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 (has_extension(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}13361337const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)1338{1339 int depth = MAXDEPTH;1340 ssize_t len;1341 char buffer[256];1342 static char refname_buffer[256];13431344 if (flag)1345 *flag = 0;13461347 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1348 return NULL;13491350 for (;;) {1351 char path[PATH_MAX];1352 struct stat st;1353 char *buf;1354 int fd;13551356 if (--depth < 0)1357 return NULL;13581359 git_snpath(path, sizeof(path), "%s", refname);13601361 /*1362 * We might have to loop back here to avoid a race1363 * condition: first we lstat() the file, then we try1364 * to read it as a link or as a file. But if somebody1365 * changes the type of the file (file <-> directory1366 * <-> symlink) between the lstat() and reading, then1367 * we don't want to report that as an error but rather1368 * try again starting with the lstat().1369 */1370 stat_ref:1371 if (lstat(path, &st) < 0) {1372 if (errno == ENOENT)1373 return handle_missing_loose_ref(refname, sha1,1374 reading, flag);1375 else1376 return NULL;1377 }13781379 /* Follow "normalized" - ie "refs/.." symlinks by hand */1380 if (S_ISLNK(st.st_mode)) {1381 len = readlink(path, buffer, sizeof(buffer)-1);1382 if (len < 0) {1383 if (errno == ENOENT || errno == EINVAL)1384 /* inconsistent with lstat; retry */1385 goto stat_ref;1386 else1387 return NULL;1388 }1389 buffer[len] = 0;1390 if (starts_with(buffer, "refs/") &&1391 !check_refname_format(buffer, 0)) {1392 strcpy(refname_buffer, buffer);1393 refname = refname_buffer;1394 if (flag)1395 *flag |= REF_ISSYMREF;1396 continue;1397 }1398 }13991400 /* Is it a directory? */1401 if (S_ISDIR(st.st_mode)) {1402 errno = EISDIR;1403 return NULL;1404 }14051406 /*1407 * Anything else, just open it and try to use it as1408 * a ref1409 */1410 fd = open(path, O_RDONLY);1411 if (fd < 0) {1412 if (errno == ENOENT)1413 /* inconsistent with lstat; retry */1414 goto stat_ref;1415 else1416 return NULL;1417 }1418 len = read_in_full(fd, buffer, sizeof(buffer)-1);1419 close(fd);1420 if (len < 0)1421 return NULL;1422 while (len && isspace(buffer[len-1]))1423 len--;1424 buffer[len] = '\0';14251426 /*1427 * Is it a symbolic ref?1428 */1429 if (!starts_with(buffer, "ref:")) {1430 /*1431 * Please note that FETCH_HEAD has a second1432 * line containing other data.1433 */1434 if (get_sha1_hex(buffer, sha1) ||1435 (buffer[40] != '\0' && !isspace(buffer[40]))) {1436 if (flag)1437 *flag |= REF_ISBROKEN;1438 return NULL;1439 }1440 return refname;1441 }1442 if (flag)1443 *flag |= REF_ISSYMREF;1444 buf = buffer + 4;1445 while (isspace(*buf))1446 buf++;1447 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1448 if (flag)1449 *flag |= REF_ISBROKEN;1450 return NULL;1451 }1452 refname = strcpy(refname_buffer, buf);1453 }1454}14551456char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)1457{1458 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);1459 return ret ? xstrdup(ret) : NULL;1460}14611462/* The argument to filter_refs */1463struct ref_filter {1464 const char *pattern;1465 each_ref_fn *fn;1466 void *cb_data;1467};14681469int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)1470{1471 if (resolve_ref_unsafe(refname, sha1, reading, flags))1472 return 0;1473 return -1;1474}14751476int read_ref(const char *refname, unsigned char *sha1)1477{1478 return read_ref_full(refname, sha1, 1, NULL);1479}14801481int ref_exists(const char *refname)1482{1483 unsigned char sha1[20];1484 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);1485}14861487static int filter_refs(const char *refname, const unsigned char *sha1, int flags,1488 void *data)1489{1490 struct ref_filter *filter = (struct ref_filter *)data;1491 if (wildmatch(filter->pattern, refname, 0, NULL))1492 return 0;1493 return filter->fn(refname, sha1, flags, filter->cb_data);1494}14951496enum peel_status {1497 /* object was peeled successfully: */1498 PEEL_PEELED = 0,14991500 /*1501 * object cannot be peeled because the named object (or an1502 * object referred to by a tag in the peel chain), does not1503 * exist.1504 */1505 PEEL_INVALID = -1,15061507 /* object cannot be peeled because it is not a tag: */1508 PEEL_NON_TAG = -2,15091510 /* ref_entry contains no peeled value because it is a symref: */1511 PEEL_IS_SYMREF = -3,15121513 /*1514 * ref_entry cannot be peeled because it is broken (i.e., the1515 * symbolic reference cannot even be resolved to an object1516 * name):1517 */1518 PEEL_BROKEN = -41519};15201521/*1522 * Peel the named object; i.e., if the object is a tag, resolve the1523 * tag recursively until a non-tag is found. If successful, store the1524 * result to sha1 and return PEEL_PEELED. If the object is not a tag1525 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1526 * and leave sha1 unchanged.1527 */1528static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)1529{1530 struct object *o = lookup_unknown_object(name);15311532 if (o->type == OBJ_NONE) {1533 int type = sha1_object_info(name, NULL);1534 if (type < 0)1535 return PEEL_INVALID;1536 o->type = type;1537 }15381539 if (o->type != OBJ_TAG)1540 return PEEL_NON_TAG;15411542 o = deref_tag_noverify(o);1543 if (!o)1544 return PEEL_INVALID;15451546 hashcpy(sha1, o->sha1);1547 return PEEL_PEELED;1548}15491550/*1551 * Peel the entry (if possible) and return its new peel_status. If1552 * repeel is true, re-peel the entry even if there is an old peeled1553 * value that is already stored in it.1554 *1555 * It is OK to call this function with a packed reference entry that1556 * might be stale and might even refer to an object that has since1557 * been garbage-collected. In such a case, if the entry has1558 * REF_KNOWS_PEELED then leave the status unchanged and return1559 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1560 */1561static enum peel_status peel_entry(struct ref_entry *entry, int repeel)1562{1563 enum peel_status status;15641565 if (entry->flag & REF_KNOWS_PEELED) {1566 if (repeel) {1567 entry->flag &= ~REF_KNOWS_PEELED;1568 hashclr(entry->u.value.peeled);1569 } else {1570 return is_null_sha1(entry->u.value.peeled) ?1571 PEEL_NON_TAG : PEEL_PEELED;1572 }1573 }1574 if (entry->flag & REF_ISBROKEN)1575 return PEEL_BROKEN;1576 if (entry->flag & REF_ISSYMREF)1577 return PEEL_IS_SYMREF;15781579 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);1580 if (status == PEEL_PEELED || status == PEEL_NON_TAG)1581 entry->flag |= REF_KNOWS_PEELED;1582 return status;1583}15841585int peel_ref(const char *refname, unsigned char *sha1)1586{1587 int flag;1588 unsigned char base[20];15891590 if (current_ref && (current_ref->name == refname1591 || !strcmp(current_ref->name, refname))) {1592 if (peel_entry(current_ref, 0))1593 return -1;1594 hashcpy(sha1, current_ref->u.value.peeled);1595 return 0;1596 }15971598 if (read_ref_full(refname, base, 1, &flag))1599 return -1;16001601 /*1602 * If the reference is packed, read its ref_entry from the1603 * cache in the hope that we already know its peeled value.1604 * We only try this optimization on packed references because1605 * (a) forcing the filling of the loose reference cache could1606 * be expensive and (b) loose references anyway usually do not1607 * have REF_KNOWS_PEELED.1608 */1609 if (flag & REF_ISPACKED) {1610 struct ref_entry *r = get_packed_ref(refname);1611 if (r) {1612 if (peel_entry(r, 0))1613 return -1;1614 hashcpy(sha1, r->u.value.peeled);1615 return 0;1616 }1617 }16181619 return peel_object(base, sha1);1620}16211622struct warn_if_dangling_data {1623 FILE *fp;1624 const char *refname;1625 const char *msg_fmt;1626};16271628static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,1629 int flags, void *cb_data)1630{1631 struct warn_if_dangling_data *d = cb_data;1632 const char *resolves_to;1633 unsigned char junk[20];16341635 if (!(flags & REF_ISSYMREF))1636 return 0;16371638 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);1639 if (!resolves_to || strcmp(resolves_to, d->refname))1640 return 0;16411642 fprintf(d->fp, d->msg_fmt, refname);1643 fputc('\n', d->fp);1644 return 0;1645}16461647void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)1648{1649 struct warn_if_dangling_data data;16501651 data.fp = fp;1652 data.refname = refname;1653 data.msg_fmt = msg_fmt;1654 for_each_rawref(warn_if_dangling_symref, &data);1655}16561657/*1658 * Call fn for each reference in the specified ref_cache, omitting1659 * references not in the containing_dir of base. fn is called for all1660 * references, including broken ones. If fn ever returns a non-zero1661 * value, stop the iteration and return that value; otherwise, return1662 * 0.1663 */1664static int do_for_each_entry(struct ref_cache *refs, const char *base,1665 each_ref_entry_fn fn, void *cb_data)1666{1667 struct packed_ref_cache *packed_ref_cache;1668 struct ref_dir *loose_dir;1669 struct ref_dir *packed_dir;1670 int retval = 0;16711672 /*1673 * We must make sure that all loose refs are read before accessing the1674 * packed-refs file; this avoids a race condition in which loose refs1675 * are migrated to the packed-refs file by a simultaneous process, but1676 * our in-memory view is from before the migration. get_packed_ref_cache()1677 * takes care of making sure our view is up to date with what is on1678 * disk.1679 */1680 loose_dir = get_loose_refs(refs);1681 if (base && *base) {1682 loose_dir = find_containing_dir(loose_dir, base, 0);1683 }1684 if (loose_dir)1685 prime_ref_dir(loose_dir);16861687 packed_ref_cache = get_packed_ref_cache(refs);1688 acquire_packed_ref_cache(packed_ref_cache);1689 packed_dir = get_packed_ref_dir(packed_ref_cache);1690 if (base && *base) {1691 packed_dir = find_containing_dir(packed_dir, base, 0);1692 }16931694 if (packed_dir && loose_dir) {1695 sort_ref_dir(packed_dir);1696 sort_ref_dir(loose_dir);1697 retval = do_for_each_entry_in_dirs(1698 packed_dir, loose_dir, fn, cb_data);1699 } else if (packed_dir) {1700 sort_ref_dir(packed_dir);1701 retval = do_for_each_entry_in_dir(1702 packed_dir, 0, fn, cb_data);1703 } else if (loose_dir) {1704 sort_ref_dir(loose_dir);1705 retval = do_for_each_entry_in_dir(1706 loose_dir, 0, fn, cb_data);1707 }17081709 release_packed_ref_cache(packed_ref_cache);1710 return retval;1711}17121713/*1714 * Call fn for each reference in the specified ref_cache for which the1715 * refname begins with base. If trim is non-zero, then trim that many1716 * characters off the beginning of each refname before passing the1717 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1718 * broken references in the iteration. If fn ever returns a non-zero1719 * value, stop the iteration and return that value; otherwise, return1720 * 0.1721 */1722static int do_for_each_ref(struct ref_cache *refs, const char *base,1723 each_ref_fn fn, int trim, int flags, void *cb_data)1724{1725 struct ref_entry_cb data;1726 data.base = base;1727 data.trim = trim;1728 data.flags = flags;1729 data.fn = fn;1730 data.cb_data = cb_data;17311732 return do_for_each_entry(refs, base, do_one_ref, &data);1733}17341735static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)1736{1737 unsigned char sha1[20];1738 int flag;17391740 if (submodule) {1741 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)1742 return fn("HEAD", sha1, 0, cb_data);17431744 return 0;1745 }17461747 if (!read_ref_full("HEAD", sha1, 1, &flag))1748 return fn("HEAD", sha1, flag, cb_data);17491750 return 0;1751}17521753int head_ref(each_ref_fn fn, void *cb_data)1754{1755 return do_head_ref(NULL, fn, cb_data);1756}17571758int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1759{1760 return do_head_ref(submodule, fn, cb_data);1761}17621763int for_each_ref(each_ref_fn fn, void *cb_data)1764{1765 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);1766}17671768int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1769{1770 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);1771}17721773int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)1774{1775 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);1776}17771778int for_each_ref_in_submodule(const char *submodule, const char *prefix,1779 each_ref_fn fn, void *cb_data)1780{1781 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);1782}17831784int for_each_tag_ref(each_ref_fn fn, void *cb_data)1785{1786 return for_each_ref_in("refs/tags/", fn, cb_data);1787}17881789int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1790{1791 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);1792}17931794int for_each_branch_ref(each_ref_fn fn, void *cb_data)1795{1796 return for_each_ref_in("refs/heads/", fn, cb_data);1797}17981799int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1800{1801 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);1802}18031804int for_each_remote_ref(each_ref_fn fn, void *cb_data)1805{1806 return for_each_ref_in("refs/remotes/", fn, cb_data);1807}18081809int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)1810{1811 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);1812}18131814int for_each_replace_ref(each_ref_fn fn, void *cb_data)1815{1816 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);1817}18181819int head_ref_namespaced(each_ref_fn fn, void *cb_data)1820{1821 struct strbuf buf = STRBUF_INIT;1822 int ret = 0;1823 unsigned char sha1[20];1824 int flag;18251826 strbuf_addf(&buf, "%sHEAD", get_git_namespace());1827 if (!read_ref_full(buf.buf, sha1, 1, &flag))1828 ret = fn(buf.buf, sha1, flag, cb_data);1829 strbuf_release(&buf);18301831 return ret;1832}18331834int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)1835{1836 struct strbuf buf = STRBUF_INIT;1837 int ret;1838 strbuf_addf(&buf, "%srefs/", get_git_namespace());1839 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);1840 strbuf_release(&buf);1841 return ret;1842}18431844int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,1845 const char *prefix, void *cb_data)1846{1847 struct strbuf real_pattern = STRBUF_INIT;1848 struct ref_filter filter;1849 int ret;18501851 if (!prefix && !starts_with(pattern, "refs/"))1852 strbuf_addstr(&real_pattern, "refs/");1853 else if (prefix)1854 strbuf_addstr(&real_pattern, prefix);1855 strbuf_addstr(&real_pattern, pattern);18561857 if (!has_glob_specials(pattern)) {1858 /* Append implied '/' '*' if not present. */1859 if (real_pattern.buf[real_pattern.len - 1] != '/')1860 strbuf_addch(&real_pattern, '/');1861 /* No need to check for '*', there is none. */1862 strbuf_addch(&real_pattern, '*');1863 }18641865 filter.pattern = real_pattern.buf;1866 filter.fn = fn;1867 filter.cb_data = cb_data;1868 ret = for_each_ref(filter_refs, &filter);18691870 strbuf_release(&real_pattern);1871 return ret;1872}18731874int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)1875{1876 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);1877}18781879int for_each_rawref(each_ref_fn fn, void *cb_data)1880{1881 return do_for_each_ref(&ref_cache, "", fn, 0,1882 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1883}18841885const char *prettify_refname(const char *name)1886{1887 return name + (1888 starts_with(name, "refs/heads/") ? 11 :1889 starts_with(name, "refs/tags/") ? 10 :1890 starts_with(name, "refs/remotes/") ? 13 :1891 0);1892}18931894static const char *ref_rev_parse_rules[] = {1895 "%.*s",1896 "refs/%.*s",1897 "refs/tags/%.*s",1898 "refs/heads/%.*s",1899 "refs/remotes/%.*s",1900 "refs/remotes/%.*s/HEAD",1901 NULL1902};19031904int refname_match(const char *abbrev_name, const char *full_name)1905{1906 const char **p;1907 const int abbrev_name_len = strlen(abbrev_name);19081909 for (p = ref_rev_parse_rules; *p; p++) {1910 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {1911 return 1;1912 }1913 }19141915 return 0;1916}19171918static struct ref_lock *verify_lock(struct ref_lock *lock,1919 const unsigned char *old_sha1, int mustexist)1920{1921 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1922 error("Can't verify ref %s", lock->ref_name);1923 unlock_ref(lock);1924 return NULL;1925 }1926 if (hashcmp(lock->old_sha1, old_sha1)) {1927 error("Ref %s is at %s but expected %s", lock->ref_name,1928 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));1929 unlock_ref(lock);1930 return NULL;1931 }1932 return lock;1933}19341935static int remove_empty_directories(const char *file)1936{1937 /* we want to create a file but there is a directory there;1938 * if that is an empty directory (or a directory that contains1939 * only empty directories), remove them.1940 */1941 struct strbuf path;1942 int result;19431944 strbuf_init(&path, 20);1945 strbuf_addstr(&path, file);19461947 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);19481949 strbuf_release(&path);19501951 return result;1952}19531954/*1955 * *string and *len will only be substituted, and *string returned (for1956 * later free()ing) if the string passed in is a magic short-hand form1957 * to name a branch.1958 */1959static char *substitute_branch_name(const char **string, int *len)1960{1961 struct strbuf buf = STRBUF_INIT;1962 int ret = interpret_branch_name(*string, *len, &buf);19631964 if (ret == *len) {1965 size_t size;1966 *string = strbuf_detach(&buf, &size);1967 *len = size;1968 return (char *)*string;1969 }19701971 return NULL;1972}19731974int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)1975{1976 char *last_branch = substitute_branch_name(&str, &len);1977 const char **p, *r;1978 int refs_found = 0;19791980 *ref = NULL;1981 for (p = ref_rev_parse_rules; *p; p++) {1982 char fullref[PATH_MAX];1983 unsigned char sha1_from_ref[20];1984 unsigned char *this_result;1985 int flag;19861987 this_result = refs_found ? sha1_from_ref : sha1;1988 mksnpath(fullref, sizeof(fullref), *p, len, str);1989 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);1990 if (r) {1991 if (!refs_found++)1992 *ref = xstrdup(r);1993 if (!warn_ambiguous_refs)1994 break;1995 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {1996 warning("ignoring dangling symref %s.", fullref);1997 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {1998 warning("ignoring broken ref %s.", fullref);1999 }2000 }2001 free(last_branch);2002 return refs_found;2003}20042005int dwim_log(const char *str, int len, unsigned char *sha1, char **log)2006{2007 char *last_branch = substitute_branch_name(&str, &len);2008 const char **p;2009 int logs_found = 0;20102011 *log = NULL;2012 for (p = ref_rev_parse_rules; *p; p++) {2013 struct stat st;2014 unsigned char hash[20];2015 char path[PATH_MAX];2016 const char *ref, *it;20172018 mksnpath(path, sizeof(path), *p, len, str);2019 ref = resolve_ref_unsafe(path, hash, 1, NULL);2020 if (!ref)2021 continue;2022 if (!stat(git_path("logs/%s", path), &st) &&2023 S_ISREG(st.st_mode))2024 it = path;2025 else if (strcmp(ref, path) &&2026 !stat(git_path("logs/%s", ref), &st) &&2027 S_ISREG(st.st_mode))2028 it = ref;2029 else2030 continue;2031 if (!logs_found++) {2032 *log = xstrdup(it);2033 hashcpy(sha1, hash);2034 }2035 if (!warn_ambiguous_refs)2036 break;2037 }2038 free(last_branch);2039 return logs_found;2040}20412042static struct ref_lock *lock_ref_sha1_basic(const char *refname,2043 const unsigned char *old_sha1,2044 int flags, int *type_p)2045{2046 char *ref_file;2047 const char *orig_refname = refname;2048 struct ref_lock *lock;2049 int last_errno = 0;2050 int type, lflags;2051 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2052 int missing = 0;2053 int attempts_remaining = 3;20542055 lock = xcalloc(1, sizeof(struct ref_lock));2056 lock->lock_fd = -1;20572058 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2059 if (!refname && errno == EISDIR) {2060 /* we are trying to lock foo but we used to2061 * have foo/bar which now does not exist;2062 * it is normal for the empty directory 'foo'2063 * to remain.2064 */2065 ref_file = git_path("%s", orig_refname);2066 if (remove_empty_directories(ref_file)) {2067 last_errno = errno;2068 error("there are still refs under '%s'", orig_refname);2069 goto error_return;2070 }2071 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2072 }2073 if (type_p)2074 *type_p = type;2075 if (!refname) {2076 last_errno = errno;2077 error("unable to resolve reference %s: %s",2078 orig_refname, strerror(errno));2079 goto error_return;2080 }2081 missing = is_null_sha1(lock->old_sha1);2082 /* When the ref did not exist and we are creating it,2083 * make sure there is no existing ref that is packed2084 * whose name begins with our refname, nor a ref whose2085 * name is a proper prefix of our refname.2086 */2087 if (missing &&2088 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {2089 last_errno = ENOTDIR;2090 goto error_return;2091 }20922093 lock->lk = xcalloc(1, sizeof(struct lock_file));20942095 lflags = 0;2096 if (flags & REF_NODEREF) {2097 refname = orig_refname;2098 lflags |= LOCK_NODEREF;2099 }2100 lock->ref_name = xstrdup(refname);2101 lock->orig_ref_name = xstrdup(orig_refname);2102 ref_file = git_path("%s", refname);2103 if (missing)2104 lock->force_write = 1;2105 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))2106 lock->force_write = 1;21072108 retry:2109 switch (safe_create_leading_directories(ref_file)) {2110 case SCLD_OK:2111 break; /* success */2112 case SCLD_VANISHED:2113 if (--attempts_remaining > 0)2114 goto retry;2115 /* fall through */2116 default:2117 last_errno = errno;2118 error("unable to create directory for %s", ref_file);2119 goto error_return;2120 }21212122 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);2123 if (lock->lock_fd < 0) {2124 if (errno == ENOENT && --attempts_remaining > 0)2125 /*2126 * Maybe somebody just deleted one of the2127 * directories leading to ref_file. Try2128 * again:2129 */2130 goto retry;2131 else2132 unable_to_lock_index_die(ref_file, errno);2133 }2134 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;21352136 error_return:2137 unlock_ref(lock);2138 errno = last_errno;2139 return NULL;2140}21412142struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)2143{2144 char refpath[PATH_MAX];2145 if (check_refname_format(refname, 0))2146 return NULL;2147 strcpy(refpath, mkpath("refs/%s", refname));2148 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);2149}21502151struct ref_lock *lock_any_ref_for_update(const char *refname,2152 const unsigned char *old_sha1,2153 int flags, int *type_p)2154{2155 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2156 return NULL;2157 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);2158}21592160/*2161 * Write an entry to the packed-refs file for the specified refname.2162 * If peeled is non-NULL, write it as the entry's peeled value.2163 */2164static void write_packed_entry(int fd, char *refname, unsigned char *sha1,2165 unsigned char *peeled)2166{2167 char line[PATH_MAX + 100];2168 int len;21692170 len = snprintf(line, sizeof(line), "%s %s\n",2171 sha1_to_hex(sha1), refname);2172 /* this should not happen but just being defensive */2173 if (len > sizeof(line))2174 die("too long a refname '%s'", refname);2175 write_or_die(fd, line, len);21762177 if (peeled) {2178 if (snprintf(line, sizeof(line), "^%s\n",2179 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2180 die("internal error");2181 write_or_die(fd, line, PEELED_LINE_LENGTH);2182 }2183}21842185/*2186 * An each_ref_entry_fn that writes the entry to a packed-refs file.2187 */2188static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)2189{2190 int *fd = cb_data;2191 enum peel_status peel_status = peel_entry(entry, 0);21922193 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2194 error("internal error: %s is not a valid packed reference!",2195 entry->name);2196 write_packed_entry(*fd, entry->name, entry->u.value.sha1,2197 peel_status == PEEL_PEELED ?2198 entry->u.value.peeled : NULL);2199 return 0;2200}22012202int lock_packed_refs(int flags)2203{2204 struct packed_ref_cache *packed_ref_cache;22052206 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)2207 return -1;2208 /*2209 * Get the current packed-refs while holding the lock. If the2210 * packed-refs file has been modified since we last read it,2211 * this will automatically invalidate the cache and re-read2212 * the packed-refs file.2213 */2214 packed_ref_cache = get_packed_ref_cache(&ref_cache);2215 packed_ref_cache->lock = &packlock;2216 /* Increment the reference count to prevent it from being freed: */2217 acquire_packed_ref_cache(packed_ref_cache);2218 return 0;2219}22202221int commit_packed_refs(void)2222{2223 struct packed_ref_cache *packed_ref_cache =2224 get_packed_ref_cache(&ref_cache);2225 int error = 0;22262227 if (!packed_ref_cache->lock)2228 die("internal error: packed-refs not locked");2229 write_or_die(packed_ref_cache->lock->fd,2230 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));22312232 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),2233 0, write_packed_entry_fn,2234 &packed_ref_cache->lock->fd);2235 if (commit_lock_file(packed_ref_cache->lock))2236 error = -1;2237 packed_ref_cache->lock = NULL;2238 release_packed_ref_cache(packed_ref_cache);2239 return error;2240}22412242void rollback_packed_refs(void)2243{2244 struct packed_ref_cache *packed_ref_cache =2245 get_packed_ref_cache(&ref_cache);22462247 if (!packed_ref_cache->lock)2248 die("internal error: packed-refs not locked");2249 rollback_lock_file(packed_ref_cache->lock);2250 packed_ref_cache->lock = NULL;2251 release_packed_ref_cache(packed_ref_cache);2252 clear_packed_ref_cache(&ref_cache);2253}22542255struct ref_to_prune {2256 struct ref_to_prune *next;2257 unsigned char sha1[20];2258 char name[FLEX_ARRAY];2259};22602261struct pack_refs_cb_data {2262 unsigned int flags;2263 struct ref_dir *packed_refs;2264 struct ref_to_prune *ref_to_prune;2265};22662267/*2268 * An each_ref_entry_fn that is run over loose references only. If2269 * the loose reference can be packed, add an entry in the packed ref2270 * cache. If the reference should be pruned, also add it to2271 * ref_to_prune in the pack_refs_cb_data.2272 */2273static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)2274{2275 struct pack_refs_cb_data *cb = cb_data;2276 enum peel_status peel_status;2277 struct ref_entry *packed_entry;2278 int is_tag_ref = starts_with(entry->name, "refs/tags/");22792280 /* ALWAYS pack tags */2281 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2282 return 0;22832284 /* Do not pack symbolic or broken refs: */2285 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2286 return 0;22872288 /* Add a packed ref cache entry equivalent to the loose entry. */2289 peel_status = peel_entry(entry, 1);2290 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2291 die("internal error peeling reference %s (%s)",2292 entry->name, sha1_to_hex(entry->u.value.sha1));2293 packed_entry = find_ref(cb->packed_refs, entry->name);2294 if (packed_entry) {2295 /* Overwrite existing packed entry with info from loose entry */2296 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2297 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2298 } else {2299 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,2300 REF_ISPACKED | REF_KNOWS_PEELED, 0);2301 add_ref(cb->packed_refs, packed_entry);2302 }2303 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);23042305 /* Schedule the loose reference for pruning if requested. */2306 if ((cb->flags & PACK_REFS_PRUNE)) {2307 int namelen = strlen(entry->name) + 1;2308 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);2309 hashcpy(n->sha1, entry->u.value.sha1);2310 strcpy(n->name, entry->name);2311 n->next = cb->ref_to_prune;2312 cb->ref_to_prune = n;2313 }2314 return 0;2315}23162317/*2318 * Remove empty parents, but spare refs/ and immediate subdirs.2319 * Note: munges *name.2320 */2321static void try_remove_empty_parents(char *name)2322{2323 char *p, *q;2324 int i;2325 p = name;2326 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */2327 while (*p && *p != '/')2328 p++;2329 /* tolerate duplicate slashes; see check_refname_format() */2330 while (*p == '/')2331 p++;2332 }2333 for (q = p; *q; q++)2334 ;2335 while (1) {2336 while (q > p && *q != '/')2337 q--;2338 while (q > p && *(q-1) == '/')2339 q--;2340 if (q == p)2341 break;2342 *q = '\0';2343 if (rmdir(git_path("%s", name)))2344 break;2345 }2346}23472348/* make sure nobody touched the ref, and unlink */2349static void prune_ref(struct ref_to_prune *r)2350{2351 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);23522353 if (lock) {2354 unlink_or_warn(git_path("%s", r->name));2355 unlock_ref(lock);2356 try_remove_empty_parents(r->name);2357 }2358}23592360static void prune_refs(struct ref_to_prune *r)2361{2362 while (r) {2363 prune_ref(r);2364 r = r->next;2365 }2366}23672368int pack_refs(unsigned int flags)2369{2370 struct pack_refs_cb_data cbdata;23712372 memset(&cbdata, 0, sizeof(cbdata));2373 cbdata.flags = flags;23742375 lock_packed_refs(LOCK_DIE_ON_ERROR);2376 cbdata.packed_refs = get_packed_refs(&ref_cache);23772378 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,2379 pack_if_possible_fn, &cbdata);23802381 if (commit_packed_refs())2382 die_errno("unable to overwrite old ref-pack file");23832384 prune_refs(cbdata.ref_to_prune);2385 return 0;2386}23872388/*2389 * If entry is no longer needed in packed-refs, add it to the string2390 * list pointed to by cb_data. Reasons for deleting entries:2391 *2392 * - Entry is broken.2393 * - Entry is overridden by a loose ref.2394 * - Entry does not point at a valid object.2395 *2396 * In the first and third cases, also emit an error message because these2397 * are indications of repository corruption.2398 */2399static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)2400{2401 struct string_list *refs_to_delete = cb_data;24022403 if (entry->flag & REF_ISBROKEN) {2404 /* This shouldn't happen to packed refs. */2405 error("%s is broken!", entry->name);2406 string_list_append(refs_to_delete, entry->name);2407 return 0;2408 }2409 if (!has_sha1_file(entry->u.value.sha1)) {2410 unsigned char sha1[20];2411 int flags;24122413 if (read_ref_full(entry->name, sha1, 0, &flags))2414 /* We should at least have found the packed ref. */2415 die("Internal error");2416 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2417 /*2418 * This packed reference is overridden by a2419 * loose reference, so it is OK that its value2420 * is no longer valid; for example, it might2421 * refer to an object that has been garbage2422 * collected. For this purpose we don't even2423 * care whether the loose reference itself is2424 * invalid, broken, symbolic, etc. Silently2425 * remove the packed reference.2426 */2427 string_list_append(refs_to_delete, entry->name);2428 return 0;2429 }2430 /*2431 * There is no overriding loose reference, so the fact2432 * that this reference doesn't refer to a valid object2433 * indicates some kind of repository corruption.2434 * Report the problem, then omit the reference from2435 * the output.2436 */2437 error("%s does not point to a valid object!", entry->name);2438 string_list_append(refs_to_delete, entry->name);2439 return 0;2440 }24412442 return 0;2443}24442445static int repack_without_refs(const char **refnames, int n)2446{2447 struct ref_dir *packed;2448 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2449 struct string_list_item *ref_to_delete;2450 int i, removed = 0;24512452 /* Look for a packed ref */2453 for (i = 0; i < n; i++)2454 if (get_packed_ref(refnames[i]))2455 break;24562457 /* Avoid locking if we have nothing to do */2458 if (i == n)2459 return 0; /* no refname exists in packed refs */24602461 if (lock_packed_refs(0)) {2462 unable_to_lock_error(git_path("packed-refs"), errno);2463 return error("cannot delete '%s' from packed refs", refnames[i]);2464 }2465 packed = get_packed_refs(&ref_cache);24662467 /* Remove refnames from the cache */2468 for (i = 0; i < n; i++)2469 if (remove_entry(packed, refnames[i]) != -1)2470 removed = 1;2471 if (!removed) {2472 /*2473 * All packed entries disappeared while we were2474 * acquiring the lock.2475 */2476 rollback_packed_refs();2477 return 0;2478 }24792480 /* Remove any other accumulated cruft */2481 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);2482 for_each_string_list_item(ref_to_delete, &refs_to_delete) {2483 if (remove_entry(packed, ref_to_delete->string) == -1)2484 die("internal error");2485 }24862487 /* Write what remains */2488 return commit_packed_refs();2489}24902491static int repack_without_ref(const char *refname)2492{2493 return repack_without_refs(&refname, 1);2494}24952496static int delete_ref_loose(struct ref_lock *lock, int flag)2497{2498 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2499 /* loose */2500 int err, i = strlen(lock->lk->filename) - 5; /* .lock */25012502 lock->lk->filename[i] = 0;2503 err = unlink_or_warn(lock->lk->filename);2504 lock->lk->filename[i] = '.';2505 if (err && errno != ENOENT)2506 return 1;2507 }2508 return 0;2509}25102511int delete_ref(const char *refname, const unsigned char *sha1, int delopt)2512{2513 struct ref_lock *lock;2514 int ret = 0, flag = 0;25152516 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);2517 if (!lock)2518 return 1;2519 ret |= delete_ref_loose(lock, flag);25202521 /* removing the loose one could have resurrected an earlier2522 * packed one. Also, if it was not loose we need to repack2523 * without it.2524 */2525 ret |= repack_without_ref(lock->ref_name);25262527 unlink_or_warn(git_path("logs/%s", lock->ref_name));2528 clear_loose_ref_cache(&ref_cache);2529 unlock_ref(lock);2530 return ret;2531}25322533/*2534 * People using contrib's git-new-workdir have .git/logs/refs ->2535 * /some/other/path/.git/logs/refs, and that may live on another device.2536 *2537 * IOW, to avoid cross device rename errors, the temporary renamed log must2538 * live into logs/refs.2539 */2540#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"25412542static int rename_tmp_log(const char *newrefname)2543{2544 int attempts_remaining = 4;25452546 retry:2547 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {2548 case SCLD_OK:2549 break; /* success */2550 case SCLD_VANISHED:2551 if (--attempts_remaining > 0)2552 goto retry;2553 /* fall through */2554 default:2555 error("unable to create directory for %s", newrefname);2556 return -1;2557 }25582559 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {2560 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {2561 /*2562 * rename(a, b) when b is an existing2563 * directory ought to result in ISDIR, but2564 * Solaris 5.8 gives ENOTDIR. Sheesh.2565 */2566 if (remove_empty_directories(git_path("logs/%s", newrefname))) {2567 error("Directory not empty: logs/%s", newrefname);2568 return -1;2569 }2570 goto retry;2571 } else if (errno == ENOENT && --attempts_remaining > 0) {2572 /*2573 * Maybe another process just deleted one of2574 * the directories in the path to newrefname.2575 * Try again from the beginning.2576 */2577 goto retry;2578 } else {2579 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",2580 newrefname, strerror(errno));2581 return -1;2582 }2583 }2584 return 0;2585}25862587int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)2588{2589 unsigned char sha1[20], orig_sha1[20];2590 int flag = 0, logmoved = 0;2591 struct ref_lock *lock;2592 struct stat loginfo;2593 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2594 const char *symref = NULL;25952596 if (log && S_ISLNK(loginfo.st_mode))2597 return error("reflog for %s is a symlink", oldrefname);25982599 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);2600 if (flag & REF_ISSYMREF)2601 return error("refname %s is a symbolic ref, renaming it is not supported",2602 oldrefname);2603 if (!symref)2604 return error("refname %s not found", oldrefname);26052606 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))2607 return 1;26082609 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))2610 return 1;26112612 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))2613 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",2614 oldrefname, strerror(errno));26152616 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2617 error("unable to delete old %s", oldrefname);2618 goto rollback;2619 }26202621 if (!read_ref_full(newrefname, sha1, 1, &flag) &&2622 delete_ref(newrefname, sha1, REF_NODEREF)) {2623 if (errno==EISDIR) {2624 if (remove_empty_directories(git_path("%s", newrefname))) {2625 error("Directory not empty: %s", newrefname);2626 goto rollback;2627 }2628 } else {2629 error("unable to delete existing %s", newrefname);2630 goto rollback;2631 }2632 }26332634 if (log && rename_tmp_log(newrefname))2635 goto rollback;26362637 logmoved = log;26382639 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);2640 if (!lock) {2641 error("unable to lock %s for update", newrefname);2642 goto rollback;2643 }2644 lock->force_write = 1;2645 hashcpy(lock->old_sha1, orig_sha1);2646 if (write_ref_sha1(lock, orig_sha1, logmsg)) {2647 error("unable to write current sha1 into %s", newrefname);2648 goto rollback;2649 }26502651 return 0;26522653 rollback:2654 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);2655 if (!lock) {2656 error("unable to lock %s for rollback", oldrefname);2657 goto rollbacklog;2658 }26592660 lock->force_write = 1;2661 flag = log_all_ref_updates;2662 log_all_ref_updates = 0;2663 if (write_ref_sha1(lock, orig_sha1, NULL))2664 error("unable to write current sha1 into %s", oldrefname);2665 log_all_ref_updates = flag;26662667 rollbacklog:2668 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))2669 error("unable to restore logfile %s from %s: %s",2670 oldrefname, newrefname, strerror(errno));2671 if (!logmoved && log &&2672 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))2673 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",2674 oldrefname, strerror(errno));26752676 return 1;2677}26782679int close_ref(struct ref_lock *lock)2680{2681 if (close_lock_file(lock->lk))2682 return -1;2683 lock->lock_fd = -1;2684 return 0;2685}26862687int commit_ref(struct ref_lock *lock)2688{2689 if (commit_lock_file(lock->lk))2690 return -1;2691 lock->lock_fd = -1;2692 return 0;2693}26942695void unlock_ref(struct ref_lock *lock)2696{2697 /* Do not free lock->lk -- atexit() still looks at them */2698 if (lock->lk)2699 rollback_lock_file(lock->lk);2700 free(lock->ref_name);2701 free(lock->orig_ref_name);2702 free(lock);2703}27042705/*2706 * copy the reflog message msg to buf, which has been allocated sufficiently2707 * large, while cleaning up the whitespaces. Especially, convert LF to space,2708 * because reflog file is one line per entry.2709 */2710static int copy_msg(char *buf, const char *msg)2711{2712 char *cp = buf;2713 char c;2714 int wasspace = 1;27152716 *cp++ = '\t';2717 while ((c = *msg++)) {2718 if (wasspace && isspace(c))2719 continue;2720 wasspace = isspace(c);2721 if (wasspace)2722 c = ' ';2723 *cp++ = c;2724 }2725 while (buf < cp && isspace(cp[-1]))2726 cp--;2727 *cp++ = '\n';2728 return cp - buf;2729}27302731int log_ref_setup(const char *refname, char *logfile, int bufsize)2732{2733 int logfd, oflags = O_APPEND | O_WRONLY;27342735 git_snpath(logfile, bufsize, "logs/%s", refname);2736 if (log_all_ref_updates &&2737 (starts_with(refname, "refs/heads/") ||2738 starts_with(refname, "refs/remotes/") ||2739 starts_with(refname, "refs/notes/") ||2740 !strcmp(refname, "HEAD"))) {2741 if (safe_create_leading_directories(logfile) < 0)2742 return error("unable to create directory for %s",2743 logfile);2744 oflags |= O_CREAT;2745 }27462747 logfd = open(logfile, oflags, 0666);2748 if (logfd < 0) {2749 if (!(oflags & O_CREAT) && errno == ENOENT)2750 return 0;27512752 if ((oflags & O_CREAT) && errno == EISDIR) {2753 if (remove_empty_directories(logfile)) {2754 return error("There are still logs under '%s'",2755 logfile);2756 }2757 logfd = open(logfile, oflags, 0666);2758 }27592760 if (logfd < 0)2761 return error("Unable to append to %s: %s",2762 logfile, strerror(errno));2763 }27642765 adjust_shared_perm(logfile);2766 close(logfd);2767 return 0;2768}27692770static int log_ref_write(const char *refname, const unsigned char *old_sha1,2771 const unsigned char *new_sha1, const char *msg)2772{2773 int logfd, result, written, oflags = O_APPEND | O_WRONLY;2774 unsigned maxlen, len;2775 int msglen;2776 char log_file[PATH_MAX];2777 char *logrec;2778 const char *committer;27792780 if (log_all_ref_updates < 0)2781 log_all_ref_updates = !is_bare_repository();27822783 result = log_ref_setup(refname, log_file, sizeof(log_file));2784 if (result)2785 return result;27862787 logfd = open(log_file, oflags);2788 if (logfd < 0)2789 return 0;2790 msglen = msg ? strlen(msg) : 0;2791 committer = git_committer_info(0);2792 maxlen = strlen(committer) + msglen + 100;2793 logrec = xmalloc(maxlen);2794 len = sprintf(logrec, "%s %s %s\n",2795 sha1_to_hex(old_sha1),2796 sha1_to_hex(new_sha1),2797 committer);2798 if (msglen)2799 len += copy_msg(logrec + len - 1, msg) - 1;2800 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;2801 free(logrec);2802 if (close(logfd) != 0 || written != len)2803 return error("Unable to append to %s", log_file);2804 return 0;2805}28062807static int is_branch(const char *refname)2808{2809 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");2810}28112812int write_ref_sha1(struct ref_lock *lock,2813 const unsigned char *sha1, const char *logmsg)2814{2815 static char term = '\n';2816 struct object *o;28172818 if (!lock)2819 return -1;2820 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2821 unlock_ref(lock);2822 return 0;2823 }2824 o = parse_object(sha1);2825 if (!o) {2826 error("Trying to write ref %s with nonexistent object %s",2827 lock->ref_name, sha1_to_hex(sha1));2828 unlock_ref(lock);2829 return -1;2830 }2831 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {2832 error("Trying to write non-commit object %s to branch %s",2833 sha1_to_hex(sha1), lock->ref_name);2834 unlock_ref(lock);2835 return -1;2836 }2837 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||2838 write_in_full(lock->lock_fd, &term, 1) != 12839 || close_ref(lock) < 0) {2840 error("Couldn't write %s", lock->lk->filename);2841 unlock_ref(lock);2842 return -1;2843 }2844 clear_loose_ref_cache(&ref_cache);2845 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||2846 (strcmp(lock->ref_name, lock->orig_ref_name) &&2847 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {2848 unlock_ref(lock);2849 return -1;2850 }2851 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {2852 /*2853 * Special hack: If a branch is updated directly and HEAD2854 * points to it (may happen on the remote side of a push2855 * for example) then logically the HEAD reflog should be2856 * updated too.2857 * A generic solution implies reverse symref information,2858 * but finding all symrefs pointing to the given branch2859 * would be rather costly for this rare event (the direct2860 * update of a branch) to be worth it. So let's cheat and2861 * check with HEAD only which should cover 99% of all usage2862 * scenarios (even 100% of the default ones).2863 */2864 unsigned char head_sha1[20];2865 int head_flag;2866 const char *head_ref;2867 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);2868 if (head_ref && (head_flag & REF_ISSYMREF) &&2869 !strcmp(head_ref, lock->ref_name))2870 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2871 }2872 if (commit_ref(lock)) {2873 error("Couldn't set %s", lock->ref_name);2874 unlock_ref(lock);2875 return -1;2876 }2877 unlock_ref(lock);2878 return 0;2879}28802881int create_symref(const char *ref_target, const char *refs_heads_master,2882 const char *logmsg)2883{2884 const char *lockpath;2885 char ref[1000];2886 int fd, len, written;2887 char *git_HEAD = git_pathdup("%s", ref_target);2888 unsigned char old_sha1[20], new_sha1[20];28892890 if (logmsg && read_ref(ref_target, old_sha1))2891 hashclr(old_sha1);28922893 if (safe_create_leading_directories(git_HEAD) < 0)2894 return error("unable to create directory for %s", git_HEAD);28952896#ifndef NO_SYMLINK_HEAD2897 if (prefer_symlink_refs) {2898 unlink(git_HEAD);2899 if (!symlink(refs_heads_master, git_HEAD))2900 goto done;2901 fprintf(stderr, "no symlink - falling back to symbolic ref\n");2902 }2903#endif29042905 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);2906 if (sizeof(ref) <= len) {2907 error("refname too long: %s", refs_heads_master);2908 goto error_free_return;2909 }2910 lockpath = mkpath("%s.lock", git_HEAD);2911 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);2912 if (fd < 0) {2913 error("Unable to open %s for writing", lockpath);2914 goto error_free_return;2915 }2916 written = write_in_full(fd, ref, len);2917 if (close(fd) != 0 || written != len) {2918 error("Unable to write to %s", lockpath);2919 goto error_unlink_return;2920 }2921 if (rename(lockpath, git_HEAD) < 0) {2922 error("Unable to create %s", git_HEAD);2923 goto error_unlink_return;2924 }2925 if (adjust_shared_perm(git_HEAD)) {2926 error("Unable to fix permissions on %s", lockpath);2927 error_unlink_return:2928 unlink_or_warn(lockpath);2929 error_free_return:2930 free(git_HEAD);2931 return -1;2932 }29332934#ifndef NO_SYMLINK_HEAD2935 done:2936#endif2937 if (logmsg && !read_ref(refs_heads_master, new_sha1))2938 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);29392940 free(git_HEAD);2941 return 0;2942}29432944static char *ref_msg(const char *line, const char *endp)2945{2946 const char *ep;2947 line += 82;2948 ep = memchr(line, '\n', endp - line);2949 if (!ep)2950 ep = endp;2951 return xmemdupz(line, ep - line);2952}29532954int read_ref_at(const char *refname, unsigned long at_time, int cnt,2955 unsigned char *sha1, char **msg,2956 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)2957{2958 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;2959 char *tz_c;2960 int logfd, tz, reccnt = 0;2961 struct stat st;2962 unsigned long date;2963 unsigned char logged_sha1[20];2964 void *log_mapped;2965 size_t mapsz;29662967 logfile = git_path("logs/%s", refname);2968 logfd = open(logfile, O_RDONLY, 0);2969 if (logfd < 0)2970 die_errno("Unable to read log '%s'", logfile);2971 fstat(logfd, &st);2972 if (!st.st_size)2973 die("Log %s is empty.", logfile);2974 mapsz = xsize_t(st.st_size);2975 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);2976 logdata = log_mapped;2977 close(logfd);29782979 lastrec = NULL;2980 rec = logend = logdata + st.st_size;2981 while (logdata < rec) {2982 reccnt++;2983 if (logdata < rec && *(rec-1) == '\n')2984 rec--;2985 lastgt = NULL;2986 while (logdata < rec && *(rec-1) != '\n') {2987 rec--;2988 if (*rec == '>')2989 lastgt = rec;2990 }2991 if (!lastgt)2992 die("Log %s is corrupt.", logfile);2993 date = strtoul(lastgt + 1, &tz_c, 10);2994 if (date <= at_time || cnt == 0) {2995 tz = strtoul(tz_c, NULL, 10);2996 if (msg)2997 *msg = ref_msg(rec, logend);2998 if (cutoff_time)2999 *cutoff_time = date;3000 if (cutoff_tz)3001 *cutoff_tz = tz;3002 if (cutoff_cnt)3003 *cutoff_cnt = reccnt - 1;3004 if (lastrec) {3005 if (get_sha1_hex(lastrec, logged_sha1))3006 die("Log %s is corrupt.", logfile);3007 if (get_sha1_hex(rec + 41, sha1))3008 die("Log %s is corrupt.", logfile);3009 if (hashcmp(logged_sha1, sha1)) {3010 warning("Log %s has gap after %s.",3011 logfile, show_date(date, tz, DATE_RFC2822));3012 }3013 }3014 else if (date == at_time) {3015 if (get_sha1_hex(rec + 41, sha1))3016 die("Log %s is corrupt.", logfile);3017 }3018 else {3019 if (get_sha1_hex(rec + 41, logged_sha1))3020 die("Log %s is corrupt.", logfile);3021 if (hashcmp(logged_sha1, sha1)) {3022 warning("Log %s unexpectedly ended on %s.",3023 logfile, show_date(date, tz, DATE_RFC2822));3024 }3025 }3026 munmap(log_mapped, mapsz);3027 return 0;3028 }3029 lastrec = rec;3030 if (cnt > 0)3031 cnt--;3032 }30333034 rec = logdata;3035 while (rec < logend && *rec != '>' && *rec != '\n')3036 rec++;3037 if (rec == logend || *rec == '\n')3038 die("Log %s is corrupt.", logfile);3039 date = strtoul(rec + 1, &tz_c, 10);3040 tz = strtoul(tz_c, NULL, 10);3041 if (get_sha1_hex(logdata, sha1))3042 die("Log %s is corrupt.", logfile);3043 if (is_null_sha1(sha1)) {3044 if (get_sha1_hex(logdata + 41, sha1))3045 die("Log %s is corrupt.", logfile);3046 }3047 if (msg)3048 *msg = ref_msg(logdata, logend);3049 munmap(log_mapped, mapsz);30503051 if (cutoff_time)3052 *cutoff_time = date;3053 if (cutoff_tz)3054 *cutoff_tz = tz;3055 if (cutoff_cnt)3056 *cutoff_cnt = reccnt;3057 return 1;3058}30593060static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)3061{3062 unsigned char osha1[20], nsha1[20];3063 char *email_end, *message;3064 unsigned long timestamp;3065 int tz;30663067 /* old SP new SP name <email> SP time TAB msg LF */3068 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||3069 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||3070 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||3071 !(email_end = strchr(sb->buf + 82, '>')) ||3072 email_end[1] != ' ' ||3073 !(timestamp = strtoul(email_end + 2, &message, 10)) ||3074 !message || message[0] != ' ' ||3075 (message[1] != '+' && message[1] != '-') ||3076 !isdigit(message[2]) || !isdigit(message[3]) ||3077 !isdigit(message[4]) || !isdigit(message[5]))3078 return 0; /* corrupt? */3079 email_end[1] = '\0';3080 tz = strtol(message + 1, NULL, 10);3081 if (message[6] != '\t')3082 message += 6;3083 else3084 message += 7;3085 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);3086}30873088static char *find_beginning_of_line(char *bob, char *scan)3089{3090 while (bob < scan && *(--scan) != '\n')3091 ; /* keep scanning backwards */3092 /*3093 * Return either beginning of the buffer, or LF at the end of3094 * the previous line.3095 */3096 return scan;3097}30983099int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)3100{3101 struct strbuf sb = STRBUF_INIT;3102 FILE *logfp;3103 long pos;3104 int ret = 0, at_tail = 1;31053106 logfp = fopen(git_path("logs/%s", refname), "r");3107 if (!logfp)3108 return -1;31093110 /* Jump to the end */3111 if (fseek(logfp, 0, SEEK_END) < 0)3112 return error("cannot seek back reflog for %s: %s",3113 refname, strerror(errno));3114 pos = ftell(logfp);3115 while (!ret && 0 < pos) {3116 int cnt;3117 size_t nread;3118 char buf[BUFSIZ];3119 char *endp, *scanp;31203121 /* Fill next block from the end */3122 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;3123 if (fseek(logfp, pos - cnt, SEEK_SET))3124 return error("cannot seek back reflog for %s: %s",3125 refname, strerror(errno));3126 nread = fread(buf, cnt, 1, logfp);3127 if (nread != 1)3128 return error("cannot read %d bytes from reflog for %s: %s",3129 cnt, refname, strerror(errno));3130 pos -= cnt;31313132 scanp = endp = buf + cnt;3133 if (at_tail && scanp[-1] == '\n')3134 /* Looking at the final LF at the end of the file */3135 scanp--;3136 at_tail = 0;31373138 while (buf < scanp) {3139 /*3140 * terminating LF of the previous line, or the beginning3141 * of the buffer.3142 */3143 char *bp;31443145 bp = find_beginning_of_line(buf, scanp);31463147 if (*bp != '\n') {3148 strbuf_splice(&sb, 0, 0, buf, endp - buf);3149 if (pos)3150 break; /* need to fill another block */3151 scanp = buf - 1; /* leave loop */3152 } else {3153 /*3154 * (bp + 1) thru endp is the beginning of the3155 * current line we have in sb3156 */3157 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));3158 scanp = bp;3159 endp = bp + 1;3160 }3161 ret = show_one_reflog_ent(&sb, fn, cb_data);3162 strbuf_reset(&sb);3163 if (ret)3164 break;3165 }31663167 }3168 if (!ret && sb.len)3169 ret = show_one_reflog_ent(&sb, fn, cb_data);31703171 fclose(logfp);3172 strbuf_release(&sb);3173 return ret;3174}31753176int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)3177{3178 FILE *logfp;3179 struct strbuf sb = STRBUF_INIT;3180 int ret = 0;31813182 logfp = fopen(git_path("logs/%s", refname), "r");3183 if (!logfp)3184 return -1;31853186 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))3187 ret = show_one_reflog_ent(&sb, fn, cb_data);3188 fclose(logfp);3189 strbuf_release(&sb);3190 return ret;3191}3192/*3193 * Call fn for each reflog in the namespace indicated by name. name3194 * must be empty or end with '/'. Name will be used as a scratch3195 * space, but its contents will be restored before return.3196 */3197static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)3198{3199 DIR *d = opendir(git_path("logs/%s", name->buf));3200 int retval = 0;3201 struct dirent *de;3202 int oldlen = name->len;32033204 if (!d)3205 return name->len ? errno : 0;32063207 while ((de = readdir(d)) != NULL) {3208 struct stat st;32093210 if (de->d_name[0] == '.')3211 continue;3212 if (has_extension(de->d_name, ".lock"))3213 continue;3214 strbuf_addstr(name, de->d_name);3215 if (stat(git_path("logs/%s", name->buf), &st) < 0) {3216 ; /* silently ignore */3217 } else {3218 if (S_ISDIR(st.st_mode)) {3219 strbuf_addch(name, '/');3220 retval = do_for_each_reflog(name, fn, cb_data);3221 } else {3222 unsigned char sha1[20];3223 if (read_ref_full(name->buf, sha1, 0, NULL))3224 retval = error("bad ref for %s", name->buf);3225 else3226 retval = fn(name->buf, sha1, 0, cb_data);3227 }3228 if (retval)3229 break;3230 }3231 strbuf_setlen(name, oldlen);3232 }3233 closedir(d);3234 return retval;3235}32363237int for_each_reflog(each_ref_fn fn, void *cb_data)3238{3239 int retval;3240 struct strbuf name;3241 strbuf_init(&name, PATH_MAX);3242 retval = do_for_each_reflog(&name, fn, cb_data);3243 strbuf_release(&name);3244 return retval;3245}32463247static struct ref_lock *update_ref_lock(const char *refname,3248 const unsigned char *oldval,3249 int flags, int *type_p,3250 enum action_on_err onerr)3251{3252 struct ref_lock *lock;3253 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);3254 if (!lock) {3255 const char *str = "Cannot lock the ref '%s'.";3256 switch (onerr) {3257 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;3258 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;3259 case UPDATE_REFS_QUIET_ON_ERR: break;3260 }3261 }3262 return lock;3263}32643265static int update_ref_write(const char *action, const char *refname,3266 const unsigned char *sha1, struct ref_lock *lock,3267 enum action_on_err onerr)3268{3269 if (write_ref_sha1(lock, sha1, action) < 0) {3270 const char *str = "Cannot update the ref '%s'.";3271 switch (onerr) {3272 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;3273 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;3274 case UPDATE_REFS_QUIET_ON_ERR: break;3275 }3276 return 1;3277 }3278 return 0;3279}32803281/**3282 * Information needed for a single ref update. Set new_sha1 to the3283 * new value or to zero to delete the ref. To check the old value3284 * while locking the ref, set have_old to 1 and set old_sha1 to the3285 * value or to zero to ensure the ref does not exist before update.3286 */3287struct ref_update {3288 unsigned char new_sha1[20];3289 unsigned char old_sha1[20];3290 int flags; /* REF_NODEREF? */3291 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */3292 struct ref_lock *lock;3293 int type;3294 const char refname[FLEX_ARRAY];3295};32963297/*3298 * Data structure for holding a reference transaction, which can3299 * consist of checks and updates to multiple references, carried out3300 * as atomically as possible. This structure is opaque to callers.3301 */3302struct ref_transaction {3303 struct ref_update **updates;3304 size_t alloc;3305 size_t nr;3306};33073308struct ref_transaction *ref_transaction_begin(void)3309{3310 return xcalloc(1, sizeof(struct ref_transaction));3311}33123313static void ref_transaction_free(struct ref_transaction *transaction)3314{3315 int i;33163317 for (i = 0; i < transaction->nr; i++)3318 free(transaction->updates[i]);33193320 free(transaction->updates);3321 free(transaction);3322}33233324void ref_transaction_rollback(struct ref_transaction *transaction)3325{3326 ref_transaction_free(transaction);3327}33283329static struct ref_update *add_update(struct ref_transaction *transaction,3330 const char *refname)3331{3332 size_t len = strlen(refname);3333 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);33343335 strcpy((char *)update->refname, refname);3336 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);3337 transaction->updates[transaction->nr++] = update;3338 return update;3339}33403341void ref_transaction_update(struct ref_transaction *transaction,3342 const char *refname,3343 unsigned char *new_sha1, unsigned char *old_sha1,3344 int flags, int have_old)3345{3346 struct ref_update *update = add_update(transaction, refname);33473348 hashcpy(update->new_sha1, new_sha1);3349 update->flags = flags;3350 update->have_old = have_old;3351 if (have_old)3352 hashcpy(update->old_sha1, old_sha1);3353}33543355void ref_transaction_create(struct ref_transaction *transaction,3356 const char *refname,3357 unsigned char *new_sha1,3358 int flags)3359{3360 struct ref_update *update = add_update(transaction, refname);33613362 assert(!is_null_sha1(new_sha1));3363 hashcpy(update->new_sha1, new_sha1);3364 hashclr(update->old_sha1);3365 update->flags = flags;3366 update->have_old = 1;3367}33683369void ref_transaction_delete(struct ref_transaction *transaction,3370 const char *refname,3371 unsigned char *old_sha1,3372 int flags, int have_old)3373{3374 struct ref_update *update = add_update(transaction, refname);33753376 update->flags = flags;3377 update->have_old = have_old;3378 if (have_old) {3379 assert(!is_null_sha1(old_sha1));3380 hashcpy(update->old_sha1, old_sha1);3381 }3382}33833384int update_ref(const char *action, const char *refname,3385 const unsigned char *sha1, const unsigned char *oldval,3386 int flags, enum action_on_err onerr)3387{3388 struct ref_lock *lock;3389 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);3390 if (!lock)3391 return 1;3392 return update_ref_write(action, refname, sha1, lock, onerr);3393}33943395static int ref_update_compare(const void *r1, const void *r2)3396{3397 const struct ref_update * const *u1 = r1;3398 const struct ref_update * const *u2 = r2;3399 return strcmp((*u1)->refname, (*u2)->refname);3400}34013402static int ref_update_reject_duplicates(struct ref_update **updates, int n,3403 enum action_on_err onerr)3404{3405 int i;3406 for (i = 1; i < n; i++)3407 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {3408 const char *str =3409 "Multiple updates for ref '%s' not allowed.";3410 switch (onerr) {3411 case UPDATE_REFS_MSG_ON_ERR:3412 error(str, updates[i]->refname); break;3413 case UPDATE_REFS_DIE_ON_ERR:3414 die(str, updates[i]->refname); break;3415 case UPDATE_REFS_QUIET_ON_ERR:3416 break;3417 }3418 return 1;3419 }3420 return 0;3421}34223423int ref_transaction_commit(struct ref_transaction *transaction,3424 const char *msg, enum action_on_err onerr)3425{3426 int ret = 0, delnum = 0, i;3427 const char **delnames;3428 int n = transaction->nr;3429 struct ref_update **updates = transaction->updates;34303431 if (!n)3432 return 0;34333434 /* Allocate work space */3435 delnames = xmalloc(sizeof(*delnames) * n);34363437 /* Copy, sort, and reject duplicate refs */3438 qsort(updates, n, sizeof(*updates), ref_update_compare);3439 ret = ref_update_reject_duplicates(updates, n, onerr);3440 if (ret)3441 goto cleanup;34423443 /* Acquire all locks while verifying old values */3444 for (i = 0; i < n; i++) {3445 struct ref_update *update = updates[i];34463447 update->lock = update_ref_lock(update->refname,3448 (update->have_old ?3449 update->old_sha1 : NULL),3450 update->flags,3451 &update->type, onerr);3452 if (!update->lock) {3453 ret = 1;3454 goto cleanup;3455 }3456 }34573458 /* Perform updates first so live commits remain referenced */3459 for (i = 0; i < n; i++) {3460 struct ref_update *update = updates[i];34613462 if (!is_null_sha1(update->new_sha1)) {3463 ret = update_ref_write(msg,3464 update->refname,3465 update->new_sha1,3466 update->lock, onerr);3467 update->lock = NULL; /* freed by update_ref_write */3468 if (ret)3469 goto cleanup;3470 }3471 }34723473 /* Perform deletes now that updates are safely completed */3474 for (i = 0; i < n; i++) {3475 struct ref_update *update = updates[i];34763477 if (update->lock) {3478 delnames[delnum++] = update->lock->ref_name;3479 ret |= delete_ref_loose(update->lock, update->type);3480 }3481 }34823483 ret |= repack_without_refs(delnames, delnum);3484 for (i = 0; i < delnum; i++)3485 unlink_or_warn(git_path("logs/%s", delnames[i]));3486 clear_loose_ref_cache(&ref_cache);34873488cleanup:3489 for (i = 0; i < n; i++)3490 if (updates[i]->lock)3491 unlock_ref(updates[i]->lock);3492 free(delnames);3493 ref_transaction_free(transaction);3494 return ret;3495}34963497char *shorten_unambiguous_ref(const char *refname, int strict)3498{3499 int i;3500 static char **scanf_fmts;3501 static int nr_rules;3502 char *short_name;35033504 if (!nr_rules) {3505 /*3506 * Pre-generate scanf formats from ref_rev_parse_rules[].3507 * Generate a format suitable for scanf from a3508 * ref_rev_parse_rules rule by interpolating "%s" at the3509 * location of the "%.*s".3510 */3511 size_t total_len = 0;3512 size_t offset = 0;35133514 /* the rule list is NULL terminated, count them first */3515 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)3516 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3517 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;35183519 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);35203521 offset = 0;3522 for (i = 0; i < nr_rules; i++) {3523 assert(offset < total_len);3524 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;3525 offset += snprintf(scanf_fmts[i], total_len - offset,3526 ref_rev_parse_rules[i], 2, "%s") + 1;3527 }3528 }35293530 /* bail out if there are no rules */3531 if (!nr_rules)3532 return xstrdup(refname);35333534 /* buffer for scanf result, at most refname must fit */3535 short_name = xstrdup(refname);35363537 /* skip first rule, it will always match */3538 for (i = nr_rules - 1; i > 0 ; --i) {3539 int j;3540 int rules_to_fail = i;3541 int short_name_len;35423543 if (1 != sscanf(refname, scanf_fmts[i], short_name))3544 continue;35453546 short_name_len = strlen(short_name);35473548 /*3549 * in strict mode, all (except the matched one) rules3550 * must fail to resolve to a valid non-ambiguous ref3551 */3552 if (strict)3553 rules_to_fail = nr_rules;35543555 /*3556 * check if the short name resolves to a valid ref,3557 * but use only rules prior to the matched one3558 */3559 for (j = 0; j < rules_to_fail; j++) {3560 const char *rule = ref_rev_parse_rules[j];3561 char refname[PATH_MAX];35623563 /* skip matched rule */3564 if (i == j)3565 continue;35663567 /*3568 * the short name is ambiguous, if it resolves3569 * (with this previous rule) to a valid ref3570 * read_ref() returns 0 on success3571 */3572 mksnpath(refname, sizeof(refname),3573 rule, short_name_len, short_name);3574 if (ref_exists(refname))3575 break;3576 }35773578 /*3579 * short name is non-ambiguous if all previous rules3580 * haven't resolved to a valid ref3581 */3582 if (j == rules_to_fail)3583 return short_name;3584 }35853586 free(short_name);3587 return xstrdup(refname);3588}35893590static struct string_list *hide_refs;35913592int parse_hide_refs_config(const char *var, const char *value, const char *section)3593{3594 if (!strcmp("transfer.hiderefs", var) ||3595 /* NEEDSWORK: use parse_config_key() once both are merged */3596 (starts_with(var, section) && var[strlen(section)] == '.' &&3597 !strcmp(var + strlen(section), ".hiderefs"))) {3598 char *ref;3599 int len;36003601 if (!value)3602 return config_error_nonbool(var);3603 ref = xstrdup(value);3604 len = strlen(ref);3605 while (len && ref[len - 1] == '/')3606 ref[--len] = '\0';3607 if (!hide_refs) {3608 hide_refs = xcalloc(1, sizeof(*hide_refs));3609 hide_refs->strdup_strings = 1;3610 }3611 string_list_append(hide_refs, ref);3612 }3613 return 0;3614}36153616int ref_is_hidden(const char *refname)3617{3618 struct string_list_item *item;36193620 if (!hide_refs)3621 return 0;3622 for_each_string_list_item(item, hide_refs) {3623 int len;3624 if (!starts_with(refname, item->string))3625 continue;3626 len = strlen(item->string);3627 if (!refname[len] || refname[len] == '/')3628 return 1;3629 }3630 return 0;3631}