1#include "cache.h" 2#include "lockfile.h" 3#include "refs.h" 4#include "object.h" 5#include "tag.h" 6#include "dir.h" 7#include "string-list.h" 8 9/* 10 * How to handle various characters in refnames: 11 * 0: An acceptable character for refs 12 * 1: End-of-component 13 * 2: ., look for a preceding . to reject .. in refs 14 * 3: {, look for a preceding @ to reject @{ in refs 15 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 16 */ 17static unsigned char refname_disposition[256] = { 18 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 19 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 20 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1, 21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0, 24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 26}; 27 28/* 29 * Used as a flag to ref_transaction_delete when a loose ref is being 30 * pruned. 31 */ 32#define REF_ISPRUNING 0x0100 33/* 34 * Try to read one refname component from the front of refname. 35 * Return the length of the component found, or -1 if the component is 36 * not legal. It is legal if it is something reasonable to have under 37 * ".git/refs/"; We do not like it if: 38 * 39 * - any path component of it begins with ".", or 40 * - it has double dots "..", or 41 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 42 * - it ends with a "/". 43 * - it ends with ".lock" 44 * - it contains a "\" (backslash) 45 */ 46static int check_refname_component(const char *refname, int flags) 47{ 48 const char *cp; 49 char last = '\0'; 50 51 for (cp = refname; ; cp++) { 52 int ch = *cp & 255; 53 unsigned char disp = refname_disposition[ch]; 54 switch (disp) { 55 case 1: 56 goto out; 57 case 2: 58 if (last == '.') 59 return -1; /* Refname contains "..". */ 60 break; 61 case 3: 62 if (last == '@') 63 return -1; /* Refname contains "@{". */ 64 break; 65 case 4: 66 return -1; 67 } 68 last = ch; 69 } 70out: 71 if (cp == refname) 72 return 0; /* Component has zero length. */ 73 if (refname[0] == '.') 74 return -1; /* Component starts with '.'. */ 75 if (cp - refname >= LOCK_SUFFIX_LEN && 76 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 77 return -1; /* Refname ends with ".lock". */ 78 return cp - refname; 79} 80 81int check_refname_format(const char *refname, int flags) 82{ 83 int component_len, component_count = 0; 84 85 if (!strcmp(refname, "@")) 86 /* Refname is a single character '@'. */ 87 return -1; 88 89 while (1) { 90 /* We are at the start of a path component. */ 91 component_len = check_refname_component(refname, flags); 92 if (component_len <= 0) { 93 if ((flags & REFNAME_REFSPEC_PATTERN) && 94 refname[0] == '*' && 95 (refname[1] == '\0' || refname[1] == '/')) { 96 /* Accept one wildcard as a full refname component. */ 97 flags &= ~REFNAME_REFSPEC_PATTERN; 98 component_len = 1; 99 } else { 100 return -1; 101 } 102 } 103 component_count++; 104 if (refname[component_len] == '\0') 105 break; 106 /* Skip to next component. */ 107 refname += component_len + 1; 108 } 109 110 if (refname[component_len - 1] == '.') 111 return -1; /* Refname ends with '.'. */ 112 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) 113 return -1; /* Refname has only one component. */ 114 return 0; 115} 116 117struct ref_entry; 118 119/* 120 * Information used (along with the information in ref_entry) to 121 * describe a single cached reference. This data structure only 122 * occurs embedded in a union in struct ref_entry, and only when 123 * (ref_entry->flag & REF_DIR) is zero. 124 */ 125struct ref_value { 126 /* 127 * The name of the object to which this reference resolves 128 * (which may be a tag object). If REF_ISBROKEN, this is 129 * null. If REF_ISSYMREF, then this is the name of the object 130 * referred to by the last reference in the symlink chain. 131 */ 132 unsigned char sha1[20]; 133 134 /* 135 * If REF_KNOWS_PEELED, then this field holds the peeled value 136 * of this reference, or null if the reference is known not to 137 * be peelable. See the documentation for peel_ref() for an 138 * exact definition of "peelable". 139 */ 140 unsigned char peeled[20]; 141}; 142 143struct ref_cache; 144 145/* 146 * Information used (along with the information in ref_entry) to 147 * describe a level in the hierarchy of references. This data 148 * structure only occurs embedded in a union in struct ref_entry, and 149 * only when (ref_entry.flag & REF_DIR) is set. In that case, 150 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 151 * in the directory have already been read: 152 * 153 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 154 * or packed references, already read. 155 * 156 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 157 * references that hasn't been read yet (nor has any of its 158 * subdirectories). 159 * 160 * Entries within a directory are stored within a growable array of 161 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 162 * sorted are sorted by their component name in strcmp() order and the 163 * remaining entries are unsorted. 164 * 165 * Loose references are read lazily, one directory at a time. When a 166 * directory of loose references is read, then all of the references 167 * in that directory are stored, and REF_INCOMPLETE stubs are created 168 * for any subdirectories, but the subdirectories themselves are not 169 * read. The reading is triggered by get_ref_dir(). 170 */ 171struct ref_dir { 172 int nr, alloc; 173 174 /* 175 * Entries with index 0 <= i < sorted are sorted by name. New 176 * entries are appended to the list unsorted, and are sorted 177 * only when required; thus we avoid the need to sort the list 178 * after the addition of every reference. 179 */ 180 int sorted; 181 182 /* A pointer to the ref_cache that contains this ref_dir. */ 183 struct ref_cache *ref_cache; 184 185 struct ref_entry **entries; 186}; 187 188/* 189 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 190 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 191 * public values; see refs.h. 192 */ 193 194/* 195 * The field ref_entry->u.value.peeled of this value entry contains 196 * the correct peeled value for the reference, which might be 197 * null_sha1 if the reference is not a tag or if it is broken. 198 */ 199#define REF_KNOWS_PEELED 0x10 200 201/* ref_entry represents a directory of references */ 202#define REF_DIR 0x20 203 204/* 205 * Entry has not yet been read from disk (used only for REF_DIR 206 * entries representing loose references) 207 */ 208#define REF_INCOMPLETE 0x40 209 210/* 211 * A ref_entry represents either a reference or a "subdirectory" of 212 * references. 213 * 214 * Each directory in the reference namespace is represented by a 215 * ref_entry with (flags & REF_DIR) set and containing a subdir member 216 * that holds the entries in that directory that have been read so 217 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 218 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 219 * used for loose reference directories. 220 * 221 * References are represented by a ref_entry with (flags & REF_DIR) 222 * unset and a value member that describes the reference's value. The 223 * flag member is at the ref_entry level, but it is also needed to 224 * interpret the contents of the value field (in other words, a 225 * ref_value object is not very much use without the enclosing 226 * ref_entry). 227 * 228 * Reference names cannot end with slash and directories' names are 229 * always stored with a trailing slash (except for the top-level 230 * directory, which is always denoted by ""). This has two nice 231 * consequences: (1) when the entries in each subdir are sorted 232 * lexicographically by name (as they usually are), the references in 233 * a whole tree can be generated in lexicographic order by traversing 234 * the tree in left-to-right, depth-first order; (2) the names of 235 * references and subdirectories cannot conflict, and therefore the 236 * presence of an empty subdirectory does not block the creation of a 237 * similarly-named reference. (The fact that reference names with the 238 * same leading components can conflict *with each other* is a 239 * separate issue that is regulated by is_refname_available().) 240 * 241 * Please note that the name field contains the fully-qualified 242 * reference (or subdirectory) name. Space could be saved by only 243 * storing the relative names. But that would require the full names 244 * to be generated on the fly when iterating in do_for_each_ref(), and 245 * would break callback functions, who have always been able to assume 246 * that the name strings that they are passed will not be freed during 247 * the iteration. 248 */ 249struct ref_entry { 250 unsigned char flag; /* ISSYMREF? ISPACKED? */ 251 union { 252 struct ref_value value; /* if not (flags&REF_DIR) */ 253 struct ref_dir subdir; /* if (flags&REF_DIR) */ 254 } u; 255 /* 256 * The full name of the reference (e.g., "refs/heads/master") 257 * or the full name of the directory with a trailing slash 258 * (e.g., "refs/heads/"): 259 */ 260 char name[FLEX_ARRAY]; 261}; 262 263static void read_loose_refs(const char *dirname, struct ref_dir *dir); 264 265static struct ref_dir *get_ref_dir(struct ref_entry *entry) 266{ 267 struct ref_dir *dir; 268 assert(entry->flag & REF_DIR); 269 dir = &entry->u.subdir; 270 if (entry->flag & REF_INCOMPLETE) { 271 read_loose_refs(entry->name, dir); 272 entry->flag &= ~REF_INCOMPLETE; 273 } 274 return dir; 275} 276 277/* 278 * Check if a refname is safe. 279 * For refs that start with "refs/" we consider it safe as long they do 280 * not try to resolve to outside of refs/. 281 * 282 * For all other refs we only consider them safe iff they only contain 283 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like 284 * "config"). 285 */ 286static int refname_is_safe(const char *refname) 287{ 288 if (starts_with(refname, "refs/")) { 289 char *buf; 290 int result; 291 292 buf = xmalloc(strlen(refname) + 1); 293 /* 294 * Does the refname try to escape refs/? 295 * For example: refs/foo/../bar is safe but refs/foo/../../bar 296 * is not. 297 */ 298 result = !normalize_path_copy(buf, refname + strlen("refs/")); 299 free(buf); 300 return result; 301 } 302 while (*refname) { 303 if (!isupper(*refname) && *refname != '_') 304 return 0; 305 refname++; 306 } 307 return 1; 308} 309 310static struct ref_entry *create_ref_entry(const char *refname, 311 const unsigned char *sha1, int flag, 312 int check_name) 313{ 314 int len; 315 struct ref_entry *ref; 316 317 if (check_name && 318 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 319 die("Reference has invalid format: '%s'", refname); 320 if (!check_name && !refname_is_safe(refname)) 321 die("Reference has invalid name: '%s'", refname); 322 len = strlen(refname) + 1; 323 ref = xmalloc(sizeof(struct ref_entry) + len); 324 hashcpy(ref->u.value.sha1, sha1); 325 hashclr(ref->u.value.peeled); 326 memcpy(ref->name, refname, len); 327 ref->flag = flag; 328 return ref; 329} 330 331static void clear_ref_dir(struct ref_dir *dir); 332 333static void free_ref_entry(struct ref_entry *entry) 334{ 335 if (entry->flag & REF_DIR) { 336 /* 337 * Do not use get_ref_dir() here, as that might 338 * trigger the reading of loose refs. 339 */ 340 clear_ref_dir(&entry->u.subdir); 341 } 342 free(entry); 343} 344 345/* 346 * Add a ref_entry to the end of dir (unsorted). Entry is always 347 * stored directly in dir; no recursion into subdirectories is 348 * done. 349 */ 350static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 351{ 352 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 353 dir->entries[dir->nr++] = entry; 354 /* optimize for the case that entries are added in order */ 355 if (dir->nr == 1 || 356 (dir->nr == dir->sorted + 1 && 357 strcmp(dir->entries[dir->nr - 2]->name, 358 dir->entries[dir->nr - 1]->name) < 0)) 359 dir->sorted = dir->nr; 360} 361 362/* 363 * Clear and free all entries in dir, recursively. 364 */ 365static void clear_ref_dir(struct ref_dir *dir) 366{ 367 int i; 368 for (i = 0; i < dir->nr; i++) 369 free_ref_entry(dir->entries[i]); 370 free(dir->entries); 371 dir->sorted = dir->nr = dir->alloc = 0; 372 dir->entries = NULL; 373} 374 375/* 376 * Create a struct ref_entry object for the specified dirname. 377 * dirname is the name of the directory with a trailing slash (e.g., 378 * "refs/heads/") or "" for the top-level directory. 379 */ 380static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 381 const char *dirname, size_t len, 382 int incomplete) 383{ 384 struct ref_entry *direntry; 385 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); 386 memcpy(direntry->name, dirname, len); 387 direntry->name[len] = '\0'; 388 direntry->u.subdir.ref_cache = ref_cache; 389 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 390 return direntry; 391} 392 393static int ref_entry_cmp(const void *a, const void *b) 394{ 395 struct ref_entry *one = *(struct ref_entry **)a; 396 struct ref_entry *two = *(struct ref_entry **)b; 397 return strcmp(one->name, two->name); 398} 399 400static void sort_ref_dir(struct ref_dir *dir); 401 402struct string_slice { 403 size_t len; 404 const char *str; 405}; 406 407static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 408{ 409 const struct string_slice *key = key_; 410 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 411 int cmp = strncmp(key->str, ent->name, key->len); 412 if (cmp) 413 return cmp; 414 return '\0' - (unsigned char)ent->name[key->len]; 415} 416 417/* 418 * Return the index of the entry with the given refname from the 419 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 420 * no such entry is found. dir must already be complete. 421 */ 422static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 423{ 424 struct ref_entry **r; 425 struct string_slice key; 426 427 if (refname == NULL || !dir->nr) 428 return -1; 429 430 sort_ref_dir(dir); 431 key.len = len; 432 key.str = refname; 433 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 434 ref_entry_cmp_sslice); 435 436 if (r == NULL) 437 return -1; 438 439 return r - dir->entries; 440} 441 442/* 443 * Search for a directory entry directly within dir (without 444 * recursing). Sort dir if necessary. subdirname must be a directory 445 * name (i.e., end in '/'). If mkdir is set, then create the 446 * directory if it is missing; otherwise, return NULL if the desired 447 * directory cannot be found. dir must already be complete. 448 */ 449static struct ref_dir *search_for_subdir(struct ref_dir *dir, 450 const char *subdirname, size_t len, 451 int mkdir) 452{ 453 int entry_index = search_ref_dir(dir, subdirname, len); 454 struct ref_entry *entry; 455 if (entry_index == -1) { 456 if (!mkdir) 457 return NULL; 458 /* 459 * Since dir is complete, the absence of a subdir 460 * means that the subdir really doesn't exist; 461 * therefore, create an empty record for it but mark 462 * the record complete. 463 */ 464 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 465 add_entry_to_dir(dir, entry); 466 } else { 467 entry = dir->entries[entry_index]; 468 } 469 return get_ref_dir(entry); 470} 471 472/* 473 * If refname is a reference name, find the ref_dir within the dir 474 * tree that should hold refname. If refname is a directory name 475 * (i.e., ends in '/'), then return that ref_dir itself. dir must 476 * represent the top-level directory and must already be complete. 477 * Sort ref_dirs and recurse into subdirectories as necessary. If 478 * mkdir is set, then create any missing directories; otherwise, 479 * return NULL if the desired directory cannot be found. 480 */ 481static struct ref_dir *find_containing_dir(struct ref_dir *dir, 482 const char *refname, int mkdir) 483{ 484 const char *slash; 485 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 486 size_t dirnamelen = slash - refname + 1; 487 struct ref_dir *subdir; 488 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 489 if (!subdir) { 490 dir = NULL; 491 break; 492 } 493 dir = subdir; 494 } 495 496 return dir; 497} 498 499/* 500 * Find the value entry with the given name in dir, sorting ref_dirs 501 * and recursing into subdirectories as necessary. If the name is not 502 * found or it corresponds to a directory entry, return NULL. 503 */ 504static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 505{ 506 int entry_index; 507 struct ref_entry *entry; 508 dir = find_containing_dir(dir, refname, 0); 509 if (!dir) 510 return NULL; 511 entry_index = search_ref_dir(dir, refname, strlen(refname)); 512 if (entry_index == -1) 513 return NULL; 514 entry = dir->entries[entry_index]; 515 return (entry->flag & REF_DIR) ? NULL : entry; 516} 517 518/* 519 * Remove the entry with the given name from dir, recursing into 520 * subdirectories as necessary. If refname is the name of a directory 521 * (i.e., ends with '/'), then remove the directory and its contents. 522 * If the removal was successful, return the number of entries 523 * remaining in the directory entry that contained the deleted entry. 524 * If the name was not found, return -1. Please note that this 525 * function only deletes the entry from the cache; it does not delete 526 * it from the filesystem or ensure that other cache entries (which 527 * might be symbolic references to the removed entry) are updated. 528 * Nor does it remove any containing dir entries that might be made 529 * empty by the removal. dir must represent the top-level directory 530 * and must already be complete. 531 */ 532static int remove_entry(struct ref_dir *dir, const char *refname) 533{ 534 int refname_len = strlen(refname); 535 int entry_index; 536 struct ref_entry *entry; 537 int is_dir = refname[refname_len - 1] == '/'; 538 if (is_dir) { 539 /* 540 * refname represents a reference directory. Remove 541 * the trailing slash; otherwise we will get the 542 * directory *representing* refname rather than the 543 * one *containing* it. 544 */ 545 char *dirname = xmemdupz(refname, refname_len - 1); 546 dir = find_containing_dir(dir, dirname, 0); 547 free(dirname); 548 } else { 549 dir = find_containing_dir(dir, refname, 0); 550 } 551 if (!dir) 552 return -1; 553 entry_index = search_ref_dir(dir, refname, refname_len); 554 if (entry_index == -1) 555 return -1; 556 entry = dir->entries[entry_index]; 557 558 memmove(&dir->entries[entry_index], 559 &dir->entries[entry_index + 1], 560 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 561 ); 562 dir->nr--; 563 if (dir->sorted > entry_index) 564 dir->sorted--; 565 free_ref_entry(entry); 566 return dir->nr; 567} 568 569/* 570 * Add a ref_entry to the ref_dir (unsorted), recursing into 571 * subdirectories as necessary. dir must represent the top-level 572 * directory. Return 0 on success. 573 */ 574static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 575{ 576 dir = find_containing_dir(dir, ref->name, 1); 577 if (!dir) 578 return -1; 579 add_entry_to_dir(dir, ref); 580 return 0; 581} 582 583/* 584 * Emit a warning and return true iff ref1 and ref2 have the same name 585 * and the same sha1. Die if they have the same name but different 586 * sha1s. 587 */ 588static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 589{ 590 if (strcmp(ref1->name, ref2->name)) 591 return 0; 592 593 /* Duplicate name; make sure that they don't conflict: */ 594 595 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 596 /* This is impossible by construction */ 597 die("Reference directory conflict: %s", ref1->name); 598 599 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 600 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 601 602 warning("Duplicated ref: %s", ref1->name); 603 return 1; 604} 605 606/* 607 * Sort the entries in dir non-recursively (if they are not already 608 * sorted) and remove any duplicate entries. 609 */ 610static void sort_ref_dir(struct ref_dir *dir) 611{ 612 int i, j; 613 struct ref_entry *last = NULL; 614 615 /* 616 * This check also prevents passing a zero-length array to qsort(), 617 * which is a problem on some platforms. 618 */ 619 if (dir->sorted == dir->nr) 620 return; 621 622 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 623 624 /* Remove any duplicates: */ 625 for (i = 0, j = 0; j < dir->nr; j++) { 626 struct ref_entry *entry = dir->entries[j]; 627 if (last && is_dup_ref(last, entry)) 628 free_ref_entry(entry); 629 else 630 last = dir->entries[i++] = entry; 631 } 632 dir->sorted = dir->nr = i; 633} 634 635/* Include broken references in a do_for_each_ref*() iteration: */ 636#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 637 638/* 639 * Return true iff the reference described by entry can be resolved to 640 * an object in the database. Emit a warning if the referred-to 641 * object does not exist. 642 */ 643static int ref_resolves_to_object(struct ref_entry *entry) 644{ 645 if (entry->flag & REF_ISBROKEN) 646 return 0; 647 if (!has_sha1_file(entry->u.value.sha1)) { 648 error("%s does not point to a valid object!", entry->name); 649 return 0; 650 } 651 return 1; 652} 653 654/* 655 * current_ref is a performance hack: when iterating over references 656 * using the for_each_ref*() functions, current_ref is set to the 657 * current reference's entry before calling the callback function. If 658 * the callback function calls peel_ref(), then peel_ref() first 659 * checks whether the reference to be peeled is the current reference 660 * (it usually is) and if so, returns that reference's peeled version 661 * if it is available. This avoids a refname lookup in a common case. 662 */ 663static struct ref_entry *current_ref; 664 665typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 666 667struct ref_entry_cb { 668 const char *base; 669 int trim; 670 int flags; 671 each_ref_fn *fn; 672 void *cb_data; 673}; 674 675/* 676 * Handle one reference in a do_for_each_ref*()-style iteration, 677 * calling an each_ref_fn for each entry. 678 */ 679static int do_one_ref(struct ref_entry *entry, void *cb_data) 680{ 681 struct ref_entry_cb *data = cb_data; 682 struct ref_entry *old_current_ref; 683 int retval; 684 685 if (!starts_with(entry->name, data->base)) 686 return 0; 687 688 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 689 !ref_resolves_to_object(entry)) 690 return 0; 691 692 /* Store the old value, in case this is a recursive call: */ 693 old_current_ref = current_ref; 694 current_ref = entry; 695 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 696 entry->flag, data->cb_data); 697 current_ref = old_current_ref; 698 return retval; 699} 700 701/* 702 * Call fn for each reference in dir that has index in the range 703 * offset <= index < dir->nr. Recurse into subdirectories that are in 704 * that index range, sorting them before iterating. This function 705 * does not sort dir itself; it should be sorted beforehand. fn is 706 * called for all references, including broken ones. 707 */ 708static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 709 each_ref_entry_fn fn, void *cb_data) 710{ 711 int i; 712 assert(dir->sorted == dir->nr); 713 for (i = offset; i < dir->nr; i++) { 714 struct ref_entry *entry = dir->entries[i]; 715 int retval; 716 if (entry->flag & REF_DIR) { 717 struct ref_dir *subdir = get_ref_dir(entry); 718 sort_ref_dir(subdir); 719 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 720 } else { 721 retval = fn(entry, cb_data); 722 } 723 if (retval) 724 return retval; 725 } 726 return 0; 727} 728 729/* 730 * Call fn for each reference in the union of dir1 and dir2, in order 731 * by refname. Recurse into subdirectories. If a value entry appears 732 * in both dir1 and dir2, then only process the version that is in 733 * dir2. The input dirs must already be sorted, but subdirs will be 734 * sorted as needed. fn is called for all references, including 735 * broken ones. 736 */ 737static int do_for_each_entry_in_dirs(struct ref_dir *dir1, 738 struct ref_dir *dir2, 739 each_ref_entry_fn fn, void *cb_data) 740{ 741 int retval; 742 int i1 = 0, i2 = 0; 743 744 assert(dir1->sorted == dir1->nr); 745 assert(dir2->sorted == dir2->nr); 746 while (1) { 747 struct ref_entry *e1, *e2; 748 int cmp; 749 if (i1 == dir1->nr) { 750 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 751 } 752 if (i2 == dir2->nr) { 753 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 754 } 755 e1 = dir1->entries[i1]; 756 e2 = dir2->entries[i2]; 757 cmp = strcmp(e1->name, e2->name); 758 if (cmp == 0) { 759 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 760 /* Both are directories; descend them in parallel. */ 761 struct ref_dir *subdir1 = get_ref_dir(e1); 762 struct ref_dir *subdir2 = get_ref_dir(e2); 763 sort_ref_dir(subdir1); 764 sort_ref_dir(subdir2); 765 retval = do_for_each_entry_in_dirs( 766 subdir1, subdir2, fn, cb_data); 767 i1++; 768 i2++; 769 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 770 /* Both are references; ignore the one from dir1. */ 771 retval = fn(e2, cb_data); 772 i1++; 773 i2++; 774 } else { 775 die("conflict between reference and directory: %s", 776 e1->name); 777 } 778 } else { 779 struct ref_entry *e; 780 if (cmp < 0) { 781 e = e1; 782 i1++; 783 } else { 784 e = e2; 785 i2++; 786 } 787 if (e->flag & REF_DIR) { 788 struct ref_dir *subdir = get_ref_dir(e); 789 sort_ref_dir(subdir); 790 retval = do_for_each_entry_in_dir( 791 subdir, 0, fn, cb_data); 792 } else { 793 retval = fn(e, cb_data); 794 } 795 } 796 if (retval) 797 return retval; 798 } 799} 800 801/* 802 * Load all of the refs from the dir into our in-memory cache. The hard work 803 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 804 * through all of the sub-directories. We do not even need to care about 805 * sorting, as traversal order does not matter to us. 806 */ 807static void prime_ref_dir(struct ref_dir *dir) 808{ 809 int i; 810 for (i = 0; i < dir->nr; i++) { 811 struct ref_entry *entry = dir->entries[i]; 812 if (entry->flag & REF_DIR) 813 prime_ref_dir(get_ref_dir(entry)); 814 } 815} 816 817static int entry_matches(struct ref_entry *entry, const struct string_list *list) 818{ 819 return list && string_list_has_string(list, entry->name); 820} 821 822struct nonmatching_ref_data { 823 const struct string_list *skip; 824 struct ref_entry *found; 825}; 826 827static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) 828{ 829 struct nonmatching_ref_data *data = vdata; 830 831 if (entry_matches(entry, data->skip)) 832 return 0; 833 834 data->found = entry; 835 return 1; 836} 837 838static void report_refname_conflict(struct ref_entry *entry, 839 const char *refname) 840{ 841 error("'%s' exists; cannot create '%s'", entry->name, refname); 842} 843 844/* 845 * Return true iff a reference named refname could be created without 846 * conflicting with the name of an existing reference in dir. If 847 * skip is non-NULL, ignore potential conflicts with refs in skip 848 * (e.g., because they are scheduled for deletion in the same 849 * operation). 850 * 851 * Two reference names conflict if one of them exactly matches the 852 * leading components of the other; e.g., "foo/bar" conflicts with 853 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 854 * "foo/barbados". 855 * 856 * skip must be sorted. 857 */ 858static int is_refname_available(const char *refname, 859 const struct string_list *skip, 860 struct ref_dir *dir) 861{ 862 const char *slash; 863 size_t len; 864 int pos; 865 char *dirname; 866 867 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 868 /* 869 * We are still at a leading dir of the refname; we are 870 * looking for a conflict with a leaf entry. 871 * 872 * If we find one, we still must make sure it is 873 * not in "skip". 874 */ 875 pos = search_ref_dir(dir, refname, slash - refname); 876 if (pos >= 0) { 877 struct ref_entry *entry = dir->entries[pos]; 878 if (entry_matches(entry, skip)) 879 return 1; 880 report_refname_conflict(entry, refname); 881 return 0; 882 } 883 884 885 /* 886 * Otherwise, we can try to continue our search with 887 * the next component; if we come up empty, we know 888 * there is nothing under this whole prefix. 889 */ 890 pos = search_ref_dir(dir, refname, slash + 1 - refname); 891 if (pos < 0) 892 return 1; 893 894 dir = get_ref_dir(dir->entries[pos]); 895 } 896 897 /* 898 * We are at the leaf of our refname; we want to 899 * make sure there are no directories which match it. 900 */ 901 len = strlen(refname); 902 dirname = xmallocz(len + 1); 903 sprintf(dirname, "%s/", refname); 904 pos = search_ref_dir(dir, dirname, len + 1); 905 free(dirname); 906 907 if (pos >= 0) { 908 /* 909 * We found a directory named "refname". It is a 910 * problem iff it contains any ref that is not 911 * in "skip". 912 */ 913 struct ref_entry *entry = dir->entries[pos]; 914 struct ref_dir *dir = get_ref_dir(entry); 915 struct nonmatching_ref_data data; 916 917 data.skip = skip; 918 sort_ref_dir(dir); 919 if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) 920 return 1; 921 922 report_refname_conflict(data.found, refname); 923 return 0; 924 } 925 926 /* 927 * There is no point in searching for another leaf 928 * node which matches it; such an entry would be the 929 * ref we are looking for, not a conflict. 930 */ 931 return 1; 932} 933 934struct packed_ref_cache { 935 struct ref_entry *root; 936 937 /* 938 * Count of references to the data structure in this instance, 939 * including the pointer from ref_cache::packed if any. The 940 * data will not be freed as long as the reference count is 941 * nonzero. 942 */ 943 unsigned int referrers; 944 945 /* 946 * Iff the packed-refs file associated with this instance is 947 * currently locked for writing, this points at the associated 948 * lock (which is owned by somebody else). The referrer count 949 * is also incremented when the file is locked and decremented 950 * when it is unlocked. 951 */ 952 struct lock_file *lock; 953 954 /* The metadata from when this packed-refs cache was read */ 955 struct stat_validity validity; 956}; 957 958/* 959 * Future: need to be in "struct repository" 960 * when doing a full libification. 961 */ 962static struct ref_cache { 963 struct ref_cache *next; 964 struct ref_entry *loose; 965 struct packed_ref_cache *packed; 966 /* 967 * The submodule name, or "" for the main repo. We allocate 968 * length 1 rather than FLEX_ARRAY so that the main ref_cache 969 * is initialized correctly. 970 */ 971 char name[1]; 972} ref_cache, *submodule_ref_caches; 973 974/* Lock used for the main packed-refs file: */ 975static struct lock_file packlock; 976 977/* 978 * Increment the reference count of *packed_refs. 979 */ 980static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 981{ 982 packed_refs->referrers++; 983} 984 985/* 986 * Decrease the reference count of *packed_refs. If it goes to zero, 987 * free *packed_refs and return true; otherwise return false. 988 */ 989static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 990{ 991 if (!--packed_refs->referrers) { 992 free_ref_entry(packed_refs->root); 993 stat_validity_clear(&packed_refs->validity); 994 free(packed_refs); 995 return 1; 996 } else { 997 return 0; 998 } 999}10001001static void clear_packed_ref_cache(struct ref_cache *refs)1002{1003 if (refs->packed) {1004 struct packed_ref_cache *packed_refs = refs->packed;10051006 if (packed_refs->lock)1007 die("internal error: packed-ref cache cleared while locked");1008 refs->packed = NULL;1009 release_packed_ref_cache(packed_refs);1010 }1011}10121013static void clear_loose_ref_cache(struct ref_cache *refs)1014{1015 if (refs->loose) {1016 free_ref_entry(refs->loose);1017 refs->loose = NULL;1018 }1019}10201021static struct ref_cache *create_ref_cache(const char *submodule)1022{1023 int len;1024 struct ref_cache *refs;1025 if (!submodule)1026 submodule = "";1027 len = strlen(submodule) + 1;1028 refs = xcalloc(1, sizeof(struct ref_cache) + len);1029 memcpy(refs->name, submodule, len);1030 return refs;1031}10321033/*1034 * Return a pointer to a ref_cache for the specified submodule. For1035 * the main repository, use submodule==NULL. The returned structure1036 * will be allocated and initialized but not necessarily populated; it1037 * should not be freed.1038 */1039static struct ref_cache *get_ref_cache(const char *submodule)1040{1041 struct ref_cache *refs;10421043 if (!submodule || !*submodule)1044 return &ref_cache;10451046 for (refs = submodule_ref_caches; refs; refs = refs->next)1047 if (!strcmp(submodule, refs->name))1048 return refs;10491050 refs = create_ref_cache(submodule);1051 refs->next = submodule_ref_caches;1052 submodule_ref_caches = refs;1053 return refs;1054}10551056/* The length of a peeled reference line in packed-refs, including EOL: */1057#define PEELED_LINE_LENGTH 4210581059/*1060 * The packed-refs header line that we write out. Perhaps other1061 * traits will be added later. The trailing space is required.1062 */1063static const char PACKED_REFS_HEADER[] =1064 "# pack-refs with: peeled fully-peeled \n";10651066/*1067 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1068 * Return a pointer to the refname within the line (null-terminated),1069 * or NULL if there was a problem.1070 */1071static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)1072{1073 const char *ref;10741075 /*1076 * 42: the answer to everything.1077 *1078 * In this case, it happens to be the answer to1079 * 40 (length of sha1 hex representation)1080 * +1 (space in between hex and name)1081 * +1 (newline at the end of the line)1082 */1083 if (line->len <= 42)1084 return NULL;10851086 if (get_sha1_hex(line->buf, sha1) < 0)1087 return NULL;1088 if (!isspace(line->buf[40]))1089 return NULL;10901091 ref = line->buf + 41;1092 if (isspace(*ref))1093 return NULL;10941095 if (line->buf[line->len - 1] != '\n')1096 return NULL;1097 line->buf[--line->len] = 0;10981099 return ref;1100}11011102/*1103 * Read f, which is a packed-refs file, into dir.1104 *1105 * A comment line of the form "# pack-refs with: " may contain zero or1106 * more traits. We interpret the traits as follows:1107 *1108 * No traits:1109 *1110 * Probably no references are peeled. But if the file contains a1111 * peeled value for a reference, we will use it.1112 *1113 * peeled:1114 *1115 * References under "refs/tags/", if they *can* be peeled, *are*1116 * peeled in this file. References outside of "refs/tags/" are1117 * probably not peeled even if they could have been, but if we find1118 * a peeled value for such a reference we will use it.1119 *1120 * fully-peeled:1121 *1122 * All references in the file that can be peeled are peeled.1123 * Inversely (and this is more important), any references in the1124 * file for which no peeled value is recorded is not peelable. This1125 * trait should typically be written alongside "peeled" for1126 * compatibility with older clients, but we do not require it1127 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1128 */1129static void read_packed_refs(FILE *f, struct ref_dir *dir)1130{1131 struct ref_entry *last = NULL;1132 struct strbuf line = STRBUF_INIT;1133 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11341135 while (strbuf_getwholeline(&line, f, '\n') != EOF) {1136 unsigned char sha1[20];1137 const char *refname;1138 const char *traits;11391140 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {1141 if (strstr(traits, " fully-peeled "))1142 peeled = PEELED_FULLY;1143 else if (strstr(traits, " peeled "))1144 peeled = PEELED_TAGS;1145 /* perhaps other traits later as well */1146 continue;1147 }11481149 refname = parse_ref_line(&line, sha1);1150 if (refname) {1151 int flag = REF_ISPACKED;11521153 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1154 hashclr(sha1);1155 flag |= REF_BAD_NAME | REF_ISBROKEN;1156 }1157 last = create_ref_entry(refname, sha1, flag, 0);1158 if (peeled == PEELED_FULLY ||1159 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1160 last->flag |= REF_KNOWS_PEELED;1161 add_ref(dir, last);1162 continue;1163 }1164 if (last &&1165 line.buf[0] == '^' &&1166 line.len == PEELED_LINE_LENGTH &&1167 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&1168 !get_sha1_hex(line.buf + 1, sha1)) {1169 hashcpy(last->u.value.peeled, sha1);1170 /*1171 * Regardless of what the file header said,1172 * we definitely know the value of *this*1173 * reference:1174 */1175 last->flag |= REF_KNOWS_PEELED;1176 }1177 }11781179 strbuf_release(&line);1180}11811182/*1183 * Get the packed_ref_cache for the specified ref_cache, creating it1184 * if necessary.1185 */1186static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1187{1188 const char *packed_refs_file;11891190 if (*refs->name)1191 packed_refs_file = git_path_submodule(refs->name, "packed-refs");1192 else1193 packed_refs_file = git_path("packed-refs");11941195 if (refs->packed &&1196 !stat_validity_check(&refs->packed->validity, packed_refs_file))1197 clear_packed_ref_cache(refs);11981199 if (!refs->packed) {1200 FILE *f;12011202 refs->packed = xcalloc(1, sizeof(*refs->packed));1203 acquire_packed_ref_cache(refs->packed);1204 refs->packed->root = create_dir_entry(refs, "", 0, 0);1205 f = fopen(packed_refs_file, "r");1206 if (f) {1207 stat_validity_update(&refs->packed->validity, fileno(f));1208 read_packed_refs(f, get_ref_dir(refs->packed->root));1209 fclose(f);1210 }1211 }1212 return refs->packed;1213}12141215static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1216{1217 return get_ref_dir(packed_ref_cache->root);1218}12191220static struct ref_dir *get_packed_refs(struct ref_cache *refs)1221{1222 return get_packed_ref_dir(get_packed_ref_cache(refs));1223}12241225void add_packed_ref(const char *refname, const unsigned char *sha1)1226{1227 struct packed_ref_cache *packed_ref_cache =1228 get_packed_ref_cache(&ref_cache);12291230 if (!packed_ref_cache->lock)1231 die("internal error: packed refs not locked");1232 add_ref(get_packed_ref_dir(packed_ref_cache),1233 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1234}12351236/*1237 * Read the loose references from the namespace dirname into dir1238 * (without recursing). dirname must end with '/'. dir must be the1239 * directory entry corresponding to dirname.1240 */1241static void read_loose_refs(const char *dirname, struct ref_dir *dir)1242{1243 struct ref_cache *refs = dir->ref_cache;1244 DIR *d;1245 const char *path;1246 struct dirent *de;1247 int dirnamelen = strlen(dirname);1248 struct strbuf refname;12491250 if (*refs->name)1251 path = git_path_submodule(refs->name, "%s", dirname);1252 else1253 path = git_path("%s", dirname);12541255 d = opendir(path);1256 if (!d)1257 return;12581259 strbuf_init(&refname, dirnamelen + 257);1260 strbuf_add(&refname, dirname, dirnamelen);12611262 while ((de = readdir(d)) != NULL) {1263 unsigned char sha1[20];1264 struct stat st;1265 int flag;1266 const char *refdir;12671268 if (de->d_name[0] == '.')1269 continue;1270 if (ends_with(de->d_name, ".lock"))1271 continue;1272 strbuf_addstr(&refname, de->d_name);1273 refdir = *refs->name1274 ? git_path_submodule(refs->name, "%s", refname.buf)1275 : git_path("%s", refname.buf);1276 if (stat(refdir, &st) < 0) {1277 ; /* silently ignore */1278 } else if (S_ISDIR(st.st_mode)) {1279 strbuf_addch(&refname, '/');1280 add_entry_to_dir(dir,1281 create_dir_entry(refs, refname.buf,1282 refname.len, 1));1283 } else {1284 if (*refs->name) {1285 hashclr(sha1);1286 flag = 0;1287 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {1288 hashclr(sha1);1289 flag |= REF_ISBROKEN;1290 }1291 } else if (read_ref_full(refname.buf,1292 RESOLVE_REF_READING,1293 sha1, &flag)) {1294 hashclr(sha1);1295 flag |= REF_ISBROKEN;1296 }1297 if (check_refname_format(refname.buf,1298 REFNAME_ALLOW_ONELEVEL)) {1299 hashclr(sha1);1300 flag |= REF_BAD_NAME | REF_ISBROKEN;1301 }1302 add_entry_to_dir(dir,1303 create_ref_entry(refname.buf, sha1, flag, 0));1304 }1305 strbuf_setlen(&refname, dirnamelen);1306 }1307 strbuf_release(&refname);1308 closedir(d);1309}13101311static struct ref_dir *get_loose_refs(struct ref_cache *refs)1312{1313 if (!refs->loose) {1314 /*1315 * Mark the top-level directory complete because we1316 * are about to read the only subdirectory that can1317 * hold references:1318 */1319 refs->loose = create_dir_entry(refs, "", 0, 0);1320 /*1321 * Create an incomplete entry for "refs/":1322 */1323 add_entry_to_dir(get_ref_dir(refs->loose),1324 create_dir_entry(refs, "refs/", 5, 1));1325 }1326 return get_ref_dir(refs->loose);1327}13281329/* We allow "recursive" symbolic refs. Only within reason, though */1330#define MAXDEPTH 51331#define MAXREFLEN (1024)13321333/*1334 * Called by resolve_gitlink_ref_recursive() after it failed to read1335 * from the loose refs in ref_cache refs. Find <refname> in the1336 * packed-refs file for the submodule.1337 */1338static int resolve_gitlink_packed_ref(struct ref_cache *refs,1339 const char *refname, unsigned char *sha1)1340{1341 struct ref_entry *ref;1342 struct ref_dir *dir = get_packed_refs(refs);13431344 ref = find_ref(dir, refname);1345 if (ref == NULL)1346 return -1;13471348 hashcpy(sha1, ref->u.value.sha1);1349 return 0;1350}13511352static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1353 const char *refname, unsigned char *sha1,1354 int recursion)1355{1356 int fd, len;1357 char buffer[128], *p;1358 char *path;13591360 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)1361 return -1;1362 path = *refs->name1363 ? git_path_submodule(refs->name, "%s", refname)1364 : git_path("%s", refname);1365 fd = open(path, O_RDONLY);1366 if (fd < 0)1367 return resolve_gitlink_packed_ref(refs, refname, sha1);13681369 len = read(fd, buffer, sizeof(buffer)-1);1370 close(fd);1371 if (len < 0)1372 return -1;1373 while (len && isspace(buffer[len-1]))1374 len--;1375 buffer[len] = 0;13761377 /* Was it a detached head or an old-fashioned symlink? */1378 if (!get_sha1_hex(buffer, sha1))1379 return 0;13801381 /* Symref? */1382 if (strncmp(buffer, "ref:", 4))1383 return -1;1384 p = buffer + 4;1385 while (isspace(*p))1386 p++;13871388 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1389}13901391int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1392{1393 int len = strlen(path), retval;1394 char *submodule;1395 struct ref_cache *refs;13961397 while (len && path[len-1] == '/')1398 len--;1399 if (!len)1400 return -1;1401 submodule = xstrndup(path, len);1402 refs = get_ref_cache(submodule);1403 free(submodule);14041405 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1406 return retval;1407}14081409/*1410 * Return the ref_entry for the given refname from the packed1411 * references. If it does not exist, return NULL.1412 */1413static struct ref_entry *get_packed_ref(const char *refname)1414{1415 return find_ref(get_packed_refs(&ref_cache), refname);1416}14171418/*1419 * A loose ref file doesn't exist; check for a packed ref. The1420 * options are forwarded from resolve_safe_unsafe().1421 */1422static int resolve_missing_loose_ref(const char *refname,1423 int resolve_flags,1424 unsigned char *sha1,1425 int *flags)1426{1427 struct ref_entry *entry;14281429 /*1430 * The loose reference file does not exist; check for a packed1431 * reference.1432 */1433 entry = get_packed_ref(refname);1434 if (entry) {1435 hashcpy(sha1, entry->u.value.sha1);1436 if (flags)1437 *flags |= REF_ISPACKED;1438 return 0;1439 }1440 /* The reference is not a packed reference, either. */1441 if (resolve_flags & RESOLVE_REF_READING) {1442 errno = ENOENT;1443 return -1;1444 } else {1445 hashclr(sha1);1446 return 0;1447 }1448}14491450/* This function needs to return a meaningful errno on failure */1451const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1452{1453 int depth = MAXDEPTH;1454 ssize_t len;1455 char buffer[256];1456 static char refname_buffer[256];1457 int bad_name = 0;14581459 if (flags)1460 *flags = 0;14611462 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1463 if (flags)1464 *flags |= REF_BAD_NAME;14651466 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1467 !refname_is_safe(refname)) {1468 errno = EINVAL;1469 return NULL;1470 }1471 /*1472 * dwim_ref() uses REF_ISBROKEN to distinguish between1473 * missing refs and refs that were present but invalid,1474 * to complain about the latter to stderr.1475 *1476 * We don't know whether the ref exists, so don't set1477 * REF_ISBROKEN yet.1478 */1479 bad_name = 1;1480 }1481 for (;;) {1482 char path[PATH_MAX];1483 struct stat st;1484 char *buf;1485 int fd;14861487 if (--depth < 0) {1488 errno = ELOOP;1489 return NULL;1490 }14911492 git_snpath(path, sizeof(path), "%s", refname);14931494 /*1495 * We might have to loop back here to avoid a race1496 * condition: first we lstat() the file, then we try1497 * to read it as a link or as a file. But if somebody1498 * changes the type of the file (file <-> directory1499 * <-> symlink) between the lstat() and reading, then1500 * we don't want to report that as an error but rather1501 * try again starting with the lstat().1502 */1503 stat_ref:1504 if (lstat(path, &st) < 0) {1505 if (errno != ENOENT)1506 return NULL;1507 if (resolve_missing_loose_ref(refname, resolve_flags,1508 sha1, flags))1509 return NULL;1510 if (bad_name) {1511 hashclr(sha1);1512 if (flags)1513 *flags |= REF_ISBROKEN;1514 }1515 return refname;1516 }15171518 /* Follow "normalized" - ie "refs/.." symlinks by hand */1519 if (S_ISLNK(st.st_mode)) {1520 len = readlink(path, buffer, sizeof(buffer)-1);1521 if (len < 0) {1522 if (errno == ENOENT || errno == EINVAL)1523 /* inconsistent with lstat; retry */1524 goto stat_ref;1525 else1526 return NULL;1527 }1528 buffer[len] = 0;1529 if (starts_with(buffer, "refs/") &&1530 !check_refname_format(buffer, 0)) {1531 strcpy(refname_buffer, buffer);1532 refname = refname_buffer;1533 if (flags)1534 *flags |= REF_ISSYMREF;1535 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1536 hashclr(sha1);1537 return refname;1538 }1539 continue;1540 }1541 }15421543 /* Is it a directory? */1544 if (S_ISDIR(st.st_mode)) {1545 errno = EISDIR;1546 return NULL;1547 }15481549 /*1550 * Anything else, just open it and try to use it as1551 * a ref1552 */1553 fd = open(path, O_RDONLY);1554 if (fd < 0) {1555 if (errno == ENOENT)1556 /* inconsistent with lstat; retry */1557 goto stat_ref;1558 else1559 return NULL;1560 }1561 len = read_in_full(fd, buffer, sizeof(buffer)-1);1562 if (len < 0) {1563 int save_errno = errno;1564 close(fd);1565 errno = save_errno;1566 return NULL;1567 }1568 close(fd);1569 while (len && isspace(buffer[len-1]))1570 len--;1571 buffer[len] = '\0';15721573 /*1574 * Is it a symbolic ref?1575 */1576 if (!starts_with(buffer, "ref:")) {1577 /*1578 * Please note that FETCH_HEAD has a second1579 * line containing other data.1580 */1581 if (get_sha1_hex(buffer, sha1) ||1582 (buffer[40] != '\0' && !isspace(buffer[40]))) {1583 if (flags)1584 *flags |= REF_ISBROKEN;1585 errno = EINVAL;1586 return NULL;1587 }1588 if (bad_name) {1589 hashclr(sha1);1590 if (flags)1591 *flags |= REF_ISBROKEN;1592 }1593 return refname;1594 }1595 if (flags)1596 *flags |= REF_ISSYMREF;1597 buf = buffer + 4;1598 while (isspace(*buf))1599 buf++;1600 refname = strcpy(refname_buffer, buf);1601 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {1602 hashclr(sha1);1603 return refname;1604 }1605 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1606 if (flags)1607 *flags |= REF_ISBROKEN;16081609 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1610 !refname_is_safe(buf)) {1611 errno = EINVAL;1612 return NULL;1613 }1614 bad_name = 1;1615 }1616 }1617}16181619char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)1620{1621 return xstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags));1622}16231624/* The argument to filter_refs */1625struct ref_filter {1626 const char *pattern;1627 each_ref_fn *fn;1628 void *cb_data;1629};16301631int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)1632{1633 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1634 return 0;1635 return -1;1636}16371638int read_ref(const char *refname, unsigned char *sha1)1639{1640 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1641}16421643int ref_exists(const char *refname)1644{1645 unsigned char sha1[20];1646 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1647}16481649static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1650 void *data)1651{1652 struct ref_filter *filter = (struct ref_filter *)data;1653 if (wildmatch(filter->pattern, refname, 0, NULL))1654 return 0;1655 return filter->fn(refname, sha1, flags, filter->cb_data);1656}16571658enum peel_status {1659 /* object was peeled successfully: */1660 PEEL_PEELED = 0,16611662 /*1663 * object cannot be peeled because the named object (or an1664 * object referred to by a tag in the peel chain), does not1665 * exist.1666 */1667 PEEL_INVALID = -1,16681669 /* object cannot be peeled because it is not a tag: */1670 PEEL_NON_TAG = -2,16711672 /* ref_entry contains no peeled value because it is a symref: */1673 PEEL_IS_SYMREF = -3,16741675 /*1676 * ref_entry cannot be peeled because it is broken (i.e., the1677 * symbolic reference cannot even be resolved to an object1678 * name):1679 */1680 PEEL_BROKEN = -41681};16821683/*1684 * Peel the named object; i.e., if the object is a tag, resolve the1685 * tag recursively until a non-tag is found. If successful, store the1686 * result to sha1 and return PEEL_PEELED. If the object is not a tag1687 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1688 * and leave sha1 unchanged.1689 */1690static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1691{1692 struct object *o = lookup_unknown_object(name);16931694 if (o->type == OBJ_NONE) {1695 int type = sha1_object_info(name, NULL);1696 if (type < 0 || !object_as_type(o, type, 0))1697 return PEEL_INVALID;1698 }16991700 if (o->type != OBJ_TAG)1701 return PEEL_NON_TAG;17021703 o = deref_tag_noverify(o);1704 if (!o)1705 return PEEL_INVALID;17061707 hashcpy(sha1, o->sha1);1708 return PEEL_PEELED;1709}17101711/*1712 * Peel the entry (if possible) and return its new peel_status. If1713 * repeel is true, re-peel the entry even if there is an old peeled1714 * value that is already stored in it.1715 *1716 * It is OK to call this function with a packed reference entry that1717 * might be stale and might even refer to an object that has since1718 * been garbage-collected. In such a case, if the entry has1719 * REF_KNOWS_PEELED then leave the status unchanged and return1720 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1721 */1722static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1723{1724 enum peel_status status;17251726 if (entry->flag & REF_KNOWS_PEELED) {1727 if (repeel) {1728 entry->flag &= ~REF_KNOWS_PEELED;1729 hashclr(entry->u.value.peeled);1730 } else {1731 return is_null_sha1(entry->u.value.peeled) ?1732 PEEL_NON_TAG : PEEL_PEELED;1733 }1734 }1735 if (entry->flag & REF_ISBROKEN)1736 return PEEL_BROKEN;1737 if (entry->flag & REF_ISSYMREF)1738 return PEEL_IS_SYMREF;17391740 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1741 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1742 entry->flag |= REF_KNOWS_PEELED;1743 return status;1744}17451746int peel_ref(const char *refname, unsigned char *sha1)1747{1748 int flag;1749 unsigned char base[20];17501751 if (current_ref && (current_ref->name == refname1752 || !strcmp(current_ref->name, refname))) {1753 if (peel_entry(current_ref, 0))1754 return -1;1755 hashcpy(sha1, current_ref->u.value.peeled);1756 return 0;1757 }17581759 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1760 return -1;17611762 /*1763 * If the reference is packed, read its ref_entry from the1764 * cache in the hope that we already know its peeled value.1765 * We only try this optimization on packed references because1766 * (a) forcing the filling of the loose reference cache could1767 * be expensive and (b) loose references anyway usually do not1768 * have REF_KNOWS_PEELED.1769 */1770 if (flag & REF_ISPACKED) {1771 struct ref_entry *r = get_packed_ref(refname);1772 if (r) {1773 if (peel_entry(r, 0))1774 return -1;1775 hashcpy(sha1, r->u.value.peeled);1776 return 0;1777 }1778 }17791780 return peel_object(base, sha1);1781}17821783struct warn_if_dangling_data {1784 FILE *fp;1785 const char *refname;1786 const struct string_list *refnames;1787 const char *msg_fmt;1788};17891790static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1791 int flags, void *cb_data)1792{1793 struct warn_if_dangling_data *d = cb_data;1794 const char *resolves_to;1795 unsigned char junk[20];17961797 if (!(flags & REF_ISSYMREF))1798 return 0;17991800 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);1801 if (!resolves_to1802 || (d->refname1803 ? strcmp(resolves_to, d->refname)1804 : !string_list_has_string(d->refnames, resolves_to))) {1805 return 0;1806 }18071808 fprintf(d->fp, d->msg_fmt, refname);1809 fputc('\n', d->fp);1810 return 0;1811}18121813void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1814{1815 struct warn_if_dangling_data data;18161817 data.fp = fp;1818 data.refname = refname;1819 data.refnames = NULL;1820 data.msg_fmt = msg_fmt;1821 for_each_rawref(warn_if_dangling_symref, &data);1822}18231824void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)1825{1826 struct warn_if_dangling_data data;18271828 data.fp = fp;1829 data.refname = NULL;1830 data.refnames = refnames;1831 data.msg_fmt = msg_fmt;1832 for_each_rawref(warn_if_dangling_symref, &data);1833}18341835/*1836 * Call fn for each reference in the specified ref_cache, omitting1837 * references not in the containing_dir of base. fn is called for all1838 * references, including broken ones. If fn ever returns a non-zero1839 * value, stop the iteration and return that value; otherwise, return1840 * 0.1841 */1842static int do_for_each_entry(struct ref_cache *refs, const char *base,1843 each_ref_entry_fn fn, void *cb_data)1844{1845 struct packed_ref_cache *packed_ref_cache;1846 struct ref_dir *loose_dir;1847 struct ref_dir *packed_dir;1848 int retval = 0;18491850 /*1851 * We must make sure that all loose refs are read before accessing the1852 * packed-refs file; this avoids a race condition in which loose refs1853 * are migrated to the packed-refs file by a simultaneous process, but1854 * our in-memory view is from before the migration. get_packed_ref_cache()1855 * takes care of making sure our view is up to date with what is on1856 * disk.1857 */1858 loose_dir = get_loose_refs(refs);1859 if (base && *base) {1860 loose_dir = find_containing_dir(loose_dir, base, 0);1861 }1862 if (loose_dir)1863 prime_ref_dir(loose_dir);18641865 packed_ref_cache = get_packed_ref_cache(refs);1866 acquire_packed_ref_cache(packed_ref_cache);1867 packed_dir = get_packed_ref_dir(packed_ref_cache);1868 if (base && *base) {1869 packed_dir = find_containing_dir(packed_dir, base, 0);1870 }18711872 if (packed_dir && loose_dir) {1873 sort_ref_dir(packed_dir);1874 sort_ref_dir(loose_dir);1875 retval = do_for_each_entry_in_dirs(1876 packed_dir, loose_dir, fn, cb_data);1877 } else if (packed_dir) {1878 sort_ref_dir(packed_dir);1879 retval = do_for_each_entry_in_dir(1880 packed_dir, 0, fn, cb_data);1881 } else if (loose_dir) {1882 sort_ref_dir(loose_dir);1883 retval = do_for_each_entry_in_dir(1884 loose_dir, 0, fn, cb_data);1885 }18861887 release_packed_ref_cache(packed_ref_cache);1888 return retval;1889}18901891/*1892 * Call fn for each reference in the specified ref_cache for which the1893 * refname begins with base. If trim is non-zero, then trim that many1894 * characters off the beginning of each refname before passing the1895 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1896 * broken references in the iteration. If fn ever returns a non-zero1897 * value, stop the iteration and return that value; otherwise, return1898 * 0.1899 */1900static int do_for_each_ref(struct ref_cache *refs, const char *base,1901 each_ref_fn fn, int trim, int flags, void *cb_data)1902{1903 struct ref_entry_cb data;1904 data.base = base;1905 data.trim = trim;1906 data.flags = flags;1907 data.fn = fn;1908 data.cb_data = cb_data;19091910 if (ref_paranoia < 0)1911 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);1912 if (ref_paranoia)1913 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;19141915 return do_for_each_entry(refs, base, do_one_ref, &data);1916}19171918static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1919{1920 unsigned char sha1[20];1921 int flag;19221923 if (submodule) {1924 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1925 return fn("HEAD", sha1, 0, cb_data);19261927 return 0;1928 }19291930 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1931 return fn("HEAD", sha1, flag, cb_data);19321933 return 0;1934}19351936int head_ref(each_ref_fn fn, void *cb_data)1937{1938 return do_head_ref(NULL, fn, cb_data);1939}19401941int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1942{1943 return do_head_ref(submodule, fn, cb_data);1944}19451946int for_each_ref(each_ref_fn fn, void *cb_data)1947{1948 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);1949}19501951int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1952{1953 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);1954}19551956int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1957{1958 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);1959}19601961int for_each_ref_in_submodule(const char *submodule, const char *prefix,1962 each_ref_fn fn, void *cb_data)1963{1964 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);1965}19661967int for_each_tag_ref(each_ref_fn fn, void *cb_data)1968{1969 return for_each_ref_in("refs/tags/", fn, cb_data);1970}19711972int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1973{1974 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1975}19761977int for_each_branch_ref(each_ref_fn fn, void *cb_data)1978{1979 return for_each_ref_in("refs/heads/", fn, cb_data);1980}19811982int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1983{1984 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1985}19861987int for_each_remote_ref(each_ref_fn fn, void *cb_data)1988{1989 return for_each_ref_in("refs/remotes/", fn, cb_data);1990}19911992int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1993{1994 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1995}19961997int for_each_replace_ref(each_ref_fn fn, void *cb_data)1998{1999 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);2000}20012002int head_ref_namespaced(each_ref_fn fn, void *cb_data)2003{2004 struct strbuf buf = STRBUF_INIT;2005 int ret = 0;2006 unsigned char sha1[20];2007 int flag;20082009 strbuf_addf(&buf, "%sHEAD", get_git_namespace());2010 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))2011 ret = fn(buf.buf, sha1, flag, cb_data);2012 strbuf_release(&buf);20132014 return ret;2015}20162017int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)2018{2019 struct strbuf buf = STRBUF_INIT;2020 int ret;2021 strbuf_addf(&buf, "%srefs/", get_git_namespace());2022 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);2023 strbuf_release(&buf);2024 return ret;2025}20262027int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,2028 const char *prefix, void *cb_data)2029{2030 struct strbuf real_pattern = STRBUF_INIT;2031 struct ref_filter filter;2032 int ret;20332034 if (!prefix && !starts_with(pattern, "refs/"))2035 strbuf_addstr(&real_pattern, "refs/");2036 else if (prefix)2037 strbuf_addstr(&real_pattern, prefix);2038 strbuf_addstr(&real_pattern, pattern);20392040 if (!has_glob_specials(pattern)) {2041 /* Append implied '/' '*' if not present. */2042 if (real_pattern.buf[real_pattern.len - 1] != '/')2043 strbuf_addch(&real_pattern, '/');2044 /* No need to check for '*', there is none. */2045 strbuf_addch(&real_pattern, '*');2046 }20472048 filter.pattern = real_pattern.buf;2049 filter.fn = fn;2050 filter.cb_data = cb_data;2051 ret = for_each_ref(filter_refs, &filter);20522053 strbuf_release(&real_pattern);2054 return ret;2055}20562057int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)2058{2059 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);2060}20612062int for_each_rawref(each_ref_fn fn, void *cb_data)2063{2064 return do_for_each_ref(&ref_cache, "", fn, 0,2065 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2066}20672068const char *prettify_refname(const char *name)2069{2070 return name + (2071 starts_with(name, "refs/heads/") ? 11 :2072 starts_with(name, "refs/tags/") ? 10 :2073 starts_with(name, "refs/remotes/") ? 13 :2074 0);2075}20762077static const char *ref_rev_parse_rules[] = {2078 "%.*s",2079 "refs/%.*s",2080 "refs/tags/%.*s",2081 "refs/heads/%.*s",2082 "refs/remotes/%.*s",2083 "refs/remotes/%.*s/HEAD",2084 NULL2085};20862087int refname_match(const char *abbrev_name, const char *full_name)2088{2089 const char **p;2090 const int abbrev_name_len = strlen(abbrev_name);20912092 for (p = ref_rev_parse_rules; *p; p++) {2093 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {2094 return 1;2095 }2096 }20972098 return 0;2099}21002101/* This function should make sure errno is meaningful on error */2102static struct ref_lock *verify_lock(struct ref_lock *lock,2103 const unsigned char *old_sha1, int mustexist)2104{2105 if (read_ref_full(lock->ref_name,2106 mustexist ? RESOLVE_REF_READING : 0,2107 lock->old_sha1, NULL)) {2108 int save_errno = errno;2109 error("Can't verify ref %s", lock->ref_name);2110 unlock_ref(lock);2111 errno = save_errno;2112 return NULL;2113 }2114 if (hashcmp(lock->old_sha1, old_sha1)) {2115 error("Ref %s is at %s but expected %s", lock->ref_name,2116 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));2117 unlock_ref(lock);2118 errno = EBUSY;2119 return NULL;2120 }2121 return lock;2122}21232124static int remove_empty_directories(const char *file)2125{2126 /* we want to create a file but there is a directory there;2127 * if that is an empty directory (or a directory that contains2128 * only empty directories), remove them.2129 */2130 struct strbuf path;2131 int result, save_errno;21322133 strbuf_init(&path, 20);2134 strbuf_addstr(&path, file);21352136 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2137 save_errno = errno;21382139 strbuf_release(&path);2140 errno = save_errno;21412142 return result;2143}21442145/*2146 * *string and *len will only be substituted, and *string returned (for2147 * later free()ing) if the string passed in is a magic short-hand form2148 * to name a branch.2149 */2150static char *substitute_branch_name(const char **string, int *len)2151{2152 struct strbuf buf = STRBUF_INIT;2153 int ret = interpret_branch_name(*string, *len, &buf);21542155 if (ret == *len) {2156 size_t size;2157 *string = strbuf_detach(&buf, &size);2158 *len = size;2159 return (char *)*string;2160 }21612162 return NULL;2163}21642165int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)2166{2167 char *last_branch = substitute_branch_name(&str, &len);2168 const char **p, *r;2169 int refs_found = 0;21702171 *ref = NULL;2172 for (p = ref_rev_parse_rules; *p; p++) {2173 char fullref[PATH_MAX];2174 unsigned char sha1_from_ref[20];2175 unsigned char *this_result;2176 int flag;21772178 this_result = refs_found ? sha1_from_ref : sha1;2179 mksnpath(fullref, sizeof(fullref), *p, len, str);2180 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2181 this_result, &flag);2182 if (r) {2183 if (!refs_found++)2184 *ref = xstrdup(r);2185 if (!warn_ambiguous_refs)2186 break;2187 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {2188 warning("ignoring dangling symref %s.", fullref);2189 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {2190 warning("ignoring broken ref %s.", fullref);2191 }2192 }2193 free(last_branch);2194 return refs_found;2195}21962197int dwim_log(const char *str, int len, unsigned char *sha1, char **log)2198{2199 char *last_branch = substitute_branch_name(&str, &len);2200 const char **p;2201 int logs_found = 0;22022203 *log = NULL;2204 for (p = ref_rev_parse_rules; *p; p++) {2205 unsigned char hash[20];2206 char path[PATH_MAX];2207 const char *ref, *it;22082209 mksnpath(path, sizeof(path), *p, len, str);2210 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,2211 hash, NULL);2212 if (!ref)2213 continue;2214 if (reflog_exists(path))2215 it = path;2216 else if (strcmp(ref, path) && reflog_exists(ref))2217 it = ref;2218 else2219 continue;2220 if (!logs_found++) {2221 *log = xstrdup(it);2222 hashcpy(sha1, hash);2223 }2224 if (!warn_ambiguous_refs)2225 break;2226 }2227 free(last_branch);2228 return logs_found;2229}22302231/*2232 * Locks a ref returning the lock on success and NULL on failure.2233 * On failure errno is set to something meaningful.2234 */2235static struct ref_lock *lock_ref_sha1_basic(const char *refname,2236 const unsigned char *old_sha1,2237 const struct string_list *skip,2238 int flags, int *type_p)2239{2240 char *ref_file;2241 const char *orig_refname = refname;2242 struct ref_lock *lock;2243 int last_errno = 0;2244 int type, lflags;2245 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2246 int resolve_flags = 0;2247 int missing = 0;2248 int attempts_remaining = 3;22492250 lock = xcalloc(1, sizeof(struct ref_lock));2251 lock->lock_fd = -1;22522253 if (mustexist)2254 resolve_flags |= RESOLVE_REF_READING;2255 if (flags & REF_DELETING) {2256 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;2257 if (flags & REF_NODEREF)2258 resolve_flags |= RESOLVE_REF_NO_RECURSE;2259 }22602261 refname = resolve_ref_unsafe(refname, resolve_flags,2262 lock->old_sha1, &type);2263 if (!refname && errno == EISDIR) {2264 /* we are trying to lock foo but we used to2265 * have foo/bar which now does not exist;2266 * it is normal for the empty directory 'foo'2267 * to remain.2268 */2269 ref_file = git_path("%s", orig_refname);2270 if (remove_empty_directories(ref_file)) {2271 last_errno = errno;2272 error("there are still refs under '%s'", orig_refname);2273 goto error_return;2274 }2275 refname = resolve_ref_unsafe(orig_refname, resolve_flags,2276 lock->old_sha1, &type);2277 }2278 if (type_p)2279 *type_p = type;2280 if (!refname) {2281 last_errno = errno;2282 error("unable to resolve reference %s: %s",2283 orig_refname, strerror(errno));2284 goto error_return;2285 }2286 missing = is_null_sha1(lock->old_sha1);2287 /* When the ref did not exist and we are creating it,2288 * make sure there is no existing ref that is packed2289 * whose name begins with our refname, nor a ref whose2290 * name is a proper prefix of our refname.2291 */2292 if (missing &&2293 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {2294 last_errno = ENOTDIR;2295 goto error_return;2296 }22972298 lock->lk = xcalloc(1, sizeof(struct lock_file));22992300 lflags = 0;2301 if (flags & REF_NODEREF) {2302 refname = orig_refname;2303 lflags |= LOCK_NO_DEREF;2304 }2305 lock->ref_name = xstrdup(refname);2306 lock->orig_ref_name = xstrdup(orig_refname);2307 ref_file = git_path("%s", refname);2308 if (missing)2309 lock->force_write = 1;2310 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))2311 lock->force_write = 1;23122313 retry:2314 switch (safe_create_leading_directories(ref_file)) {2315 case SCLD_OK:2316 break; /* success */2317 case SCLD_VANISHED:2318 if (--attempts_remaining > 0)2319 goto retry;2320 /* fall through */2321 default:2322 last_errno = errno;2323 error("unable to create directory for %s", ref_file);2324 goto error_return;2325 }23262327 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);2328 if (lock->lock_fd < 0) {2329 last_errno = errno;2330 if (errno == ENOENT && --attempts_remaining > 0)2331 /*2332 * Maybe somebody just deleted one of the2333 * directories leading to ref_file. Try2334 * again:2335 */2336 goto retry;2337 else {2338 struct strbuf err = STRBUF_INIT;2339 unable_to_lock_message(ref_file, errno, &err);2340 error("%s", err.buf);2341 strbuf_release(&err);2342 goto error_return;2343 }2344 }2345 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;23462347 error_return:2348 unlock_ref(lock);2349 errno = last_errno;2350 return NULL;2351}23522353struct ref_lock *lock_any_ref_for_update(const char *refname,2354 const unsigned char *old_sha1,2355 int flags, int *type_p)2356{2357 return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);2358}23592360/*2361 * Write an entry to the packed-refs file for the specified refname.2362 * If peeled is non-NULL, write it as the entry's peeled value.2363 */2364static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,2365 unsigned char *peeled)2366{2367 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);2368 if (peeled)2369 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));2370}23712372/*2373 * An each_ref_entry_fn that writes the entry to a packed-refs file.2374 */2375static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2376{2377 enum peel_status peel_status = peel_entry(entry, 0);23782379 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2380 error("internal error: %s is not a valid packed reference!",2381 entry->name);2382 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2383 peel_status == PEEL_PEELED ?2384 entry->u.value.peeled : NULL);2385 return 0;2386}23872388/* This should return a meaningful errno on failure */2389int lock_packed_refs(int flags)2390{2391 struct packed_ref_cache *packed_ref_cache;23922393 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)2394 return -1;2395 /*2396 * Get the current packed-refs while holding the lock. If the2397 * packed-refs file has been modified since we last read it,2398 * this will automatically invalidate the cache and re-read2399 * the packed-refs file.2400 */2401 packed_ref_cache = get_packed_ref_cache(&ref_cache);2402 packed_ref_cache->lock = &packlock;2403 /* Increment the reference count to prevent it from being freed: */2404 acquire_packed_ref_cache(packed_ref_cache);2405 return 0;2406}24072408/*2409 * Commit the packed refs changes.2410 * On error we must make sure that errno contains a meaningful value.2411 */2412int commit_packed_refs(void)2413{2414 struct packed_ref_cache *packed_ref_cache =2415 get_packed_ref_cache(&ref_cache);2416 int error = 0;2417 int save_errno = 0;2418 FILE *out;24192420 if (!packed_ref_cache->lock)2421 die("internal error: packed-refs not locked");24222423 out = fdopen_lock_file(packed_ref_cache->lock, "w");2424 if (!out)2425 die_errno("unable to fdopen packed-refs descriptor");24262427 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);2428 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2429 0, write_packed_entry_fn, out);24302431 if (commit_lock_file(packed_ref_cache->lock)) {2432 save_errno = errno;2433 error = -1;2434 }2435 packed_ref_cache->lock = NULL;2436 release_packed_ref_cache(packed_ref_cache);2437 errno = save_errno;2438 return error;2439}24402441void rollback_packed_refs(void)2442{2443 struct packed_ref_cache *packed_ref_cache =2444 get_packed_ref_cache(&ref_cache);24452446 if (!packed_ref_cache->lock)2447 die("internal error: packed-refs not locked");2448 rollback_lock_file(packed_ref_cache->lock);2449 packed_ref_cache->lock = NULL;2450 release_packed_ref_cache(packed_ref_cache);2451 clear_packed_ref_cache(&ref_cache);2452}24532454struct ref_to_prune {2455 struct ref_to_prune *next;2456 unsigned char sha1[20];2457 char name[FLEX_ARRAY];2458};24592460struct pack_refs_cb_data {2461 unsigned int flags;2462 struct ref_dir *packed_refs;2463 struct ref_to_prune *ref_to_prune;2464};24652466/*2467 * An each_ref_entry_fn that is run over loose references only. If2468 * the loose reference can be packed, add an entry in the packed ref2469 * cache. If the reference should be pruned, also add it to2470 * ref_to_prune in the pack_refs_cb_data.2471 */2472static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2473{2474 struct pack_refs_cb_data *cb = cb_data;2475 enum peel_status peel_status;2476 struct ref_entry *packed_entry;2477 int is_tag_ref = starts_with(entry->name, "refs/tags/");24782479 /* ALWAYS pack tags */2480 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2481 return 0;24822483 /* Do not pack symbolic or broken refs: */2484 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2485 return 0;24862487 /* Add a packed ref cache entry equivalent to the loose entry. */2488 peel_status = peel_entry(entry, 1);2489 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2490 die("internal error peeling reference %s (%s)",2491 entry->name, sha1_to_hex(entry->u.value.sha1));2492 packed_entry = find_ref(cb->packed_refs, entry->name);2493 if (packed_entry) {2494 /* Overwrite existing packed entry with info from loose entry */2495 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2496 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2497 } else {2498 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,2499 REF_ISPACKED | REF_KNOWS_PEELED, 0);2500 add_ref(cb->packed_refs, packed_entry);2501 }2502 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25032504 /* Schedule the loose reference for pruning if requested. */2505 if ((cb->flags & PACK_REFS_PRUNE)) {2506 int namelen = strlen(entry->name) + 1;2507 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2508 hashcpy(n->sha1, entry->u.value.sha1);2509 strcpy(n->name, entry->name);2510 n->next = cb->ref_to_prune;2511 cb->ref_to_prune = n;2512 }2513 return 0;2514}25152516/*2517 * Remove empty parents, but spare refs/ and immediate subdirs.2518 * Note: munges *name.2519 */2520static void try_remove_empty_parents(char *name)2521{2522 char *p, *q;2523 int i;2524 p = name;2525 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2526 while (*p && *p != '/')2527 p++;2528 /* tolerate duplicate slashes; see check_refname_format() */2529 while (*p == '/')2530 p++;2531 }2532 for (q = p; *q; q++)2533 ;2534 while (1) {2535 while (q > p && *q != '/')2536 q--;2537 while (q > p && *(q-1) == '/')2538 q--;2539 if (q == p)2540 break;2541 *q = '\0';2542 if (rmdir(git_path("%s", name)))2543 break;2544 }2545}25462547/* make sure nobody touched the ref, and unlink */2548static void prune_ref(struct ref_to_prune *r)2549{2550 struct ref_transaction *transaction;2551 struct strbuf err = STRBUF_INIT;25522553 if (check_refname_format(r->name, 0))2554 return;25552556 transaction = ref_transaction_begin(&err);2557 if (!transaction ||2558 ref_transaction_delete(transaction, r->name, r->sha1,2559 REF_ISPRUNING, 1, NULL, &err) ||2560 ref_transaction_commit(transaction, &err)) {2561 ref_transaction_free(transaction);2562 error("%s", err.buf);2563 strbuf_release(&err);2564 return;2565 }2566 ref_transaction_free(transaction);2567 strbuf_release(&err);2568 try_remove_empty_parents(r->name);2569}25702571static void prune_refs(struct ref_to_prune *r)2572{2573 while (r) {2574 prune_ref(r);2575 r = r->next;2576 }2577}25782579int pack_refs(unsigned int flags)2580{2581 struct pack_refs_cb_data cbdata;25822583 memset(&cbdata, 0, sizeof(cbdata));2584 cbdata.flags = flags;25852586 lock_packed_refs(LOCK_DIE_ON_ERROR);2587 cbdata.packed_refs = get_packed_refs(&ref_cache);25882589 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2590 pack_if_possible_fn, &cbdata);25912592 if (commit_packed_refs())2593 die_errno("unable to overwrite old ref-pack file");25942595 prune_refs(cbdata.ref_to_prune);2596 return 0;2597}25982599/*2600 * If entry is no longer needed in packed-refs, add it to the string2601 * list pointed to by cb_data. Reasons for deleting entries:2602 *2603 * - Entry is broken.2604 * - Entry is overridden by a loose ref.2605 * - Entry does not point at a valid object.2606 *2607 * In the first and third cases, also emit an error message because these2608 * are indications of repository corruption.2609 */2610static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)2611{2612 struct string_list *refs_to_delete = cb_data;26132614 if (entry->flag & REF_ISBROKEN) {2615 /* This shouldn't happen to packed refs. */2616 error("%s is broken!", entry->name);2617 string_list_append(refs_to_delete, entry->name);2618 return 0;2619 }2620 if (!has_sha1_file(entry->u.value.sha1)) {2621 unsigned char sha1[20];2622 int flags;26232624 if (read_ref_full(entry->name, 0, sha1, &flags))2625 /* We should at least have found the packed ref. */2626 die("Internal error");2627 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2628 /*2629 * This packed reference is overridden by a2630 * loose reference, so it is OK that its value2631 * is no longer valid; for example, it might2632 * refer to an object that has been garbage2633 * collected. For this purpose we don't even2634 * care whether the loose reference itself is2635 * invalid, broken, symbolic, etc. Silently2636 * remove the packed reference.2637 */2638 string_list_append(refs_to_delete, entry->name);2639 return 0;2640 }2641 /*2642 * There is no overriding loose reference, so the fact2643 * that this reference doesn't refer to a valid object2644 * indicates some kind of repository corruption.2645 * Report the problem, then omit the reference from2646 * the output.2647 */2648 error("%s does not point to a valid object!", entry->name);2649 string_list_append(refs_to_delete, entry->name);2650 return 0;2651 }26522653 return 0;2654}26552656int repack_without_refs(struct string_list *refnames, struct strbuf *err)2657{2658 struct ref_dir *packed;2659 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2660 struct string_list_item *refname, *ref_to_delete;2661 int ret, needs_repacking = 0, removed = 0;26622663 assert(err);26642665 /* Look for a packed ref */2666 for_each_string_list_item(refname, refnames) {2667 if (get_packed_ref(refname->string)) {2668 needs_repacking = 1;2669 break;2670 }2671 }26722673 /* Avoid locking if we have nothing to do */2674 if (!needs_repacking)2675 return 0; /* no refname exists in packed refs */26762677 if (lock_packed_refs(0)) {2678 unable_to_lock_message(git_path("packed-refs"), errno, err);2679 return -1;2680 }2681 packed = get_packed_refs(&ref_cache);26822683 /* Remove refnames from the cache */2684 for_each_string_list_item(refname, refnames)2685 if (remove_entry(packed, refname->string) != -1)2686 removed = 1;2687 if (!removed) {2688 /*2689 * All packed entries disappeared while we were2690 * acquiring the lock.2691 */2692 rollback_packed_refs();2693 return 0;2694 }26952696 /* Remove any other accumulated cruft */2697 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);2698 for_each_string_list_item(ref_to_delete, &refs_to_delete) {2699 if (remove_entry(packed, ref_to_delete->string) == -1)2700 die("internal error");2701 }27022703 /* Write what remains */2704 ret = commit_packed_refs();2705 if (ret)2706 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2707 strerror(errno));2708 return ret;2709}27102711static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)2712{2713 assert(err);27142715 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2716 /*2717 * loose. The loose file name is the same as the2718 * lockfile name, minus ".lock":2719 */2720 char *loose_filename = get_locked_file_path(lock->lk);2721 int res = unlink_or_msg(loose_filename, err);2722 free(loose_filename);2723 if (res)2724 return 1;2725 }2726 return 0;2727}27282729int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2730{2731 struct ref_transaction *transaction;2732 struct strbuf err = STRBUF_INIT;27332734 transaction = ref_transaction_begin(&err);2735 if (!transaction ||2736 ref_transaction_delete(transaction, refname, sha1, delopt,2737 sha1 && !is_null_sha1(sha1), NULL, &err) ||2738 ref_transaction_commit(transaction, &err)) {2739 error("%s", err.buf);2740 ref_transaction_free(transaction);2741 strbuf_release(&err);2742 return 1;2743 }2744 ref_transaction_free(transaction);2745 strbuf_release(&err);2746 return 0;2747}27482749/*2750 * People using contrib's git-new-workdir have .git/logs/refs ->2751 * /some/other/path/.git/logs/refs, and that may live on another device.2752 *2753 * IOW, to avoid cross device rename errors, the temporary renamed log must2754 * live into logs/refs.2755 */2756#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"27572758static int rename_tmp_log(const char *newrefname)2759{2760 int attempts_remaining = 4;27612762 retry:2763 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {2764 case SCLD_OK:2765 break; /* success */2766 case SCLD_VANISHED:2767 if (--attempts_remaining > 0)2768 goto retry;2769 /* fall through */2770 default:2771 error("unable to create directory for %s", newrefname);2772 return -1;2773 }27742775 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2776 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2777 /*2778 * rename(a, b) when b is an existing2779 * directory ought to result in ISDIR, but2780 * Solaris 5.8 gives ENOTDIR. Sheesh.2781 */2782 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2783 error("Directory not empty: logs/%s", newrefname);2784 return -1;2785 }2786 goto retry;2787 } else if (errno == ENOENT && --attempts_remaining > 0) {2788 /*2789 * Maybe another process just deleted one of2790 * the directories in the path to newrefname.2791 * Try again from the beginning.2792 */2793 goto retry;2794 } else {2795 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2796 newrefname, strerror(errno));2797 return -1;2798 }2799 }2800 return 0;2801}28022803static int rename_ref_available(const char *oldname, const char *newname)2804{2805 struct string_list skip = STRING_LIST_INIT_NODUP;2806 int ret;28072808 string_list_insert(&skip, oldname);2809 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))2810 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));2811 string_list_clear(&skip, 0);2812 return ret;2813}28142815static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,2816 const char *logmsg);28172818int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2819{2820 unsigned char sha1[20], orig_sha1[20];2821 int flag = 0, logmoved = 0;2822 struct ref_lock *lock;2823 struct stat loginfo;2824 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2825 const char *symref = NULL;28262827 if (log && S_ISLNK(loginfo.st_mode))2828 return error("reflog for %s is a symlink", oldrefname);28292830 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2831 orig_sha1, &flag);2832 if (flag & REF_ISSYMREF)2833 return error("refname %s is a symbolic ref, renaming it is not supported",2834 oldrefname);2835 if (!symref)2836 return error("refname %s not found", oldrefname);28372838 if (!rename_ref_available(oldrefname, newrefname))2839 return 1;28402841 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2842 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2843 oldrefname, strerror(errno));28442845 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2846 error("unable to delete old %s", oldrefname);2847 goto rollback;2848 }28492850 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2851 delete_ref(newrefname, sha1, REF_NODEREF)) {2852 if (errno==EISDIR) {2853 if (remove_empty_directories(git_path("%s", newrefname))) {2854 error("Directory not empty: %s", newrefname);2855 goto rollback;2856 }2857 } else {2858 error("unable to delete existing %s", newrefname);2859 goto rollback;2860 }2861 }28622863 if (log && rename_tmp_log(newrefname))2864 goto rollback;28652866 logmoved = log;28672868 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);2869 if (!lock) {2870 error("unable to lock %s for update", newrefname);2871 goto rollback;2872 }2873 lock->force_write = 1;2874 hashcpy(lock->old_sha1, orig_sha1);2875 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2876 error("unable to write current sha1 into %s", newrefname);2877 goto rollback;2878 }28792880 return 0;28812882 rollback:2883 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);2884 if (!lock) {2885 error("unable to lock %s for rollback", oldrefname);2886 goto rollbacklog;2887 }28882889 lock->force_write = 1;2890 flag = log_all_ref_updates;2891 log_all_ref_updates = 0;2892 if (write_ref_sha1(lock, orig_sha1, NULL))2893 error("unable to write current sha1 into %s", oldrefname);2894 log_all_ref_updates = flag;28952896 rollbacklog:2897 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2898 error("unable to restore logfile %s from %s: %s",2899 oldrefname, newrefname, strerror(errno));2900 if (!logmoved && log &&2901 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2902 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2903 oldrefname, strerror(errno));29042905 return 1;2906}29072908int close_ref(struct ref_lock *lock)2909{2910 if (close_lock_file(lock->lk))2911 return -1;2912 lock->lock_fd = -1;2913 return 0;2914}29152916int commit_ref(struct ref_lock *lock)2917{2918 if (commit_lock_file(lock->lk))2919 return -1;2920 lock->lock_fd = -1;2921 return 0;2922}29232924void unlock_ref(struct ref_lock *lock)2925{2926 /* Do not free lock->lk -- atexit() still looks at them */2927 if (lock->lk)2928 rollback_lock_file(lock->lk);2929 free(lock->ref_name);2930 free(lock->orig_ref_name);2931 free(lock);2932}29332934/*2935 * copy the reflog message msg to buf, which has been allocated sufficiently2936 * large, while cleaning up the whitespaces. Especially, convert LF to space,2937 * because reflog file is one line per entry.2938 */2939static int copy_msg(char *buf, const char *msg)2940{2941 char *cp = buf;2942 char c;2943 int wasspace = 1;29442945 *cp++ = '\t';2946 while ((c = *msg++)) {2947 if (wasspace && isspace(c))2948 continue;2949 wasspace = isspace(c);2950 if (wasspace)2951 c = ' ';2952 *cp++ = c;2953 }2954 while (buf < cp && isspace(cp[-1]))2955 cp--;2956 *cp++ = '\n';2957 return cp - buf;2958}29592960/* This function must set a meaningful errno on failure */2961int log_ref_setup(const char *refname, char *logfile, int bufsize)2962{2963 int logfd, oflags = O_APPEND | O_WRONLY;29642965 git_snpath(logfile, bufsize, "logs/%s", refname);2966 if (log_all_ref_updates &&2967 (starts_with(refname, "refs/heads/") ||2968 starts_with(refname, "refs/remotes/") ||2969 starts_with(refname, "refs/notes/") ||2970 !strcmp(refname, "HEAD"))) {2971 if (safe_create_leading_directories(logfile) < 0) {2972 int save_errno = errno;2973 error("unable to create directory for %s", logfile);2974 errno = save_errno;2975 return -1;2976 }2977 oflags |= O_CREAT;2978 }29792980 logfd = open(logfile, oflags, 0666);2981 if (logfd < 0) {2982 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2983 return 0;29842985 if (errno == EISDIR) {2986 if (remove_empty_directories(logfile)) {2987 int save_errno = errno;2988 error("There are still logs under '%s'",2989 logfile);2990 errno = save_errno;2991 return -1;2992 }2993 logfd = open(logfile, oflags, 0666);2994 }29952996 if (logfd < 0) {2997 int save_errno = errno;2998 error("Unable to append to %s: %s", logfile,2999 strerror(errno));3000 errno = save_errno;3001 return -1;3002 }3003 }30043005 adjust_shared_perm(logfile);3006 close(logfd);3007 return 0;3008}30093010static int log_ref_write(const char *refname, const unsigned char *old_sha1,3011 const unsigned char *new_sha1, const char *msg)3012{3013 int logfd, result, written, oflags = O_APPEND | O_WRONLY;3014 unsigned maxlen, len;3015 int msglen;3016 char log_file[PATH_MAX];3017 char *logrec;3018 const char *committer;30193020 if (log_all_ref_updates < 0)3021 log_all_ref_updates = !is_bare_repository();30223023 result = log_ref_setup(refname, log_file, sizeof(log_file));3024 if (result)3025 return result;30263027 logfd = open(log_file, oflags);3028 if (logfd < 0)3029 return 0;3030 msglen = msg ? strlen(msg) : 0;3031 committer = git_committer_info(0);3032 maxlen = strlen(committer) + msglen + 100;3033 logrec = xmalloc(maxlen);3034 len = sprintf(logrec, "%s %s %s\n",3035 sha1_to_hex(old_sha1),3036 sha1_to_hex(new_sha1),3037 committer);3038 if (msglen)3039 len += copy_msg(logrec + len - 1, msg) - 1;3040 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;3041 free(logrec);3042 if (written != len) {3043 int save_errno = errno;3044 close(logfd);3045 error("Unable to append to %s", log_file);3046 errno = save_errno;3047 return -1;3048 }3049 if (close(logfd)) {3050 int save_errno = errno;3051 error("Unable to append to %s", log_file);3052 errno = save_errno;3053 return -1;3054 }3055 return 0;3056}30573058int is_branch(const char *refname)3059{3060 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");3061}30623063/*3064 * Write sha1 into the ref specified by the lock. Make sure that errno3065 * is sane on error.3066 */3067static int write_ref_sha1(struct ref_lock *lock,3068 const unsigned char *sha1, const char *logmsg)3069{3070 static char term = '\n';3071 struct object *o;30723073 if (!lock) {3074 errno = EINVAL;3075 return -1;3076 }3077 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3078 unlock_ref(lock);3079 return 0;3080 }3081 o = parse_object(sha1);3082 if (!o) {3083 error("Trying to write ref %s with nonexistent object %s",3084 lock->ref_name, sha1_to_hex(sha1));3085 unlock_ref(lock);3086 errno = EINVAL;3087 return -1;3088 }3089 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {3090 error("Trying to write non-commit object %s to branch %s",3091 sha1_to_hex(sha1), lock->ref_name);3092 unlock_ref(lock);3093 errno = EINVAL;3094 return -1;3095 }3096 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||3097 write_in_full(lock->lock_fd, &term, 1) != 1 ||3098 close_ref(lock) < 0) {3099 int save_errno = errno;3100 error("Couldn't write %s", lock->lk->filename.buf);3101 unlock_ref(lock);3102 errno = save_errno;3103 return -1;3104 }3105 clear_loose_ref_cache(&ref_cache);3106 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||3107 (strcmp(lock->ref_name, lock->orig_ref_name) &&3108 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {3109 unlock_ref(lock);3110 return -1;3111 }3112 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {3113 /*3114 * Special hack: If a branch is updated directly and HEAD3115 * points to it (may happen on the remote side of a push3116 * for example) then logically the HEAD reflog should be3117 * updated too.3118 * A generic solution implies reverse symref information,3119 * but finding all symrefs pointing to the given branch3120 * would be rather costly for this rare event (the direct3121 * update of a branch) to be worth it. So let's cheat and3122 * check with HEAD only which should cover 99% of all usage3123 * scenarios (even 100% of the default ones).3124 */3125 unsigned char head_sha1[20];3126 int head_flag;3127 const char *head_ref;3128 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3129 head_sha1, &head_flag);3130 if (head_ref && (head_flag & REF_ISSYMREF) &&3131 !strcmp(head_ref, lock->ref_name))3132 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3133 }3134 if (commit_ref(lock)) {3135 error("Couldn't set %s", lock->ref_name);3136 unlock_ref(lock);3137 return -1;3138 }3139 unlock_ref(lock);3140 return 0;3141}31423143int create_symref(const char *ref_target, const char *refs_heads_master,3144 const char *logmsg)3145{3146 const char *lockpath;3147 char ref[1000];3148 int fd, len, written;3149 char *git_HEAD = git_pathdup("%s", ref_target);3150 unsigned char old_sha1[20], new_sha1[20];31513152 if (logmsg && read_ref(ref_target, old_sha1))3153 hashclr(old_sha1);31543155 if (safe_create_leading_directories(git_HEAD) < 0)3156 return error("unable to create directory for %s", git_HEAD);31573158#ifndef NO_SYMLINK_HEAD3159 if (prefer_symlink_refs) {3160 unlink(git_HEAD);3161 if (!symlink(refs_heads_master, git_HEAD))3162 goto done;3163 fprintf(stderr, "no symlink - falling back to symbolic ref\n");3164 }3165#endif31663167 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);3168 if (sizeof(ref) <= len) {3169 error("refname too long: %s", refs_heads_master);3170 goto error_free_return;3171 }3172 lockpath = mkpath("%s.lock", git_HEAD);3173 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);3174 if (fd < 0) {3175 error("Unable to open %s for writing", lockpath);3176 goto error_free_return;3177 }3178 written = write_in_full(fd, ref, len);3179 if (close(fd) != 0 || written != len) {3180 error("Unable to write to %s", lockpath);3181 goto error_unlink_return;3182 }3183 if (rename(lockpath, git_HEAD) < 0) {3184 error("Unable to create %s", git_HEAD);3185 goto error_unlink_return;3186 }3187 if (adjust_shared_perm(git_HEAD)) {3188 error("Unable to fix permissions on %s", lockpath);3189 error_unlink_return:3190 unlink_or_warn(lockpath);3191 error_free_return:3192 free(git_HEAD);3193 return -1;3194 }31953196#ifndef NO_SYMLINK_HEAD3197 done:3198#endif3199 if (logmsg && !read_ref(refs_heads_master, new_sha1))3200 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);32013202 free(git_HEAD);3203 return 0;3204}32053206struct read_ref_at_cb {3207 const char *refname;3208 unsigned long at_time;3209 int cnt;3210 int reccnt;3211 unsigned char *sha1;3212 int found_it;32133214 unsigned char osha1[20];3215 unsigned char nsha1[20];3216 int tz;3217 unsigned long date;3218 char **msg;3219 unsigned long *cutoff_time;3220 int *cutoff_tz;3221 int *cutoff_cnt;3222};32233224static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,3225 const char *email, unsigned long timestamp, int tz,3226 const char *message, void *cb_data)3227{3228 struct read_ref_at_cb *cb = cb_data;32293230 cb->reccnt++;3231 cb->tz = tz;3232 cb->date = timestamp;32333234 if (timestamp <= cb->at_time || cb->cnt == 0) {3235 if (cb->msg)3236 *cb->msg = xstrdup(message);3237 if (cb->cutoff_time)3238 *cb->cutoff_time = timestamp;3239 if (cb->cutoff_tz)3240 *cb->cutoff_tz = tz;3241 if (cb->cutoff_cnt)3242 *cb->cutoff_cnt = cb->reccnt - 1;3243 /*3244 * we have not yet updated cb->[n|o]sha1 so they still3245 * hold the values for the previous record.3246 */3247 if (!is_null_sha1(cb->osha1)) {3248 hashcpy(cb->sha1, nsha1);3249 if (hashcmp(cb->osha1, nsha1))3250 warning("Log for ref %s has gap after %s.",3251 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));3252 }3253 else if (cb->date == cb->at_time)3254 hashcpy(cb->sha1, nsha1);3255 else if (hashcmp(nsha1, cb->sha1))3256 warning("Log for ref %s unexpectedly ended on %s.",3257 cb->refname, show_date(cb->date, cb->tz,3258 DATE_RFC2822));3259 hashcpy(cb->osha1, osha1);3260 hashcpy(cb->nsha1, nsha1);3261 cb->found_it = 1;3262 return 1;3263 }3264 hashcpy(cb->osha1, osha1);3265 hashcpy(cb->nsha1, nsha1);3266 if (cb->cnt > 0)3267 cb->cnt--;3268 return 0;3269}32703271static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,3272 const char *email, unsigned long timestamp,3273 int tz, const char *message, void *cb_data)3274{3275 struct read_ref_at_cb *cb = cb_data;32763277 if (cb->msg)3278 *cb->msg = xstrdup(message);3279 if (cb->cutoff_time)3280 *cb->cutoff_time = timestamp;3281 if (cb->cutoff_tz)3282 *cb->cutoff_tz = tz;3283 if (cb->cutoff_cnt)3284 *cb->cutoff_cnt = cb->reccnt;3285 hashcpy(cb->sha1, osha1);3286 if (is_null_sha1(cb->sha1))3287 hashcpy(cb->sha1, nsha1);3288 /* We just want the first entry */3289 return 1;3290}32913292int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,3293 unsigned char *sha1, char **msg,3294 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)3295{3296 struct read_ref_at_cb cb;32973298 memset(&cb, 0, sizeof(cb));3299 cb.refname = refname;3300 cb.at_time = at_time;3301 cb.cnt = cnt;3302 cb.msg = msg;3303 cb.cutoff_time = cutoff_time;3304 cb.cutoff_tz = cutoff_tz;3305 cb.cutoff_cnt = cutoff_cnt;3306 cb.sha1 = sha1;33073308 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);33093310 if (!cb.reccnt) {3311 if (flags & GET_SHA1_QUIETLY)3312 exit(128);3313 else3314 die("Log for %s is empty.", refname);3315 }3316 if (cb.found_it)3317 return 0;33183319 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33203321 return 1;3322}33233324int reflog_exists(const char *refname)3325{3326 struct stat st;33273328 return !lstat(git_path("logs/%s", refname), &st) &&3329 S_ISREG(st.st_mode);3330}33313332int delete_reflog(const char *refname)3333{3334 return remove_path(git_path("logs/%s", refname));3335}33363337static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3338{3339 unsigned char osha1[20], nsha1[20];3340 char *email_end, *message;3341 unsigned long timestamp;3342 int tz;33433344 /* old SP new SP name <email> SP time TAB msg LF */3345 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3346 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3347 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3348 !(email_end = strchr(sb->buf + 82, '>')) ||3349 email_end[1] != ' ' ||3350 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3351 !message || message[0] != ' ' ||3352 (message[1] != '+' && message[1] != '-') ||3353 !isdigit(message[2]) || !isdigit(message[3]) ||3354 !isdigit(message[4]) || !isdigit(message[5]))3355 return 0; /* corrupt? */3356 email_end[1] = '\0';3357 tz = strtol(message + 1, NULL, 10);3358 if (message[6] != '\t')3359 message += 6;3360 else3361 message += 7;3362 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3363}33643365static char *find_beginning_of_line(char *bob, char *scan)3366{3367 while (bob < scan && *(--scan) != '\n')3368 ; /* keep scanning backwards */3369 /*3370 * Return either beginning of the buffer, or LF at the end of3371 * the previous line.3372 */3373 return scan;3374}33753376int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3377{3378 struct strbuf sb = STRBUF_INIT;3379 FILE *logfp;3380 long pos;3381 int ret = 0, at_tail = 1;33823383 logfp = fopen(git_path("logs/%s", refname), "r");3384 if (!logfp)3385 return -1;33863387 /* Jump to the end */3388 if (fseek(logfp, 0, SEEK_END) < 0)3389 return error("cannot seek back reflog for %s: %s",3390 refname, strerror(errno));3391 pos = ftell(logfp);3392 while (!ret && 0 < pos) {3393 int cnt;3394 size_t nread;3395 char buf[BUFSIZ];3396 char *endp, *scanp;33973398 /* Fill next block from the end */3399 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3400 if (fseek(logfp, pos - cnt, SEEK_SET))3401 return error("cannot seek back reflog for %s: %s",3402 refname, strerror(errno));3403 nread = fread(buf, cnt, 1, logfp);3404 if (nread != 1)3405 return error("cannot read %d bytes from reflog for %s: %s",3406 cnt, refname, strerror(errno));3407 pos -= cnt;34083409 scanp = endp = buf + cnt;3410 if (at_tail && scanp[-1] == '\n')3411 /* Looking at the final LF at the end of the file */3412 scanp--;3413 at_tail = 0;34143415 while (buf < scanp) {3416 /*3417 * terminating LF of the previous line, or the beginning3418 * of the buffer.3419 */3420 char *bp;34213422 bp = find_beginning_of_line(buf, scanp);34233424 if (*bp == '\n') {3425 /*3426 * The newline is the end of the previous line,3427 * so we know we have complete line starting3428 * at (bp + 1). Prefix it onto any prior data3429 * we collected for the line and process it.3430 */3431 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3432 scanp = bp;3433 endp = bp + 1;3434 ret = show_one_reflog_ent(&sb, fn, cb_data);3435 strbuf_reset(&sb);3436 if (ret)3437 break;3438 } else if (!pos) {3439 /*3440 * We are at the start of the buffer, and the3441 * start of the file; there is no previous3442 * line, and we have everything for this one.3443 * Process it, and we can end the loop.3444 */3445 strbuf_splice(&sb, 0, 0, buf, endp - buf);3446 ret = show_one_reflog_ent(&sb, fn, cb_data);3447 strbuf_reset(&sb);3448 break;3449 }34503451 if (bp == buf) {3452 /*3453 * We are at the start of the buffer, and there3454 * is more file to read backwards. Which means3455 * we are in the middle of a line. Note that we3456 * may get here even if *bp was a newline; that3457 * just means we are at the exact end of the3458 * previous line, rather than some spot in the3459 * middle.3460 *3461 * Save away what we have to be combined with3462 * the data from the next read.3463 */3464 strbuf_splice(&sb, 0, 0, buf, endp - buf);3465 break;3466 }3467 }34683469 }3470 if (!ret && sb.len)3471 die("BUG: reverse reflog parser had leftover data");34723473 fclose(logfp);3474 strbuf_release(&sb);3475 return ret;3476}34773478int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3479{3480 FILE *logfp;3481 struct strbuf sb = STRBUF_INIT;3482 int ret = 0;34833484 logfp = fopen(git_path("logs/%s", refname), "r");3485 if (!logfp)3486 return -1;34873488 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3489 ret = show_one_reflog_ent(&sb, fn, cb_data);3490 fclose(logfp);3491 strbuf_release(&sb);3492 return ret;3493}3494/*3495 * Call fn for each reflog in the namespace indicated by name. name3496 * must be empty or end with '/'. Name will be used as a scratch3497 * space, but its contents will be restored before return.3498 */3499static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3500{3501 DIR *d = opendir(git_path("logs/%s", name->buf));3502 int retval = 0;3503 struct dirent *de;3504 int oldlen = name->len;35053506 if (!d)3507 return name->len ? errno : 0;35083509 while ((de = readdir(d)) != NULL) {3510 struct stat st;35113512 if (de->d_name[0] == '.')3513 continue;3514 if (ends_with(de->d_name, ".lock"))3515 continue;3516 strbuf_addstr(name, de->d_name);3517 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3518 ; /* silently ignore */3519 } else {3520 if (S_ISDIR(st.st_mode)) {3521 strbuf_addch(name, '/');3522 retval = do_for_each_reflog(name, fn, cb_data);3523 } else {3524 unsigned char sha1[20];3525 if (read_ref_full(name->buf, 0, sha1, NULL))3526 retval = error("bad ref for %s", name->buf);3527 else3528 retval = fn(name->buf, sha1, 0, cb_data);3529 }3530 if (retval)3531 break;3532 }3533 strbuf_setlen(name, oldlen);3534 }3535 closedir(d);3536 return retval;3537}35383539int for_each_reflog(each_ref_fn fn, void *cb_data)3540{3541 int retval;3542 struct strbuf name;3543 strbuf_init(&name, PATH_MAX);3544 retval = do_for_each_reflog(&name, fn, cb_data);3545 strbuf_release(&name);3546 return retval;3547}35483549/**3550 * Information needed for a single ref update. Set new_sha1 to the3551 * new value or to zero to delete the ref. To check the old value3552 * while locking the ref, set have_old to 1 and set old_sha1 to the3553 * value or to zero to ensure the ref does not exist before update.3554 */3555struct ref_update {3556 unsigned char new_sha1[20];3557 unsigned char old_sha1[20];3558 int flags; /* REF_NODEREF? */3559 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */3560 struct ref_lock *lock;3561 int type;3562 char *msg;3563 const char refname[FLEX_ARRAY];3564};35653566/*3567 * Transaction states.3568 * OPEN: The transaction is in a valid state and can accept new updates.3569 * An OPEN transaction can be committed.3570 * CLOSED: A closed transaction is no longer active and no other operations3571 * than free can be used on it in this state.3572 * A transaction can either become closed by successfully committing3573 * an active transaction or if there is a failure while building3574 * the transaction thus rendering it failed/inactive.3575 */3576enum ref_transaction_state {3577 REF_TRANSACTION_OPEN = 0,3578 REF_TRANSACTION_CLOSED = 13579};35803581/*3582 * Data structure for holding a reference transaction, which can3583 * consist of checks and updates to multiple references, carried out3584 * as atomically as possible. This structure is opaque to callers.3585 */3586struct ref_transaction {3587 struct ref_update **updates;3588 size_t alloc;3589 size_t nr;3590 enum ref_transaction_state state;3591};35923593struct ref_transaction *ref_transaction_begin(struct strbuf *err)3594{3595 assert(err);35963597 return xcalloc(1, sizeof(struct ref_transaction));3598}35993600void ref_transaction_free(struct ref_transaction *transaction)3601{3602 int i;36033604 if (!transaction)3605 return;36063607 for (i = 0; i < transaction->nr; i++) {3608 free(transaction->updates[i]->msg);3609 free(transaction->updates[i]);3610 }3611 free(transaction->updates);3612 free(transaction);3613}36143615static struct ref_update *add_update(struct ref_transaction *transaction,3616 const char *refname)3617{3618 size_t len = strlen(refname);3619 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);36203621 strcpy((char *)update->refname, refname);3622 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);3623 transaction->updates[transaction->nr++] = update;3624 return update;3625}36263627int ref_transaction_update(struct ref_transaction *transaction,3628 const char *refname,3629 const unsigned char *new_sha1,3630 const unsigned char *old_sha1,3631 int flags, int have_old, const char *msg,3632 struct strbuf *err)3633{3634 struct ref_update *update;36353636 assert(err);36373638 if (transaction->state != REF_TRANSACTION_OPEN)3639 die("BUG: update called for transaction that is not open");36403641 if (have_old && !old_sha1)3642 die("BUG: have_old is true but old_sha1 is NULL");36433644 if (!is_null_sha1(new_sha1) &&3645 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3646 strbuf_addf(err, "refusing to update ref with bad name %s",3647 refname);3648 return -1;3649 }36503651 update = add_update(transaction, refname);3652 hashcpy(update->new_sha1, new_sha1);3653 update->flags = flags;3654 update->have_old = have_old;3655 if (have_old)3656 hashcpy(update->old_sha1, old_sha1);3657 if (msg)3658 update->msg = xstrdup(msg);3659 return 0;3660}36613662int ref_transaction_create(struct ref_transaction *transaction,3663 const char *refname,3664 const unsigned char *new_sha1,3665 int flags, const char *msg,3666 struct strbuf *err)3667{3668 struct ref_update *update;36693670 assert(err);36713672 if (transaction->state != REF_TRANSACTION_OPEN)3673 die("BUG: create called for transaction that is not open");36743675 if (!new_sha1 || is_null_sha1(new_sha1))3676 die("BUG: create ref with null new_sha1");36773678 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3679 strbuf_addf(err, "refusing to create ref with bad name %s",3680 refname);3681 return -1;3682 }36833684 update = add_update(transaction, refname);36853686 hashcpy(update->new_sha1, new_sha1);3687 hashclr(update->old_sha1);3688 update->flags = flags;3689 update->have_old = 1;3690 if (msg)3691 update->msg = xstrdup(msg);3692 return 0;3693}36943695int ref_transaction_delete(struct ref_transaction *transaction,3696 const char *refname,3697 const unsigned char *old_sha1,3698 int flags, int have_old, const char *msg,3699 struct strbuf *err)3700{3701 struct ref_update *update;37023703 assert(err);37043705 if (transaction->state != REF_TRANSACTION_OPEN)3706 die("BUG: delete called for transaction that is not open");37073708 if (have_old && !old_sha1)3709 die("BUG: have_old is true but old_sha1 is NULL");37103711 update = add_update(transaction, refname);3712 update->flags = flags;3713 update->have_old = have_old;3714 if (have_old) {3715 assert(!is_null_sha1(old_sha1));3716 hashcpy(update->old_sha1, old_sha1);3717 }3718 if (msg)3719 update->msg = xstrdup(msg);3720 return 0;3721}37223723int update_ref(const char *action, const char *refname,3724 const unsigned char *sha1, const unsigned char *oldval,3725 int flags, enum action_on_err onerr)3726{3727 struct ref_transaction *t;3728 struct strbuf err = STRBUF_INIT;37293730 t = ref_transaction_begin(&err);3731 if (!t ||3732 ref_transaction_update(t, refname, sha1, oldval, flags,3733 !!oldval, action, &err) ||3734 ref_transaction_commit(t, &err)) {3735 const char *str = "update_ref failed for ref '%s': %s";37363737 ref_transaction_free(t);3738 switch (onerr) {3739 case UPDATE_REFS_MSG_ON_ERR:3740 error(str, refname, err.buf);3741 break;3742 case UPDATE_REFS_DIE_ON_ERR:3743 die(str, refname, err.buf);3744 break;3745 case UPDATE_REFS_QUIET_ON_ERR:3746 break;3747 }3748 strbuf_release(&err);3749 return 1;3750 }3751 strbuf_release(&err);3752 ref_transaction_free(t);3753 return 0;3754}37553756static int ref_update_compare(const void *r1, const void *r2)3757{3758 const struct ref_update * const *u1 = r1;3759 const struct ref_update * const *u2 = r2;3760 return strcmp((*u1)->refname, (*u2)->refname);3761}37623763static int ref_update_reject_duplicates(struct ref_update **updates, int n,3764 struct strbuf *err)3765{3766 int i;37673768 assert(err);37693770 for (i = 1; i < n; i++)3771 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {3772 strbuf_addf(err,3773 "Multiple updates for ref '%s' not allowed.",3774 updates[i]->refname);3775 return 1;3776 }3777 return 0;3778}37793780int ref_transaction_commit(struct ref_transaction *transaction,3781 struct strbuf *err)3782{3783 int ret = 0, i;3784 int n = transaction->nr;3785 struct ref_update **updates = transaction->updates;3786 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3787 struct string_list_item *ref_to_delete;37883789 assert(err);37903791 if (transaction->state != REF_TRANSACTION_OPEN)3792 die("BUG: commit called for transaction that is not open");37933794 if (!n) {3795 transaction->state = REF_TRANSACTION_CLOSED;3796 return 0;3797 }37983799 /* Copy, sort, and reject duplicate refs */3800 qsort(updates, n, sizeof(*updates), ref_update_compare);3801 if (ref_update_reject_duplicates(updates, n, err)) {3802 ret = TRANSACTION_GENERIC_ERROR;3803 goto cleanup;3804 }38053806 /* Acquire all locks while verifying old values */3807 for (i = 0; i < n; i++) {3808 struct ref_update *update = updates[i];3809 int flags = update->flags;38103811 if (is_null_sha1(update->new_sha1))3812 flags |= REF_DELETING;3813 update->lock = lock_ref_sha1_basic(update->refname,3814 (update->have_old ?3815 update->old_sha1 :3816 NULL),3817 NULL,3818 flags,3819 &update->type);3820 if (!update->lock) {3821 ret = (errno == ENOTDIR)3822 ? TRANSACTION_NAME_CONFLICT3823 : TRANSACTION_GENERIC_ERROR;3824 strbuf_addf(err, "Cannot lock the ref '%s'.",3825 update->refname);3826 goto cleanup;3827 }3828 }38293830 /* Perform updates first so live commits remain referenced */3831 for (i = 0; i < n; i++) {3832 struct ref_update *update = updates[i];38333834 if (!is_null_sha1(update->new_sha1)) {3835 if (write_ref_sha1(update->lock, update->new_sha1,3836 update->msg)) {3837 update->lock = NULL; /* freed by write_ref_sha1 */3838 strbuf_addf(err, "Cannot update the ref '%s'.",3839 update->refname);3840 ret = TRANSACTION_GENERIC_ERROR;3841 goto cleanup;3842 }3843 update->lock = NULL; /* freed by write_ref_sha1 */3844 }3845 }38463847 /* Perform deletes now that updates are safely completed */3848 for (i = 0; i < n; i++) {3849 struct ref_update *update = updates[i];38503851 if (update->lock) {3852 if (delete_ref_loose(update->lock, update->type, err)) {3853 ret = TRANSACTION_GENERIC_ERROR;3854 goto cleanup;3855 }38563857 if (!(update->flags & REF_ISPRUNING))3858 string_list_append(&refs_to_delete,3859 update->lock->ref_name);3860 }3861 }38623863 if (repack_without_refs(&refs_to_delete, err)) {3864 ret = TRANSACTION_GENERIC_ERROR;3865 goto cleanup;3866 }3867 for_each_string_list_item(ref_to_delete, &refs_to_delete)3868 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3869 clear_loose_ref_cache(&ref_cache);38703871cleanup:3872 transaction->state = REF_TRANSACTION_CLOSED;38733874 for (i = 0; i < n; i++)3875 if (updates[i]->lock)3876 unlock_ref(updates[i]->lock);3877 string_list_clear(&refs_to_delete, 0);3878 return ret;3879}38803881char *shorten_unambiguous_ref(const char *refname, int strict)3882{3883 int i;3884 static char **scanf_fmts;3885 static int nr_rules;3886 char *short_name;38873888 if (!nr_rules) {3889 /*3890 * Pre-generate scanf formats from ref_rev_parse_rules[].3891 * Generate a format suitable for scanf from a3892 * ref_rev_parse_rules rule by interpolating "%s" at the3893 * location of the "%.*s".3894 */3895 size_t total_len = 0;3896 size_t offset = 0;38973898 /* the rule list is NULL terminated, count them first */3899 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)3900 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3901 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;39023903 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);39043905 offset = 0;3906 for (i = 0; i < nr_rules; i++) {3907 assert(offset < total_len);3908 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;3909 offset += snprintf(scanf_fmts[i], total_len - offset,3910 ref_rev_parse_rules[i], 2, "%s") + 1;3911 }3912 }39133914 /* bail out if there are no rules */3915 if (!nr_rules)3916 return xstrdup(refname);39173918 /* buffer for scanf result, at most refname must fit */3919 short_name = xstrdup(refname);39203921 /* skip first rule, it will always match */3922 for (i = nr_rules - 1; i > 0 ; --i) {3923 int j;3924 int rules_to_fail = i;3925 int short_name_len;39263927 if (1 != sscanf(refname, scanf_fmts[i], short_name))3928 continue;39293930 short_name_len = strlen(short_name);39313932 /*3933 * in strict mode, all (except the matched one) rules3934 * must fail to resolve to a valid non-ambiguous ref3935 */3936 if (strict)3937 rules_to_fail = nr_rules;39383939 /*3940 * check if the short name resolves to a valid ref,3941 * but use only rules prior to the matched one3942 */3943 for (j = 0; j < rules_to_fail; j++) {3944 const char *rule = ref_rev_parse_rules[j];3945 char refname[PATH_MAX];39463947 /* skip matched rule */3948 if (i == j)3949 continue;39503951 /*3952 * the short name is ambiguous, if it resolves3953 * (with this previous rule) to a valid ref3954 * read_ref() returns 0 on success3955 */3956 mksnpath(refname, sizeof(refname),3957 rule, short_name_len, short_name);3958 if (ref_exists(refname))3959 break;3960 }39613962 /*3963 * short name is non-ambiguous if all previous rules3964 * haven't resolved to a valid ref3965 */3966 if (j == rules_to_fail)3967 return short_name;3968 }39693970 free(short_name);3971 return xstrdup(refname);3972}39733974static struct string_list *hide_refs;39753976int parse_hide_refs_config(const char *var, const char *value, const char *section)3977{3978 if (!strcmp("transfer.hiderefs", var) ||3979 /* NEEDSWORK: use parse_config_key() once both are merged */3980 (starts_with(var, section) && var[strlen(section)] == '.' &&3981 !strcmp(var + strlen(section), ".hiderefs"))) {3982 char *ref;3983 int len;39843985 if (!value)3986 return config_error_nonbool(var);3987 ref = xstrdup(value);3988 len = strlen(ref);3989 while (len && ref[len - 1] == '/')3990 ref[--len] = '\0';3991 if (!hide_refs) {3992 hide_refs = xcalloc(1, sizeof(*hide_refs));3993 hide_refs->strdup_strings = 1;3994 }3995 string_list_append(hide_refs, ref);3996 }3997 return 0;3998}39994000int ref_is_hidden(const char *refname)4001{4002 struct string_list_item *item;40034004 if (!hide_refs)4005 return 0;4006 for_each_string_list_item(item, hide_refs) {4007 int len;4008 if (!starts_with(refname, item->string))4009 continue;4010 len = strlen(item->string);4011 if (!refname[len] || refname[len] == '/')4012 return 1;4013 }4014 return 0;4015}