376 size_t len; 377 const char *str; 378}; 379 380static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 381{ 382 const struct string_slice *key = key_; 383 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 384 int cmp = strncmp(key->str, ent->name, key->len); 385 if (cmp) 386 return cmp; 387 return '\0' - (unsigned char)ent->name[key->len]; 388} 389 390/* 391 * Return the index of the entry with the given refname from the 392 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 393 * no such entry is found. dir must already be complete. 394 */ 395static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 396{ 397 struct ref_entry **r; 398 struct string_slice key; 399 400 if (refname == NULL || !dir->nr) 401 return -1; 402 403 sort_ref_dir(dir); 404 key.len = len; 405 key.str = refname; 406 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 407 ref_entry_cmp_sslice); 408 409 if (r == NULL) 410 return -1; 411 412 return r - dir->entries; 413} 414 415/* 416 * Search for a directory entry directly within dir (without 417 * recursing). Sort dir if necessary. subdirname must be a directory 418 * name (i.e., end in '/'). If mkdir is set, then create the 419 * directory if it is missing; otherwise, return NULL if the desired 420 * directory cannot be found. dir must already be complete. 421 */ 422static struct ref_dir *search_for_subdir(struct ref_dir *dir, 423 const char *subdirname, size_t len, 424 int mkdir) 425{ 426 int entry_index = search_ref_dir(dir, subdirname, len); 427 struct ref_entry *entry; 428 if (entry_index == -1) { 429 if (!mkdir) 430 return NULL; 431 /* 432 * Since dir is complete, the absence of a subdir 433 * means that the subdir really doesn't exist; 434 * therefore, create an empty record for it but mark 435 * the record complete. 436 */ 437 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 438 add_entry_to_dir(dir, entry); 439 } else { 440 entry = dir->entries[entry_index]; 441 } 442 return get_ref_dir(entry); 443} 444 445/* 446 * If refname is a reference name, find the ref_dir within the dir 447 * tree that should hold refname. If refname is a directory name 448 * (i.e., ends in '/'), then return that ref_dir itself. dir must 449 * represent the top-level directory and must already be complete. 450 * Sort ref_dirs and recurse into subdirectories as necessary. If 451 * mkdir is set, then create any missing directories; otherwise, 452 * return NULL if the desired directory cannot be found. 453 */ 454static struct ref_dir *find_containing_dir(struct ref_dir *dir, 455 const char *refname, int mkdir) 456{ 457 const char *slash; 458 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 459 size_t dirnamelen = slash - refname + 1; 460 struct ref_dir *subdir; 461 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 462 if (!subdir) { 463 dir = NULL; 464 break; 465 } 466 dir = subdir; 467 } 468 469 return dir; 470} 471 472/* 473 * Find the value entry with the given name in dir, sorting ref_dirs 474 * and recursing into subdirectories as necessary. If the name is not 475 * found or it corresponds to a directory entry, return NULL. 476 */ 477static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 478{ 479 int entry_index; 480 struct ref_entry *entry; 481 dir = find_containing_dir(dir, refname, 0); 482 if (!dir) 483 return NULL; 484 entry_index = search_ref_dir(dir, refname, strlen(refname)); 485 if (entry_index == -1) 486 return NULL; 487 entry = dir->entries[entry_index]; 488 return (entry->flag & REF_DIR) ? NULL : entry; 489} 490 491/* 492 * Remove the entry with the given name from dir, recursing into 493 * subdirectories as necessary. If refname is the name of a directory 494 * (i.e., ends with '/'), then remove the directory and its contents. 495 * If the removal was successful, return the number of entries 496 * remaining in the directory entry that contained the deleted entry. 497 * If the name was not found, return -1. Please note that this 498 * function only deletes the entry from the cache; it does not delete 499 * it from the filesystem or ensure that other cache entries (which 500 * might be symbolic references to the removed entry) are updated. 501 * Nor does it remove any containing dir entries that might be made 502 * empty by the removal. dir must represent the top-level directory 503 * and must already be complete. 504 */ 505static int remove_entry(struct ref_dir *dir, const char *refname) 506{ 507 int refname_len = strlen(refname); 508 int entry_index; 509 struct ref_entry *entry; 510 int is_dir = refname[refname_len - 1] == '/'; 511 if (is_dir) { 512 /* 513 * refname represents a reference directory. Remove 514 * the trailing slash; otherwise we will get the 515 * directory *representing* refname rather than the 516 * one *containing* it. 517 */ 518 char *dirname = xmemdupz(refname, refname_len - 1); 519 dir = find_containing_dir(dir, dirname, 0); 520 free(dirname); 521 } else { 522 dir = find_containing_dir(dir, refname, 0); 523 } 524 if (!dir) 525 return -1; 526 entry_index = search_ref_dir(dir, refname, refname_len); 527 if (entry_index == -1) 528 return -1; 529 entry = dir->entries[entry_index]; 530 531 memmove(&dir->entries[entry_index], 532 &dir->entries[entry_index + 1], 533 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 534 ); 535 dir->nr--; 536 if (dir->sorted > entry_index) 537 dir->sorted--; 538 free_ref_entry(entry); 539 return dir->nr; 540} 541 542/* 543 * Add a ref_entry to the ref_dir (unsorted), recursing into 544 * subdirectories as necessary. dir must represent the top-level 545 * directory. Return 0 on success. 546 */ 547static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 548{ 549 dir = find_containing_dir(dir, ref->name, 1); 550 if (!dir) 551 return -1; 552 add_entry_to_dir(dir, ref); 553 return 0; 554} 555 556/* 557 * Emit a warning and return true iff ref1 and ref2 have the same name 558 * and the same sha1. Die if they have the same name but different 559 * sha1s. 560 */ 561static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 562{ 563 if (strcmp(ref1->name, ref2->name)) 564 return 0; 565 566 /* Duplicate name; make sure that they don't conflict: */ 567 568 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 569 /* This is impossible by construction */ 570 die("Reference directory conflict: %s", ref1->name); 571 572 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 573 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 574 575 warning("Duplicated ref: %s", ref1->name); 576 return 1; 577} 578 579/* 580 * Sort the entries in dir non-recursively (if they are not already 581 * sorted) and remove any duplicate entries. 582 */ 583static void sort_ref_dir(struct ref_dir *dir) 584{ 585 int i, j; 586 struct ref_entry *last = NULL; 587 588 /* 589 * This check also prevents passing a zero-length array to qsort(), 590 * which is a problem on some platforms. 591 */ 592 if (dir->sorted == dir->nr) 593 return; 594 595 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 596 597 /* Remove any duplicates: */ 598 for (i = 0, j = 0; j < dir->nr; j++) { 599 struct ref_entry *entry = dir->entries[j]; 600 if (last && is_dup_ref(last, entry)) 601 free_ref_entry(entry); 602 else 603 last = dir->entries[i++] = entry; 604 } 605 dir->sorted = dir->nr = i; 606} 607 608/* Include broken references in a do_for_each_ref*() iteration: */ 609#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 610 611/* 612 * Return true iff the reference described by entry can be resolved to 613 * an object in the database. Emit a warning if the referred-to 614 * object does not exist. 615 */ 616static int ref_resolves_to_object(struct ref_entry *entry) 617{ 618 if (entry->flag & REF_ISBROKEN) 619 return 0; 620 if (!has_sha1_file(entry->u.value.sha1)) { 621 error("%s does not point to a valid object!", entry->name); 622 return 0; 623 } 624 return 1; 625} 626 627/* 628 * current_ref is a performance hack: when iterating over references 629 * using the for_each_ref*() functions, current_ref is set to the 630 * current reference's entry before calling the callback function. If 631 * the callback function calls peel_ref(), then peel_ref() first 632 * checks whether the reference to be peeled is the current reference 633 * (it usually is) and if so, returns that reference's peeled version 634 * if it is available. This avoids a refname lookup in a common case. 635 */ 636static struct ref_entry *current_ref; 637 638typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 639 640struct ref_entry_cb { 641 const char *base; 642 int trim; 643 int flags; 644 each_ref_fn *fn; 645 void *cb_data; 646}; 647 648/* 649 * Handle one reference in a do_for_each_ref*()-style iteration, 650 * calling an each_ref_fn for each entry. 651 */ 652static int do_one_ref(struct ref_entry *entry, void *cb_data) 653{ 654 struct ref_entry_cb *data = cb_data; 655 struct ref_entry *old_current_ref; 656 int retval; 657 658 if (!starts_with(entry->name, data->base)) 659 return 0; 660 661 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 662 !ref_resolves_to_object(entry)) 663 return 0; 664 665 /* Store the old value, in case this is a recursive call: */ 666 old_current_ref = current_ref; 667 current_ref = entry; 668 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 669 entry->flag, data->cb_data); 670 current_ref = old_current_ref; 671 return retval; 672} 673 674/* 675 * Call fn for each reference in dir that has index in the range 676 * offset <= index < dir->nr. Recurse into subdirectories that are in 677 * that index range, sorting them before iterating. This function 678 * does not sort dir itself; it should be sorted beforehand. fn is 679 * called for all references, including broken ones. 680 */ 681static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 682 each_ref_entry_fn fn, void *cb_data) 683{ 684 int i; 685 assert(dir->sorted == dir->nr); 686 for (i = offset; i < dir->nr; i++) { 687 struct ref_entry *entry = dir->entries[i]; 688 int retval; 689 if (entry->flag & REF_DIR) { 690 struct ref_dir *subdir = get_ref_dir(entry); 691 sort_ref_dir(subdir); 692 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 693 } else { 694 retval = fn(entry, cb_data); 695 } 696 if (retval) 697 return retval; 698 } 699 return 0; 700} 701 702/* 703 * Call fn for each reference in the union of dir1 and dir2, in order 704 * by refname. Recurse into subdirectories. If a value entry appears 705 * in both dir1 and dir2, then only process the version that is in 706 * dir2. The input dirs must already be sorted, but subdirs will be 707 * sorted as needed. fn is called for all references, including 708 * broken ones. 709 */ 710static int do_for_each_entry_in_dirs(struct ref_dir *dir1, 711 struct ref_dir *dir2, 712 each_ref_entry_fn fn, void *cb_data) 713{ 714 int retval; 715 int i1 = 0, i2 = 0; 716 717 assert(dir1->sorted == dir1->nr); 718 assert(dir2->sorted == dir2->nr); 719 while (1) { 720 struct ref_entry *e1, *e2; 721 int cmp; 722 if (i1 == dir1->nr) { 723 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 724 } 725 if (i2 == dir2->nr) { 726 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 727 } 728 e1 = dir1->entries[i1]; 729 e2 = dir2->entries[i2]; 730 cmp = strcmp(e1->name, e2->name); 731 if (cmp == 0) { 732 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 733 /* Both are directories; descend them in parallel. */ 734 struct ref_dir *subdir1 = get_ref_dir(e1); 735 struct ref_dir *subdir2 = get_ref_dir(e2); 736 sort_ref_dir(subdir1); 737 sort_ref_dir(subdir2); 738 retval = do_for_each_entry_in_dirs( 739 subdir1, subdir2, fn, cb_data); 740 i1++; 741 i2++; 742 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 743 /* Both are references; ignore the one from dir1. */ 744 retval = fn(e2, cb_data); 745 i1++; 746 i2++; 747 } else { 748 die("conflict between reference and directory: %s", 749 e1->name); 750 } 751 } else { 752 struct ref_entry *e; 753 if (cmp < 0) { 754 e = e1; 755 i1++; 756 } else { 757 e = e2; 758 i2++; 759 } 760 if (e->flag & REF_DIR) { 761 struct ref_dir *subdir = get_ref_dir(e); 762 sort_ref_dir(subdir); 763 retval = do_for_each_entry_in_dir( 764 subdir, 0, fn, cb_data); 765 } else { 766 retval = fn(e, cb_data); 767 } 768 } 769 if (retval) 770 return retval; 771 } 772} 773 774/* 775 * Load all of the refs from the dir into our in-memory cache. The hard work 776 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 777 * through all of the sub-directories. We do not even need to care about 778 * sorting, as traversal order does not matter to us. 779 */ 780static void prime_ref_dir(struct ref_dir *dir) 781{ 782 int i; 783 for (i = 0; i < dir->nr; i++) { 784 struct ref_entry *entry = dir->entries[i]; 785 if (entry->flag & REF_DIR) 786 prime_ref_dir(get_ref_dir(entry)); 787 } 788} 789 790static int entry_matches(struct ref_entry *entry, const struct string_list *list) 791{ 792 return list && string_list_has_string(list, entry->name); 793} 794 795struct nonmatching_ref_data { 796 const struct string_list *skip; 797 struct ref_entry *found; 798}; 799 800static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) 801{ 802 struct nonmatching_ref_data *data = vdata; 803 804 if (entry_matches(entry, data->skip)) 805 return 0; 806 807 data->found = entry; 808 return 1; 809} 810 811static void report_refname_conflict(struct ref_entry *entry, 812 const char *refname) 813{ 814 error("'%s' exists; cannot create '%s'", entry->name, refname); 815} 816 817/* 818 * Return true iff a reference named refname could be created without 819 * conflicting with the name of an existing reference in dir. If 820 * skip is non-NULL, ignore potential conflicts with refs in skip 821 * (e.g., because they are scheduled for deletion in the same 822 * operation). 823 * 824 * Two reference names conflict if one of them exactly matches the 825 * leading components of the other; e.g., "foo/bar" conflicts with 826 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 827 * "foo/barbados". 828 * 829 * skip must be sorted. 830 */ 831static int is_refname_available(const char *refname, 832 const struct string_list *skip, 833 struct ref_dir *dir) 834{ 835 const char *slash; 836 size_t len; 837 int pos; 838 char *dirname; 839 840 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 841 /* 842 * We are still at a leading dir of the refname; we are 843 * looking for a conflict with a leaf entry. 844 * 845 * If we find one, we still must make sure it is 846 * not in "skip". 847 */ 848 pos = search_ref_dir(dir, refname, slash - refname); 849 if (pos >= 0) { 850 struct ref_entry *entry = dir->entries[pos]; 851 if (entry_matches(entry, skip)) 852 return 1; 853 report_refname_conflict(entry, refname); 854 return 0; 855 } 856 857 858 /* 859 * Otherwise, we can try to continue our search with 860 * the next component; if we come up empty, we know 861 * there is nothing under this whole prefix. 862 */ 863 pos = search_ref_dir(dir, refname, slash + 1 - refname); 864 if (pos < 0) 865 return 1; 866 867 dir = get_ref_dir(dir->entries[pos]); 868 } 869 870 /* 871 * We are at the leaf of our refname; we want to 872 * make sure there are no directories which match it. 873 */ 874 len = strlen(refname); 875 dirname = xmallocz(len + 1); 876 sprintf(dirname, "%s/", refname); 877 pos = search_ref_dir(dir, dirname, len + 1); 878 free(dirname); 879 880 if (pos >= 0) { 881 /* 882 * We found a directory named "refname". It is a 883 * problem iff it contains any ref that is not 884 * in "skip". 885 */ 886 struct ref_entry *entry = dir->entries[pos]; 887 struct ref_dir *dir = get_ref_dir(entry); 888 struct nonmatching_ref_data data; 889 890 data.skip = skip; 891 sort_ref_dir(dir); 892 if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) 893 return 1; 894 895 report_refname_conflict(data.found, refname); 896 return 0; 897 } 898 899 /* 900 * There is no point in searching for another leaf 901 * node which matches it; such an entry would be the 902 * ref we are looking for, not a conflict. 903 */ 904 return 1; 905} 906 907struct packed_ref_cache { 908 struct ref_entry *root; 909 910 /* 911 * Count of references to the data structure in this instance, 912 * including the pointer from ref_cache::packed if any. The 913 * data will not be freed as long as the reference count is 914 * nonzero. 915 */ 916 unsigned int referrers; 917 918 /* 919 * Iff the packed-refs file associated with this instance is 920 * currently locked for writing, this points at the associated 921 * lock (which is owned by somebody else). The referrer count 922 * is also incremented when the file is locked and decremented 923 * when it is unlocked. 924 */ 925 struct lock_file *lock; 926 927 /* The metadata from when this packed-refs cache was read */ 928 struct stat_validity validity; 929}; 930 931/* 932 * Future: need to be in "struct repository" 933 * when doing a full libification. 934 */ 935static struct ref_cache { 936 struct ref_cache *next; 937 struct ref_entry *loose; 938 struct packed_ref_cache *packed; 939 /* 940 * The submodule name, or "" for the main repo. We allocate 941 * length 1 rather than FLEX_ARRAY so that the main ref_cache 942 * is initialized correctly. 943 */ 944 char name[1]; 945} ref_cache, *submodule_ref_caches; 946 947/* Lock used for the main packed-refs file: */ 948static struct lock_file packlock; 949 950/* 951 * Increment the reference count of *packed_refs. 952 */ 953static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 954{ 955 packed_refs->referrers++; 956} 957 958/* 959 * Decrease the reference count of *packed_refs. If it goes to zero, 960 * free *packed_refs and return true; otherwise return false. 961 */ 962static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 963{ 964 if (!--packed_refs->referrers) { 965 free_ref_entry(packed_refs->root); 966 stat_validity_clear(&packed_refs->validity); 967 free(packed_refs); 968 return 1; 969 } else { 970 return 0; 971 } 972} 973 974static void clear_packed_ref_cache(struct ref_cache *refs) 975{ 976 if (refs->packed) { 977 struct packed_ref_cache *packed_refs = refs->packed; 978 979 if (packed_refs->lock) 980 die("internal error: packed-ref cache cleared while locked"); 981 refs->packed = NULL; 982 release_packed_ref_cache(packed_refs); 983 } 984} 985 986static void clear_loose_ref_cache(struct ref_cache *refs) 987{ 988 if (refs->loose) { 989 free_ref_entry(refs->loose); 990 refs->loose = NULL; 991 } 992} 993 994static struct ref_cache *create_ref_cache(const char *submodule) 995{ 996 int len; 997 struct ref_cache *refs; 998 if (!submodule) 999 submodule = "";1000 len = strlen(submodule) + 1;1001 refs = xcalloc(1, sizeof(struct ref_cache) + len);1002 memcpy(refs->name, submodule, len);1003 return refs;1004}10051006/*1007 * Return a pointer to a ref_cache for the specified submodule. For1008 * the main repository, use submodule==NULL. The returned structure1009 * will be allocated and initialized but not necessarily populated; it1010 * should not be freed.1011 */1012static struct ref_cache *get_ref_cache(const char *submodule)1013{1014 struct ref_cache *refs;10151016 if (!submodule || !*submodule)1017 return &ref_cache;10181019 for (refs = submodule_ref_caches; refs; refs = refs->next)1020 if (!strcmp(submodule, refs->name))1021 return refs;10221023 refs = create_ref_cache(submodule);1024 refs->next = submodule_ref_caches;1025 submodule_ref_caches = refs;1026 return refs;1027}10281029/* The length of a peeled reference line in packed-refs, including EOL: */1030#define PEELED_LINE_LENGTH 4210311032/*1033 * The packed-refs header line that we write out. Perhaps other1034 * traits will be added later. The trailing space is required.1035 */1036static const char PACKED_REFS_HEADER[] =1037 "# pack-refs with: peeled fully-peeled \n";10381039/*1040 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1041 * Return a pointer to the refname within the line (null-terminated),1042 * or NULL if there was a problem.1043 */1044static const char *parse_ref_line(char *line, unsigned char *sha1)1045{1046 /*1047 * 42: the answer to everything.1048 *1049 * In this case, it happens to be the answer to1050 * 40 (length of sha1 hex representation)1051 * +1 (space in between hex and name)1052 * +1 (newline at the end of the line)1053 */1054 int len = strlen(line) - 42;10551056 if (len <= 0)1057 return NULL;1058 if (get_sha1_hex(line, sha1) < 0)1059 return NULL;1060 if (!isspace(line[40]))1061 return NULL;1062 line += 41;1063 if (isspace(*line))1064 return NULL;1065 if (line[len] != '\n')1066 return NULL;1067 line[len] = 0;10681069 return line;1070}10711072/*1073 * Read f, which is a packed-refs file, into dir.1074 *1075 * A comment line of the form "# pack-refs with: " may contain zero or1076 * more traits. We interpret the traits as follows:1077 *1078 * No traits:1079 *1080 * Probably no references are peeled. But if the file contains a1081 * peeled value for a reference, we will use it.1082 *1083 * peeled:1084 *1085 * References under "refs/tags/", if they *can* be peeled, *are*1086 * peeled in this file. References outside of "refs/tags/" are1087 * probably not peeled even if they could have been, but if we find1088 * a peeled value for such a reference we will use it.1089 *1090 * fully-peeled:1091 *1092 * All references in the file that can be peeled are peeled.1093 * Inversely (and this is more important), any references in the1094 * file for which no peeled value is recorded is not peelable. This1095 * trait should typically be written alongside "peeled" for1096 * compatibility with older clients, but we do not require it1097 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1098 */1099static void read_packed_refs(FILE *f, struct ref_dir *dir)1100{1101 struct ref_entry *last = NULL;1102 char refline[PATH_MAX];1103 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11041105 while (fgets(refline, sizeof(refline), f)) {1106 unsigned char sha1[20];1107 const char *refname;1108 static const char header[] = "# pack-refs with:";11091110 if (!strncmp(refline, header, sizeof(header)-1)) {1111 const char *traits = refline + sizeof(header) - 1;1112 if (strstr(traits, " fully-peeled "))1113 peeled = PEELED_FULLY;1114 else if (strstr(traits, " peeled "))1115 peeled = PEELED_TAGS;1116 /* perhaps other traits later as well */1117 continue;1118 }11191120 refname = parse_ref_line(refline, sha1);1121 if (refname) {1122 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);1123 if (peeled == PEELED_FULLY ||1124 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1125 last->flag |= REF_KNOWS_PEELED;1126 add_ref(dir, last);1127 continue;1128 }1129 if (last &&1130 refline[0] == '^' &&1131 strlen(refline) == PEELED_LINE_LENGTH &&1132 refline[PEELED_LINE_LENGTH - 1] == '\n' &&1133 !get_sha1_hex(refline + 1, sha1)) {1134 hashcpy(last->u.value.peeled, sha1);1135 /*1136 * Regardless of what the file header said,1137 * we definitely know the value of *this*1138 * reference:1139 */1140 last->flag |= REF_KNOWS_PEELED;1141 }1142 }1143}11441145/*1146 * Get the packed_ref_cache for the specified ref_cache, creating it1147 * if necessary.1148 */1149static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1150{1151 const char *packed_refs_file;11521153 if (*refs->name)1154 packed_refs_file = git_path_submodule(refs->name, "packed-refs");1155 else1156 packed_refs_file = git_path("packed-refs");11571158 if (refs->packed &&1159 !stat_validity_check(&refs->packed->validity, packed_refs_file))1160 clear_packed_ref_cache(refs);11611162 if (!refs->packed) {1163 FILE *f;11641165 refs->packed = xcalloc(1, sizeof(*refs->packed));1166 acquire_packed_ref_cache(refs->packed);1167 refs->packed->root = create_dir_entry(refs, "", 0, 0);1168 f = fopen(packed_refs_file, "r");1169 if (f) {1170 stat_validity_update(&refs->packed->validity, fileno(f));1171 read_packed_refs(f, get_ref_dir(refs->packed->root));1172 fclose(f);1173 }1174 }1175 return refs->packed;1176}11771178static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1179{1180 return get_ref_dir(packed_ref_cache->root);1181}11821183static struct ref_dir *get_packed_refs(struct ref_cache *refs)1184{1185 return get_packed_ref_dir(get_packed_ref_cache(refs));1186}11871188void add_packed_ref(const char *refname, const unsigned char *sha1)1189{1190 struct packed_ref_cache *packed_ref_cache =1191 get_packed_ref_cache(&ref_cache);11921193 if (!packed_ref_cache->lock)1194 die("internal error: packed refs not locked");1195 add_ref(get_packed_ref_dir(packed_ref_cache),1196 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1197}11981199/*1200 * Read the loose references from the namespace dirname into dir1201 * (without recursing). dirname must end with '/'. dir must be the1202 * directory entry corresponding to dirname.1203 */1204static void read_loose_refs(const char *dirname, struct ref_dir *dir)1205{1206 struct ref_cache *refs = dir->ref_cache;1207 DIR *d;1208 const char *path;1209 struct dirent *de;1210 int dirnamelen = strlen(dirname);1211 struct strbuf refname;12121213 if (*refs->name)1214 path = git_path_submodule(refs->name, "%s", dirname);1215 else1216 path = git_path("%s", dirname);12171218 d = opendir(path);1219 if (!d)1220 return;12211222 strbuf_init(&refname, dirnamelen + 257);1223 strbuf_add(&refname, dirname, dirnamelen);12241225 while ((de = readdir(d)) != NULL) {1226 unsigned char sha1[20];1227 struct stat st;1228 int flag;1229 const char *refdir;12301231 if (de->d_name[0] == '.')1232 continue;1233 if (ends_with(de->d_name, ".lock"))1234 continue;1235 strbuf_addstr(&refname, de->d_name);1236 refdir = *refs->name1237 ? git_path_submodule(refs->name, "%s", refname.buf)1238 : git_path("%s", refname.buf);1239 if (stat(refdir, &st) < 0) {1240 ; /* silently ignore */1241 } else if (S_ISDIR(st.st_mode)) {1242 strbuf_addch(&refname, '/');1243 add_entry_to_dir(dir,1244 create_dir_entry(refs, refname.buf,1245 refname.len, 1));1246 } else {1247 if (*refs->name) {1248 hashclr(sha1);1249 flag = 0;1250 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {1251 hashclr(sha1);1252 flag |= REF_ISBROKEN;1253 }1254 } else if (read_ref_full(refname.buf,1255 RESOLVE_REF_READING,1256 sha1, &flag)) {1257 hashclr(sha1);1258 flag |= REF_ISBROKEN;1259 }1260 add_entry_to_dir(dir,1261 create_ref_entry(refname.buf, sha1, flag, 1));1262 }1263 strbuf_setlen(&refname, dirnamelen);1264 }1265 strbuf_release(&refname);1266 closedir(d);1267}12681269static struct ref_dir *get_loose_refs(struct ref_cache *refs)1270{1271 if (!refs->loose) {1272 /*1273 * Mark the top-level directory complete because we1274 * are about to read the only subdirectory that can1275 * hold references:1276 */1277 refs->loose = create_dir_entry(refs, "", 0, 0);1278 /*1279 * Create an incomplete entry for "refs/":1280 */1281 add_entry_to_dir(get_ref_dir(refs->loose),1282 create_dir_entry(refs, "refs/", 5, 1));1283 }1284 return get_ref_dir(refs->loose);1285}12861287/* We allow "recursive" symbolic refs. Only within reason, though */1288#define MAXDEPTH 51289#define MAXREFLEN (1024)12901291/*1292 * Called by resolve_gitlink_ref_recursive() after it failed to read1293 * from the loose refs in ref_cache refs. Find <refname> in the1294 * packed-refs file for the submodule.1295 */1296static int resolve_gitlink_packed_ref(struct ref_cache *refs,1297 const char *refname, unsigned char *sha1)1298{1299 struct ref_entry *ref;1300 struct ref_dir *dir = get_packed_refs(refs);13011302 ref = find_ref(dir, refname);1303 if (ref == NULL)1304 return -1;13051306 hashcpy(sha1, ref->u.value.sha1);1307 return 0;1308}13091310static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1311 const char *refname, unsigned char *sha1,1312 int recursion)1313{1314 int fd, len;1315 char buffer[128], *p;1316 char *path;13171318 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)1319 return -1;1320 path = *refs->name1321 ? git_path_submodule(refs->name, "%s", refname)1322 : git_path("%s", refname);1323 fd = open(path, O_RDONLY);1324 if (fd < 0)1325 return resolve_gitlink_packed_ref(refs, refname, sha1);13261327 len = read(fd, buffer, sizeof(buffer)-1);1328 close(fd);1329 if (len < 0)1330 return -1;1331 while (len && isspace(buffer[len-1]))1332 len--;1333 buffer[len] = 0;13341335 /* Was it a detached head or an old-fashioned symlink? */1336 if (!get_sha1_hex(buffer, sha1))1337 return 0;13381339 /* Symref? */1340 if (strncmp(buffer, "ref:", 4))1341 return -1;1342 p = buffer + 4;1343 while (isspace(*p))1344 p++;13451346 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1347}13481349int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1350{1351 int len = strlen(path), retval;1352 char *submodule;1353 struct ref_cache *refs;13541355 while (len && path[len-1] == '/')1356 len--;1357 if (!len)1358 return -1;1359 submodule = xstrndup(path, len);1360 refs = get_ref_cache(submodule);1361 free(submodule);13621363 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1364 return retval;1365}13661367/*1368 * Return the ref_entry for the given refname from the packed1369 * references. If it does not exist, return NULL.1370 */1371static struct ref_entry *get_packed_ref(const char *refname)1372{1373 return find_ref(get_packed_refs(&ref_cache), refname);1374}13751376/*1377 * A loose ref file doesn't exist; check for a packed ref. The1378 * options are forwarded from resolve_safe_unsafe().1379 */1380static const char *handle_missing_loose_ref(const char *refname,1381 int resolve_flags,1382 unsigned char *sha1,1383 int *flags)1384{1385 struct ref_entry *entry;13861387 /*1388 * The loose reference file does not exist; check for a packed1389 * reference.1390 */1391 entry = get_packed_ref(refname);1392 if (entry) {1393 hashcpy(sha1, entry->u.value.sha1);1394 if (flags)1395 *flags |= REF_ISPACKED;1396 return refname;1397 }1398 /* The reference is not a packed reference, either. */1399 if (resolve_flags & RESOLVE_REF_READING) {1400 return NULL;1401 } else {1402 hashclr(sha1);1403 return refname;1404 }1405}14061407/* This function needs to return a meaningful errno on failure */1408const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1409{1410 int depth = MAXDEPTH;1411 ssize_t len;1412 char buffer[256];1413 static char refname_buffer[256];14141415 if (flags)1416 *flags = 0;14171418 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1419 errno = EINVAL;1420 return NULL;1421 }1422 for (;;) {1423 char path[PATH_MAX];1424 struct stat st;1425 char *buf;1426 int fd;14271428 if (--depth < 0) {1429 errno = ELOOP;1430 return NULL;1431 }14321433 git_snpath(path, sizeof(path), "%s", refname);14341435 /*1436 * We might have to loop back here to avoid a race1437 * condition: first we lstat() the file, then we try1438 * to read it as a link or as a file. But if somebody1439 * changes the type of the file (file <-> directory1440 * <-> symlink) between the lstat() and reading, then1441 * we don't want to report that as an error but rather1442 * try again starting with the lstat().1443 */1444 stat_ref:1445 if (lstat(path, &st) < 0) {1446 if (errno == ENOENT)1447 return handle_missing_loose_ref(refname,1448 resolve_flags, sha1, flags);1449 else1450 return NULL;1451 }14521453 /* Follow "normalized" - ie "refs/.." symlinks by hand */1454 if (S_ISLNK(st.st_mode)) {1455 len = readlink(path, buffer, sizeof(buffer)-1);1456 if (len < 0) {1457 if (errno == ENOENT || errno == EINVAL)1458 /* inconsistent with lstat; retry */1459 goto stat_ref;1460 else1461 return NULL;1462 }1463 buffer[len] = 0;1464 if (starts_with(buffer, "refs/") &&1465 !check_refname_format(buffer, 0)) {1466 strcpy(refname_buffer, buffer);1467 refname = refname_buffer;1468 if (flags)1469 *flags |= REF_ISSYMREF;1470 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1471 hashclr(sha1);1472 return refname;1473 }1474 continue;1475 }1476 }14771478 /* Is it a directory? */1479 if (S_ISDIR(st.st_mode)) {1480 errno = EISDIR;1481 return NULL;1482 }14831484 /*1485 * Anything else, just open it and try to use it as1486 * a ref1487 */1488 fd = open(path, O_RDONLY);1489 if (fd < 0) {1490 if (errno == ENOENT)1491 /* inconsistent with lstat; retry */1492 goto stat_ref;1493 else1494 return NULL;1495 }1496 len = read_in_full(fd, buffer, sizeof(buffer)-1);1497 if (len < 0) {1498 int save_errno = errno;1499 close(fd);1500 errno = save_errno;1501 return NULL;1502 }1503 close(fd);1504 while (len && isspace(buffer[len-1]))1505 len--;1506 buffer[len] = '\0';15071508 /*1509 * Is it a symbolic ref?1510 */1511 if (!starts_with(buffer, "ref:")) {1512 /*1513 * Please note that FETCH_HEAD has a second1514 * line containing other data.1515 */1516 if (get_sha1_hex(buffer, sha1) ||1517 (buffer[40] != '\0' && !isspace(buffer[40]))) {1518 if (flags)1519 *flags |= REF_ISBROKEN;1520 errno = EINVAL;1521 return NULL;1522 }1523 return refname;1524 }1525 if (flags)1526 *flags |= REF_ISSYMREF;1527 buf = buffer + 4;1528 while (isspace(*buf))1529 buf++;1530 refname = strcpy(refname_buffer, buf);1531 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1532 hashclr(sha1);1533 return refname;1534 }1535 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1536 if (flags)1537 *flags |= REF_ISBROKEN;1538 errno = EINVAL;1539 return NULL;1540 }1541 }1542}15431544char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)1545{1546 const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags);1547 return ret ? xstrdup(ret) : NULL;1548}15491550/* The argument to filter_refs */1551struct ref_filter {1552 const char *pattern;1553 each_ref_fn *fn;1554 void *cb_data;1555};15561557int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1558{1559 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1560 return 0;1561 return -1;1562}15631564int read_ref(const char *refname, unsigned char *sha1)1565{1566 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1567}15681569int ref_exists(const char *refname)1570{1571 unsigned char sha1[20];1572 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1573}15741575static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1576 void *data)1577{1578 struct ref_filter *filter = (struct ref_filter *)data;1579 if (wildmatch(filter->pattern, refname, 0, NULL))1580 return 0;1581 return filter->fn(refname, sha1, flags, filter->cb_data);1582}15831584enum peel_status {1585 /* object was peeled successfully: */1586 PEEL_PEELED = 0,15871588 /*1589 * object cannot be peeled because the named object (or an1590 * object referred to by a tag in the peel chain), does not1591 * exist.1592 */1593 PEEL_INVALID = -1,15941595 /* object cannot be peeled because it is not a tag: */1596 PEEL_NON_TAG = -2,15971598 /* ref_entry contains no peeled value because it is a symref: */1599 PEEL_IS_SYMREF = -3,16001601 /*1602 * ref_entry cannot be peeled because it is broken (i.e., the1603 * symbolic reference cannot even be resolved to an object1604 * name):1605 */1606 PEEL_BROKEN = -41607};16081609/*1610 * Peel the named object; i.e., if the object is a tag, resolve the1611 * tag recursively until a non-tag is found. If successful, store the1612 * result to sha1 and return PEEL_PEELED. If the object is not a tag1613 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1614 * and leave sha1 unchanged.1615 */1616static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1617{1618 struct object *o = lookup_unknown_object(name);16191620 if (o->type == OBJ_NONE) {1621 int type = sha1_object_info(name, NULL);1622 if (type < 0 || !object_as_type(o, type, 0))1623 return PEEL_INVALID;1624 }16251626 if (o->type != OBJ_TAG)1627 return PEEL_NON_TAG;16281629 o = deref_tag_noverify(o);1630 if (!o)1631 return PEEL_INVALID;16321633 hashcpy(sha1, o->sha1);1634 return PEEL_PEELED;1635}16361637/*1638 * Peel the entry (if possible) and return its new peel_status. If1639 * repeel is true, re-peel the entry even if there is an old peeled1640 * value that is already stored in it.1641 *1642 * It is OK to call this function with a packed reference entry that1643 * might be stale and might even refer to an object that has since1644 * been garbage-collected. In such a case, if the entry has1645 * REF_KNOWS_PEELED then leave the status unchanged and return1646 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1647 */1648static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1649{1650 enum peel_status status;16511652 if (entry->flag & REF_KNOWS_PEELED) {1653 if (repeel) {1654 entry->flag &= ~REF_KNOWS_PEELED;1655 hashclr(entry->u.value.peeled);1656 } else {1657 return is_null_sha1(entry->u.value.peeled) ?1658 PEEL_NON_TAG : PEEL_PEELED;1659 }1660 }1661 if (entry->flag & REF_ISBROKEN)1662 return PEEL_BROKEN;1663 if (entry->flag & REF_ISSYMREF)1664 return PEEL_IS_SYMREF;16651666 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1667 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1668 entry->flag |= REF_KNOWS_PEELED;1669 return status;1670}16711672int peel_ref(const char *refname, unsigned char *sha1)1673{1674 int flag;1675 unsigned char base[20];16761677 if (current_ref && (current_ref->name == refname1678 || !strcmp(current_ref->name, refname))) {1679 if (peel_entry(current_ref, 0))1680 return -1;1681 hashcpy(sha1, current_ref->u.value.peeled);1682 return 0;1683 }16841685 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1686 return -1;16871688 /*1689 * If the reference is packed, read its ref_entry from the1690 * cache in the hope that we already know its peeled value.1691 * We only try this optimization on packed references because1692 * (a) forcing the filling of the loose reference cache could1693 * be expensive and (b) loose references anyway usually do not1694 * have REF_KNOWS_PEELED.1695 */1696 if (flag & REF_ISPACKED) {1697 struct ref_entry *r = get_packed_ref(refname);1698 if (r) {1699 if (peel_entry(r, 0))1700 return -1;1701 hashcpy(sha1, r->u.value.peeled);1702 return 0;1703 }1704 }17051706 return peel_object(base, sha1);1707}17081709struct warn_if_dangling_data {1710 FILE *fp;1711 const char *refname;1712 const struct string_list *refnames;1713 const char *msg_fmt;1714};17151716static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1717 int flags, void *cb_data)1718{1719 struct warn_if_dangling_data *d = cb_data;1720 const char *resolves_to;1721 unsigned char junk[20];17221723 if (!(flags & REF_ISSYMREF))1724 return 0;17251726 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);1727 if (!resolves_to1728 || (d->refname1729 ? strcmp(resolves_to, d->refname)1730 : !string_list_has_string(d->refnames, resolves_to))) {1731 return 0;1732 }17331734 fprintf(d->fp, d->msg_fmt, refname);1735 fputc('\n', d->fp);1736 return 0;1737}17381739void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1740{1741 struct warn_if_dangling_data data;17421743 data.fp = fp;1744 data.refname = refname;1745 data.refnames = NULL;1746 data.msg_fmt = msg_fmt;1747 for_each_rawref(warn_if_dangling_symref, &data);1748}17491750void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)1751{1752 struct warn_if_dangling_data data;17531754 data.fp = fp;1755 data.refname = NULL;1756 data.refnames = refnames;1757 data.msg_fmt = msg_fmt;1758 for_each_rawref(warn_if_dangling_symref, &data);1759}17601761/*1762 * Call fn for each reference in the specified ref_cache, omitting1763 * references not in the containing_dir of base. fn is called for all1764 * references, including broken ones. If fn ever returns a non-zero1765 * value, stop the iteration and return that value; otherwise, return1766 * 0.1767 */1768static int do_for_each_entry(struct ref_cache *refs, const char *base,1769 each_ref_entry_fn fn, void *cb_data)1770{1771 struct packed_ref_cache *packed_ref_cache;1772 struct ref_dir *loose_dir;1773 struct ref_dir *packed_dir;1774 int retval = 0;17751776 /*1777 * We must make sure that all loose refs are read before accessing the1778 * packed-refs file; this avoids a race condition in which loose refs1779 * are migrated to the packed-refs file by a simultaneous process, but1780 * our in-memory view is from before the migration. get_packed_ref_cache()1781 * takes care of making sure our view is up to date with what is on1782 * disk.1783 */1784 loose_dir = get_loose_refs(refs);1785 if (base && *base) {1786 loose_dir = find_containing_dir(loose_dir, base, 0);1787 }1788 if (loose_dir)1789 prime_ref_dir(loose_dir);17901791 packed_ref_cache = get_packed_ref_cache(refs);1792 acquire_packed_ref_cache(packed_ref_cache);1793 packed_dir = get_packed_ref_dir(packed_ref_cache);1794 if (base && *base) {1795 packed_dir = find_containing_dir(packed_dir, base, 0);1796 }17971798 if (packed_dir && loose_dir) {1799 sort_ref_dir(packed_dir);1800 sort_ref_dir(loose_dir);1801 retval = do_for_each_entry_in_dirs(1802 packed_dir, loose_dir, fn, cb_data);1803 } else if (packed_dir) {1804 sort_ref_dir(packed_dir);1805 retval = do_for_each_entry_in_dir(1806 packed_dir, 0, fn, cb_data);1807 } else if (loose_dir) {1808 sort_ref_dir(loose_dir);1809 retval = do_for_each_entry_in_dir(1810 loose_dir, 0, fn, cb_data);1811 }18121813 release_packed_ref_cache(packed_ref_cache);1814 return retval;1815}18161817/*1818 * Call fn for each reference in the specified ref_cache for which the1819 * refname begins with base. If trim is non-zero, then trim that many1820 * characters off the beginning of each refname before passing the1821 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1822 * broken references in the iteration. If fn ever returns a non-zero1823 * value, stop the iteration and return that value; otherwise, return1824 * 0.1825 */1826static int do_for_each_ref(struct ref_cache *refs, const char *base,1827 each_ref_fn fn, int trim, int flags, void *cb_data)1828{1829 struct ref_entry_cb data;1830 data.base = base;1831 data.trim = trim;1832 data.flags = flags;1833 data.fn = fn;1834 data.cb_data = cb_data;18351836 return do_for_each_entry(refs, base, do_one_ref, &data);1837}18381839static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1840{1841 unsigned char sha1[20];1842 int flag;18431844 if (submodule) {1845 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1846 return fn("HEAD", sha1, 0, cb_data);18471848 return 0;1849 }18501851 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1852 return fn("HEAD", sha1, flag, cb_data);18531854 return 0;1855}18561857int head_ref(each_ref_fn fn, void *cb_data)1858{1859 return do_head_ref(NULL, fn, cb_data);1860}18611862int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1863{1864 return do_head_ref(submodule, fn, cb_data);1865}18661867int for_each_ref(each_ref_fn fn, void *cb_data)1868{1869 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);1870}18711872int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1873{1874 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);1875}18761877int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1878{1879 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);1880}18811882int for_each_ref_in_submodule(const char *submodule, const char *prefix,1883 each_ref_fn fn, void *cb_data)1884{1885 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);1886}18871888int for_each_tag_ref(each_ref_fn fn, void *cb_data)1889{1890 return for_each_ref_in("refs/tags/", fn, cb_data);1891}18921893int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1894{1895 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1896}18971898int for_each_branch_ref(each_ref_fn fn, void *cb_data)1899{1900 return for_each_ref_in("refs/heads/", fn, cb_data);1901}19021903int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1904{1905 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1906}19071908int for_each_remote_ref(each_ref_fn fn, void *cb_data)1909{1910 return for_each_ref_in("refs/remotes/", fn, cb_data);1911}19121913int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1914{1915 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1916}19171918int for_each_replace_ref(each_ref_fn fn, void *cb_data)1919{1920 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);1921}19221923int head_ref_namespaced(each_ref_fn fn, void *cb_data)1924{1925 struct strbuf buf = STRBUF_INIT;1926 int ret = 0;1927 unsigned char sha1[20];1928 int flag;19291930 strbuf_addf(&buf, "%sHEAD", get_git_namespace());1931 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))1932 ret = fn(buf.buf, sha1, flag, cb_data);1933 strbuf_release(&buf);19341935 return ret;1936}19371938int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)1939{1940 struct strbuf buf = STRBUF_INIT;1941 int ret;1942 strbuf_addf(&buf, "%srefs/", get_git_namespace());1943 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);1944 strbuf_release(&buf);1945 return ret;1946}19471948int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,1949 const char *prefix, void *cb_data)1950{1951 struct strbuf real_pattern = STRBUF_INIT;1952 struct ref_filter filter;1953 int ret;19541955 if (!prefix && !starts_with(pattern, "refs/"))1956 strbuf_addstr(&real_pattern, "refs/");1957 else if (prefix)1958 strbuf_addstr(&real_pattern, prefix);1959 strbuf_addstr(&real_pattern, pattern);19601961 if (!has_glob_specials(pattern)) {1962 /* Append implied '/' '*' if not present. */1963 if (real_pattern.buf[real_pattern.len - 1] != '/')1964 strbuf_addch(&real_pattern, '/');1965 /* No need to check for '*', there is none. */1966 strbuf_addch(&real_pattern, '*');1967 }19681969 filter.pattern = real_pattern.buf;1970 filter.fn = fn;1971 filter.cb_data = cb_data;1972 ret = for_each_ref(filter_refs, &filter);19731974 strbuf_release(&real_pattern);1975 return ret;1976}19771978int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)1979{1980 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);1981}19821983int for_each_rawref(each_ref_fn fn, void *cb_data)1984{1985 return do_for_each_ref(&ref_cache, "", fn, 0,1986 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1987}19881989const char *prettify_refname(const char *name)1990{1991 return name + (1992 starts_with(name, "refs/heads/") ? 11 :1993 starts_with(name, "refs/tags/") ? 10 :1994 starts_with(name, "refs/remotes/") ? 13 :1995 0);1996}19971998static const char *ref_rev_parse_rules[] = {1999 "%.*s",2000 "refs/%.*s",2001 "refs/tags/%.*s",2002 "refs/heads/%.*s",2003 "refs/remotes/%.*s",2004 "refs/remotes/%.*s/HEAD",2005 NULL2006};20072008int refname_match(const char *abbrev_name, const char *full_name)2009{2010 const char **p;2011 const int abbrev_name_len = strlen(abbrev_name);20122013 for (p = ref_rev_parse_rules; *p; p++) {2014 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {2015 return 1;2016 }2017 }20182019 return 0;2020}20212022/* This function should make sure errno is meaningful on error */2023static struct ref_lock *verify_lock(struct ref_lock *lock,2024 const unsigned char *old_sha1, int mustexist)2025{2026 if (read_ref_full(lock->ref_name,2027 mustexist ? RESOLVE_REF_READING : 0,2028 lock->old_sha1, NULL)) {2029 int save_errno = errno;2030 error("Can't verify ref %s", lock->ref_name);2031 unlock_ref(lock);2032 errno = save_errno;2033 return NULL;2034 }2035 if (hashcmp(lock->old_sha1, old_sha1)) {2036 error("Ref %s is at %s but expected %s", lock->ref_name,2037 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));2038 unlock_ref(lock);2039 errno = EBUSY;2040 return NULL;2041 }2042 return lock;2043}20442045static int remove_empty_directories(const char *file)2046{2047 /* we want to create a file but there is a directory there;2048 * if that is an empty directory (or a directory that contains2049 * only empty directories), remove them.2050 */2051 struct strbuf path;2052 int result, save_errno;20532054 strbuf_init(&path, 20);2055 strbuf_addstr(&path, file);20562057 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2058 save_errno = errno;20592060 strbuf_release(&path);2061 errno = save_errno;20622063 return result;2064}20652066/*2067 * *string and *len will only be substituted, and *string returned (for2068 * later free()ing) if the string passed in is a magic short-hand form2069 * to name a branch.2070 */2071static char *substitute_branch_name(const char **string, int *len)2072{2073 struct strbuf buf = STRBUF_INIT;2074 int ret = interpret_branch_name(*string, *len, &buf);20752076 if (ret == *len) {2077 size_t size;2078 *string = strbuf_detach(&buf, &size);2079 *len = size;2080 return (char *)*string;2081 }20822083 return NULL;2084}20852086int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)2087{2088 char *last_branch = substitute_branch_name(&str, &len);2089 const char **p, *r;2090 int refs_found = 0;20912092 *ref = NULL;2093 for (p = ref_rev_parse_rules; *p; p++) {2094 char fullref[PATH_MAX];2095 unsigned char sha1_from_ref[20];2096 unsigned char *this_result;2097 int flag;20982099 this_result = refs_found ? sha1_from_ref : sha1;2100 mksnpath(fullref, sizeof(fullref), *p, len, str);2101 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2102 this_result, &flag);2103 if (r) {2104 if (!refs_found++)2105 *ref = xstrdup(r);2106 if (!warn_ambiguous_refs)2107 break;2108 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {2109 warning("ignoring dangling symref %s.", fullref);2110 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {2111 warning("ignoring broken ref %s.", fullref);2112 }2113 }2114 free(last_branch);2115 return refs_found;2116}21172118int dwim_log(const char *str, int len, unsigned char *sha1, char **log)2119{2120 char *last_branch = substitute_branch_name(&str, &len);2121 const char **p;2122 int logs_found = 0;21232124 *log = NULL;2125 for (p = ref_rev_parse_rules; *p; p++) {2126 unsigned char hash[20];2127 char path[PATH_MAX];2128 const char *ref, *it;21292130 mksnpath(path, sizeof(path), *p, len, str);2131 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,2132 hash, NULL);2133 if (!ref)2134 continue;2135 if (reflog_exists(path))2136 it = path;2137 else if (strcmp(ref, path) && reflog_exists(ref))2138 it = ref;2139 else2140 continue;2141 if (!logs_found++) {2142 *log = xstrdup(it);2143 hashcpy(sha1, hash);2144 }2145 if (!warn_ambiguous_refs)2146 break;2147 }2148 free(last_branch);2149 return logs_found;2150}21512152/*2153 * Locks a ref returning the lock on success and NULL on failure.2154 * On failure errno is set to something meaningful.2155 */2156static struct ref_lock *lock_ref_sha1_basic(const char *refname,2157 const unsigned char *old_sha1,2158 const struct string_list *skip,2159 int flags, int *type_p)2160{2161 char *ref_file;2162 const char *orig_refname = refname;2163 struct ref_lock *lock;2164 int last_errno = 0;2165 int type, lflags;2166 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2167 int resolve_flags = 0;2168 int missing = 0;2169 int attempts_remaining = 3;21702171 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {2172 errno = EINVAL;2173 return NULL;2174 }21752176 lock = xcalloc(1, sizeof(struct ref_lock));2177 lock->lock_fd = -1;21782179 if (mustexist)2180 resolve_flags |= RESOLVE_REF_READING;2181 if (flags & REF_NODEREF && flags & REF_DELETING)2182 resolve_flags |= RESOLVE_REF_NO_RECURSE;21832184 refname = resolve_ref_unsafe(refname, resolve_flags,2185 lock->old_sha1, &type);2186 if (!refname && errno == EISDIR) {2187 /* we are trying to lock foo but we used to2188 * have foo/bar which now does not exist;2189 * it is normal for the empty directory 'foo'2190 * to remain.2191 */2192 ref_file = git_path("%s", orig_refname);2193 if (remove_empty_directories(ref_file)) {2194 last_errno = errno;2195 error("there are still refs under '%s'", orig_refname);2196 goto error_return;2197 }2198 refname = resolve_ref_unsafe(orig_refname, resolve_flags,2199 lock->old_sha1, &type);2200 }2201 if (type_p)2202 *type_p = type;2203 if (!refname) {2204 last_errno = errno;2205 error("unable to resolve reference %s: %s",2206 orig_refname, strerror(errno));2207 goto error_return;2208 }2209 missing = is_null_sha1(lock->old_sha1);2210 /* When the ref did not exist and we are creating it,2211 * make sure there is no existing ref that is packed2212 * whose name begins with our refname, nor a ref whose2213 * name is a proper prefix of our refname.2214 */2215 if (missing &&2216 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {2217 last_errno = ENOTDIR;2218 goto error_return;2219 }22202221 lock->lk = xcalloc(1, sizeof(struct lock_file));22222223 lflags = 0;2224 if (flags & REF_NODEREF) {2225 refname = orig_refname;2226 lflags |= LOCK_NO_DEREF;2227 }2228 lock->ref_name = xstrdup(refname);2229 lock->orig_ref_name = xstrdup(orig_refname);2230 ref_file = git_path("%s", refname);2231 if (missing)2232 lock->force_write = 1;2233 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))2234 lock->force_write = 1;22352236 retry:2237 switch (safe_create_leading_directories(ref_file)) {2238 case SCLD_OK:2239 break; /* success */2240 case SCLD_VANISHED:2241 if (--attempts_remaining > 0)2242 goto retry;2243 /* fall through */2244 default:2245 last_errno = errno;2246 error("unable to create directory for %s", ref_file);2247 goto error_return;2248 }22492250 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);2251 if (lock->lock_fd < 0) {2252 if (errno == ENOENT && --attempts_remaining > 0)2253 /*2254 * Maybe somebody just deleted one of the2255 * directories leading to ref_file. Try2256 * again:2257 */2258 goto retry;2259 else2260 unable_to_lock_die(ref_file, errno);2261 }2262 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;22632264 error_return:2265 unlock_ref(lock);2266 errno = last_errno;2267 return NULL;2268}22692270struct ref_lock *lock_any_ref_for_update(const char *refname,2271 const unsigned char *old_sha1,2272 int flags, int *type_p)2273{2274 return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);2275}22762277/*2278 * Write an entry to the packed-refs file for the specified refname.2279 * If peeled is non-NULL, write it as the entry's peeled value.2280 */2281static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2282 unsigned char *peeled)2283{2284 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2285 if (peeled)2286 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2287}22882289/*2290 * An each_ref_entry_fn that writes the entry to a packed-refs file.2291 */2292static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2293{2294 enum peel_status peel_status = peel_entry(entry, 0);22952296 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2297 error("internal error: %s is not a valid packed reference!",2298 entry->name);2299 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2300 peel_status == PEEL_PEELED ?2301 entry->u.value.peeled : NULL);2302 return 0;2303}23042305/* This should return a meaningful errno on failure */2306int lock_packed_refs(int flags)2307{2308 struct packed_ref_cache *packed_ref_cache;23092310 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)2311 return -1;2312 /*2313 * Get the current packed-refs while holding the lock. If the2314 * packed-refs file has been modified since we last read it,2315 * this will automatically invalidate the cache and re-read2316 * the packed-refs file.2317 */2318 packed_ref_cache = get_packed_ref_cache(&ref_cache);2319 packed_ref_cache->lock = &packlock;2320 /* Increment the reference count to prevent it from being freed: */2321 acquire_packed_ref_cache(packed_ref_cache);2322 return 0;2323}23242325/*2326 * Commit the packed refs changes.2327 * On error we must make sure that errno contains a meaningful value.2328 */2329int commit_packed_refs(void)2330{2331 struct packed_ref_cache *packed_ref_cache =2332 get_packed_ref_cache(&ref_cache);2333 int error = 0;2334 int save_errno = 0;2335 FILE *out;23362337 if (!packed_ref_cache->lock)2338 die("internal error: packed-refs not locked");23392340 out = fdopen_lock_file(packed_ref_cache->lock, "w");2341 if (!out)2342 die_errno("unable to fdopen packed-refs descriptor");23432344 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2345 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2346 0, write_packed_entry_fn, out);23472348 if (commit_lock_file(packed_ref_cache->lock)) {2349 save_errno = errno;2350 error = -1;2351 }2352 packed_ref_cache->lock = NULL;2353 release_packed_ref_cache(packed_ref_cache);2354 errno = save_errno;2355 return error;2356}23572358void rollback_packed_refs(void)2359{2360 struct packed_ref_cache *packed_ref_cache =2361 get_packed_ref_cache(&ref_cache);23622363 if (!packed_ref_cache->lock)2364 die("internal error: packed-refs not locked");2365 rollback_lock_file(packed_ref_cache->lock);2366 packed_ref_cache->lock = NULL;2367 release_packed_ref_cache(packed_ref_cache);2368 clear_packed_ref_cache(&ref_cache);2369}23702371struct ref_to_prune {2372 struct ref_to_prune *next;2373 unsigned char sha1[20];2374 char name[FLEX_ARRAY];2375};23762377struct pack_refs_cb_data {2378 unsigned int flags;2379 struct ref_dir *packed_refs;2380 struct ref_to_prune *ref_to_prune;2381};23822383/*2384 * An each_ref_entry_fn that is run over loose references only. If2385 * the loose reference can be packed, add an entry in the packed ref2386 * cache. If the reference should be pruned, also add it to2387 * ref_to_prune in the pack_refs_cb_data.2388 */2389static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2390{2391 struct pack_refs_cb_data *cb = cb_data;2392 enum peel_status peel_status;2393 struct ref_entry *packed_entry;2394 int is_tag_ref = starts_with(entry->name, "refs/tags/");23952396 /* ALWAYS pack tags */2397 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2398 return 0;23992400 /* Do not pack symbolic or broken refs: */2401 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2402 return 0;24032404 /* Add a packed ref cache entry equivalent to the loose entry. */2405 peel_status = peel_entry(entry, 1);2406 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2407 die("internal error peeling reference %s (%s)",2408 entry->name, sha1_to_hex(entry->u.value.sha1));2409 packed_entry = find_ref(cb->packed_refs, entry->name);2410 if (packed_entry) {2411 /* Overwrite existing packed entry with info from loose entry */2412 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2413 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2414 } else {2415 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,2416 REF_ISPACKED | REF_KNOWS_PEELED, 0);2417 add_ref(cb->packed_refs, packed_entry);2418 }2419 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);24202421 /* Schedule the loose reference for pruning if requested. */2422 if ((cb->flags & PACK_REFS_PRUNE)) {2423 int namelen = strlen(entry->name) + 1;2424 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2425 hashcpy(n->sha1, entry->u.value.sha1);2426 strcpy(n->name, entry->name);2427 n->next = cb->ref_to_prune;2428 cb->ref_to_prune = n;2429 }2430 return 0;2431}24322433/*2434 * Remove empty parents, but spare refs/ and immediate subdirs.2435 * Note: munges *name.2436 */2437static void try_remove_empty_parents(char *name)2438{2439 char *p, *q;2440 int i;2441 p = name;2442 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2443 while (*p && *p != '/')2444 p++;2445 /* tolerate duplicate slashes; see check_refname_format() */2446 while (*p == '/')2447 p++;2448 }2449 for (q = p; *q; q++)2450 ;2451 while (1) {2452 while (q > p && *q != '/')2453 q--;2454 while (q > p && *(q-1) == '/')2455 q--;2456 if (q == p)2457 break;2458 *q = '\0';2459 if (rmdir(git_path("%s", name)))2460 break;2461 }2462}24632464/* make sure nobody touched the ref, and unlink */2465static void prune_ref(struct ref_to_prune *r)2466{2467 struct ref_transaction *transaction;2468 struct strbuf err = STRBUF_INIT;24692470 if (check_refname_format(r->name, 0))2471 return;24722473 transaction = ref_transaction_begin(&err);2474 if (!transaction ||2475 ref_transaction_delete(transaction, r->name, r->sha1,2476 REF_ISPRUNING, 1, NULL, &err) ||2477 ref_transaction_commit(transaction, &err)) {2478 ref_transaction_free(transaction);2479 error("%s", err.buf);2480 strbuf_release(&err);2481 return;2482 }2483 ref_transaction_free(transaction);2484 strbuf_release(&err);2485 try_remove_empty_parents(r->name);2486}24872488static void prune_refs(struct ref_to_prune *r)2489{2490 while (r) {2491 prune_ref(r);2492 r = r->next;2493 }2494}24952496int pack_refs(unsigned int flags)2497{2498 struct pack_refs_cb_data cbdata;24992500 memset(&cbdata, 0, sizeof(cbdata));2501 cbdata.flags = flags;25022503 lock_packed_refs(LOCK_DIE_ON_ERROR);2504 cbdata.packed_refs = get_packed_refs(&ref_cache);25052506 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2507 pack_if_possible_fn, &cbdata);25082509 if (commit_packed_refs())2510 die_errno("unable to overwrite old ref-pack file");25112512 prune_refs(cbdata.ref_to_prune);2513 return 0;2514}25152516/*2517 * If entry is no longer needed in packed-refs, add it to the string2518 * list pointed to by cb_data. Reasons for deleting entries:2519 *2520 * - Entry is broken.2521 * - Entry is overridden by a loose ref.2522 * - Entry does not point at a valid object.2523 *2524 * In the first and third cases, also emit an error message because these2525 * are indications of repository corruption.2526 */2527static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)2528{2529 struct string_list *refs_to_delete = cb_data;25302531 if (entry->flag & REF_ISBROKEN) {2532 /* This shouldn't happen to packed refs. */2533 error("%s is broken!", entry->name);2534 string_list_append(refs_to_delete, entry->name);2535 return 0;2536 }2537 if (!has_sha1_file(entry->u.value.sha1)) {2538 unsigned char sha1[20];2539 int flags;25402541 if (read_ref_full(entry->name, 0, sha1, &flags))2542 /* We should at least have found the packed ref. */2543 die("Internal error");2544 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2545 /*2546 * This packed reference is overridden by a2547 * loose reference, so it is OK that its value2548 * is no longer valid; for example, it might2549 * refer to an object that has been garbage2550 * collected. For this purpose we don't even2551 * care whether the loose reference itself is2552 * invalid, broken, symbolic, etc. Silently2553 * remove the packed reference.2554 */2555 string_list_append(refs_to_delete, entry->name);2556 return 0;2557 }2558 /*2559 * There is no overriding loose reference, so the fact2560 * that this reference doesn't refer to a valid object2561 * indicates some kind of repository corruption.2562 * Report the problem, then omit the reference from2563 * the output.2564 */2565 error("%s does not point to a valid object!", entry->name);2566 string_list_append(refs_to_delete, entry->name);2567 return 0;2568 }25692570 return 0;2571}25722573int repack_without_refs(const char **refnames, int n, struct strbuf *err)2574{2575 struct ref_dir *packed;2576 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2577 struct string_list_item *ref_to_delete;2578 int i, ret, removed = 0;25792580 /* Look for a packed ref */2581 for (i = 0; i < n; i++)2582 if (get_packed_ref(refnames[i]))2583 break;25842585 /* Avoid locking if we have nothing to do */2586 if (i == n)2587 return 0; /* no refname exists in packed refs */25882589 if (lock_packed_refs(0)) {2590 if (err) {2591 unable_to_lock_message(git_path("packed-refs"), errno,2592 err);2593 return -1;2594 }2595 unable_to_lock_error(git_path("packed-refs"), errno);2596 return error("cannot delete '%s' from packed refs", refnames[i]);2597 }2598 packed = get_packed_refs(&ref_cache);25992600 /* Remove refnames from the cache */2601 for (i = 0; i < n; i++)2602 if (remove_entry(packed, refnames[i]) != -1)2603 removed = 1;2604 if (!removed) {2605 /*2606 * All packed entries disappeared while we were2607 * acquiring the lock.2608 */2609 rollback_packed_refs();2610 return 0;2611 }26122613 /* Remove any other accumulated cruft */2614 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);2615 for_each_string_list_item(ref_to_delete, &refs_to_delete) {2616 if (remove_entry(packed, ref_to_delete->string) == -1)2617 die("internal error");2618 }26192620 /* Write what remains */2621 ret = commit_packed_refs();2622 if (ret && err)2623 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2624 strerror(errno));2625 return ret;2626}26272628static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2629{2630 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2631 /*2632 * loose. The loose file name is the same as the2633 * lockfile name, minus ".lock":2634 */2635 char *loose_filename = get_locked_file_path(lock->lk);2636 int res = unlink_or_msg(loose_filename, err);2637 free(loose_filename);2638 if (res)2639 return 1;2640 }2641 return 0;2642}26432644int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2645{2646 struct ref_transaction *transaction;2647 struct strbuf err = STRBUF_INIT;26482649 transaction = ref_transaction_begin(&err);2650 if (!transaction ||2651 ref_transaction_delete(transaction, refname, sha1, delopt,2652 sha1 && !is_null_sha1(sha1), NULL, &err) ||2653 ref_transaction_commit(transaction, &err)) {2654 error("%s", err.buf);2655 ref_transaction_free(transaction);2656 strbuf_release(&err);2657 return 1;2658 }2659 ref_transaction_free(transaction);2660 strbuf_release(&err);2661 return 0;2662}26632664/*2665 * People using contrib's git-new-workdir have .git/logs/refs ->2666 * /some/other/path/.git/logs/refs, and that may live on another device.2667 *2668 * IOW, to avoid cross device rename errors, the temporary renamed log must2669 * live into logs/refs.2670 */2671#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"26722673static int rename_tmp_log(const char *newrefname)2674{2675 int attempts_remaining = 4;26762677 retry:2678 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {2679 case SCLD_OK:2680 break; /* success */2681 case SCLD_VANISHED:2682 if (--attempts_remaining > 0)2683 goto retry;2684 /* fall through */2685 default:2686 error("unable to create directory for %s", newrefname);2687 return -1;2688 }26892690 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2691 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2692 /*2693 * rename(a, b) when b is an existing2694 * directory ought to result in ISDIR, but2695 * Solaris 5.8 gives ENOTDIR. Sheesh.2696 */2697 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2698 error("Directory not empty: logs/%s", newrefname);2699 return -1;2700 }2701 goto retry;2702 } else if (errno == ENOENT && --attempts_remaining > 0) {2703 /*2704 * Maybe another process just deleted one of2705 * the directories in the path to newrefname.2706 * Try again from the beginning.2707 */2708 goto retry;2709 } else {2710 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2711 newrefname, strerror(errno));2712 return -1;2713 }2714 }2715 return 0;2716}27172718static int rename_ref_available(const char *oldname, const char *newname)2719{2720 struct string_list skip = STRING_LIST_INIT_NODUP;2721 int ret;27222723 string_list_insert(&skip, oldname);2724 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))2725 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));2726 string_list_clear(&skip, 0);2727 return ret;2728}27292730static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,2731 const char *logmsg);27322733int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2734{2735 unsigned char sha1[20], orig_sha1[20];2736 int flag = 0, logmoved = 0;2737 struct ref_lock *lock;2738 struct stat loginfo;2739 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2740 const char *symref = NULL;27412742 if (log && S_ISLNK(loginfo.st_mode))2743 return error("reflog for %s is a symlink", oldrefname);27442745 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2746 orig_sha1, &flag);2747 if (flag & REF_ISSYMREF)2748 return error("refname %s is a symbolic ref, renaming it is not supported",2749 oldrefname);2750 if (!symref)2751 return error("refname %s not found", oldrefname);27522753 if (!rename_ref_available(oldrefname, newrefname))2754 return 1;27552756 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2757 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2758 oldrefname, strerror(errno));27592760 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2761 error("unable to delete old %s", oldrefname);2762 goto rollback;2763 }27642765 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2766 delete_ref(newrefname, sha1, REF_NODEREF)) {2767 if (errno==EISDIR) {2768 if (remove_empty_directories(git_path("%s", newrefname))) {2769 error("Directory not empty: %s", newrefname);2770 goto rollback;2771 }2772 } else {2773 error("unable to delete existing %s", newrefname);2774 goto rollback;2775 }2776 }27772778 if (log && rename_tmp_log(newrefname))2779 goto rollback;27802781 logmoved = log;27822783 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);2784 if (!lock) {2785 error("unable to lock %s for update", newrefname);2786 goto rollback;2787 }2788 lock->force_write = 1;2789 hashcpy(lock->old_sha1, orig_sha1);2790 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2791 error("unable to write current sha1 into %s", newrefname);2792 goto rollback;2793 }27942795 return 0;27962797 rollback:2798 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);2799 if (!lock) {2800 error("unable to lock %s for rollback", oldrefname);2801 goto rollbacklog;2802 }28032804 lock->force_write = 1;2805 flag = log_all_ref_updates;2806 log_all_ref_updates = 0;2807 if (write_ref_sha1(lock, orig_sha1, NULL))2808 error("unable to write current sha1 into %s", oldrefname);2809 log_all_ref_updates = flag;28102811 rollbacklog:2812 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2813 error("unable to restore logfile %s from %s: %s",2814 oldrefname, newrefname, strerror(errno));2815 if (!logmoved && log &&2816 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2817 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2818 oldrefname, strerror(errno));28192820 return 1;2821}28222823int close_ref(struct ref_lock *lock)2824{2825 if (close_lock_file(lock->lk))2826 return -1;2827 lock->lock_fd = -1;2828 return 0;2829}28302831int commit_ref(struct ref_lock *lock)2832{2833 if (commit_lock_file(lock->lk))2834 return -1;2835 lock->lock_fd = -1;2836 return 0;2837}28382839void unlock_ref(struct ref_lock *lock)2840{2841 /* Do not free lock->lk -- atexit() still looks at them */2842 if (lock->lk)2843 rollback_lock_file(lock->lk);2844 free(lock->ref_name);2845 free(lock->orig_ref_name);2846 free(lock);2847}28482849/*2850 * copy the reflog message msg to buf, which has been allocated sufficiently2851 * large, while cleaning up the whitespaces. Especially, convert LF to space,2852 * because reflog file is one line per entry.2853 */2854static int copy_msg(char *buf, const char *msg)2855{2856 char *cp = buf;2857 char c;2858 int wasspace = 1;28592860 *cp++ = '\t';2861 while ((c = *msg++)) {2862 if (wasspace && isspace(c))2863 continue;2864 wasspace = isspace(c);2865 if (wasspace)2866 c = ' ';2867 *cp++ = c;2868 }2869 while (buf < cp && isspace(cp[-1]))2870 cp--;2871 *cp++ = '\n';2872 return cp - buf;2873}28742875/* This function must set a meaningful errno on failure */2876int log_ref_setup(const char *refname, char *logfile, int bufsize)2877{2878 int logfd, oflags = O_APPEND | O_WRONLY;28792880 git_snpath(logfile, bufsize, "logs/%s", refname);2881 if (log_all_ref_updates &&2882 (starts_with(refname, "refs/heads/") ||2883 starts_with(refname, "refs/remotes/") ||2884 starts_with(refname, "refs/notes/") ||2885 !strcmp(refname, "HEAD"))) {2886 if (safe_create_leading_directories(logfile) < 0) {2887 int save_errno = errno;2888 error("unable to create directory for %s", logfile);2889 errno = save_errno;2890 return -1;2891 }2892 oflags |= O_CREAT;2893 }28942895 logfd = open(logfile, oflags, 0666);2896 if (logfd < 0) {2897 if (!(oflags & O_CREAT) && errno == ENOENT)2898 return 0;28992900 if ((oflags & O_CREAT) && errno == EISDIR) {2901 if (remove_empty_directories(logfile)) {2902 int save_errno = errno;2903 error("There are still logs under '%s'",2904 logfile);2905 errno = save_errno;2906 return -1;2907 }2908 logfd = open(logfile, oflags, 0666);2909 }29102911 if (logfd < 0) {2912 int save_errno = errno;2913 error("Unable to append to %s: %s", logfile,2914 strerror(errno));2915 errno = save_errno;2916 return -1;2917 }2918 }29192920 adjust_shared_perm(logfile);2921 close(logfd);2922 return 0;2923}29242925static int log_ref_write(const char *refname, const unsigned char *old_sha1,2926 const unsigned char *new_sha1, const char *msg)2927{2928 int logfd, result, written, oflags = O_APPEND | O_WRONLY;2929 unsigned maxlen, len;2930 int msglen;2931 char log_file[PATH_MAX];2932 char *logrec;2933 const char *committer;29342935 if (log_all_ref_updates < 0)2936 log_all_ref_updates = !is_bare_repository();29372938 result = log_ref_setup(refname, log_file, sizeof(log_file));2939 if (result)2940 return result;29412942 logfd = open(log_file, oflags);2943 if (logfd < 0)2944 return 0;2945 msglen = msg ? strlen(msg) : 0;2946 committer = git_committer_info(0);2947 maxlen = strlen(committer) + msglen + 100;2948 logrec = xmalloc(maxlen);2949 len = sprintf(logrec, "%s %s %s\n",2950 sha1_to_hex(old_sha1),2951 sha1_to_hex(new_sha1),2952 committer);2953 if (msglen)2954 len += copy_msg(logrec + len - 1, msg) - 1;2955 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;2956 free(logrec);2957 if (written != len) {2958 int save_errno = errno;2959 close(logfd);2960 error("Unable to append to %s", log_file);2961 errno = save_errno;2962 return -1;2963 }2964 if (close(logfd)) {2965 int save_errno = errno;2966 error("Unable to append to %s", log_file);2967 errno = save_errno;2968 return -1;2969 }2970 return 0;2971}29722973int is_branch(const char *refname)2974{2975 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");2976}29772978/*2979 * Write sha1 into the ref specified by the lock. Make sure that errno2980 * is sane on error.2981 */2982static int write_ref_sha1(struct ref_lock *lock,2983 const unsigned char *sha1, const char *logmsg)2984{2985 static char term = '\n';2986 struct object *o;29872988 if (!lock) {2989 errno = EINVAL;2990 return -1;2991 }2992 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2993 unlock_ref(lock);2994 return 0;2995 }2996 o = parse_object(sha1);2997 if (!o) {2998 error("Trying to write ref %s with nonexistent object %s",2999 lock->ref_name, sha1_to_hex(sha1));3000 unlock_ref(lock);3001 errno = EINVAL;3002 return -1;3003 }3004 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {3005 error("Trying to write non-commit object %s to branch %s",3006 sha1_to_hex(sha1), lock->ref_name);3007 unlock_ref(lock);3008 errno = EINVAL;3009 return -1;3010 }3011 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||3012 write_in_full(lock->lock_fd, &term, 1) != 1 ||3013 close_ref(lock) < 0) {3014 int save_errno = errno;3015 error("Couldn't write %s", lock->lk->filename.buf);3016 unlock_ref(lock);3017 errno = save_errno;3018 return -1;3019 }3020 clear_loose_ref_cache(&ref_cache);3021 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||3022 (strcmp(lock->ref_name, lock->orig_ref_name) &&3023 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {3024 unlock_ref(lock);3025 return -1;3026 }3027 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {3028 /*3029 * Special hack: If a branch is updated directly and HEAD3030 * points to it (may happen on the remote side of a push3031 * for example) then logically the HEAD reflog should be3032 * updated too.3033 * A generic solution implies reverse symref information,3034 * but finding all symrefs pointing to the given branch3035 * would be rather costly for this rare event (the direct3036 * update of a branch) to be worth it. So let's cheat and3037 * check with HEAD only which should cover 99% of all usage3038 * scenarios (even 100% of the default ones).3039 */3040 unsigned char head_sha1[20];3041 int head_flag;3042 const char *head_ref;3043 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3044 head_sha1, &head_flag);3045 if (head_ref && (head_flag & REF_ISSYMREF) &&3046 !strcmp(head_ref, lock->ref_name))3047 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3048 }3049 if (commit_ref(lock)) {3050 error("Couldn't set %s", lock->ref_name);3051 unlock_ref(lock);3052 return -1;3053 }3054 unlock_ref(lock);3055 return 0;3056}30573058int create_symref(const char *ref_target, const char *refs_heads_master,3059 const char *logmsg)3060{3061 const char *lockpath;3062 char ref[1000];3063 int fd, len, written;3064 char *git_HEAD = git_pathdup("%s", ref_target);3065 unsigned char old_sha1[20], new_sha1[20];30663067 if (logmsg && read_ref(ref_target, old_sha1))3068 hashclr(old_sha1);30693070 if (safe_create_leading_directories(git_HEAD) < 0)3071 return error("unable to create directory for %s", git_HEAD);30723073#ifndef NO_SYMLINK_HEAD3074 if (prefer_symlink_refs) {3075 unlink(git_HEAD);3076 if (!symlink(refs_heads_master, git_HEAD))3077 goto done;3078 fprintf(stderr, "no symlink - falling back to symbolic ref\n");3079 }3080#endif30813082 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);3083 if (sizeof(ref) <= len) {3084 error("refname too long: %s", refs_heads_master);3085 goto error_free_return;3086 }3087 lockpath = mkpath("%s.lock", git_HEAD);3088 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);3089 if (fd < 0) {3090 error("Unable to open %s for writing", lockpath);3091 goto error_free_return;3092 }3093 written = write_in_full(fd, ref, len);3094 if (close(fd) != 0 || written != len) {3095 error("Unable to write to %s", lockpath);3096 goto error_unlink_return;3097 }3098 if (rename(lockpath, git_HEAD) < 0) {3099 error("Unable to create %s", git_HEAD);3100 goto error_unlink_return;3101 }3102 if (adjust_shared_perm(git_HEAD)) {3103 error("Unable to fix permissions on %s", lockpath);3104 error_unlink_return:3105 unlink_or_warn(lockpath);3106 error_free_return:3107 free(git_HEAD);3108 return -1;3109 }31103111#ifndef NO_SYMLINK_HEAD3112 done:3113#endif3114 if (logmsg && !read_ref(refs_heads_master, new_sha1))3115 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31163117 free(git_HEAD);3118 return 0;3119}31203121struct read_ref_at_cb {3122 const char *refname;3123 unsigned long at_time;3124 int cnt;3125 int reccnt;3126 unsigned char *sha1;3127 int found_it;31283129 unsigned char osha1[20];3130 unsigned char nsha1[20];3131 int tz;3132 unsigned long date;3133 char **msg;3134 unsigned long *cutoff_time;3135 int *cutoff_tz;3136 int *cutoff_cnt;3137};31383139static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,3140 const char *email, unsigned long timestamp, int tz,3141 const char *message, void *cb_data)3142{3143 struct read_ref_at_cb *cb = cb_data;31443145 cb->reccnt++;3146 cb->tz = tz;3147 cb->date = timestamp;31483149 if (timestamp <= cb->at_time || cb->cnt == 0) {3150 if (cb->msg)3151 *cb->msg = xstrdup(message);3152 if (cb->cutoff_time)3153 *cb->cutoff_time = timestamp;3154 if (cb->cutoff_tz)3155 *cb->cutoff_tz = tz;3156 if (cb->cutoff_cnt)3157 *cb->cutoff_cnt = cb->reccnt - 1;3158 /*3159 * we have not yet updated cb->[n|o]sha1 so they still3160 * hold the values for the previous record.3161 */3162 if (!is_null_sha1(cb->osha1)) {3163 hashcpy(cb->sha1, nsha1);3164 if (hashcmp(cb->osha1, nsha1))3165 warning("Log for ref %s has gap after %s.",3166 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));3167 }3168 else if (cb->date == cb->at_time)3169 hashcpy(cb->sha1, nsha1);3170 else if (hashcmp(nsha1, cb->sha1))3171 warning("Log for ref %s unexpectedly ended on %s.",3172 cb->refname, show_date(cb->date, cb->tz,3173 DATE_RFC2822));3174 hashcpy(cb->osha1, osha1);3175 hashcpy(cb->nsha1, nsha1);3176 cb->found_it = 1;3177 return 1;3178 }3179 hashcpy(cb->osha1, osha1);3180 hashcpy(cb->nsha1, nsha1);3181 if (cb->cnt > 0)3182 cb->cnt--;3183 return 0;3184}31853186static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,3187 const char *email, unsigned long timestamp,3188 int tz, const char *message, void *cb_data)3189{3190 struct read_ref_at_cb *cb = cb_data;31913192 if (cb->msg)3193 *cb->msg = xstrdup(message);3194 if (cb->cutoff_time)3195 *cb->cutoff_time = timestamp;3196 if (cb->cutoff_tz)3197 *cb->cutoff_tz = tz;3198 if (cb->cutoff_cnt)3199 *cb->cutoff_cnt = cb->reccnt;3200 hashcpy(cb->sha1, osha1);3201 if (is_null_sha1(cb->sha1))3202 hashcpy(cb->sha1, nsha1);3203 /* We just want the first entry */3204 return 1;3205}32063207int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,3208 unsigned char *sha1, char **msg,3209 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)3210{3211 struct read_ref_at_cb cb;32123213 memset(&cb, 0, sizeof(cb));3214 cb.refname = refname;3215 cb.at_time = at_time;3216 cb.cnt = cnt;3217 cb.msg = msg;3218 cb.cutoff_time = cutoff_time;3219 cb.cutoff_tz = cutoff_tz;3220 cb.cutoff_cnt = cutoff_cnt;3221 cb.sha1 = sha1;32223223 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);32243225 if (!cb.reccnt) {3226 if (flags & GET_SHA1_QUIETLY)3227 exit(128);3228 else3229 die("Log for %s is empty.", refname);3230 }3231 if (cb.found_it)3232 return 0;32333234 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);32353236 return 1;3237}32383239int reflog_exists(const char *refname)3240{3241 struct stat st;32423243 return !lstat(git_path("logs/%s", refname), &st) &&3244 S_ISREG(st.st_mode);3245}32463247int delete_reflog(const char *refname)3248{3249 return remove_path(git_path("logs/%s", refname));3250}32513252static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3253{3254 unsigned char osha1[20], nsha1[20];3255 char *email_end, *message;3256 unsigned long timestamp;3257 int tz;32583259 /* old SP new SP name <email> SP time TAB msg LF */3260 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3261 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3262 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3263 !(email_end = strchr(sb->buf + 82, '>')) ||3264 email_end[1] != ' ' ||3265 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3266 !message || message[0] != ' ' ||3267 (message[1] != '+' && message[1] != '-') ||3268 !isdigit(message[2]) || !isdigit(message[3]) ||3269 !isdigit(message[4]) || !isdigit(message[5]))3270 return 0; /* corrupt? */3271 email_end[1] = '\0';3272 tz = strtol(message + 1, NULL, 10);3273 if (message[6] != '\t')3274 message += 6;3275 else3276 message += 7;3277 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3278}32793280static char *find_beginning_of_line(char *bob, char *scan)3281{3282 while (bob < scan && *(--scan) != '\n')3283 ; /* keep scanning backwards */3284 /*3285 * Return either beginning of the buffer, or LF at the end of3286 * the previous line.3287 */3288 return scan;3289}32903291int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3292{3293 struct strbuf sb = STRBUF_INIT;3294 FILE *logfp;3295 long pos;3296 int ret = 0, at_tail = 1;32973298 logfp = fopen(git_path("logs/%s", refname), "r");3299 if (!logfp)3300 return -1;33013302 /* Jump to the end */3303 if (fseek(logfp, 0, SEEK_END) < 0)3304 return error("cannot seek back reflog for %s: %s",3305 refname, strerror(errno));3306 pos = ftell(logfp);3307 while (!ret && 0 < pos) {3308 int cnt;3309 size_t nread;3310 char buf[BUFSIZ];3311 char *endp, *scanp;33123313 /* Fill next block from the end */3314 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3315 if (fseek(logfp, pos - cnt, SEEK_SET))3316 return error("cannot seek back reflog for %s: %s",3317 refname, strerror(errno));3318 nread = fread(buf, cnt, 1, logfp);3319 if (nread != 1)3320 return error("cannot read %d bytes from reflog for %s: %s",3321 cnt, refname, strerror(errno));3322 pos -= cnt;33233324 scanp = endp = buf + cnt;3325 if (at_tail && scanp[-1] == '\n')3326 /* Looking at the final LF at the end of the file */3327 scanp--;3328 at_tail = 0;33293330 while (buf < scanp) {3331 /*3332 * terminating LF of the previous line, or the beginning3333 * of the buffer.3334 */3335 char *bp;33363337 bp = find_beginning_of_line(buf, scanp);33383339 if (*bp != '\n') {3340 strbuf_splice(&sb, 0, 0, buf, endp - buf);3341 if (pos)3342 break; /* need to fill another block */3343 scanp = buf - 1; /* leave loop */3344 } else {3345 /*3346 * (bp + 1) thru endp is the beginning of the3347 * current line we have in sb3348 */3349 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3350 scanp = bp;3351 endp = bp + 1;3352 }3353 ret = show_one_reflog_ent(&sb, fn, cb_data);3354 strbuf_reset(&sb);3355 if (ret)3356 break;3357 }33583359 }3360 if (!ret && sb.len)3361 ret = show_one_reflog_ent(&sb, fn, cb_data);33623363 fclose(logfp);3364 strbuf_release(&sb);3365 return ret;3366}33673368int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3369{3370 FILE *logfp;3371 struct strbuf sb = STRBUF_INIT;3372 int ret = 0;33733374 logfp = fopen(git_path("logs/%s", refname), "r");3375 if (!logfp)3376 return -1;33773378 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3379 ret = show_one_reflog_ent(&sb, fn, cb_data);3380 fclose(logfp);3381 strbuf_release(&sb);3382 return ret;3383}3384/*3385 * Call fn for each reflog in the namespace indicated by name. name3386 * must be empty or end with '/'. Name will be used as a scratch3387 * space, but its contents will be restored before return.3388 */3389static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3390{3391 DIR *d = opendir(git_path("logs/%s", name->buf));3392 int retval = 0;3393 struct dirent *de;3394 int oldlen = name->len;33953396 if (!d)3397 return name->len ? errno : 0;33983399 while ((de = readdir(d)) != NULL) {3400 struct stat st;34013402 if (de->d_name[0] == '.')3403 continue;3404 if (ends_with(de->d_name, ".lock"))3405 continue;3406 strbuf_addstr(name, de->d_name);3407 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3408 ; /* silently ignore */3409 } else {3410 if (S_ISDIR(st.st_mode)) {3411 strbuf_addch(name, '/');3412 retval = do_for_each_reflog(name, fn, cb_data);3413 } else {3414 unsigned char sha1[20];3415 if (read_ref_full(name->buf, 0, sha1, NULL))3416 retval = error("bad ref for %s", name->buf);3417 else3418 retval = fn(name->buf, sha1, 0, cb_data);3419 }3420 if (retval)3421 break;3422 }3423 strbuf_setlen(name, oldlen);3424 }3425 closedir(d);3426 return retval;3427}34283429int for_each_reflog(each_ref_fn fn, void *cb_data)3430{3431 int retval;3432 struct strbuf name;3433 strbuf_init(&name, PATH_MAX);3434 retval = do_for_each_reflog(&name, fn, cb_data);3435 strbuf_release(&name);3436 return retval;3437}34383439/**3440 * Information needed for a single ref update. Set new_sha1 to the3441 * new value or to zero to delete the ref. To check the old value3442 * while locking the ref, set have_old to 1 and set old_sha1 to the3443 * value or to zero to ensure the ref does not exist before update.3444 */3445struct ref_update {3446 unsigned char new_sha1[20];3447 unsigned char old_sha1[20];3448 int flags; /* REF_NODEREF? */3449 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */3450 struct ref_lock *lock;3451 int type;3452 char *msg;3453 const char refname[FLEX_ARRAY];3454};34553456/*3457 * Transaction states.3458 * OPEN: The transaction is in a valid state and can accept new updates.3459 * An OPEN transaction can be committed.3460 * CLOSED: A closed transaction is no longer active and no other operations3461 * than free can be used on it in this state.3462 * A transaction can either become closed by successfully committing3463 * an active transaction or if there is a failure while building3464 * the transaction thus rendering it failed/inactive.3465 */3466enum ref_transaction_state {3467 REF_TRANSACTION_OPEN = 0,3468 REF_TRANSACTION_CLOSED = 13469};34703471/*3472 * Data structure for holding a reference transaction, which can3473 * consist of checks and updates to multiple references, carried out3474 * as atomically as possible. This structure is opaque to callers.3475 */3476struct ref_transaction {3477 struct ref_update **updates;3478 size_t alloc;3479 size_t nr;3480 enum ref_transaction_state state;3481};34823483struct ref_transaction *ref_transaction_begin(struct strbuf *err)3484{3485 return xcalloc(1, sizeof(struct ref_transaction));3486}34873488void ref_transaction_free(struct ref_transaction *transaction)3489{3490 int i;34913492 if (!transaction)3493 return;34943495 for (i = 0; i < transaction->nr; i++) {3496 free(transaction->updates[i]->msg);3497 free(transaction->updates[i]);3498 }3499 free(transaction->updates);3500 free(transaction);3501}35023503static struct ref_update *add_update(struct ref_transaction *transaction,3504 const char *refname)3505{3506 size_t len = strlen(refname);3507 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);35083509 strcpy((char *)update->refname, refname);3510 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);3511 transaction->updates[transaction->nr++] = update;3512 return update;3513}35143515int ref_transaction_update(struct ref_transaction *transaction,3516 const char *refname,3517 const unsigned char *new_sha1,3518 const unsigned char *old_sha1,3519 int flags, int have_old, const char *msg,3520 struct strbuf *err)3521{3522 struct ref_update *update;35233524 if (transaction->state != REF_TRANSACTION_OPEN)3525 die("BUG: update called for transaction that is not open");35263527 if (have_old && !old_sha1)3528 die("BUG: have_old is true but old_sha1 is NULL");35293530 update = add_update(transaction, refname);3531 hashcpy(update->new_sha1, new_sha1);3532 update->flags = flags;3533 update->have_old = have_old;3534 if (have_old)3535 hashcpy(update->old_sha1, old_sha1);3536 if (msg)3537 update->msg = xstrdup(msg);3538 return 0;3539}35403541int ref_transaction_create(struct ref_transaction *transaction,3542 const char *refname,3543 const unsigned char *new_sha1,3544 int flags, const char *msg,3545 struct strbuf *err)3546{3547 struct ref_update *update;35483549 if (transaction->state != REF_TRANSACTION_OPEN)3550 die("BUG: create called for transaction that is not open");35513552 if (!new_sha1 || is_null_sha1(new_sha1))3553 die("BUG: create ref with null new_sha1");35543555 update = add_update(transaction, refname);35563557 hashcpy(update->new_sha1, new_sha1);3558 hashclr(update->old_sha1);3559 update->flags = flags;3560 update->have_old = 1;3561 if (msg)3562 update->msg = xstrdup(msg);3563 return 0;3564}35653566int ref_transaction_delete(struct ref_transaction *transaction,3567 const char *refname,3568 const unsigned char *old_sha1,3569 int flags, int have_old, const char *msg,3570 struct strbuf *err)3571{3572 struct ref_update *update;35733574 if (transaction->state != REF_TRANSACTION_OPEN)3575 die("BUG: delete called for transaction that is not open");35763577 if (have_old && !old_sha1)3578 die("BUG: have_old is true but old_sha1 is NULL");35793580 update = add_update(transaction, refname);3581 update->flags = flags;3582 update->have_old = have_old;3583 if (have_old) {3584 assert(!is_null_sha1(old_sha1));3585 hashcpy(update->old_sha1, old_sha1);3586 }3587 if (msg)3588 update->msg = xstrdup(msg);3589 return 0;3590}35913592int update_ref(const char *action, const char *refname,3593 const unsigned char *sha1, const unsigned char *oldval,3594 int flags, enum action_on_err onerr)3595{3596 struct ref_transaction *t;3597 struct strbuf err = STRBUF_INIT;35983599 t = ref_transaction_begin(&err);3600 if (!t ||3601 ref_transaction_update(t, refname, sha1, oldval, flags,3602 !!oldval, action, &err) ||3603 ref_transaction_commit(t, &err)) {3604 const char *str = "update_ref failed for ref '%s': %s";36053606 ref_transaction_free(t);3607 switch (onerr) {3608 case UPDATE_REFS_MSG_ON_ERR:3609 error(str, refname, err.buf);3610 break;3611 case UPDATE_REFS_DIE_ON_ERR:3612 die(str, refname, err.buf);3613 break;3614 case UPDATE_REFS_QUIET_ON_ERR:3615 break;3616 }3617 strbuf_release(&err);3618 return 1;3619 }3620 strbuf_release(&err);3621 ref_transaction_free(t);3622 return 0;3623}36243625static int ref_update_compare(const void *r1, const void *r2)3626{3627 const struct ref_update * const *u1 = r1;3628 const struct ref_update * const *u2 = r2;3629 return strcmp((*u1)->refname, (*u2)->refname);3630}36313632static int ref_update_reject_duplicates(struct ref_update **updates, int n,3633 struct strbuf *err)3634{3635 int i;3636 for (i = 1; i < n; i++)3637 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {3638 const char *str =3639 "Multiple updates for ref '%s' not allowed.";3640 if (err)3641 strbuf_addf(err, str, updates[i]->refname);36423643 return 1;3644 }3645 return 0;3646}36473648int ref_transaction_commit(struct ref_transaction *transaction,3649 struct strbuf *err)3650{3651 int ret = 0, delnum = 0, i;3652 const char **delnames;3653 int n = transaction->nr;3654 struct ref_update **updates = transaction->updates;36553656 if (transaction->state != REF_TRANSACTION_OPEN)3657 die("BUG: commit called for transaction that is not open");36583659 if (!n) {3660 transaction->state = REF_TRANSACTION_CLOSED;3661 return 0;3662 }36633664 /* Allocate work space */3665 delnames = xmalloc(sizeof(*delnames) * n);36663667 /* Copy, sort, and reject duplicate refs */3668 qsort(updates, n, sizeof(*updates), ref_update_compare);3669 if (ref_update_reject_duplicates(updates, n, err)) {3670 ret = TRANSACTION_GENERIC_ERROR;3671 goto cleanup;3672 }36733674 /* Acquire all locks while verifying old values */3675 for (i = 0; i < n; i++) {3676 struct ref_update *update = updates[i];3677 int flags = update->flags;36783679 if (is_null_sha1(update->new_sha1))3680 flags |= REF_DELETING;3681 update->lock = lock_ref_sha1_basic(update->refname,3682 (update->have_old ?3683 update->old_sha1 :3684 NULL),3685 NULL,3686 flags,3687 &update->type);3688 if (!update->lock) {3689 ret = (errno == ENOTDIR)3690 ? TRANSACTION_NAME_CONFLICT3691 : TRANSACTION_GENERIC_ERROR;3692 if (err)3693 strbuf_addf(err, "Cannot lock the ref '%s'.",3694 update->refname);3695 goto cleanup;3696 }3697 }36983699 /* Perform updates first so live commits remain referenced */3700 for (i = 0; i < n; i++) {3701 struct ref_update *update = updates[i];37023703 if (!is_null_sha1(update->new_sha1)) {3704 if (write_ref_sha1(update->lock, update->new_sha1,3705 update->msg)) {3706 update->lock = NULL; /* freed by write_ref_sha1 */3707 if (err)3708 strbuf_addf(err, "Cannot update the ref '%s'.",3709 update->refname);3710 ret = TRANSACTION_GENERIC_ERROR;3711 goto cleanup;3712 }3713 update->lock = NULL; /* freed by write_ref_sha1 */3714 }3715 }37163717 /* Perform deletes now that updates are safely completed */3718 for (i = 0; i < n; i++) {3719 struct ref_update *update = updates[i];37203721 if (update->lock) {3722 if (delete_ref_loose(update->lock, update->type, err))3723 ret = TRANSACTION_GENERIC_ERROR;37243725 if (!(update->flags & REF_ISPRUNING))3726 delnames[delnum++] = update->lock->ref_name;3727 }3728 }37293730 if (repack_without_refs(delnames, delnum, err))3731 ret = TRANSACTION_GENERIC_ERROR;3732 for (i = 0; i < delnum; i++)3733 unlink_or_warn(git_path("logs/%s", delnames[i]));3734 clear_loose_ref_cache(&ref_cache);37353736cleanup:3737 transaction->state = REF_TRANSACTION_CLOSED;37383739 for (i = 0; i < n; i++)3740 if (updates[i]->lock)3741 unlock_ref(updates[i]->lock);3742 free(delnames);3743 return ret;3744}37453746char *shorten_unambiguous_ref(const char *refname, int strict)3747{3748 int i;3749 static char **scanf_fmts;3750 static int nr_rules;3751 char *short_name;37523753 if (!nr_rules) {3754 /*3755 * Pre-generate scanf formats from ref_rev_parse_rules[].3756 * Generate a format suitable for scanf from a3757 * ref_rev_parse_rules rule by interpolating "%s" at the3758 * location of the "%.*s".3759 */3760 size_t total_len = 0;3761 size_t offset = 0;37623763 /* the rule list is NULL terminated, count them first */3764 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)3765 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3766 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;37673768 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);37693770 offset = 0;3771 for (i = 0; i < nr_rules; i++) {3772 assert(offset < total_len);3773 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;3774 offset += snprintf(scanf_fmts[i], total_len - offset,3775 ref_rev_parse_rules[i], 2, "%s") + 1;3776 }3777 }37783779 /* bail out if there are no rules */3780 if (!nr_rules)3781 return xstrdup(refname);37823783 /* buffer for scanf result, at most refname must fit */3784 short_name = xstrdup(refname);37853786 /* skip first rule, it will always match */3787 for (i = nr_rules - 1; i > 0 ; --i) {3788 int j;3789 int rules_to_fail = i;3790 int short_name_len;37913792 if (1 != sscanf(refname, scanf_fmts[i], short_name))3793 continue;37943795 short_name_len = strlen(short_name);37963797 /*3798 * in strict mode, all (except the matched one) rules3799 * must fail to resolve to a valid non-ambiguous ref3800 */3801 if (strict)3802 rules_to_fail = nr_rules;38033804 /*3805 * check if the short name resolves to a valid ref,3806 * but use only rules prior to the matched one3807 */3808 for (j = 0; j < rules_to_fail; j++) {3809 const char *rule = ref_rev_parse_rules[j];3810 char refname[PATH_MAX];38113812 /* skip matched rule */3813 if (i == j)3814 continue;38153816 /*3817 * the short name is ambiguous, if it resolves3818 * (with this previous rule) to a valid ref3819 * read_ref() returns 0 on success3820 */3821 mksnpath(refname, sizeof(refname),3822 rule, short_name_len, short_name);3823 if (ref_exists(refname))3824 break;3825 }38263827 /*3828 * short name is non-ambiguous if all previous rules3829 * haven't resolved to a valid ref3830 */3831 if (j == rules_to_fail)3832 return short_name;3833 }38343835 free(short_name);3836 return xstrdup(refname);3837}38383839static struct string_list *hide_refs;38403841int parse_hide_refs_config(const char *var, const char *value, const char *section)3842{3843 if (!strcmp("transfer.hiderefs", var) ||3844 /* NEEDSWORK: use parse_config_key() once both are merged */3845 (starts_with(var, section) && var[strlen(section)] == '.' &&3846 !strcmp(var + strlen(section), ".hiderefs"))) {3847 char *ref;3848 int len;38493850 if (!value)3851 return config_error_nonbool(var);3852 ref = xstrdup(value);3853 len = strlen(ref);3854 while (len && ref[len - 1] == '/')3855 ref[--len] = '\0';3856 if (!hide_refs) {3857 hide_refs = xcalloc(1, sizeof(*hide_refs));3858 hide_refs->strdup_strings = 1;3859 }3860 string_list_append(hide_refs, ref);3861 }3862 return 0;3863}38643865int ref_is_hidden(const char *refname)3866{3867 struct string_list_item *item;38683869 if (!hide_refs)3870 return 0;3871 for_each_string_list_item(item, hide_refs) {3872 int len;3873 if (!starts_with(refname, item->string))3874 continue;3875 len = strlen(item->string);3876 if (!refname[len] || refname[len] == '/')3877 return 1;3878 }3879 return 0;3880}