1#include "cache.h" 2#include "refs.h" 3#include "object.h" 4#include "tag.h" 5#include "dir.h" 6#include "string-list.h" 7 8/* 9 * How to handle various characters in refnames: 10 * 0: An acceptable character for refs 11 * 1: End-of-component 12 * 2: ., look for a preceding . to reject .. in refs 13 * 3: {, look for a preceding @ to reject @{ in refs 14 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 15 */ 16static unsigned char refname_disposition[256] = { 17 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 18 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 19 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1, 20 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0, 23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 25}; 26 27/* 28 * Try to read one refname component from the front of refname. 29 * Return the length of the component found, or -1 if the component is 30 * not legal. It is legal if it is something reasonable to have under 31 * ".git/refs/"; We do not like it if: 32 * 33 * - any path component of it begins with ".", or 34 * - it has double dots "..", or 35 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 36 * - it ends with a "/". 37 * - it ends with ".lock" 38 * - it contains a "\" (backslash) 39 */ 40static int check_refname_component(const char *refname, int flags) 41{ 42 const char *cp; 43 char last = '\0'; 44 45 for (cp = refname; ; cp++) { 46 int ch = *cp & 255; 47 unsigned char disp = refname_disposition[ch]; 48 switch (disp) { 49 case 1: 50 goto out; 51 case 2: 52 if (last == '.') 53 return -1; /* Refname contains "..". */ 54 break; 55 case 3: 56 if (last == '@') 57 return -1; /* Refname contains "@{". */ 58 break; 59 case 4: 60 return -1; 61 } 62 last = ch; 63 } 64out: 65 if (cp == refname) 66 return 0; /* Component has zero length. */ 67 if (refname[0] == '.') { 68 if (!(flags & REFNAME_DOT_COMPONENT)) 69 return -1; /* Component starts with '.'. */ 70 /* 71 * Even if leading dots are allowed, don't allow "." 72 * as a component (".." is prevented by a rule above). 73 */ 74 if (refname[1] == '\0') 75 return -1; /* Component equals ".". */ 76 } 77 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5)) 78 return -1; /* Refname ends with ".lock". */ 79 return cp - refname; 80} 81 82int check_refname_format(const char *refname, int flags) 83{ 84 int component_len, component_count = 0; 85 86 if (!strcmp(refname, "@")) 87 /* Refname is a single character '@'. */ 88 return -1; 89 90 while (1) { 91 /* We are at the start of a path component. */ 92 component_len = check_refname_component(refname, flags); 93 if (component_len <= 0) { 94 if ((flags & REFNAME_REFSPEC_PATTERN) && 95 refname[0] == '*' && 96 (refname[1] == '\0' || refname[1] == '/')) { 97 /* Accept one wildcard as a full refname component. */ 98 flags &= ~REFNAME_REFSPEC_PATTERN; 99 component_len = 1; 100 } else { 101 return -1; 102 } 103 } 104 component_count++; 105 if (refname[component_len] == '\0') 106 break; 107 /* Skip to next component. */ 108 refname += component_len + 1; 109 } 110 111 if (refname[component_len - 1] == '.') 112 return -1; /* Refname ends with '.'. */ 113 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) 114 return -1; /* Refname has only one component. */ 115 return 0; 116} 117 118struct ref_entry; 119 120/* 121 * Information used (along with the information in ref_entry) to 122 * describe a single cached reference. This data structure only 123 * occurs embedded in a union in struct ref_entry, and only when 124 * (ref_entry->flag & REF_DIR) is zero. 125 */ 126struct ref_value { 127 /* 128 * The name of the object to which this reference resolves 129 * (which may be a tag object). If REF_ISBROKEN, this is 130 * null. If REF_ISSYMREF, then this is the name of the object 131 * referred to by the last reference in the symlink chain. 132 */ 133 unsigned char sha1[20]; 134 135 /* 136 * If REF_KNOWS_PEELED, then this field holds the peeled value 137 * of this reference, or null if the reference is known not to 138 * be peelable. See the documentation for peel_ref() for an 139 * exact definition of "peelable". 140 */ 141 unsigned char peeled[20]; 142}; 143 144struct ref_cache; 145 146/* 147 * Information used (along with the information in ref_entry) to 148 * describe a level in the hierarchy of references. This data 149 * structure only occurs embedded in a union in struct ref_entry, and 150 * only when (ref_entry.flag & REF_DIR) is set. In that case, 151 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 152 * in the directory have already been read: 153 * 154 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 155 * or packed references, already read. 156 * 157 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 158 * references that hasn't been read yet (nor has any of its 159 * subdirectories). 160 * 161 * Entries within a directory are stored within a growable array of 162 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 163 * sorted are sorted by their component name in strcmp() order and the 164 * remaining entries are unsorted. 165 * 166 * Loose references are read lazily, one directory at a time. When a 167 * directory of loose references is read, then all of the references 168 * in that directory are stored, and REF_INCOMPLETE stubs are created 169 * for any subdirectories, but the subdirectories themselves are not 170 * read. The reading is triggered by get_ref_dir(). 171 */ 172struct ref_dir { 173 int nr, alloc; 174 175 /* 176 * Entries with index 0 <= i < sorted are sorted by name. New 177 * entries are appended to the list unsorted, and are sorted 178 * only when required; thus we avoid the need to sort the list 179 * after the addition of every reference. 180 */ 181 int sorted; 182 183 /* A pointer to the ref_cache that contains this ref_dir. */ 184 struct ref_cache *ref_cache; 185 186 struct ref_entry **entries; 187}; 188 189/* 190 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 191 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 192 * refs.h. 193 */ 194 195/* 196 * The field ref_entry->u.value.peeled of this value entry contains 197 * the correct peeled value for the reference, which might be 198 * null_sha1 if the reference is not a tag or if it is broken. 199 */ 200#define REF_KNOWS_PEELED 0x08 201 202/* ref_entry represents a directory of references */ 203#define REF_DIR 0x10 204 205/* 206 * Entry has not yet been read from disk (used only for REF_DIR 207 * entries representing loose references) 208 */ 209#define REF_INCOMPLETE 0x20 210 211/* 212 * A ref_entry represents either a reference or a "subdirectory" of 213 * references. 214 * 215 * Each directory in the reference namespace is represented by a 216 * ref_entry with (flags & REF_DIR) set and containing a subdir member 217 * that holds the entries in that directory that have been read so 218 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 219 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 220 * used for loose reference directories. 221 * 222 * References are represented by a ref_entry with (flags & REF_DIR) 223 * unset and a value member that describes the reference's value. The 224 * flag member is at the ref_entry level, but it is also needed to 225 * interpret the contents of the value field (in other words, a 226 * ref_value object is not very much use without the enclosing 227 * ref_entry). 228 * 229 * Reference names cannot end with slash and directories' names are 230 * always stored with a trailing slash (except for the top-level 231 * directory, which is always denoted by ""). This has two nice 232 * consequences: (1) when the entries in each subdir are sorted 233 * lexicographically by name (as they usually are), the references in 234 * a whole tree can be generated in lexicographic order by traversing 235 * the tree in left-to-right, depth-first order; (2) the names of 236 * references and subdirectories cannot conflict, and therefore the 237 * presence of an empty subdirectory does not block the creation of a 238 * similarly-named reference. (The fact that reference names with the 239 * same leading components can conflict *with each other* is a 240 * separate issue that is regulated by is_refname_available().) 241 * 242 * Please note that the name field contains the fully-qualified 243 * reference (or subdirectory) name. Space could be saved by only 244 * storing the relative names. But that would require the full names 245 * to be generated on the fly when iterating in do_for_each_ref(), and 246 * would break callback functions, who have always been able to assume 247 * that the name strings that they are passed will not be freed during 248 * the iteration. 249 */ 250struct ref_entry { 251 unsigned char flag; /* ISSYMREF? ISPACKED? */ 252 union { 253 struct ref_value value; /* if not (flags&REF_DIR) */ 254 struct ref_dir subdir; /* if (flags&REF_DIR) */ 255 } u; 256 /* 257 * The full name of the reference (e.g., "refs/heads/master") 258 * or the full name of the directory with a trailing slash 259 * (e.g., "refs/heads/"): 260 */ 261 char name[FLEX_ARRAY]; 262}; 263 264static void read_loose_refs(const char *dirname, struct ref_dir *dir); 265 266static struct ref_dir *get_ref_dir(struct ref_entry *entry) 267{ 268 struct ref_dir *dir; 269 assert(entry->flag & REF_DIR); 270 dir = &entry->u.subdir; 271 if (entry->flag & REF_INCOMPLETE) { 272 read_loose_refs(entry->name, dir); 273 entry->flag &= ~REF_INCOMPLETE; 274 } 275 return dir; 276} 277 278static struct ref_entry *create_ref_entry(const char *refname, 279 const unsigned char *sha1, int flag, 280 int check_name) 281{ 282 int len; 283 struct ref_entry *ref; 284 285 if (check_name && 286 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 287 die("Reference has invalid format: '%s'", refname); 288 len = strlen(refname) + 1; 289 ref = xmalloc(sizeof(struct ref_entry) + len); 290 hashcpy(ref->u.value.sha1, sha1); 291 hashclr(ref->u.value.peeled); 292 memcpy(ref->name, refname, len); 293 ref->flag = flag; 294 return ref; 295} 296 297static void clear_ref_dir(struct ref_dir *dir); 298 299static void free_ref_entry(struct ref_entry *entry) 300{ 301 if (entry->flag & REF_DIR) { 302 /* 303 * Do not use get_ref_dir() here, as that might 304 * trigger the reading of loose refs. 305 */ 306 clear_ref_dir(&entry->u.subdir); 307 } 308 free(entry); 309} 310 311/* 312 * Add a ref_entry to the end of dir (unsorted). Entry is always 313 * stored directly in dir; no recursion into subdirectories is 314 * done. 315 */ 316static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) 317{ 318 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); 319 dir->entries[dir->nr++] = entry; 320 /* optimize for the case that entries are added in order */ 321 if (dir->nr == 1 || 322 (dir->nr == dir->sorted + 1 && 323 strcmp(dir->entries[dir->nr - 2]->name, 324 dir->entries[dir->nr - 1]->name) < 0)) 325 dir->sorted = dir->nr; 326} 327 328/* 329 * Clear and free all entries in dir, recursively. 330 */ 331static void clear_ref_dir(struct ref_dir *dir) 332{ 333 int i; 334 for (i = 0; i < dir->nr; i++) 335 free_ref_entry(dir->entries[i]); 336 free(dir->entries); 337 dir->sorted = dir->nr = dir->alloc = 0; 338 dir->entries = NULL; 339} 340 341/* 342 * Create a struct ref_entry object for the specified dirname. 343 * dirname is the name of the directory with a trailing slash (e.g., 344 * "refs/heads/") or "" for the top-level directory. 345 */ 346static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 347 const char *dirname, size_t len, 348 int incomplete) 349{ 350 struct ref_entry *direntry; 351 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); 352 memcpy(direntry->name, dirname, len); 353 direntry->name[len] = '\0'; 354 direntry->u.subdir.ref_cache = ref_cache; 355 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); 356 return direntry; 357} 358 359static int ref_entry_cmp(const void *a, const void *b) 360{ 361 struct ref_entry *one = *(struct ref_entry **)a; 362 struct ref_entry *two = *(struct ref_entry **)b; 363 return strcmp(one->name, two->name); 364} 365 366static void sort_ref_dir(struct ref_dir *dir); 367 368struct string_slice { 369 size_t len; 370 const char *str; 371}; 372 373static int ref_entry_cmp_sslice(const void *key_, const void *ent_) 374{ 375 const struct string_slice *key = key_; 376 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; 377 int cmp = strncmp(key->str, ent->name, key->len); 378 if (cmp) 379 return cmp; 380 return '\0' - (unsigned char)ent->name[key->len]; 381} 382 383/* 384 * Return the index of the entry with the given refname from the 385 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 386 * no such entry is found. dir must already be complete. 387 */ 388static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) 389{ 390 struct ref_entry **r; 391 struct string_slice key; 392 393 if (refname == NULL || !dir->nr) 394 return -1; 395 396 sort_ref_dir(dir); 397 key.len = len; 398 key.str = refname; 399 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), 400 ref_entry_cmp_sslice); 401 402 if (r == NULL) 403 return -1; 404 405 return r - dir->entries; 406} 407 408/* 409 * Search for a directory entry directly within dir (without 410 * recursing). Sort dir if necessary. subdirname must be a directory 411 * name (i.e., end in '/'). If mkdir is set, then create the 412 * directory if it is missing; otherwise, return NULL if the desired 413 * directory cannot be found. dir must already be complete. 414 */ 415static struct ref_dir *search_for_subdir(struct ref_dir *dir, 416 const char *subdirname, size_t len, 417 int mkdir) 418{ 419 int entry_index = search_ref_dir(dir, subdirname, len); 420 struct ref_entry *entry; 421 if (entry_index == -1) { 422 if (!mkdir) 423 return NULL; 424 /* 425 * Since dir is complete, the absence of a subdir 426 * means that the subdir really doesn't exist; 427 * therefore, create an empty record for it but mark 428 * the record complete. 429 */ 430 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); 431 add_entry_to_dir(dir, entry); 432 } else { 433 entry = dir->entries[entry_index]; 434 } 435 return get_ref_dir(entry); 436} 437 438/* 439 * If refname is a reference name, find the ref_dir within the dir 440 * tree that should hold refname. If refname is a directory name 441 * (i.e., ends in '/'), then return that ref_dir itself. dir must 442 * represent the top-level directory and must already be complete. 443 * Sort ref_dirs and recurse into subdirectories as necessary. If 444 * mkdir is set, then create any missing directories; otherwise, 445 * return NULL if the desired directory cannot be found. 446 */ 447static struct ref_dir *find_containing_dir(struct ref_dir *dir, 448 const char *refname, int mkdir) 449{ 450 const char *slash; 451 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { 452 size_t dirnamelen = slash - refname + 1; 453 struct ref_dir *subdir; 454 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); 455 if (!subdir) { 456 dir = NULL; 457 break; 458 } 459 dir = subdir; 460 } 461 462 return dir; 463} 464 465/* 466 * Find the value entry with the given name in dir, sorting ref_dirs 467 * and recursing into subdirectories as necessary. If the name is not 468 * found or it corresponds to a directory entry, return NULL. 469 */ 470static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) 471{ 472 int entry_index; 473 struct ref_entry *entry; 474 dir = find_containing_dir(dir, refname, 0); 475 if (!dir) 476 return NULL; 477 entry_index = search_ref_dir(dir, refname, strlen(refname)); 478 if (entry_index == -1) 479 return NULL; 480 entry = dir->entries[entry_index]; 481 return (entry->flag & REF_DIR) ? NULL : entry; 482} 483 484/* 485 * Remove the entry with the given name from dir, recursing into 486 * subdirectories as necessary. If refname is the name of a directory 487 * (i.e., ends with '/'), then remove the directory and its contents. 488 * If the removal was successful, return the number of entries 489 * remaining in the directory entry that contained the deleted entry. 490 * If the name was not found, return -1. Please note that this 491 * function only deletes the entry from the cache; it does not delete 492 * it from the filesystem or ensure that other cache entries (which 493 * might be symbolic references to the removed entry) are updated. 494 * Nor does it remove any containing dir entries that might be made 495 * empty by the removal. dir must represent the top-level directory 496 * and must already be complete. 497 */ 498static int remove_entry(struct ref_dir *dir, const char *refname) 499{ 500 int refname_len = strlen(refname); 501 int entry_index; 502 struct ref_entry *entry; 503 int is_dir = refname[refname_len - 1] == '/'; 504 if (is_dir) { 505 /* 506 * refname represents a reference directory. Remove 507 * the trailing slash; otherwise we will get the 508 * directory *representing* refname rather than the 509 * one *containing* it. 510 */ 511 char *dirname = xmemdupz(refname, refname_len - 1); 512 dir = find_containing_dir(dir, dirname, 0); 513 free(dirname); 514 } else { 515 dir = find_containing_dir(dir, refname, 0); 516 } 517 if (!dir) 518 return -1; 519 entry_index = search_ref_dir(dir, refname, refname_len); 520 if (entry_index == -1) 521 return -1; 522 entry = dir->entries[entry_index]; 523 524 memmove(&dir->entries[entry_index], 525 &dir->entries[entry_index + 1], 526 (dir->nr - entry_index - 1) * sizeof(*dir->entries) 527 ); 528 dir->nr--; 529 if (dir->sorted > entry_index) 530 dir->sorted--; 531 free_ref_entry(entry); 532 return dir->nr; 533} 534 535/* 536 * Add a ref_entry to the ref_dir (unsorted), recursing into 537 * subdirectories as necessary. dir must represent the top-level 538 * directory. Return 0 on success. 539 */ 540static int add_ref(struct ref_dir *dir, struct ref_entry *ref) 541{ 542 dir = find_containing_dir(dir, ref->name, 1); 543 if (!dir) 544 return -1; 545 add_entry_to_dir(dir, ref); 546 return 0; 547} 548 549/* 550 * Emit a warning and return true iff ref1 and ref2 have the same name 551 * and the same sha1. Die if they have the same name but different 552 * sha1s. 553 */ 554static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) 555{ 556 if (strcmp(ref1->name, ref2->name)) 557 return 0; 558 559 /* Duplicate name; make sure that they don't conflict: */ 560 561 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 562 /* This is impossible by construction */ 563 die("Reference directory conflict: %s", ref1->name); 564 565 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 566 die("Duplicated ref, and SHA1s don't match: %s", ref1->name); 567 568 warning("Duplicated ref: %s", ref1->name); 569 return 1; 570} 571 572/* 573 * Sort the entries in dir non-recursively (if they are not already 574 * sorted) and remove any duplicate entries. 575 */ 576static void sort_ref_dir(struct ref_dir *dir) 577{ 578 int i, j; 579 struct ref_entry *last = NULL; 580 581 /* 582 * This check also prevents passing a zero-length array to qsort(), 583 * which is a problem on some platforms. 584 */ 585 if (dir->sorted == dir->nr) 586 return; 587 588 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); 589 590 /* Remove any duplicates: */ 591 for (i = 0, j = 0; j < dir->nr; j++) { 592 struct ref_entry *entry = dir->entries[j]; 593 if (last && is_dup_ref(last, entry)) 594 free_ref_entry(entry); 595 else 596 last = dir->entries[i++] = entry; 597 } 598 dir->sorted = dir->nr = i; 599} 600 601/* Include broken references in a do_for_each_ref*() iteration: */ 602#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 603 604/* 605 * Return true iff the reference described by entry can be resolved to 606 * an object in the database. Emit a warning if the referred-to 607 * object does not exist. 608 */ 609static int ref_resolves_to_object(struct ref_entry *entry) 610{ 611 if (entry->flag & REF_ISBROKEN) 612 return 0; 613 if (!has_sha1_file(entry->u.value.sha1)) { 614 error("%s does not point to a valid object!", entry->name); 615 return 0; 616 } 617 return 1; 618} 619 620/* 621 * current_ref is a performance hack: when iterating over references 622 * using the for_each_ref*() functions, current_ref is set to the 623 * current reference's entry before calling the callback function. If 624 * the callback function calls peel_ref(), then peel_ref() first 625 * checks whether the reference to be peeled is the current reference 626 * (it usually is) and if so, returns that reference's peeled version 627 * if it is available. This avoids a refname lookup in a common case. 628 */ 629static struct ref_entry *current_ref; 630 631typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); 632 633struct ref_entry_cb { 634 const char *base; 635 int trim; 636 int flags; 637 each_ref_fn *fn; 638 void *cb_data; 639}; 640 641/* 642 * Handle one reference in a do_for_each_ref*()-style iteration, 643 * calling an each_ref_fn for each entry. 644 */ 645static int do_one_ref(struct ref_entry *entry, void *cb_data) 646{ 647 struct ref_entry_cb *data = cb_data; 648 struct ref_entry *old_current_ref; 649 int retval; 650 651 if (!starts_with(entry->name, data->base)) 652 return 0; 653 654 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 655 !ref_resolves_to_object(entry)) 656 return 0; 657 658 /* Store the old value, in case this is a recursive call: */ 659 old_current_ref = current_ref; 660 current_ref = entry; 661 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 662 entry->flag, data->cb_data); 663 current_ref = old_current_ref; 664 return retval; 665} 666 667/* 668 * Call fn for each reference in dir that has index in the range 669 * offset <= index < dir->nr. Recurse into subdirectories that are in 670 * that index range, sorting them before iterating. This function 671 * does not sort dir itself; it should be sorted beforehand. fn is 672 * called for all references, including broken ones. 673 */ 674static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, 675 each_ref_entry_fn fn, void *cb_data) 676{ 677 int i; 678 assert(dir->sorted == dir->nr); 679 for (i = offset; i < dir->nr; i++) { 680 struct ref_entry *entry = dir->entries[i]; 681 int retval; 682 if (entry->flag & REF_DIR) { 683 struct ref_dir *subdir = get_ref_dir(entry); 684 sort_ref_dir(subdir); 685 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); 686 } else { 687 retval = fn(entry, cb_data); 688 } 689 if (retval) 690 return retval; 691 } 692 return 0; 693} 694 695/* 696 * Call fn for each reference in the union of dir1 and dir2, in order 697 * by refname. Recurse into subdirectories. If a value entry appears 698 * in both dir1 and dir2, then only process the version that is in 699 * dir2. The input dirs must already be sorted, but subdirs will be 700 * sorted as needed. fn is called for all references, including 701 * broken ones. 702 */ 703static int do_for_each_entry_in_dirs(struct ref_dir *dir1, 704 struct ref_dir *dir2, 705 each_ref_entry_fn fn, void *cb_data) 706{ 707 int retval; 708 int i1 = 0, i2 = 0; 709 710 assert(dir1->sorted == dir1->nr); 711 assert(dir2->sorted == dir2->nr); 712 while (1) { 713 struct ref_entry *e1, *e2; 714 int cmp; 715 if (i1 == dir1->nr) { 716 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); 717 } 718 if (i2 == dir2->nr) { 719 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); 720 } 721 e1 = dir1->entries[i1]; 722 e2 = dir2->entries[i2]; 723 cmp = strcmp(e1->name, e2->name); 724 if (cmp == 0) { 725 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 726 /* Both are directories; descend them in parallel. */ 727 struct ref_dir *subdir1 = get_ref_dir(e1); 728 struct ref_dir *subdir2 = get_ref_dir(e2); 729 sort_ref_dir(subdir1); 730 sort_ref_dir(subdir2); 731 retval = do_for_each_entry_in_dirs( 732 subdir1, subdir2, fn, cb_data); 733 i1++; 734 i2++; 735 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 736 /* Both are references; ignore the one from dir1. */ 737 retval = fn(e2, cb_data); 738 i1++; 739 i2++; 740 } else { 741 die("conflict between reference and directory: %s", 742 e1->name); 743 } 744 } else { 745 struct ref_entry *e; 746 if (cmp < 0) { 747 e = e1; 748 i1++; 749 } else { 750 e = e2; 751 i2++; 752 } 753 if (e->flag & REF_DIR) { 754 struct ref_dir *subdir = get_ref_dir(e); 755 sort_ref_dir(subdir); 756 retval = do_for_each_entry_in_dir( 757 subdir, 0, fn, cb_data); 758 } else { 759 retval = fn(e, cb_data); 760 } 761 } 762 if (retval) 763 return retval; 764 } 765} 766 767/* 768 * Load all of the refs from the dir into our in-memory cache. The hard work 769 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 770 * through all of the sub-directories. We do not even need to care about 771 * sorting, as traversal order does not matter to us. 772 */ 773static void prime_ref_dir(struct ref_dir *dir) 774{ 775 int i; 776 for (i = 0; i < dir->nr; i++) { 777 struct ref_entry *entry = dir->entries[i]; 778 if (entry->flag & REF_DIR) 779 prime_ref_dir(get_ref_dir(entry)); 780 } 781} 782/* 783 * Return true iff refname1 and refname2 conflict with each other. 784 * Two reference names conflict if one of them exactly matches the 785 * leading components of the other; e.g., "foo/bar" conflicts with 786 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 787 * "foo/barbados". 788 */ 789static int names_conflict(const char *refname1, const char *refname2) 790{ 791 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++) 792 ; 793 return (*refname1 == '\0' && *refname2 == '/') 794 || (*refname1 == '/' && *refname2 == '\0'); 795} 796 797struct name_conflict_cb { 798 const char *refname; 799 const char *oldrefname; 800 const char *conflicting_refname; 801}; 802 803static int name_conflict_fn(struct ref_entry *entry, void *cb_data) 804{ 805 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; 806 if (data->oldrefname && !strcmp(data->oldrefname, entry->name)) 807 return 0; 808 if (names_conflict(data->refname, entry->name)) { 809 data->conflicting_refname = entry->name; 810 return 1; 811 } 812 return 0; 813} 814 815/* 816 * Return true iff a reference named refname could be created without 817 * conflicting with the name of an existing reference in dir. If 818 * oldrefname is non-NULL, ignore potential conflicts with oldrefname 819 * (e.g., because oldrefname is scheduled for deletion in the same 820 * operation). 821 */ 822static int is_refname_available(const char *refname, const char *oldrefname, 823 struct ref_dir *dir) 824{ 825 struct name_conflict_cb data; 826 data.refname = refname; 827 data.oldrefname = oldrefname; 828 data.conflicting_refname = NULL; 829 830 sort_ref_dir(dir); 831 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) { 832 error("'%s' exists; cannot create '%s'", 833 data.conflicting_refname, refname); 834 return 0; 835 } 836 return 1; 837} 838 839struct packed_ref_cache { 840 struct ref_entry *root; 841 842 /* 843 * Count of references to the data structure in this instance, 844 * including the pointer from ref_cache::packed if any. The 845 * data will not be freed as long as the reference count is 846 * nonzero. 847 */ 848 unsigned int referrers; 849 850 /* 851 * Iff the packed-refs file associated with this instance is 852 * currently locked for writing, this points at the associated 853 * lock (which is owned by somebody else). The referrer count 854 * is also incremented when the file is locked and decremented 855 * when it is unlocked. 856 */ 857 struct lock_file *lock; 858 859 /* The metadata from when this packed-refs cache was read */ 860 struct stat_validity validity; 861}; 862 863/* 864 * Future: need to be in "struct repository" 865 * when doing a full libification. 866 */ 867static struct ref_cache { 868 struct ref_cache *next; 869 struct ref_entry *loose; 870 struct packed_ref_cache *packed; 871 /* 872 * The submodule name, or "" for the main repo. We allocate 873 * length 1 rather than FLEX_ARRAY so that the main ref_cache 874 * is initialized correctly. 875 */ 876 char name[1]; 877} ref_cache, *submodule_ref_caches; 878 879/* Lock used for the main packed-refs file: */ 880static struct lock_file packlock; 881 882/* 883 * Increment the reference count of *packed_refs. 884 */ 885static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 886{ 887 packed_refs->referrers++; 888} 889 890/* 891 * Decrease the reference count of *packed_refs. If it goes to zero, 892 * free *packed_refs and return true; otherwise return false. 893 */ 894static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) 895{ 896 if (!--packed_refs->referrers) { 897 free_ref_entry(packed_refs->root); 898 stat_validity_clear(&packed_refs->validity); 899 free(packed_refs); 900 return 1; 901 } else { 902 return 0; 903 } 904} 905 906static void clear_packed_ref_cache(struct ref_cache *refs) 907{ 908 if (refs->packed) { 909 struct packed_ref_cache *packed_refs = refs->packed; 910 911 if (packed_refs->lock) 912 die("internal error: packed-ref cache cleared while locked"); 913 refs->packed = NULL; 914 release_packed_ref_cache(packed_refs); 915 } 916} 917 918static void clear_loose_ref_cache(struct ref_cache *refs) 919{ 920 if (refs->loose) { 921 free_ref_entry(refs->loose); 922 refs->loose = NULL; 923 } 924} 925 926static struct ref_cache *create_ref_cache(const char *submodule) 927{ 928 int len; 929 struct ref_cache *refs; 930 if (!submodule) 931 submodule = ""; 932 len = strlen(submodule) + 1; 933 refs = xcalloc(1, sizeof(struct ref_cache) + len); 934 memcpy(refs->name, submodule, len); 935 return refs; 936} 937 938/* 939 * Return a pointer to a ref_cache for the specified submodule. For 940 * the main repository, use submodule==NULL. The returned structure 941 * will be allocated and initialized but not necessarily populated; it 942 * should not be freed. 943 */ 944static struct ref_cache *get_ref_cache(const char *submodule) 945{ 946 struct ref_cache *refs; 947 948 if (!submodule || !*submodule) 949 return &ref_cache; 950 951 for (refs = submodule_ref_caches; refs; refs = refs->next) 952 if (!strcmp(submodule, refs->name)) 953 return refs; 954 955 refs = create_ref_cache(submodule); 956 refs->next = submodule_ref_caches; 957 submodule_ref_caches = refs; 958 return refs; 959} 960 961/* The length of a peeled reference line in packed-refs, including EOL: */ 962#define PEELED_LINE_LENGTH 42 963 964/* 965 * The packed-refs header line that we write out. Perhaps other 966 * traits will be added later. The trailing space is required. 967 */ 968static const char PACKED_REFS_HEADER[] = 969 "# pack-refs with: peeled fully-peeled \n"; 970 971/* 972 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 973 * Return a pointer to the refname within the line (null-terminated), 974 * or NULL if there was a problem. 975 */ 976static const char *parse_ref_line(char *line, unsigned char *sha1) 977{ 978 /* 979 * 42: the answer to everything. 980 * 981 * In this case, it happens to be the answer to 982 * 40 (length of sha1 hex representation) 983 * +1 (space in between hex and name) 984 * +1 (newline at the end of the line) 985 */ 986 int len = strlen(line) - 42; 987 988 if (len <= 0) 989 return NULL; 990 if (get_sha1_hex(line, sha1) < 0) 991 return NULL; 992 if (!isspace(line[40])) 993 return NULL; 994 line += 41; 995 if (isspace(*line)) 996 return NULL; 997 if (line[len] != '\n') 998 return NULL; 999 line[len] = 0;10001001 return line;1002}10031004/*1005 * Read f, which is a packed-refs file, into dir.1006 *1007 * A comment line of the form "# pack-refs with: " may contain zero or1008 * more traits. We interpret the traits as follows:1009 *1010 * No traits:1011 *1012 * Probably no references are peeled. But if the file contains a1013 * peeled value for a reference, we will use it.1014 *1015 * peeled:1016 *1017 * References under "refs/tags/", if they *can* be peeled, *are*1018 * peeled in this file. References outside of "refs/tags/" are1019 * probably not peeled even if they could have been, but if we find1020 * a peeled value for such a reference we will use it.1021 *1022 * fully-peeled:1023 *1024 * All references in the file that can be peeled are peeled.1025 * Inversely (and this is more important), any references in the1026 * file for which no peeled value is recorded is not peelable. This1027 * trait should typically be written alongside "peeled" for1028 * compatibility with older clients, but we do not require it1029 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1030 */1031static void read_packed_refs(FILE *f, struct ref_dir *dir)1032{1033 struct ref_entry *last = NULL;1034 char refline[PATH_MAX];1035 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10361037 while (fgets(refline, sizeof(refline), f)) {1038 unsigned char sha1[20];1039 const char *refname;1040 static const char header[] = "# pack-refs with:";10411042 if (!strncmp(refline, header, sizeof(header)-1)) {1043 const char *traits = refline + sizeof(header) - 1;1044 if (strstr(traits, " fully-peeled "))1045 peeled = PEELED_FULLY;1046 else if (strstr(traits, " peeled "))1047 peeled = PEELED_TAGS;1048 /* perhaps other traits later as well */1049 continue;1050 }10511052 refname = parse_ref_line(refline, sha1);1053 if (refname) {1054 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);1055 if (peeled == PEELED_FULLY ||1056 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))1057 last->flag |= REF_KNOWS_PEELED;1058 add_ref(dir, last);1059 continue;1060 }1061 if (last &&1062 refline[0] == '^' &&1063 strlen(refline) == PEELED_LINE_LENGTH &&1064 refline[PEELED_LINE_LENGTH - 1] == '\n' &&1065 !get_sha1_hex(refline + 1, sha1)) {1066 hashcpy(last->u.value.peeled, sha1);1067 /*1068 * Regardless of what the file header said,1069 * we definitely know the value of *this*1070 * reference:1071 */1072 last->flag |= REF_KNOWS_PEELED;1073 }1074 }1075}10761077/*1078 * Get the packed_ref_cache for the specified ref_cache, creating it1079 * if necessary.1080 */1081static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1082{1083 const char *packed_refs_file;10841085 if (*refs->name)1086 packed_refs_file = git_path_submodule(refs->name, "packed-refs");1087 else1088 packed_refs_file = git_path("packed-refs");10891090 if (refs->packed &&1091 !stat_validity_check(&refs->packed->validity, packed_refs_file))1092 clear_packed_ref_cache(refs);10931094 if (!refs->packed) {1095 FILE *f;10961097 refs->packed = xcalloc(1, sizeof(*refs->packed));1098 acquire_packed_ref_cache(refs->packed);1099 refs->packed->root = create_dir_entry(refs, "", 0, 0);1100 f = fopen(packed_refs_file, "r");1101 if (f) {1102 stat_validity_update(&refs->packed->validity, fileno(f));1103 read_packed_refs(f, get_ref_dir(refs->packed->root));1104 fclose(f);1105 }1106 }1107 return refs->packed;1108}11091110static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1111{1112 return get_ref_dir(packed_ref_cache->root);1113}11141115static struct ref_dir *get_packed_refs(struct ref_cache *refs)1116{1117 return get_packed_ref_dir(get_packed_ref_cache(refs));1118}11191120void add_packed_ref(const char *refname, const unsigned char *sha1)1121{1122 struct packed_ref_cache *packed_ref_cache =1123 get_packed_ref_cache(&ref_cache);11241125 if (!packed_ref_cache->lock)1126 die("internal error: packed refs not locked");1127 add_ref(get_packed_ref_dir(packed_ref_cache),1128 create_ref_entry(refname, sha1, REF_ISPACKED, 1));1129}11301131/*1132 * Read the loose references from the namespace dirname into dir1133 * (without recursing). dirname must end with '/'. dir must be the1134 * directory entry corresponding to dirname.1135 */1136static void read_loose_refs(const char *dirname, struct ref_dir *dir)1137{1138 struct ref_cache *refs = dir->ref_cache;1139 DIR *d;1140 const char *path;1141 struct dirent *de;1142 int dirnamelen = strlen(dirname);1143 struct strbuf refname;11441145 if (*refs->name)1146 path = git_path_submodule(refs->name, "%s", dirname);1147 else1148 path = git_path("%s", dirname);11491150 d = opendir(path);1151 if (!d)1152 return;11531154 strbuf_init(&refname, dirnamelen + 257);1155 strbuf_add(&refname, dirname, dirnamelen);11561157 while ((de = readdir(d)) != NULL) {1158 unsigned char sha1[20];1159 struct stat st;1160 int flag;1161 const char *refdir;11621163 if (de->d_name[0] == '.')1164 continue;1165 if (ends_with(de->d_name, ".lock"))1166 continue;1167 strbuf_addstr(&refname, de->d_name);1168 refdir = *refs->name1169 ? git_path_submodule(refs->name, "%s", refname.buf)1170 : git_path("%s", refname.buf);1171 if (stat(refdir, &st) < 0) {1172 ; /* silently ignore */1173 } else if (S_ISDIR(st.st_mode)) {1174 strbuf_addch(&refname, '/');1175 add_entry_to_dir(dir,1176 create_dir_entry(refs, refname.buf,1177 refname.len, 1));1178 } else {1179 if (*refs->name) {1180 hashclr(sha1);1181 flag = 0;1182 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {1183 hashclr(sha1);1184 flag |= REF_ISBROKEN;1185 }1186 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {1187 hashclr(sha1);1188 flag |= REF_ISBROKEN;1189 }1190 add_entry_to_dir(dir,1191 create_ref_entry(refname.buf, sha1, flag, 1));1192 }1193 strbuf_setlen(&refname, dirnamelen);1194 }1195 strbuf_release(&refname);1196 closedir(d);1197}11981199static struct ref_dir *get_loose_refs(struct ref_cache *refs)1200{1201 if (!refs->loose) {1202 /*1203 * Mark the top-level directory complete because we1204 * are about to read the only subdirectory that can1205 * hold references:1206 */1207 refs->loose = create_dir_entry(refs, "", 0, 0);1208 /*1209 * Create an incomplete entry for "refs/":1210 */1211 add_entry_to_dir(get_ref_dir(refs->loose),1212 create_dir_entry(refs, "refs/", 5, 1));1213 }1214 return get_ref_dir(refs->loose);1215}12161217/* We allow "recursive" symbolic refs. Only within reason, though */1218#define MAXDEPTH 51219#define MAXREFLEN (1024)12201221/*1222 * Called by resolve_gitlink_ref_recursive() after it failed to read1223 * from the loose refs in ref_cache refs. Find <refname> in the1224 * packed-refs file for the submodule.1225 */1226static int resolve_gitlink_packed_ref(struct ref_cache *refs,1227 const char *refname, unsigned char *sha1)1228{1229 struct ref_entry *ref;1230 struct ref_dir *dir = get_packed_refs(refs);12311232 ref = find_ref(dir, refname);1233 if (ref == NULL)1234 return -1;12351236 hashcpy(sha1, ref->u.value.sha1);1237 return 0;1238}12391240static int resolve_gitlink_ref_recursive(struct ref_cache *refs,1241 const char *refname, unsigned char *sha1,1242 int recursion)1243{1244 int fd, len;1245 char buffer[128], *p;1246 char *path;12471248 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)1249 return -1;1250 path = *refs->name1251 ? git_path_submodule(refs->name, "%s", refname)1252 : git_path("%s", refname);1253 fd = open(path, O_RDONLY);1254 if (fd < 0)1255 return resolve_gitlink_packed_ref(refs, refname, sha1);12561257 len = read(fd, buffer, sizeof(buffer)-1);1258 close(fd);1259 if (len < 0)1260 return -1;1261 while (len && isspace(buffer[len-1]))1262 len--;1263 buffer[len] = 0;12641265 /* Was it a detached head or an old-fashioned symlink? */1266 if (!get_sha1_hex(buffer, sha1))1267 return 0;12681269 /* Symref? */1270 if (strncmp(buffer, "ref:", 4))1271 return -1;1272 p = buffer + 4;1273 while (isspace(*p))1274 p++;12751276 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1277}12781279int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)1280{1281 int len = strlen(path), retval;1282 char *submodule;1283 struct ref_cache *refs;12841285 while (len && path[len-1] == '/')1286 len--;1287 if (!len)1288 return -1;1289 submodule = xstrndup(path, len);1290 refs = get_ref_cache(submodule);1291 free(submodule);12921293 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);1294 return retval;1295}12961297/*1298 * Return the ref_entry for the given refname from the packed1299 * references. If it does not exist, return NULL.1300 */1301static struct ref_entry *get_packed_ref(const char *refname)1302{1303 return find_ref(get_packed_refs(&ref_cache), refname);1304}13051306/*1307 * A loose ref file doesn't exist; check for a packed ref. The1308 * options are forwarded from resolve_safe_unsafe().1309 */1310static const char *handle_missing_loose_ref(const char *refname,1311 unsigned char *sha1,1312 int reading,1313 int *flag)1314{1315 struct ref_entry *entry;13161317 /*1318 * The loose reference file does not exist; check for a packed1319 * reference.1320 */1321 entry = get_packed_ref(refname);1322 if (entry) {1323 hashcpy(sha1, entry->u.value.sha1);1324 if (flag)1325 *flag |= REF_ISPACKED;1326 return refname;1327 }1328 /* The reference is not a packed reference, either. */1329 if (reading) {1330 return NULL;1331 } else {1332 hashclr(sha1);1333 return refname;1334 }1335}13361337/* This function needs to return a meaningful errno on failure */1338const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)1339{1340 int depth = MAXDEPTH;1341 ssize_t len;1342 char buffer[256];1343 static char refname_buffer[256];13441345 if (flag)1346 *flag = 0;13471348 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1349 errno = EINVAL;1350 return NULL;1351 }13521353 for (;;) {1354 char path[PATH_MAX];1355 struct stat st;1356 char *buf;1357 int fd;13581359 if (--depth < 0) {1360 errno = ELOOP;1361 return NULL;1362 }13631364 git_snpath(path, sizeof(path), "%s", refname);13651366 /*1367 * We might have to loop back here to avoid a race1368 * condition: first we lstat() the file, then we try1369 * to read it as a link or as a file. But if somebody1370 * changes the type of the file (file <-> directory1371 * <-> symlink) between the lstat() and reading, then1372 * we don't want to report that as an error but rather1373 * try again starting with the lstat().1374 */1375 stat_ref:1376 if (lstat(path, &st) < 0) {1377 if (errno == ENOENT)1378 return handle_missing_loose_ref(refname, sha1,1379 reading, flag);1380 else1381 return NULL;1382 }13831384 /* Follow "normalized" - ie "refs/.." symlinks by hand */1385 if (S_ISLNK(st.st_mode)) {1386 len = readlink(path, buffer, sizeof(buffer)-1);1387 if (len < 0) {1388 if (errno == ENOENT || errno == EINVAL)1389 /* inconsistent with lstat; retry */1390 goto stat_ref;1391 else1392 return NULL;1393 }1394 buffer[len] = 0;1395 if (starts_with(buffer, "refs/") &&1396 !check_refname_format(buffer, 0)) {1397 strcpy(refname_buffer, buffer);1398 refname = refname_buffer;1399 if (flag)1400 *flag |= REF_ISSYMREF;1401 continue;1402 }1403 }14041405 /* Is it a directory? */1406 if (S_ISDIR(st.st_mode)) {1407 errno = EISDIR;1408 return NULL;1409 }14101411 /*1412 * Anything else, just open it and try to use it as1413 * a ref1414 */1415 fd = open(path, O_RDONLY);1416 if (fd < 0) {1417 if (errno == ENOENT)1418 /* inconsistent with lstat; retry */1419 goto stat_ref;1420 else1421 return NULL;1422 }1423 len = read_in_full(fd, buffer, sizeof(buffer)-1);1424 if (len < 0) {1425 int save_errno = errno;1426 close(fd);1427 errno = save_errno;1428 return NULL;1429 }1430 close(fd);1431 while (len && isspace(buffer[len-1]))1432 len--;1433 buffer[len] = '\0';14341435 /*1436 * Is it a symbolic ref?1437 */1438 if (!starts_with(buffer, "ref:")) {1439 /*1440 * Please note that FETCH_HEAD has a second1441 * line containing other data.1442 */1443 if (get_sha1_hex(buffer, sha1) ||1444 (buffer[40] != '\0' && !isspace(buffer[40]))) {1445 if (flag)1446 *flag |= REF_ISBROKEN;1447 errno = EINVAL;1448 return NULL;1449 }1450 return refname;1451 }1452 if (flag)1453 *flag |= REF_ISSYMREF;1454 buf = buffer + 4;1455 while (isspace(*buf))1456 buf++;1457 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1458 if (flag)1459 *flag |= REF_ISBROKEN;1460 errno = EINVAL;1461 return NULL;1462 }1463 refname = strcpy(refname_buffer, buf);1464 }1465}14661467char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)1468{1469 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);1470 return ret ? xstrdup(ret) : NULL;1471}14721473/* The argument to filter_refs */1474struct ref_filter {1475 const char *pattern;1476 each_ref_fn *fn;1477 void *cb_data;1478};14791480int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)1481{1482 if (resolve_ref_unsafe(refname, sha1, reading, flags))1483 return 0;1484 return -1;1485}14861487int read_ref(const char *refname, unsigned char *sha1)1488{1489 return read_ref_full(refname, sha1, 1, NULL);1490}14911492int ref_exists(const char *refname)1493{1494 unsigned char sha1[20];1495 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);1496}14971498static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1499 void *data)1500{1501 struct ref_filter *filter = (struct ref_filter *)data;1502 if (wildmatch(filter->pattern, refname, 0, NULL))1503 return 0;1504 return filter->fn(refname, sha1, flags, filter->cb_data);1505}15061507enum peel_status {1508 /* object was peeled successfully: */1509 PEEL_PEELED = 0,15101511 /*1512 * object cannot be peeled because the named object (or an1513 * object referred to by a tag in the peel chain), does not1514 * exist.1515 */1516 PEEL_INVALID = -1,15171518 /* object cannot be peeled because it is not a tag: */1519 PEEL_NON_TAG = -2,15201521 /* ref_entry contains no peeled value because it is a symref: */1522 PEEL_IS_SYMREF = -3,15231524 /*1525 * ref_entry cannot be peeled because it is broken (i.e., the1526 * symbolic reference cannot even be resolved to an object1527 * name):1528 */1529 PEEL_BROKEN = -41530};15311532/*1533 * Peel the named object; i.e., if the object is a tag, resolve the1534 * tag recursively until a non-tag is found. If successful, store the1535 * result to sha1 and return PEEL_PEELED. If the object is not a tag1536 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1537 * and leave sha1 unchanged.1538 */1539static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1540{1541 struct object *o = lookup_unknown_object(name);15421543 if (o->type == OBJ_NONE) {1544 int type = sha1_object_info(name, NULL);1545 if (type < 0 || !object_as_type(o, type, 0))1546 return PEEL_INVALID;1547 }15481549 if (o->type != OBJ_TAG)1550 return PEEL_NON_TAG;15511552 o = deref_tag_noverify(o);1553 if (!o)1554 return PEEL_INVALID;15551556 hashcpy(sha1, o->sha1);1557 return PEEL_PEELED;1558}15591560/*1561 * Peel the entry (if possible) and return its new peel_status. If1562 * repeel is true, re-peel the entry even if there is an old peeled1563 * value that is already stored in it.1564 *1565 * It is OK to call this function with a packed reference entry that1566 * might be stale and might even refer to an object that has since1567 * been garbage-collected. In such a case, if the entry has1568 * REF_KNOWS_PEELED then leave the status unchanged and return1569 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1570 */1571static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1572{1573 enum peel_status status;15741575 if (entry->flag & REF_KNOWS_PEELED) {1576 if (repeel) {1577 entry->flag &= ~REF_KNOWS_PEELED;1578 hashclr(entry->u.value.peeled);1579 } else {1580 return is_null_sha1(entry->u.value.peeled) ?1581 PEEL_NON_TAG : PEEL_PEELED;1582 }1583 }1584 if (entry->flag & REF_ISBROKEN)1585 return PEEL_BROKEN;1586 if (entry->flag & REF_ISSYMREF)1587 return PEEL_IS_SYMREF;15881589 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1590 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1591 entry->flag |= REF_KNOWS_PEELED;1592 return status;1593}15941595int peel_ref(const char *refname, unsigned char *sha1)1596{1597 int flag;1598 unsigned char base[20];15991600 if (current_ref && (current_ref->name == refname1601 || !strcmp(current_ref->name, refname))) {1602 if (peel_entry(current_ref, 0))1603 return -1;1604 hashcpy(sha1, current_ref->u.value.peeled);1605 return 0;1606 }16071608 if (read_ref_full(refname, base, 1, &flag))1609 return -1;16101611 /*1612 * If the reference is packed, read its ref_entry from the1613 * cache in the hope that we already know its peeled value.1614 * We only try this optimization on packed references because1615 * (a) forcing the filling of the loose reference cache could1616 * be expensive and (b) loose references anyway usually do not1617 * have REF_KNOWS_PEELED.1618 */1619 if (flag & REF_ISPACKED) {1620 struct ref_entry *r = get_packed_ref(refname);1621 if (r) {1622 if (peel_entry(r, 0))1623 return -1;1624 hashcpy(sha1, r->u.value.peeled);1625 return 0;1626 }1627 }16281629 return peel_object(base, sha1);1630}16311632struct warn_if_dangling_data {1633 FILE *fp;1634 const char *refname;1635 const struct string_list *refnames;1636 const char *msg_fmt;1637};16381639static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1640 int flags, void *cb_data)1641{1642 struct warn_if_dangling_data *d = cb_data;1643 const char *resolves_to;1644 unsigned char junk[20];16451646 if (!(flags & REF_ISSYMREF))1647 return 0;16481649 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);1650 if (!resolves_to1651 || (d->refname1652 ? strcmp(resolves_to, d->refname)1653 : !string_list_has_string(d->refnames, resolves_to))) {1654 return 0;1655 }16561657 fprintf(d->fp, d->msg_fmt, refname);1658 fputc('\n', d->fp);1659 return 0;1660}16611662void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1663{1664 struct warn_if_dangling_data data;16651666 data.fp = fp;1667 data.refname = refname;1668 data.refnames = NULL;1669 data.msg_fmt = msg_fmt;1670 for_each_rawref(warn_if_dangling_symref, &data);1671}16721673void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)1674{1675 struct warn_if_dangling_data data;16761677 data.fp = fp;1678 data.refname = NULL;1679 data.refnames = refnames;1680 data.msg_fmt = msg_fmt;1681 for_each_rawref(warn_if_dangling_symref, &data);1682}16831684/*1685 * Call fn for each reference in the specified ref_cache, omitting1686 * references not in the containing_dir of base. fn is called for all1687 * references, including broken ones. If fn ever returns a non-zero1688 * value, stop the iteration and return that value; otherwise, return1689 * 0.1690 */1691static int do_for_each_entry(struct ref_cache *refs, const char *base,1692 each_ref_entry_fn fn, void *cb_data)1693{1694 struct packed_ref_cache *packed_ref_cache;1695 struct ref_dir *loose_dir;1696 struct ref_dir *packed_dir;1697 int retval = 0;16981699 /*1700 * We must make sure that all loose refs are read before accessing the1701 * packed-refs file; this avoids a race condition in which loose refs1702 * are migrated to the packed-refs file by a simultaneous process, but1703 * our in-memory view is from before the migration. get_packed_ref_cache()1704 * takes care of making sure our view is up to date with what is on1705 * disk.1706 */1707 loose_dir = get_loose_refs(refs);1708 if (base && *base) {1709 loose_dir = find_containing_dir(loose_dir, base, 0);1710 }1711 if (loose_dir)1712 prime_ref_dir(loose_dir);17131714 packed_ref_cache = get_packed_ref_cache(refs);1715 acquire_packed_ref_cache(packed_ref_cache);1716 packed_dir = get_packed_ref_dir(packed_ref_cache);1717 if (base && *base) {1718 packed_dir = find_containing_dir(packed_dir, base, 0);1719 }17201721 if (packed_dir && loose_dir) {1722 sort_ref_dir(packed_dir);1723 sort_ref_dir(loose_dir);1724 retval = do_for_each_entry_in_dirs(1725 packed_dir, loose_dir, fn, cb_data);1726 } else if (packed_dir) {1727 sort_ref_dir(packed_dir);1728 retval = do_for_each_entry_in_dir(1729 packed_dir, 0, fn, cb_data);1730 } else if (loose_dir) {1731 sort_ref_dir(loose_dir);1732 retval = do_for_each_entry_in_dir(1733 loose_dir, 0, fn, cb_data);1734 }17351736 release_packed_ref_cache(packed_ref_cache);1737 return retval;1738}17391740/*1741 * Call fn for each reference in the specified ref_cache for which the1742 * refname begins with base. If trim is non-zero, then trim that many1743 * characters off the beginning of each refname before passing the1744 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1745 * broken references in the iteration. If fn ever returns a non-zero1746 * value, stop the iteration and return that value; otherwise, return1747 * 0.1748 */1749static int do_for_each_ref(struct ref_cache *refs, const char *base,1750 each_ref_fn fn, int trim, int flags, void *cb_data)1751{1752 struct ref_entry_cb data;1753 data.base = base;1754 data.trim = trim;1755 data.flags = flags;1756 data.fn = fn;1757 data.cb_data = cb_data;17581759 return do_for_each_entry(refs, base, do_one_ref, &data);1760}17611762static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1763{1764 unsigned char sha1[20];1765 int flag;17661767 if (submodule) {1768 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1769 return fn("HEAD", sha1, 0, cb_data);17701771 return 0;1772 }17731774 if (!read_ref_full("HEAD", sha1, 1, &flag))1775 return fn("HEAD", sha1, flag, cb_data);17761777 return 0;1778}17791780int head_ref(each_ref_fn fn, void *cb_data)1781{1782 return do_head_ref(NULL, fn, cb_data);1783}17841785int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1786{1787 return do_head_ref(submodule, fn, cb_data);1788}17891790int for_each_ref(each_ref_fn fn, void *cb_data)1791{1792 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);1793}17941795int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1796{1797 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);1798}17991800int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1801{1802 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);1803}18041805int for_each_ref_in_submodule(const char *submodule, const char *prefix,1806 each_ref_fn fn, void *cb_data)1807{1808 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);1809}18101811int for_each_tag_ref(each_ref_fn fn, void *cb_data)1812{1813 return for_each_ref_in("refs/tags/", fn, cb_data);1814}18151816int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1817{1818 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1819}18201821int for_each_branch_ref(each_ref_fn fn, void *cb_data)1822{1823 return for_each_ref_in("refs/heads/", fn, cb_data);1824}18251826int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1827{1828 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1829}18301831int for_each_remote_ref(each_ref_fn fn, void *cb_data)1832{1833 return for_each_ref_in("refs/remotes/", fn, cb_data);1834}18351836int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1837{1838 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1839}18401841int for_each_replace_ref(each_ref_fn fn, void *cb_data)1842{1843 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);1844}18451846int head_ref_namespaced(each_ref_fn fn, void *cb_data)1847{1848 struct strbuf buf = STRBUF_INIT;1849 int ret = 0;1850 unsigned char sha1[20];1851 int flag;18521853 strbuf_addf(&buf, "%sHEAD", get_git_namespace());1854 if (!read_ref_full(buf.buf, sha1, 1, &flag))1855 ret = fn(buf.buf, sha1, flag, cb_data);1856 strbuf_release(&buf);18571858 return ret;1859}18601861int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)1862{1863 struct strbuf buf = STRBUF_INIT;1864 int ret;1865 strbuf_addf(&buf, "%srefs/", get_git_namespace());1866 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);1867 strbuf_release(&buf);1868 return ret;1869}18701871int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,1872 const char *prefix, void *cb_data)1873{1874 struct strbuf real_pattern = STRBUF_INIT;1875 struct ref_filter filter;1876 int ret;18771878 if (!prefix && !starts_with(pattern, "refs/"))1879 strbuf_addstr(&real_pattern, "refs/");1880 else if (prefix)1881 strbuf_addstr(&real_pattern, prefix);1882 strbuf_addstr(&real_pattern, pattern);18831884 if (!has_glob_specials(pattern)) {1885 /* Append implied '/' '*' if not present. */1886 if (real_pattern.buf[real_pattern.len - 1] != '/')1887 strbuf_addch(&real_pattern, '/');1888 /* No need to check for '*', there is none. */1889 strbuf_addch(&real_pattern, '*');1890 }18911892 filter.pattern = real_pattern.buf;1893 filter.fn = fn;1894 filter.cb_data = cb_data;1895 ret = for_each_ref(filter_refs, &filter);18961897 strbuf_release(&real_pattern);1898 return ret;1899}19001901int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)1902{1903 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);1904}19051906int for_each_rawref(each_ref_fn fn, void *cb_data)1907{1908 return do_for_each_ref(&ref_cache, "", fn, 0,1909 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1910}19111912const char *prettify_refname(const char *name)1913{1914 return name + (1915 starts_with(name, "refs/heads/") ? 11 :1916 starts_with(name, "refs/tags/") ? 10 :1917 starts_with(name, "refs/remotes/") ? 13 :1918 0);1919}19201921static const char *ref_rev_parse_rules[] = {1922 "%.*s",1923 "refs/%.*s",1924 "refs/tags/%.*s",1925 "refs/heads/%.*s",1926 "refs/remotes/%.*s",1927 "refs/remotes/%.*s/HEAD",1928 NULL1929};19301931int refname_match(const char *abbrev_name, const char *full_name)1932{1933 const char **p;1934 const int abbrev_name_len = strlen(abbrev_name);19351936 for (p = ref_rev_parse_rules; *p; p++) {1937 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {1938 return 1;1939 }1940 }19411942 return 0;1943}19441945/* This function should make sure errno is meaningful on error */1946static struct ref_lock *verify_lock(struct ref_lock *lock,1947 const unsigned char *old_sha1, int mustexist)1948{1949 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1950 int save_errno = errno;1951 error("Can't verify ref %s", lock->ref_name);1952 unlock_ref(lock);1953 errno = save_errno;1954 return NULL;1955 }1956 if (hashcmp(lock->old_sha1, old_sha1)) {1957 error("Ref %s is at %s but expected %s", lock->ref_name,1958 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));1959 unlock_ref(lock);1960 errno = EBUSY;1961 return NULL;1962 }1963 return lock;1964}19651966static int remove_empty_directories(const char *file)1967{1968 /* we want to create a file but there is a directory there;1969 * if that is an empty directory (or a directory that contains1970 * only empty directories), remove them.1971 */1972 struct strbuf path;1973 int result, save_errno;19741975 strbuf_init(&path, 20);1976 strbuf_addstr(&path, file);19771978 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);1979 save_errno = errno;19801981 strbuf_release(&path);1982 errno = save_errno;19831984 return result;1985}19861987/*1988 * *string and *len will only be substituted, and *string returned (for1989 * later free()ing) if the string passed in is a magic short-hand form1990 * to name a branch.1991 */1992static char *substitute_branch_name(const char **string, int *len)1993{1994 struct strbuf buf = STRBUF_INIT;1995 int ret = interpret_branch_name(*string, *len, &buf);19961997 if (ret == *len) {1998 size_t size;1999 *string = strbuf_detach(&buf, &size);2000 *len = size;2001 return (char *)*string;2002 }20032004 return NULL;2005}20062007int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)2008{2009 char *last_branch = substitute_branch_name(&str, &len);2010 const char **p, *r;2011 int refs_found = 0;20122013 *ref = NULL;2014 for (p = ref_rev_parse_rules; *p; p++) {2015 char fullref[PATH_MAX];2016 unsigned char sha1_from_ref[20];2017 unsigned char *this_result;2018 int flag;20192020 this_result = refs_found ? sha1_from_ref : sha1;2021 mksnpath(fullref, sizeof(fullref), *p, len, str);2022 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);2023 if (r) {2024 if (!refs_found++)2025 *ref = xstrdup(r);2026 if (!warn_ambiguous_refs)2027 break;2028 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {2029 warning("ignoring dangling symref %s.", fullref);2030 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {2031 warning("ignoring broken ref %s.", fullref);2032 }2033 }2034 free(last_branch);2035 return refs_found;2036}20372038int dwim_log(const char *str, int len, unsigned char *sha1, char **log)2039{2040 char *last_branch = substitute_branch_name(&str, &len);2041 const char **p;2042 int logs_found = 0;20432044 *log = NULL;2045 for (p = ref_rev_parse_rules; *p; p++) {2046 unsigned char hash[20];2047 char path[PATH_MAX];2048 const char *ref, *it;20492050 mksnpath(path, sizeof(path), *p, len, str);2051 ref = resolve_ref_unsafe(path, hash, 1, NULL);2052 if (!ref)2053 continue;2054 if (reflog_exists(path))2055 it = path;2056 else if (strcmp(ref, path) && reflog_exists(ref))2057 it = ref;2058 else2059 continue;2060 if (!logs_found++) {2061 *log = xstrdup(it);2062 hashcpy(sha1, hash);2063 }2064 if (!warn_ambiguous_refs)2065 break;2066 }2067 free(last_branch);2068 return logs_found;2069}20702071/* This function should make sure errno is meaningful on error */2072static struct ref_lock *lock_ref_sha1_basic(const char *refname,2073 const unsigned char *old_sha1,2074 int flags, int *type_p)2075{2076 char *ref_file;2077 const char *orig_refname = refname;2078 struct ref_lock *lock;2079 int last_errno = 0;2080 int type, lflags;2081 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2082 int missing = 0;2083 int attempts_remaining = 3;20842085 lock = xcalloc(1, sizeof(struct ref_lock));2086 lock->lock_fd = -1;20872088 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2089 if (!refname && errno == EISDIR) {2090 /* we are trying to lock foo but we used to2091 * have foo/bar which now does not exist;2092 * it is normal for the empty directory 'foo'2093 * to remain.2094 */2095 ref_file = git_path("%s", orig_refname);2096 if (remove_empty_directories(ref_file)) {2097 last_errno = errno;2098 error("there are still refs under '%s'", orig_refname);2099 goto error_return;2100 }2101 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2102 }2103 if (type_p)2104 *type_p = type;2105 if (!refname) {2106 last_errno = errno;2107 error("unable to resolve reference %s: %s",2108 orig_refname, strerror(errno));2109 goto error_return;2110 }2111 missing = is_null_sha1(lock->old_sha1);2112 /* When the ref did not exist and we are creating it,2113 * make sure there is no existing ref that is packed2114 * whose name begins with our refname, nor a ref whose2115 * name is a proper prefix of our refname.2116 */2117 if (missing &&2118 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {2119 last_errno = ENOTDIR;2120 goto error_return;2121 }21222123 lock->lk = xcalloc(1, sizeof(struct lock_file));21242125 lflags = 0;2126 if (flags & REF_NODEREF) {2127 refname = orig_refname;2128 lflags |= LOCK_NODEREF;2129 }2130 lock->ref_name = xstrdup(refname);2131 lock->orig_ref_name = xstrdup(orig_refname);2132 ref_file = git_path("%s", refname);2133 if (missing)2134 lock->force_write = 1;2135 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))2136 lock->force_write = 1;21372138 retry:2139 switch (safe_create_leading_directories(ref_file)) {2140 case SCLD_OK:2141 break; /* success */2142 case SCLD_VANISHED:2143 if (--attempts_remaining > 0)2144 goto retry;2145 /* fall through */2146 default:2147 last_errno = errno;2148 error("unable to create directory for %s", ref_file);2149 goto error_return;2150 }21512152 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);2153 if (lock->lock_fd < 0) {2154 if (errno == ENOENT && --attempts_remaining > 0)2155 /*2156 * Maybe somebody just deleted one of the2157 * directories leading to ref_file. Try2158 * again:2159 */2160 goto retry;2161 else2162 unable_to_lock_index_die(ref_file, errno);2163 }2164 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;21652166 error_return:2167 unlock_ref(lock);2168 errno = last_errno;2169 return NULL;2170}21712172struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)2173{2174 char refpath[PATH_MAX];2175 if (check_refname_format(refname, 0))2176 return NULL;2177 strcpy(refpath, mkpath("refs/%s", refname));2178 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);2179}21802181struct ref_lock *lock_any_ref_for_update(const char *refname,2182 const unsigned char *old_sha1,2183 int flags, int *type_p)2184{2185 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2186 return NULL;2187 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);2188}21892190/*2191 * Write an entry to the packed-refs file for the specified refname.2192 * If peeled is non-NULL, write it as the entry's peeled value.2193 */2194static void write_packed_entry(int fd, char *refname, unsigned char *sha1,2195 unsigned char *peeled)2196{2197 char line[PATH_MAX + 100];2198 int len;21992200 len = snprintf(line, sizeof(line), "%s %s\n",2201 sha1_to_hex(sha1), refname);2202 /* this should not happen but just being defensive */2203 if (len > sizeof(line))2204 die("too long a refname '%s'", refname);2205 write_or_die(fd, line, len);22062207 if (peeled) {2208 if (snprintf(line, sizeof(line), "^%s\n",2209 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2210 die("internal error");2211 write_or_die(fd, line, PEELED_LINE_LENGTH);2212 }2213}22142215/*2216 * An each_ref_entry_fn that writes the entry to a packed-refs file.2217 */2218static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2219{2220 int *fd = cb_data;2221 enum peel_status peel_status = peel_entry(entry, 0);22222223 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2224 error("internal error: %s is not a valid packed reference!",2225 entry->name);2226 write_packed_entry(*fd, entry->name, entry->u.value.sha1,2227 peel_status == PEEL_PEELED ?2228 entry->u.value.peeled : NULL);2229 return 0;2230}22312232/* This should return a meaningful errno on failure */2233int lock_packed_refs(int flags)2234{2235 struct packed_ref_cache *packed_ref_cache;22362237 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)2238 return -1;2239 /*2240 * Get the current packed-refs while holding the lock. If the2241 * packed-refs file has been modified since we last read it,2242 * this will automatically invalidate the cache and re-read2243 * the packed-refs file.2244 */2245 packed_ref_cache = get_packed_ref_cache(&ref_cache);2246 packed_ref_cache->lock = &packlock;2247 /* Increment the reference count to prevent it from being freed: */2248 acquire_packed_ref_cache(packed_ref_cache);2249 return 0;2250}22512252/*2253 * Commit the packed refs changes.2254 * On error we must make sure that errno contains a meaningful value.2255 */2256int commit_packed_refs(void)2257{2258 struct packed_ref_cache *packed_ref_cache =2259 get_packed_ref_cache(&ref_cache);2260 int error = 0;2261 int save_errno = 0;22622263 if (!packed_ref_cache->lock)2264 die("internal error: packed-refs not locked");2265 write_or_die(packed_ref_cache->lock->fd,2266 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));22672268 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2269 0, write_packed_entry_fn,2270 &packed_ref_cache->lock->fd);2271 if (commit_lock_file(packed_ref_cache->lock)) {2272 save_errno = errno;2273 error = -1;2274 }2275 packed_ref_cache->lock = NULL;2276 release_packed_ref_cache(packed_ref_cache);2277 errno = save_errno;2278 return error;2279}22802281void rollback_packed_refs(void)2282{2283 struct packed_ref_cache *packed_ref_cache =2284 get_packed_ref_cache(&ref_cache);22852286 if (!packed_ref_cache->lock)2287 die("internal error: packed-refs not locked");2288 rollback_lock_file(packed_ref_cache->lock);2289 packed_ref_cache->lock = NULL;2290 release_packed_ref_cache(packed_ref_cache);2291 clear_packed_ref_cache(&ref_cache);2292}22932294struct ref_to_prune {2295 struct ref_to_prune *next;2296 unsigned char sha1[20];2297 char name[FLEX_ARRAY];2298};22992300struct pack_refs_cb_data {2301 unsigned int flags;2302 struct ref_dir *packed_refs;2303 struct ref_to_prune *ref_to_prune;2304};23052306/*2307 * An each_ref_entry_fn that is run over loose references only. If2308 * the loose reference can be packed, add an entry in the packed ref2309 * cache. If the reference should be pruned, also add it to2310 * ref_to_prune in the pack_refs_cb_data.2311 */2312static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2313{2314 struct pack_refs_cb_data *cb = cb_data;2315 enum peel_status peel_status;2316 struct ref_entry *packed_entry;2317 int is_tag_ref = starts_with(entry->name, "refs/tags/");23182319 /* ALWAYS pack tags */2320 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2321 return 0;23222323 /* Do not pack symbolic or broken refs: */2324 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2325 return 0;23262327 /* Add a packed ref cache entry equivalent to the loose entry. */2328 peel_status = peel_entry(entry, 1);2329 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2330 die("internal error peeling reference %s (%s)",2331 entry->name, sha1_to_hex(entry->u.value.sha1));2332 packed_entry = find_ref(cb->packed_refs, entry->name);2333 if (packed_entry) {2334 /* Overwrite existing packed entry with info from loose entry */2335 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2336 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2337 } else {2338 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,2339 REF_ISPACKED | REF_KNOWS_PEELED, 0);2340 add_ref(cb->packed_refs, packed_entry);2341 }2342 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);23432344 /* Schedule the loose reference for pruning if requested. */2345 if ((cb->flags & PACK_REFS_PRUNE)) {2346 int namelen = strlen(entry->name) + 1;2347 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2348 hashcpy(n->sha1, entry->u.value.sha1);2349 strcpy(n->name, entry->name);2350 n->next = cb->ref_to_prune;2351 cb->ref_to_prune = n;2352 }2353 return 0;2354}23552356/*2357 * Remove empty parents, but spare refs/ and immediate subdirs.2358 * Note: munges *name.2359 */2360static void try_remove_empty_parents(char *name)2361{2362 char *p, *q;2363 int i;2364 p = name;2365 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2366 while (*p && *p != '/')2367 p++;2368 /* tolerate duplicate slashes; see check_refname_format() */2369 while (*p == '/')2370 p++;2371 }2372 for (q = p; *q; q++)2373 ;2374 while (1) {2375 while (q > p && *q != '/')2376 q--;2377 while (q > p && *(q-1) == '/')2378 q--;2379 if (q == p)2380 break;2381 *q = '\0';2382 if (rmdir(git_path("%s", name)))2383 break;2384 }2385}23862387/* make sure nobody touched the ref, and unlink */2388static void prune_ref(struct ref_to_prune *r)2389{2390 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);23912392 if (lock) {2393 unlink_or_warn(git_path("%s", r->name));2394 unlock_ref(lock);2395 try_remove_empty_parents(r->name);2396 }2397}23982399static void prune_refs(struct ref_to_prune *r)2400{2401 while (r) {2402 prune_ref(r);2403 r = r->next;2404 }2405}24062407int pack_refs(unsigned int flags)2408{2409 struct pack_refs_cb_data cbdata;24102411 memset(&cbdata, 0, sizeof(cbdata));2412 cbdata.flags = flags;24132414 lock_packed_refs(LOCK_DIE_ON_ERROR);2415 cbdata.packed_refs = get_packed_refs(&ref_cache);24162417 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2418 pack_if_possible_fn, &cbdata);24192420 if (commit_packed_refs())2421 die_errno("unable to overwrite old ref-pack file");24222423 prune_refs(cbdata.ref_to_prune);2424 return 0;2425}24262427/*2428 * If entry is no longer needed in packed-refs, add it to the string2429 * list pointed to by cb_data. Reasons for deleting entries:2430 *2431 * - Entry is broken.2432 * - Entry is overridden by a loose ref.2433 * - Entry does not point at a valid object.2434 *2435 * In the first and third cases, also emit an error message because these2436 * are indications of repository corruption.2437 */2438static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)2439{2440 struct string_list *refs_to_delete = cb_data;24412442 if (entry->flag & REF_ISBROKEN) {2443 /* This shouldn't happen to packed refs. */2444 error("%s is broken!", entry->name);2445 string_list_append(refs_to_delete, entry->name);2446 return 0;2447 }2448 if (!has_sha1_file(entry->u.value.sha1)) {2449 unsigned char sha1[20];2450 int flags;24512452 if (read_ref_full(entry->name, sha1, 0, &flags))2453 /* We should at least have found the packed ref. */2454 die("Internal error");2455 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2456 /*2457 * This packed reference is overridden by a2458 * loose reference, so it is OK that its value2459 * is no longer valid; for example, it might2460 * refer to an object that has been garbage2461 * collected. For this purpose we don't even2462 * care whether the loose reference itself is2463 * invalid, broken, symbolic, etc. Silently2464 * remove the packed reference.2465 */2466 string_list_append(refs_to_delete, entry->name);2467 return 0;2468 }2469 /*2470 * There is no overriding loose reference, so the fact2471 * that this reference doesn't refer to a valid object2472 * indicates some kind of repository corruption.2473 * Report the problem, then omit the reference from2474 * the output.2475 */2476 error("%s does not point to a valid object!", entry->name);2477 string_list_append(refs_to_delete, entry->name);2478 return 0;2479 }24802481 return 0;2482}24832484int repack_without_refs(const char **refnames, int n, struct strbuf *err)2485{2486 struct ref_dir *packed;2487 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2488 struct string_list_item *ref_to_delete;2489 int i, ret, removed = 0;24902491 /* Look for a packed ref */2492 for (i = 0; i < n; i++)2493 if (get_packed_ref(refnames[i]))2494 break;24952496 /* Avoid locking if we have nothing to do */2497 if (i == n)2498 return 0; /* no refname exists in packed refs */24992500 if (lock_packed_refs(0)) {2501 if (err) {2502 unable_to_lock_message(git_path("packed-refs"), errno,2503 err);2504 return -1;2505 }2506 unable_to_lock_error(git_path("packed-refs"), errno);2507 return error("cannot delete '%s' from packed refs", refnames[i]);2508 }2509 packed = get_packed_refs(&ref_cache);25102511 /* Remove refnames from the cache */2512 for (i = 0; i < n; i++)2513 if (remove_entry(packed, refnames[i]) != -1)2514 removed = 1;2515 if (!removed) {2516 /*2517 * All packed entries disappeared while we were2518 * acquiring the lock.2519 */2520 rollback_packed_refs();2521 return 0;2522 }25232524 /* Remove any other accumulated cruft */2525 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);2526 for_each_string_list_item(ref_to_delete, &refs_to_delete) {2527 if (remove_entry(packed, ref_to_delete->string) == -1)2528 die("internal error");2529 }25302531 /* Write what remains */2532 ret = commit_packed_refs();2533 if (ret && err)2534 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",2535 strerror(errno));2536 return ret;2537}25382539static int repack_without_ref(const char *refname)2540{2541 return repack_without_refs(&refname, 1, NULL);2542}25432544static int delete_ref_loose(struct ref_lock *lock, int flag)2545{2546 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2547 /* loose */2548 int err, i = strlen(lock->lk->filename) - 5; /* .lock */25492550 lock->lk->filename[i] = 0;2551 err = unlink_or_warn(lock->lk->filename);2552 lock->lk->filename[i] = '.';2553 if (err && errno != ENOENT)2554 return 1;2555 }2556 return 0;2557}25582559int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2560{2561 struct ref_lock *lock;2562 int ret = 0, flag = 0;25632564 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);2565 if (!lock)2566 return 1;2567 ret |= delete_ref_loose(lock, flag);25682569 /* removing the loose one could have resurrected an earlier2570 * packed one. Also, if it was not loose we need to repack2571 * without it.2572 */2573 ret |= repack_without_ref(lock->ref_name);25742575 unlink_or_warn(git_path("logs/%s", lock->ref_name));2576 clear_loose_ref_cache(&ref_cache);2577 unlock_ref(lock);2578 return ret;2579}25802581/*2582 * People using contrib's git-new-workdir have .git/logs/refs ->2583 * /some/other/path/.git/logs/refs, and that may live on another device.2584 *2585 * IOW, to avoid cross device rename errors, the temporary renamed log must2586 * live into logs/refs.2587 */2588#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"25892590static int rename_tmp_log(const char *newrefname)2591{2592 int attempts_remaining = 4;25932594 retry:2595 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {2596 case SCLD_OK:2597 break; /* success */2598 case SCLD_VANISHED:2599 if (--attempts_remaining > 0)2600 goto retry;2601 /* fall through */2602 default:2603 error("unable to create directory for %s", newrefname);2604 return -1;2605 }26062607 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2608 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2609 /*2610 * rename(a, b) when b is an existing2611 * directory ought to result in ISDIR, but2612 * Solaris 5.8 gives ENOTDIR. Sheesh.2613 */2614 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2615 error("Directory not empty: logs/%s", newrefname);2616 return -1;2617 }2618 goto retry;2619 } else if (errno == ENOENT && --attempts_remaining > 0) {2620 /*2621 * Maybe another process just deleted one of2622 * the directories in the path to newrefname.2623 * Try again from the beginning.2624 */2625 goto retry;2626 } else {2627 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2628 newrefname, strerror(errno));2629 return -1;2630 }2631 }2632 return 0;2633}26342635int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2636{2637 unsigned char sha1[20], orig_sha1[20];2638 int flag = 0, logmoved = 0;2639 struct ref_lock *lock;2640 struct stat loginfo;2641 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2642 const char *symref = NULL;26432644 if (log && S_ISLNK(loginfo.st_mode))2645 return error("reflog for %s is a symlink", oldrefname);26462647 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);2648 if (flag & REF_ISSYMREF)2649 return error("refname %s is a symbolic ref, renaming it is not supported",2650 oldrefname);2651 if (!symref)2652 return error("refname %s not found", oldrefname);26532654 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))2655 return 1;26562657 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))2658 return 1;26592660 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2661 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2662 oldrefname, strerror(errno));26632664 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2665 error("unable to delete old %s", oldrefname);2666 goto rollback;2667 }26682669 if (!read_ref_full(newrefname, sha1, 1, &flag) &&2670 delete_ref(newrefname, sha1, REF_NODEREF)) {2671 if (errno==EISDIR) {2672 if (remove_empty_directories(git_path("%s", newrefname))) {2673 error("Directory not empty: %s", newrefname);2674 goto rollback;2675 }2676 } else {2677 error("unable to delete existing %s", newrefname);2678 goto rollback;2679 }2680 }26812682 if (log && rename_tmp_log(newrefname))2683 goto rollback;26842685 logmoved = log;26862687 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);2688 if (!lock) {2689 error("unable to lock %s for update", newrefname);2690 goto rollback;2691 }2692 lock->force_write = 1;2693 hashcpy(lock->old_sha1, orig_sha1);2694 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2695 error("unable to write current sha1 into %s", newrefname);2696 goto rollback;2697 }26982699 return 0;27002701 rollback:2702 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);2703 if (!lock) {2704 error("unable to lock %s for rollback", oldrefname);2705 goto rollbacklog;2706 }27072708 lock->force_write = 1;2709 flag = log_all_ref_updates;2710 log_all_ref_updates = 0;2711 if (write_ref_sha1(lock, orig_sha1, NULL))2712 error("unable to write current sha1 into %s", oldrefname);2713 log_all_ref_updates = flag;27142715 rollbacklog:2716 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2717 error("unable to restore logfile %s from %s: %s",2718 oldrefname, newrefname, strerror(errno));2719 if (!logmoved && log &&2720 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2721 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2722 oldrefname, strerror(errno));27232724 return 1;2725}27262727int close_ref(struct ref_lock *lock)2728{2729 if (close_lock_file(lock->lk))2730 return -1;2731 lock->lock_fd = -1;2732 return 0;2733}27342735int commit_ref(struct ref_lock *lock)2736{2737 if (commit_lock_file(lock->lk))2738 return -1;2739 lock->lock_fd = -1;2740 return 0;2741}27422743void unlock_ref(struct ref_lock *lock)2744{2745 /* Do not free lock->lk -- atexit() still looks at them */2746 if (lock->lk)2747 rollback_lock_file(lock->lk);2748 free(lock->ref_name);2749 free(lock->orig_ref_name);2750 free(lock);2751}27522753/*2754 * copy the reflog message msg to buf, which has been allocated sufficiently2755 * large, while cleaning up the whitespaces. Especially, convert LF to space,2756 * because reflog file is one line per entry.2757 */2758static int copy_msg(char *buf, const char *msg)2759{2760 char *cp = buf;2761 char c;2762 int wasspace = 1;27632764 *cp++ = '\t';2765 while ((c = *msg++)) {2766 if (wasspace && isspace(c))2767 continue;2768 wasspace = isspace(c);2769 if (wasspace)2770 c = ' ';2771 *cp++ = c;2772 }2773 while (buf < cp && isspace(cp[-1]))2774 cp--;2775 *cp++ = '\n';2776 return cp - buf;2777}27782779/* This function must set a meaningful errno on failure */2780int log_ref_setup(const char *refname, char *logfile, int bufsize)2781{2782 int logfd, oflags = O_APPEND | O_WRONLY;27832784 git_snpath(logfile, bufsize, "logs/%s", refname);2785 if (log_all_ref_updates &&2786 (starts_with(refname, "refs/heads/") ||2787 starts_with(refname, "refs/remotes/") ||2788 starts_with(refname, "refs/notes/") ||2789 !strcmp(refname, "HEAD"))) {2790 if (safe_create_leading_directories(logfile) < 0) {2791 int save_errno = errno;2792 error("unable to create directory for %s", logfile);2793 errno = save_errno;2794 return -1;2795 }2796 oflags |= O_CREAT;2797 }27982799 logfd = open(logfile, oflags, 0666);2800 if (logfd < 0) {2801 if (!(oflags & O_CREAT) && errno == ENOENT)2802 return 0;28032804 if ((oflags & O_CREAT) && errno == EISDIR) {2805 if (remove_empty_directories(logfile)) {2806 int save_errno = errno;2807 error("There are still logs under '%s'",2808 logfile);2809 errno = save_errno;2810 return -1;2811 }2812 logfd = open(logfile, oflags, 0666);2813 }28142815 if (logfd < 0) {2816 int save_errno = errno;2817 error("Unable to append to %s: %s", logfile,2818 strerror(errno));2819 errno = save_errno;2820 return -1;2821 }2822 }28232824 adjust_shared_perm(logfile);2825 close(logfd);2826 return 0;2827}28282829static int log_ref_write(const char *refname, const unsigned char *old_sha1,2830 const unsigned char *new_sha1, const char *msg)2831{2832 int logfd, result, written, oflags = O_APPEND | O_WRONLY;2833 unsigned maxlen, len;2834 int msglen;2835 char log_file[PATH_MAX];2836 char *logrec;2837 const char *committer;28382839 if (log_all_ref_updates < 0)2840 log_all_ref_updates = !is_bare_repository();28412842 result = log_ref_setup(refname, log_file, sizeof(log_file));2843 if (result)2844 return result;28452846 logfd = open(log_file, oflags);2847 if (logfd < 0)2848 return 0;2849 msglen = msg ? strlen(msg) : 0;2850 committer = git_committer_info(0);2851 maxlen = strlen(committer) + msglen + 100;2852 logrec = xmalloc(maxlen);2853 len = sprintf(logrec, "%s %s %s\n",2854 sha1_to_hex(old_sha1),2855 sha1_to_hex(new_sha1),2856 committer);2857 if (msglen)2858 len += copy_msg(logrec + len - 1, msg) - 1;2859 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;2860 free(logrec);2861 if (written != len) {2862 int save_errno = errno;2863 close(logfd);2864 error("Unable to append to %s", log_file);2865 errno = save_errno;2866 return -1;2867 }2868 if (close(logfd)) {2869 int save_errno = errno;2870 error("Unable to append to %s", log_file);2871 errno = save_errno;2872 return -1;2873 }2874 return 0;2875}28762877int is_branch(const char *refname)2878{2879 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");2880}28812882/* This function must return a meaningful errno */2883int write_ref_sha1(struct ref_lock *lock,2884 const unsigned char *sha1, const char *logmsg)2885{2886 static char term = '\n';2887 struct object *o;28882889 if (!lock) {2890 errno = EINVAL;2891 return -1;2892 }2893 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2894 unlock_ref(lock);2895 return 0;2896 }2897 o = parse_object(sha1);2898 if (!o) {2899 error("Trying to write ref %s with nonexistent object %s",2900 lock->ref_name, sha1_to_hex(sha1));2901 unlock_ref(lock);2902 errno = EINVAL;2903 return -1;2904 }2905 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2906 error("Trying to write non-commit object %s to branch %s",2907 sha1_to_hex(sha1), lock->ref_name);2908 unlock_ref(lock);2909 errno = EINVAL;2910 return -1;2911 }2912 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||2913 write_in_full(lock->lock_fd, &term, 1) != 1 ||2914 close_ref(lock) < 0) {2915 int save_errno = errno;2916 error("Couldn't write %s", lock->lk->filename);2917 unlock_ref(lock);2918 errno = save_errno;2919 return -1;2920 }2921 clear_loose_ref_cache(&ref_cache);2922 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||2923 (strcmp(lock->ref_name, lock->orig_ref_name) &&2924 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {2925 unlock_ref(lock);2926 return -1;2927 }2928 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {2929 /*2930 * Special hack: If a branch is updated directly and HEAD2931 * points to it (may happen on the remote side of a push2932 * for example) then logically the HEAD reflog should be2933 * updated too.2934 * A generic solution implies reverse symref information,2935 * but finding all symrefs pointing to the given branch2936 * would be rather costly for this rare event (the direct2937 * update of a branch) to be worth it. So let's cheat and2938 * check with HEAD only which should cover 99% of all usage2939 * scenarios (even 100% of the default ones).2940 */2941 unsigned char head_sha1[20];2942 int head_flag;2943 const char *head_ref;2944 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);2945 if (head_ref && (head_flag & REF_ISSYMREF) &&2946 !strcmp(head_ref, lock->ref_name))2947 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2948 }2949 if (commit_ref(lock)) {2950 error("Couldn't set %s", lock->ref_name);2951 unlock_ref(lock);2952 return -1;2953 }2954 unlock_ref(lock);2955 return 0;2956}29572958int create_symref(const char *ref_target, const char *refs_heads_master,2959 const char *logmsg)2960{2961 const char *lockpath;2962 char ref[1000];2963 int fd, len, written;2964 char *git_HEAD = git_pathdup("%s", ref_target);2965 unsigned char old_sha1[20], new_sha1[20];29662967 if (logmsg && read_ref(ref_target, old_sha1))2968 hashclr(old_sha1);29692970 if (safe_create_leading_directories(git_HEAD) < 0)2971 return error("unable to create directory for %s", git_HEAD);29722973#ifndef NO_SYMLINK_HEAD2974 if (prefer_symlink_refs) {2975 unlink(git_HEAD);2976 if (!symlink(refs_heads_master, git_HEAD))2977 goto done;2978 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2979 }2980#endif29812982 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);2983 if (sizeof(ref) <= len) {2984 error("refname too long: %s", refs_heads_master);2985 goto error_free_return;2986 }2987 lockpath = mkpath("%s.lock", git_HEAD);2988 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);2989 if (fd < 0) {2990 error("Unable to open %s for writing", lockpath);2991 goto error_free_return;2992 }2993 written = write_in_full(fd, ref, len);2994 if (close(fd) != 0 || written != len) {2995 error("Unable to write to %s", lockpath);2996 goto error_unlink_return;2997 }2998 if (rename(lockpath, git_HEAD) < 0) {2999 error("Unable to create %s", git_HEAD);3000 goto error_unlink_return;3001 }3002 if (adjust_shared_perm(git_HEAD)) {3003 error("Unable to fix permissions on %s", lockpath);3004 error_unlink_return:3005 unlink_or_warn(lockpath);3006 error_free_return:3007 free(git_HEAD);3008 return -1;3009 }30103011#ifndef NO_SYMLINK_HEAD3012 done:3013#endif3014 if (logmsg && !read_ref(refs_heads_master, new_sha1))3015 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);30163017 free(git_HEAD);3018 return 0;3019}30203021struct read_ref_at_cb {3022 const char *refname;3023 unsigned long at_time;3024 int cnt;3025 int reccnt;3026 unsigned char *sha1;3027 int found_it;30283029 unsigned char osha1[20];3030 unsigned char nsha1[20];3031 int tz;3032 unsigned long date;3033 char **msg;3034 unsigned long *cutoff_time;3035 int *cutoff_tz;3036 int *cutoff_cnt;3037};30383039static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,3040 const char *email, unsigned long timestamp, int tz,3041 const char *message, void *cb_data)3042{3043 struct read_ref_at_cb *cb = cb_data;30443045 cb->reccnt++;3046 cb->tz = tz;3047 cb->date = timestamp;30483049 if (timestamp <= cb->at_time || cb->cnt == 0) {3050 if (cb->msg)3051 *cb->msg = xstrdup(message);3052 if (cb->cutoff_time)3053 *cb->cutoff_time = timestamp;3054 if (cb->cutoff_tz)3055 *cb->cutoff_tz = tz;3056 if (cb->cutoff_cnt)3057 *cb->cutoff_cnt = cb->reccnt - 1;3058 /*3059 * we have not yet updated cb->[n|o]sha1 so they still3060 * hold the values for the previous record.3061 */3062 if (!is_null_sha1(cb->osha1)) {3063 hashcpy(cb->sha1, nsha1);3064 if (hashcmp(cb->osha1, nsha1))3065 warning("Log for ref %s has gap after %s.",3066 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));3067 }3068 else if (cb->date == cb->at_time)3069 hashcpy(cb->sha1, nsha1);3070 else if (hashcmp(nsha1, cb->sha1))3071 warning("Log for ref %s unexpectedly ended on %s.",3072 cb->refname, show_date(cb->date, cb->tz,3073 DATE_RFC2822));3074 hashcpy(cb->osha1, osha1);3075 hashcpy(cb->nsha1, nsha1);3076 cb->found_it = 1;3077 return 1;3078 }3079 hashcpy(cb->osha1, osha1);3080 hashcpy(cb->nsha1, nsha1);3081 if (cb->cnt > 0)3082 cb->cnt--;3083 return 0;3084}30853086static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,3087 const char *email, unsigned long timestamp,3088 int tz, const char *message, void *cb_data)3089{3090 struct read_ref_at_cb *cb = cb_data;30913092 if (cb->msg)3093 *cb->msg = xstrdup(message);3094 if (cb->cutoff_time)3095 *cb->cutoff_time = timestamp;3096 if (cb->cutoff_tz)3097 *cb->cutoff_tz = tz;3098 if (cb->cutoff_cnt)3099 *cb->cutoff_cnt = cb->reccnt;3100 hashcpy(cb->sha1, osha1);3101 if (is_null_sha1(cb->sha1))3102 hashcpy(cb->sha1, nsha1);3103 /* We just want the first entry */3104 return 1;3105}31063107int read_ref_at(const char *refname, unsigned long at_time, int cnt,3108 unsigned char *sha1, char **msg,3109 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)3110{3111 struct read_ref_at_cb cb;31123113 memset(&cb, 0, sizeof(cb));3114 cb.refname = refname;3115 cb.at_time = at_time;3116 cb.cnt = cnt;3117 cb.msg = msg;3118 cb.cutoff_time = cutoff_time;3119 cb.cutoff_tz = cutoff_tz;3120 cb.cutoff_cnt = cutoff_cnt;3121 cb.sha1 = sha1;31223123 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);31243125 if (!cb.reccnt)3126 die("Log for %s is empty.", refname);3127 if (cb.found_it)3128 return 0;31293130 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);31313132 return 1;3133}31343135int reflog_exists(const char *refname)3136{3137 struct stat st;31383139 return !lstat(git_path("logs/%s", refname), &st) &&3140 S_ISREG(st.st_mode);3141}31423143int delete_reflog(const char *refname)3144{3145 return remove_path(git_path("logs/%s", refname));3146}31473148static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3149{3150 unsigned char osha1[20], nsha1[20];3151 char *email_end, *message;3152 unsigned long timestamp;3153 int tz;31543155 /* old SP new SP name <email> SP time TAB msg LF */3156 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3157 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3158 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3159 !(email_end = strchr(sb->buf + 82, '>')) ||3160 email_end[1] != ' ' ||3161 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3162 !message || message[0] != ' ' ||3163 (message[1] != '+' && message[1] != '-') ||3164 !isdigit(message[2]) || !isdigit(message[3]) ||3165 !isdigit(message[4]) || !isdigit(message[5]))3166 return 0; /* corrupt? */3167 email_end[1] = '\0';3168 tz = strtol(message + 1, NULL, 10);3169 if (message[6] != '\t')3170 message += 6;3171 else3172 message += 7;3173 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3174}31753176static char *find_beginning_of_line(char *bob, char *scan)3177{3178 while (bob < scan && *(--scan) != '\n')3179 ; /* keep scanning backwards */3180 /*3181 * Return either beginning of the buffer, or LF at the end of3182 * the previous line.3183 */3184 return scan;3185}31863187int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3188{3189 struct strbuf sb = STRBUF_INIT;3190 FILE *logfp;3191 long pos;3192 int ret = 0, at_tail = 1;31933194 logfp = fopen(git_path("logs/%s", refname), "r");3195 if (!logfp)3196 return -1;31973198 /* Jump to the end */3199 if (fseek(logfp, 0, SEEK_END) < 0)3200 return error("cannot seek back reflog for %s: %s",3201 refname, strerror(errno));3202 pos = ftell(logfp);3203 while (!ret && 0 < pos) {3204 int cnt;3205 size_t nread;3206 char buf[BUFSIZ];3207 char *endp, *scanp;32083209 /* Fill next block from the end */3210 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3211 if (fseek(logfp, pos - cnt, SEEK_SET))3212 return error("cannot seek back reflog for %s: %s",3213 refname, strerror(errno));3214 nread = fread(buf, cnt, 1, logfp);3215 if (nread != 1)3216 return error("cannot read %d bytes from reflog for %s: %s",3217 cnt, refname, strerror(errno));3218 pos -= cnt;32193220 scanp = endp = buf + cnt;3221 if (at_tail && scanp[-1] == '\n')3222 /* Looking at the final LF at the end of the file */3223 scanp--;3224 at_tail = 0;32253226 while (buf < scanp) {3227 /*3228 * terminating LF of the previous line, or the beginning3229 * of the buffer.3230 */3231 char *bp;32323233 bp = find_beginning_of_line(buf, scanp);32343235 if (*bp != '\n') {3236 strbuf_splice(&sb, 0, 0, buf, endp - buf);3237 if (pos)3238 break; /* need to fill another block */3239 scanp = buf - 1; /* leave loop */3240 } else {3241 /*3242 * (bp + 1) thru endp is the beginning of the3243 * current line we have in sb3244 */3245 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3246 scanp = bp;3247 endp = bp + 1;3248 }3249 ret = show_one_reflog_ent(&sb, fn, cb_data);3250 strbuf_reset(&sb);3251 if (ret)3252 break;3253 }32543255 }3256 if (!ret && sb.len)3257 ret = show_one_reflog_ent(&sb, fn, cb_data);32583259 fclose(logfp);3260 strbuf_release(&sb);3261 return ret;3262}32633264int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3265{3266 FILE *logfp;3267 struct strbuf sb = STRBUF_INIT;3268 int ret = 0;32693270 logfp = fopen(git_path("logs/%s", refname), "r");3271 if (!logfp)3272 return -1;32733274 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3275 ret = show_one_reflog_ent(&sb, fn, cb_data);3276 fclose(logfp);3277 strbuf_release(&sb);3278 return ret;3279}3280/*3281 * Call fn for each reflog in the namespace indicated by name. name3282 * must be empty or end with '/'. Name will be used as a scratch3283 * space, but its contents will be restored before return.3284 */3285static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3286{3287 DIR *d = opendir(git_path("logs/%s", name->buf));3288 int retval = 0;3289 struct dirent *de;3290 int oldlen = name->len;32913292 if (!d)3293 return name->len ? errno : 0;32943295 while ((de = readdir(d)) != NULL) {3296 struct stat st;32973298 if (de->d_name[0] == '.')3299 continue;3300 if (ends_with(de->d_name, ".lock"))3301 continue;3302 strbuf_addstr(name, de->d_name);3303 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3304 ; /* silently ignore */3305 } else {3306 if (S_ISDIR(st.st_mode)) {3307 strbuf_addch(name, '/');3308 retval = do_for_each_reflog(name, fn, cb_data);3309 } else {3310 unsigned char sha1[20];3311 if (read_ref_full(name->buf, sha1, 0, NULL))3312 retval = error("bad ref for %s", name->buf);3313 else3314 retval = fn(name->buf, sha1, 0, cb_data);3315 }3316 if (retval)3317 break;3318 }3319 strbuf_setlen(name, oldlen);3320 }3321 closedir(d);3322 return retval;3323}33243325int for_each_reflog(each_ref_fn fn, void *cb_data)3326{3327 int retval;3328 struct strbuf name;3329 strbuf_init(&name, PATH_MAX);3330 retval = do_for_each_reflog(&name, fn, cb_data);3331 strbuf_release(&name);3332 return retval;3333}33343335static struct ref_lock *update_ref_lock(const char *refname,3336 const unsigned char *oldval,3337 int flags, int *type_p,3338 enum action_on_err onerr)3339{3340 struct ref_lock *lock;3341 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);3342 if (!lock) {3343 const char *str = "Cannot lock the ref '%s'.";3344 switch (onerr) {3345 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;3346 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;3347 case UPDATE_REFS_QUIET_ON_ERR: break;3348 }3349 }3350 return lock;3351}33523353static int update_ref_write(const char *action, const char *refname,3354 const unsigned char *sha1, struct ref_lock *lock,3355 struct strbuf *err, enum action_on_err onerr)3356{3357 if (write_ref_sha1(lock, sha1, action) < 0) {3358 const char *str = "Cannot update the ref '%s'.";3359 if (err)3360 strbuf_addf(err, str, refname);33613362 switch (onerr) {3363 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;3364 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;3365 case UPDATE_REFS_QUIET_ON_ERR: break;3366 }3367 return 1;3368 }3369 return 0;3370}33713372/**3373 * Information needed for a single ref update. Set new_sha1 to the3374 * new value or to zero to delete the ref. To check the old value3375 * while locking the ref, set have_old to 1 and set old_sha1 to the3376 * value or to zero to ensure the ref does not exist before update.3377 */3378struct ref_update {3379 unsigned char new_sha1[20];3380 unsigned char old_sha1[20];3381 int flags; /* REF_NODEREF? */3382 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */3383 struct ref_lock *lock;3384 int type;3385 const char refname[FLEX_ARRAY];3386};33873388/*3389 * Data structure for holding a reference transaction, which can3390 * consist of checks and updates to multiple references, carried out3391 * as atomically as possible. This structure is opaque to callers.3392 */3393struct ref_transaction {3394 struct ref_update **updates;3395 size_t alloc;3396 size_t nr;3397};33983399struct ref_transaction *ref_transaction_begin(void)3400{3401 return xcalloc(1, sizeof(struct ref_transaction));3402}34033404void ref_transaction_free(struct ref_transaction *transaction)3405{3406 int i;34073408 if (!transaction)3409 return;34103411 for (i = 0; i < transaction->nr; i++)3412 free(transaction->updates[i]);34133414 free(transaction->updates);3415 free(transaction);3416}34173418static struct ref_update *add_update(struct ref_transaction *transaction,3419 const char *refname)3420{3421 size_t len = strlen(refname);3422 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);34233424 strcpy((char *)update->refname, refname);3425 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);3426 transaction->updates[transaction->nr++] = update;3427 return update;3428}34293430int ref_transaction_update(struct ref_transaction *transaction,3431 const char *refname,3432 const unsigned char *new_sha1,3433 const unsigned char *old_sha1,3434 int flags, int have_old,3435 struct strbuf *err)3436{3437 struct ref_update *update;34383439 if (have_old && !old_sha1)3440 die("BUG: have_old is true but old_sha1 is NULL");34413442 update = add_update(transaction, refname);3443 hashcpy(update->new_sha1, new_sha1);3444 update->flags = flags;3445 update->have_old = have_old;3446 if (have_old)3447 hashcpy(update->old_sha1, old_sha1);3448 return 0;3449}34503451void ref_transaction_create(struct ref_transaction *transaction,3452 const char *refname,3453 const unsigned char *new_sha1,3454 int flags)3455{3456 struct ref_update *update = add_update(transaction, refname);34573458 assert(!is_null_sha1(new_sha1));3459 hashcpy(update->new_sha1, new_sha1);3460 hashclr(update->old_sha1);3461 update->flags = flags;3462 update->have_old = 1;3463}34643465void ref_transaction_delete(struct ref_transaction *transaction,3466 const char *refname,3467 const unsigned char *old_sha1,3468 int flags, int have_old)3469{3470 struct ref_update *update = add_update(transaction, refname);34713472 update->flags = flags;3473 update->have_old = have_old;3474 if (have_old) {3475 assert(!is_null_sha1(old_sha1));3476 hashcpy(update->old_sha1, old_sha1);3477 }3478}34793480int update_ref(const char *action, const char *refname,3481 const unsigned char *sha1, const unsigned char *oldval,3482 int flags, enum action_on_err onerr)3483{3484 struct ref_lock *lock;3485 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);3486 if (!lock)3487 return 1;3488 return update_ref_write(action, refname, sha1, lock, NULL, onerr);3489}34903491static int ref_update_compare(const void *r1, const void *r2)3492{3493 const struct ref_update * const *u1 = r1;3494 const struct ref_update * const *u2 = r2;3495 return strcmp((*u1)->refname, (*u2)->refname);3496}34973498static int ref_update_reject_duplicates(struct ref_update **updates, int n,3499 struct strbuf *err)3500{3501 int i;3502 for (i = 1; i < n; i++)3503 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {3504 const char *str =3505 "Multiple updates for ref '%s' not allowed.";3506 if (err)3507 strbuf_addf(err, str, updates[i]->refname);35083509 return 1;3510 }3511 return 0;3512}35133514int ref_transaction_commit(struct ref_transaction *transaction,3515 const char *msg, struct strbuf *err)3516{3517 int ret = 0, delnum = 0, i;3518 const char **delnames;3519 int n = transaction->nr;3520 struct ref_update **updates = transaction->updates;35213522 if (!n)3523 return 0;35243525 /* Allocate work space */3526 delnames = xmalloc(sizeof(*delnames) * n);35273528 /* Copy, sort, and reject duplicate refs */3529 qsort(updates, n, sizeof(*updates), ref_update_compare);3530 ret = ref_update_reject_duplicates(updates, n, err);3531 if (ret)3532 goto cleanup;35333534 /* Acquire all locks while verifying old values */3535 for (i = 0; i < n; i++) {3536 struct ref_update *update = updates[i];35373538 update->lock = update_ref_lock(update->refname,3539 (update->have_old ?3540 update->old_sha1 : NULL),3541 update->flags,3542 &update->type,3543 UPDATE_REFS_QUIET_ON_ERR);3544 if (!update->lock) {3545 if (err)3546 strbuf_addf(err, "Cannot lock the ref '%s'.",3547 update->refname);3548 ret = 1;3549 goto cleanup;3550 }3551 }35523553 /* Perform updates first so live commits remain referenced */3554 for (i = 0; i < n; i++) {3555 struct ref_update *update = updates[i];35563557 if (!is_null_sha1(update->new_sha1)) {3558 ret = update_ref_write(msg,3559 update->refname,3560 update->new_sha1,3561 update->lock, err,3562 UPDATE_REFS_QUIET_ON_ERR);3563 update->lock = NULL; /* freed by update_ref_write */3564 if (ret)3565 goto cleanup;3566 }3567 }35683569 /* Perform deletes now that updates are safely completed */3570 for (i = 0; i < n; i++) {3571 struct ref_update *update = updates[i];35723573 if (update->lock) {3574 delnames[delnum++] = update->lock->ref_name;3575 ret |= delete_ref_loose(update->lock, update->type);3576 }3577 }35783579 ret |= repack_without_refs(delnames, delnum, err);3580 for (i = 0; i < delnum; i++)3581 unlink_or_warn(git_path("logs/%s", delnames[i]));3582 clear_loose_ref_cache(&ref_cache);35833584cleanup:3585 for (i = 0; i < n; i++)3586 if (updates[i]->lock)3587 unlock_ref(updates[i]->lock);3588 free(delnames);3589 return ret;3590}35913592char *shorten_unambiguous_ref(const char *refname, int strict)3593{3594 int i;3595 static char **scanf_fmts;3596 static int nr_rules;3597 char *short_name;35983599 if (!nr_rules) {3600 /*3601 * Pre-generate scanf formats from ref_rev_parse_rules[].3602 * Generate a format suitable for scanf from a3603 * ref_rev_parse_rules rule by interpolating "%s" at the3604 * location of the "%.*s".3605 */3606 size_t total_len = 0;3607 size_t offset = 0;36083609 /* the rule list is NULL terminated, count them first */3610 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)3611 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3612 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;36133614 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);36153616 offset = 0;3617 for (i = 0; i < nr_rules; i++) {3618 assert(offset < total_len);3619 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;3620 offset += snprintf(scanf_fmts[i], total_len - offset,3621 ref_rev_parse_rules[i], 2, "%s") + 1;3622 }3623 }36243625 /* bail out if there are no rules */3626 if (!nr_rules)3627 return xstrdup(refname);36283629 /* buffer for scanf result, at most refname must fit */3630 short_name = xstrdup(refname);36313632 /* skip first rule, it will always match */3633 for (i = nr_rules - 1; i > 0 ; --i) {3634 int j;3635 int rules_to_fail = i;3636 int short_name_len;36373638 if (1 != sscanf(refname, scanf_fmts[i], short_name))3639 continue;36403641 short_name_len = strlen(short_name);36423643 /*3644 * in strict mode, all (except the matched one) rules3645 * must fail to resolve to a valid non-ambiguous ref3646 */3647 if (strict)3648 rules_to_fail = nr_rules;36493650 /*3651 * check if the short name resolves to a valid ref,3652 * but use only rules prior to the matched one3653 */3654 for (j = 0; j < rules_to_fail; j++) {3655 const char *rule = ref_rev_parse_rules[j];3656 char refname[PATH_MAX];36573658 /* skip matched rule */3659 if (i == j)3660 continue;36613662 /*3663 * the short name is ambiguous, if it resolves3664 * (with this previous rule) to a valid ref3665 * read_ref() returns 0 on success3666 */3667 mksnpath(refname, sizeof(refname),3668 rule, short_name_len, short_name);3669 if (ref_exists(refname))3670 break;3671 }36723673 /*3674 * short name is non-ambiguous if all previous rules3675 * haven't resolved to a valid ref3676 */3677 if (j == rules_to_fail)3678 return short_name;3679 }36803681 free(short_name);3682 return xstrdup(refname);3683}36843685static struct string_list *hide_refs;36863687int parse_hide_refs_config(const char *var, const char *value, const char *section)3688{3689 if (!strcmp("transfer.hiderefs", var) ||3690 /* NEEDSWORK: use parse_config_key() once both are merged */3691 (starts_with(var, section) && var[strlen(section)] == '.' &&3692 !strcmp(var + strlen(section), ".hiderefs"))) {3693 char *ref;3694 int len;36953696 if (!value)3697 return config_error_nonbool(var);3698 ref = xstrdup(value);3699 len = strlen(ref);3700 while (len && ref[len - 1] == '/')3701 ref[--len] = '\0';3702 if (!hide_refs) {3703 hide_refs = xcalloc(1, sizeof(*hide_refs));3704 hide_refs->strdup_strings = 1;3705 }3706 string_list_append(hide_refs, ref);3707 }3708 return 0;3709}37103711int ref_is_hidden(const char *refname)3712{3713 struct string_list_item *item;37143715 if (!hide_refs)3716 return 0;3717 for_each_string_list_item(item, hide_refs) {3718 int len;3719 if (!starts_with(refname, item->string))3720 continue;3721 len = strlen(item->string);3722 if (!refname[len] || refname[len] == '/')3723 return 1;3724 }3725 return 0;3726}