#include "cache.h" #include "lockfile.h" #include "refs.h" #include "object.h" #include "tag.h" #include "dir.h" #include "string-list.h" struct ref_lock { char *ref_name; char *orig_ref_name; struct lock_file *lk; unsigned char old_sha1[20]; int lock_fd; }; /* * How to handle various characters in refnames: * 0: An acceptable character for refs * 1: End-of-component * 2: ., look for a preceding . to reject .. in refs * 3: {, look for a preceding @ to reject @{ in refs * 4: A bad character: ASCII control characters, "~", "^", ":" or SP */ static unsigned char refname_disposition[256] = { 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4 }; /* * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken * refs (i.e., because the reference is about to be deleted anyway). */ #define REF_DELETING 0x02 /* * Used as a flag in ref_update::flags when a loose ref is being * pruned. */ #define REF_ISPRUNING 0x04 /* * Used as a flag in ref_update::flags when the reference should be * updated to new_sha1. */ #define REF_HAVE_NEW 0x08 /* * Used as a flag in ref_update::flags when old_sha1 should be * checked. */ #define REF_HAVE_OLD 0x10 /* * Try to read one refname component from the front of refname. * Return the length of the component found, or -1 if the component is * not legal. It is legal if it is something reasonable to have under * ".git/refs/"; We do not like it if: * * - any path component of it begins with ".", or * - it has double dots "..", or * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or * - it ends with a "/". * - it ends with ".lock" * - it contains a "\" (backslash) */ static int check_refname_component(const char *refname, int flags) { const char *cp; char last = '\0'; for (cp = refname; ; cp++) { int ch = *cp & 255; unsigned char disp = refname_disposition[ch]; switch (disp) { case 1: goto out; case 2: if (last == '.') return -1; /* Refname contains "..". */ break; case 3: if (last == '@') return -1; /* Refname contains "@{". */ break; case 4: return -1; } last = ch; } out: if (cp == refname) return 0; /* Component has zero length. */ if (refname[0] == '.') return -1; /* Component starts with '.'. */ if (cp - refname >= LOCK_SUFFIX_LEN && !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) return -1; /* Refname ends with ".lock". */ return cp - refname; } int check_refname_format(const char *refname, int flags) { int component_len, component_count = 0; if (!strcmp(refname, "@")) /* Refname is a single character '@'. */ return -1; while (1) { /* We are at the start of a path component. */ component_len = check_refname_component(refname, flags); if (component_len <= 0) { if ((flags & REFNAME_REFSPEC_PATTERN) && refname[0] == '*' && (refname[1] == '\0' || refname[1] == '/')) { /* Accept one wildcard as a full refname component. */ flags &= ~REFNAME_REFSPEC_PATTERN; component_len = 1; } else { return -1; } } component_count++; if (refname[component_len] == '\0') break; /* Skip to next component. */ refname += component_len + 1; } if (refname[component_len - 1] == '.') return -1; /* Refname ends with '.'. */ if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2) return -1; /* Refname has only one component. */ return 0; } struct ref_entry; /* * Information used (along with the information in ref_entry) to * describe a single cached reference. This data structure only * occurs embedded in a union in struct ref_entry, and only when * (ref_entry->flag & REF_DIR) is zero. */ struct ref_value { /* * The name of the object to which this reference resolves * (which may be a tag object). If REF_ISBROKEN, this is * null. If REF_ISSYMREF, then this is the name of the object * referred to by the last reference in the symlink chain. */ unsigned char sha1[20]; /* * If REF_KNOWS_PEELED, then this field holds the peeled value * of this reference, or null if the reference is known not to * be peelable. See the documentation for peel_ref() for an * exact definition of "peelable". */ unsigned char peeled[20]; }; struct ref_cache; /* * Information used (along with the information in ref_entry) to * describe a level in the hierarchy of references. This data * structure only occurs embedded in a union in struct ref_entry, and * only when (ref_entry.flag & REF_DIR) is set. In that case, * (ref_entry.flag & REF_INCOMPLETE) determines whether the references * in the directory have already been read: * * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose * or packed references, already read. * * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose * references that hasn't been read yet (nor has any of its * subdirectories). * * Entries within a directory are stored within a growable array of * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < * sorted are sorted by their component name in strcmp() order and the * remaining entries are unsorted. * * Loose references are read lazily, one directory at a time. When a * directory of loose references is read, then all of the references * in that directory are stored, and REF_INCOMPLETE stubs are created * for any subdirectories, but the subdirectories themselves are not * read. The reading is triggered by get_ref_dir(). */ struct ref_dir { int nr, alloc; /* * Entries with index 0 <= i < sorted are sorted by name. New * entries are appended to the list unsorted, and are sorted * only when required; thus we avoid the need to sort the list * after the addition of every reference. */ int sorted; /* A pointer to the ref_cache that contains this ref_dir. */ struct ref_cache *ref_cache; struct ref_entry **entries; }; /* * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are * public values; see refs.h. */ /* * The field ref_entry->u.value.peeled of this value entry contains * the correct peeled value for the reference, which might be * null_sha1 if the reference is not a tag or if it is broken. */ #define REF_KNOWS_PEELED 0x10 /* ref_entry represents a directory of references */ #define REF_DIR 0x20 /* * Entry has not yet been read from disk (used only for REF_DIR * entries representing loose references) */ #define REF_INCOMPLETE 0x40 /* * A ref_entry represents either a reference or a "subdirectory" of * references. * * Each directory in the reference namespace is represented by a * ref_entry with (flags & REF_DIR) set and containing a subdir member * that holds the entries in that directory that have been read so * far. If (flags & REF_INCOMPLETE) is set, then the directory and * its subdirectories haven't been read yet. REF_INCOMPLETE is only * used for loose reference directories. * * References are represented by a ref_entry with (flags & REF_DIR) * unset and a value member that describes the reference's value. The * flag member is at the ref_entry level, but it is also needed to * interpret the contents of the value field (in other words, a * ref_value object is not very much use without the enclosing * ref_entry). * * Reference names cannot end with slash and directories' names are * always stored with a trailing slash (except for the top-level * directory, which is always denoted by ""). This has two nice * consequences: (1) when the entries in each subdir are sorted * lexicographically by name (as they usually are), the references in * a whole tree can be generated in lexicographic order by traversing * the tree in left-to-right, depth-first order; (2) the names of * references and subdirectories cannot conflict, and therefore the * presence of an empty subdirectory does not block the creation of a * similarly-named reference. (The fact that reference names with the * same leading components can conflict *with each other* is a * separate issue that is regulated by verify_refname_available().) * * Please note that the name field contains the fully-qualified * reference (or subdirectory) name. Space could be saved by only * storing the relative names. But that would require the full names * to be generated on the fly when iterating in do_for_each_ref(), and * would break callback functions, who have always been able to assume * that the name strings that they are passed will not be freed during * the iteration. */ struct ref_entry { unsigned char flag; /* ISSYMREF? ISPACKED? */ union { struct ref_value value; /* if not (flags&REF_DIR) */ struct ref_dir subdir; /* if (flags&REF_DIR) */ } u; /* * The full name of the reference (e.g., "refs/heads/master") * or the full name of the directory with a trailing slash * (e.g., "refs/heads/"): */ char name[FLEX_ARRAY]; }; static void read_loose_refs(const char *dirname, struct ref_dir *dir); static struct ref_dir *get_ref_dir(struct ref_entry *entry) { struct ref_dir *dir; assert(entry->flag & REF_DIR); dir = &entry->u.subdir; if (entry->flag & REF_INCOMPLETE) { read_loose_refs(entry->name, dir); entry->flag &= ~REF_INCOMPLETE; } return dir; } /* * Check if a refname is safe. * For refs that start with "refs/" we consider it safe as long they do * not try to resolve to outside of refs/. * * For all other refs we only consider them safe iff they only contain * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like * "config"). */ static int refname_is_safe(const char *refname) { if (starts_with(refname, "refs/")) { char *buf; int result; buf = xmalloc(strlen(refname) + 1); /* * Does the refname try to escape refs/? * For example: refs/foo/../bar is safe but refs/foo/../../bar * is not. */ result = !normalize_path_copy(buf, refname + strlen("refs/")); free(buf); return result; } while (*refname) { if (!isupper(*refname) && *refname != '_') return 0; refname++; } return 1; } static struct ref_entry *create_ref_entry(const char *refname, const unsigned char *sha1, int flag, int check_name) { int len; struct ref_entry *ref; if (check_name && check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) die("Reference has invalid format: '%s'", refname); if (!check_name && !refname_is_safe(refname)) die("Reference has invalid name: '%s'", refname); len = strlen(refname) + 1; ref = xmalloc(sizeof(struct ref_entry) + len); hashcpy(ref->u.value.sha1, sha1); hashclr(ref->u.value.peeled); memcpy(ref->name, refname, len); ref->flag = flag; return ref; } static void clear_ref_dir(struct ref_dir *dir); static void free_ref_entry(struct ref_entry *entry) { if (entry->flag & REF_DIR) { /* * Do not use get_ref_dir() here, as that might * trigger the reading of loose refs. */ clear_ref_dir(&entry->u.subdir); } free(entry); } /* * Add a ref_entry to the end of dir (unsorted). Entry is always * stored directly in dir; no recursion into subdirectories is * done. */ static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry) { ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc); dir->entries[dir->nr++] = entry; /* optimize for the case that entries are added in order */ if (dir->nr == 1 || (dir->nr == dir->sorted + 1 && strcmp(dir->entries[dir->nr - 2]->name, dir->entries[dir->nr - 1]->name) < 0)) dir->sorted = dir->nr; } /* * Clear and free all entries in dir, recursively. */ static void clear_ref_dir(struct ref_dir *dir) { int i; for (i = 0; i < dir->nr; i++) free_ref_entry(dir->entries[i]); free(dir->entries); dir->sorted = dir->nr = dir->alloc = 0; dir->entries = NULL; } /* * Create a struct ref_entry object for the specified dirname. * dirname is the name of the directory with a trailing slash (e.g., * "refs/heads/") or "" for the top-level directory. */ static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, const char *dirname, size_t len, int incomplete) { struct ref_entry *direntry; direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1); memcpy(direntry->name, dirname, len); direntry->name[len] = '\0'; direntry->u.subdir.ref_cache = ref_cache; direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0); return direntry; } static int ref_entry_cmp(const void *a, const void *b) { struct ref_entry *one = *(struct ref_entry **)a; struct ref_entry *two = *(struct ref_entry **)b; return strcmp(one->name, two->name); } static void sort_ref_dir(struct ref_dir *dir); struct string_slice { size_t len; const char *str; }; static int ref_entry_cmp_sslice(const void *key_, const void *ent_) { const struct string_slice *key = key_; const struct ref_entry *ent = *(const struct ref_entry * const *)ent_; int cmp = strncmp(key->str, ent->name, key->len); if (cmp) return cmp; return '\0' - (unsigned char)ent->name[key->len]; } /* * Return the index of the entry with the given refname from the * ref_dir (non-recursively), sorting dir if necessary. Return -1 if * no such entry is found. dir must already be complete. */ static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len) { struct ref_entry **r; struct string_slice key; if (refname == NULL || !dir->nr) return -1; sort_ref_dir(dir); key.len = len; key.str = refname; r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp_sslice); if (r == NULL) return -1; return r - dir->entries; } /* * Search for a directory entry directly within dir (without * recursing). Sort dir if necessary. subdirname must be a directory * name (i.e., end in '/'). If mkdir is set, then create the * directory if it is missing; otherwise, return NULL if the desired * directory cannot be found. dir must already be complete. */ static struct ref_dir *search_for_subdir(struct ref_dir *dir, const char *subdirname, size_t len, int mkdir) { int entry_index = search_ref_dir(dir, subdirname, len); struct ref_entry *entry; if (entry_index == -1) { if (!mkdir) return NULL; /* * Since dir is complete, the absence of a subdir * means that the subdir really doesn't exist; * therefore, create an empty record for it but mark * the record complete. */ entry = create_dir_entry(dir->ref_cache, subdirname, len, 0); add_entry_to_dir(dir, entry); } else { entry = dir->entries[entry_index]; } return get_ref_dir(entry); } /* * If refname is a reference name, find the ref_dir within the dir * tree that should hold refname. If refname is a directory name * (i.e., ends in '/'), then return that ref_dir itself. dir must * represent the top-level directory and must already be complete. * Sort ref_dirs and recurse into subdirectories as necessary. If * mkdir is set, then create any missing directories; otherwise, * return NULL if the desired directory cannot be found. */ static struct ref_dir *find_containing_dir(struct ref_dir *dir, const char *refname, int mkdir) { const char *slash; for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { size_t dirnamelen = slash - refname + 1; struct ref_dir *subdir; subdir = search_for_subdir(dir, refname, dirnamelen, mkdir); if (!subdir) { dir = NULL; break; } dir = subdir; } return dir; } /* * Find the value entry with the given name in dir, sorting ref_dirs * and recursing into subdirectories as necessary. If the name is not * found or it corresponds to a directory entry, return NULL. */ static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname) { int entry_index; struct ref_entry *entry; dir = find_containing_dir(dir, refname, 0); if (!dir) return NULL; entry_index = search_ref_dir(dir, refname, strlen(refname)); if (entry_index == -1) return NULL; entry = dir->entries[entry_index]; return (entry->flag & REF_DIR) ? NULL : entry; } /* * Remove the entry with the given name from dir, recursing into * subdirectories as necessary. If refname is the name of a directory * (i.e., ends with '/'), then remove the directory and its contents. * If the removal was successful, return the number of entries * remaining in the directory entry that contained the deleted entry. * If the name was not found, return -1. Please note that this * function only deletes the entry from the cache; it does not delete * it from the filesystem or ensure that other cache entries (which * might be symbolic references to the removed entry) are updated. * Nor does it remove any containing dir entries that might be made * empty by the removal. dir must represent the top-level directory * and must already be complete. */ static int remove_entry(struct ref_dir *dir, const char *refname) { int refname_len = strlen(refname); int entry_index; struct ref_entry *entry; int is_dir = refname[refname_len - 1] == '/'; if (is_dir) { /* * refname represents a reference directory. Remove * the trailing slash; otherwise we will get the * directory *representing* refname rather than the * one *containing* it. */ char *dirname = xmemdupz(refname, refname_len - 1); dir = find_containing_dir(dir, dirname, 0); free(dirname); } else { dir = find_containing_dir(dir, refname, 0); } if (!dir) return -1; entry_index = search_ref_dir(dir, refname, refname_len); if (entry_index == -1) return -1; entry = dir->entries[entry_index]; memmove(&dir->entries[entry_index], &dir->entries[entry_index + 1], (dir->nr - entry_index - 1) * sizeof(*dir->entries) ); dir->nr--; if (dir->sorted > entry_index) dir->sorted--; free_ref_entry(entry); return dir->nr; } /* * Add a ref_entry to the ref_dir (unsorted), recursing into * subdirectories as necessary. dir must represent the top-level * directory. Return 0 on success. */ static int add_ref(struct ref_dir *dir, struct ref_entry *ref) { dir = find_containing_dir(dir, ref->name, 1); if (!dir) return -1; add_entry_to_dir(dir, ref); return 0; } /* * Emit a warning and return true iff ref1 and ref2 have the same name * and the same sha1. Die if they have the same name but different * sha1s. */ static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) { if (strcmp(ref1->name, ref2->name)) return 0; /* Duplicate name; make sure that they don't conflict: */ if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) /* This is impossible by construction */ die("Reference directory conflict: %s", ref1->name); if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) die("Duplicated ref, and SHA1s don't match: %s", ref1->name); warning("Duplicated ref: %s", ref1->name); return 1; } /* * Sort the entries in dir non-recursively (if they are not already * sorted) and remove any duplicate entries. */ static void sort_ref_dir(struct ref_dir *dir) { int i, j; struct ref_entry *last = NULL; /* * This check also prevents passing a zero-length array to qsort(), * which is a problem on some platforms. */ if (dir->sorted == dir->nr) return; qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); /* Remove any duplicates: */ for (i = 0, j = 0; j < dir->nr; j++) { struct ref_entry *entry = dir->entries[j]; if (last && is_dup_ref(last, entry)) free_ref_entry(entry); else last = dir->entries[i++] = entry; } dir->sorted = dir->nr = i; } /* Include broken references in a do_for_each_ref*() iteration: */ #define DO_FOR_EACH_INCLUDE_BROKEN 0x01 /* * Return true iff the reference described by entry can be resolved to * an object in the database. Emit a warning if the referred-to * object does not exist. */ static int ref_resolves_to_object(struct ref_entry *entry) { if (entry->flag & REF_ISBROKEN) return 0; if (!has_sha1_file(entry->u.value.sha1)) { error("%s does not point to a valid object!", entry->name); return 0; } return 1; } /* * current_ref is a performance hack: when iterating over references * using the for_each_ref*() functions, current_ref is set to the * current reference's entry before calling the callback function. If * the callback function calls peel_ref(), then peel_ref() first * checks whether the reference to be peeled is the current reference * (it usually is) and if so, returns that reference's peeled version * if it is available. This avoids a refname lookup in a common case. */ static struct ref_entry *current_ref; typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); struct ref_entry_cb { const char *base; int trim; int flags; each_ref_fn *fn; void *cb_data; }; /* * Handle one reference in a do_for_each_ref*()-style iteration, * calling an each_ref_fn for each entry. */ static int do_one_ref(struct ref_entry *entry, void *cb_data) { struct ref_entry_cb *data = cb_data; struct ref_entry *old_current_ref; int retval; if (!starts_with(entry->name, data->base)) return 0; if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && !ref_resolves_to_object(entry)) return 0; /* Store the old value, in case this is a recursive call: */ old_current_ref = current_ref; current_ref = entry; retval = data->fn(entry->name + data->trim, entry->u.value.sha1, entry->flag, data->cb_data); current_ref = old_current_ref; return retval; } /* * Call fn for each reference in dir that has index in the range * offset <= index < dir->nr. Recurse into subdirectories that are in * that index range, sorting them before iterating. This function * does not sort dir itself; it should be sorted beforehand. fn is * called for all references, including broken ones. */ static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset, each_ref_entry_fn fn, void *cb_data) { int i; assert(dir->sorted == dir->nr); for (i = offset; i < dir->nr; i++) { struct ref_entry *entry = dir->entries[i]; int retval; if (entry->flag & REF_DIR) { struct ref_dir *subdir = get_ref_dir(entry); sort_ref_dir(subdir); retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data); } else { retval = fn(entry, cb_data); } if (retval) return retval; } return 0; } /* * Call fn for each reference in the union of dir1 and dir2, in order * by refname. Recurse into subdirectories. If a value entry appears * in both dir1 and dir2, then only process the version that is in * dir2. The input dirs must already be sorted, but subdirs will be * sorted as needed. fn is called for all references, including * broken ones. */ static int do_for_each_entry_in_dirs(struct ref_dir *dir1, struct ref_dir *dir2, each_ref_entry_fn fn, void *cb_data) { int retval; int i1 = 0, i2 = 0; assert(dir1->sorted == dir1->nr); assert(dir2->sorted == dir2->nr); while (1) { struct ref_entry *e1, *e2; int cmp; if (i1 == dir1->nr) { return do_for_each_entry_in_dir(dir2, i2, fn, cb_data); } if (i2 == dir2->nr) { return do_for_each_entry_in_dir(dir1, i1, fn, cb_data); } e1 = dir1->entries[i1]; e2 = dir2->entries[i2]; cmp = strcmp(e1->name, e2->name); if (cmp == 0) { if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { /* Both are directories; descend them in parallel. */ struct ref_dir *subdir1 = get_ref_dir(e1); struct ref_dir *subdir2 = get_ref_dir(e2); sort_ref_dir(subdir1); sort_ref_dir(subdir2); retval = do_for_each_entry_in_dirs( subdir1, subdir2, fn, cb_data); i1++; i2++; } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { /* Both are references; ignore the one from dir1. */ retval = fn(e2, cb_data); i1++; i2++; } else { die("conflict between reference and directory: %s", e1->name); } } else { struct ref_entry *e; if (cmp < 0) { e = e1; i1++; } else { e = e2; i2++; } if (e->flag & REF_DIR) { struct ref_dir *subdir = get_ref_dir(e); sort_ref_dir(subdir); retval = do_for_each_entry_in_dir( subdir, 0, fn, cb_data); } else { retval = fn(e, cb_data); } } if (retval) return retval; } } /* * Load all of the refs from the dir into our in-memory cache. The hard work * of loading loose refs is done by get_ref_dir(), so we just need to recurse * through all of the sub-directories. We do not even need to care about * sorting, as traversal order does not matter to us. */ static void prime_ref_dir(struct ref_dir *dir) { int i; for (i = 0; i < dir->nr; i++) { struct ref_entry *entry = dir->entries[i]; if (entry->flag & REF_DIR) prime_ref_dir(get_ref_dir(entry)); } } struct nonmatching_ref_data { const struct string_list *skip; const char *conflicting_refname; }; static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata) { struct nonmatching_ref_data *data = vdata; if (data->skip && string_list_has_string(data->skip, entry->name)) return 0; data->conflicting_refname = entry->name; return 1; } /* * Return 0 if a reference named refname could be created without * conflicting with the name of an existing reference in dir. * Otherwise, return a negative value and write an explanation to err. * If extras is non-NULL, it is a list of additional refnames with * which refname is not allowed to conflict. If skip is non-NULL, * ignore potential conflicts with refs in skip (e.g., because they * are scheduled for deletion in the same operation). Behavior is * undefined if the same name is listed in both extras and skip. * * Two reference names conflict if one of them exactly matches the * leading components of the other; e.g., "refs/foo/bar" conflicts * with both "refs/foo" and with "refs/foo/bar/baz" but not with * "refs/foo/bar" or "refs/foo/barbados". * * extras and skip must be sorted. */ static int verify_refname_available(const char *refname, const struct string_list *extras, const struct string_list *skip, struct ref_dir *dir, struct strbuf *err) { const char *slash; int pos; struct strbuf dirname = STRBUF_INIT; int ret = -1; /* * For the sake of comments in this function, suppose that * refname is "refs/foo/bar". */ assert(err); strbuf_grow(&dirname, strlen(refname) + 1); for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) { /* Expand dirname to the new prefix, not including the trailing slash: */ strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); /* * We are still at a leading dir of the refname (e.g., * "refs/foo"; if there is a reference with that name, * it is a conflict, *unless* it is in skip. */ if (dir) { pos = search_ref_dir(dir, dirname.buf, dirname.len); if (pos >= 0 && (!skip || !string_list_has_string(skip, dirname.buf))) { /* * We found a reference whose name is * a proper prefix of refname; e.g., * "refs/foo", and is not in skip. */ strbuf_addf(err, "'%s' exists; cannot create '%s'", dirname.buf, refname); goto cleanup; } } if (extras && string_list_has_string(extras, dirname.buf) && (!skip || !string_list_has_string(skip, dirname.buf))) { strbuf_addf(err, "cannot process '%s' and '%s' at the same time", refname, dirname.buf); goto cleanup; } /* * Otherwise, we can try to continue our search with * the next component. So try to look up the * directory, e.g., "refs/foo/". If we come up empty, * we know there is nothing under this whole prefix, * but even in that case we still have to continue the * search for conflicts with extras. */ strbuf_addch(&dirname, '/'); if (dir) { pos = search_ref_dir(dir, dirname.buf, dirname.len); if (pos < 0) { /* * There was no directory "refs/foo/", * so there is nothing under this * whole prefix. So there is no need * to continue looking for conflicting * references. But we need to continue * looking for conflicting extras. */ dir = NULL; } else { dir = get_ref_dir(dir->entries[pos]); } } } /* * We are at the leaf of our refname (e.g., "refs/foo/bar"). * There is no point in searching for a reference with that * name, because a refname isn't considered to conflict with * itself. But we still need to check for references whose * names are in the "refs/foo/bar/" namespace, because they * *do* conflict. */ strbuf_addstr(&dirname, refname + dirname.len); strbuf_addch(&dirname, '/'); if (dir) { pos = search_ref_dir(dir, dirname.buf, dirname.len); if (pos >= 0) { /* * We found a directory named "$refname/" * (e.g., "refs/foo/bar/"). It is a problem * iff it contains any ref that is not in * "skip". */ struct nonmatching_ref_data data; data.skip = skip; data.conflicting_refname = NULL; dir = get_ref_dir(dir->entries[pos]); sort_ref_dir(dir); if (do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data)) { strbuf_addf(err, "'%s' exists; cannot create '%s'", data.conflicting_refname, refname); goto cleanup; } } } if (extras) { /* * Check for entries in extras that start with * "$refname/". We do that by looking for the place * where "$refname/" would be inserted in extras. If * there is an entry at that position that starts with * "$refname/" and is not in skip, then we have a * conflict. */ for (pos = string_list_find_insert_index(extras, dirname.buf, 0); pos < extras->nr; pos++) { const char *extra_refname = extras->items[pos].string; if (!starts_with(extra_refname, dirname.buf)) break; if (!skip || !string_list_has_string(skip, extra_refname)) { strbuf_addf(err, "cannot process '%s' and '%s' at the same time", refname, extra_refname); goto cleanup; } } } /* No conflicts were found */ ret = 0; cleanup: strbuf_release(&dirname); return ret; } struct packed_ref_cache { struct ref_entry *root; /* * Count of references to the data structure in this instance, * including the pointer from ref_cache::packed if any. The * data will not be freed as long as the reference count is * nonzero. */ unsigned int referrers; /* * Iff the packed-refs file associated with this instance is * currently locked for writing, this points at the associated * lock (which is owned by somebody else). The referrer count * is also incremented when the file is locked and decremented * when it is unlocked. */ struct lock_file *lock; /* The metadata from when this packed-refs cache was read */ struct stat_validity validity; }; /* * Future: need to be in "struct repository" * when doing a full libification. */ static struct ref_cache { struct ref_cache *next; struct ref_entry *loose; struct packed_ref_cache *packed; /* * The submodule name, or "" for the main repo. We allocate * length 1 rather than FLEX_ARRAY so that the main ref_cache * is initialized correctly. */ char name[1]; } ref_cache, *submodule_ref_caches; /* Lock used for the main packed-refs file: */ static struct lock_file packlock; /* * Increment the reference count of *packed_refs. */ static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) { packed_refs->referrers++; } /* * Decrease the reference count of *packed_refs. If it goes to zero, * free *packed_refs and return true; otherwise return false. */ static int release_packed_ref_cache(struct packed_ref_cache *packed_refs) { if (!--packed_refs->referrers) { free_ref_entry(packed_refs->root); stat_validity_clear(&packed_refs->validity); free(packed_refs); return 1; } else { return 0; } } static void clear_packed_ref_cache(struct ref_cache *refs) { if (refs->packed) { struct packed_ref_cache *packed_refs = refs->packed; if (packed_refs->lock) die("internal error: packed-ref cache cleared while locked"); refs->packed = NULL; release_packed_ref_cache(packed_refs); } } static void clear_loose_ref_cache(struct ref_cache *refs) { if (refs->loose) { free_ref_entry(refs->loose); refs->loose = NULL; } } static struct ref_cache *create_ref_cache(const char *submodule) { int len; struct ref_cache *refs; if (!submodule) submodule = ""; len = strlen(submodule) + 1; refs = xcalloc(1, sizeof(struct ref_cache) + len); memcpy(refs->name, submodule, len); return refs; } /* * Return a pointer to a ref_cache for the specified submodule. For * the main repository, use submodule==NULL. The returned structure * will be allocated and initialized but not necessarily populated; it * should not be freed. */ static struct ref_cache *get_ref_cache(const char *submodule) { struct ref_cache *refs; if (!submodule || !*submodule) return &ref_cache; for (refs = submodule_ref_caches; refs; refs = refs->next) if (!strcmp(submodule, refs->name)) return refs; refs = create_ref_cache(submodule); refs->next = submodule_ref_caches; submodule_ref_caches = refs; return refs; } /* The length of a peeled reference line in packed-refs, including EOL: */ #define PEELED_LINE_LENGTH 42 /* * The packed-refs header line that we write out. Perhaps other * traits will be added later. The trailing space is required. */ static const char PACKED_REFS_HEADER[] = "# pack-refs with: peeled fully-peeled \n"; /* * Parse one line from a packed-refs file. Write the SHA1 to sha1. * Return a pointer to the refname within the line (null-terminated), * or NULL if there was a problem. */ static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1) { const char *ref; /* * 42: the answer to everything. * * In this case, it happens to be the answer to * 40 (length of sha1 hex representation) * +1 (space in between hex and name) * +1 (newline at the end of the line) */ if (line->len <= 42) return NULL; if (get_sha1_hex(line->buf, sha1) < 0) return NULL; if (!isspace(line->buf[40])) return NULL; ref = line->buf + 41; if (isspace(*ref)) return NULL; if (line->buf[line->len - 1] != '\n') return NULL; line->buf[--line->len] = 0; return ref; } /* * Read f, which is a packed-refs file, into dir. * * A comment line of the form "# pack-refs with: " may contain zero or * more traits. We interpret the traits as follows: * * No traits: * * Probably no references are peeled. But if the file contains a * peeled value for a reference, we will use it. * * peeled: * * References under "refs/tags/", if they *can* be peeled, *are* * peeled in this file. References outside of "refs/tags/" are * probably not peeled even if they could have been, but if we find * a peeled value for such a reference we will use it. * * fully-peeled: * * All references in the file that can be peeled are peeled. * Inversely (and this is more important), any references in the * file for which no peeled value is recorded is not peelable. This * trait should typically be written alongside "peeled" for * compatibility with older clients, but we do not require it * (i.e., "peeled" is a no-op if "fully-peeled" is set). */ static void read_packed_refs(FILE *f, struct ref_dir *dir) { struct ref_entry *last = NULL; struct strbuf line = STRBUF_INIT; enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; while (strbuf_getwholeline(&line, f, '\n') != EOF) { unsigned char sha1[20]; const char *refname; const char *traits; if (skip_prefix(line.buf, "# pack-refs with:", &traits)) { if (strstr(traits, " fully-peeled ")) peeled = PEELED_FULLY; else if (strstr(traits, " peeled ")) peeled = PEELED_TAGS; /* perhaps other traits later as well */ continue; } refname = parse_ref_line(&line, sha1); if (refname) { int flag = REF_ISPACKED; if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { hashclr(sha1); flag |= REF_BAD_NAME | REF_ISBROKEN; } last = create_ref_entry(refname, sha1, flag, 0); if (peeled == PEELED_FULLY || (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/"))) last->flag |= REF_KNOWS_PEELED; add_ref(dir, last); continue; } if (last && line.buf[0] == '^' && line.len == PEELED_LINE_LENGTH && line.buf[PEELED_LINE_LENGTH - 1] == '\n' && !get_sha1_hex(line.buf + 1, sha1)) { hashcpy(last->u.value.peeled, sha1); /* * Regardless of what the file header said, * we definitely know the value of *this* * reference: */ last->flag |= REF_KNOWS_PEELED; } } strbuf_release(&line); } /* * Get the packed_ref_cache for the specified ref_cache, creating it * if necessary. */ static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs) { const char *packed_refs_file; if (*refs->name) packed_refs_file = git_path_submodule(refs->name, "packed-refs"); else packed_refs_file = git_path("packed-refs"); if (refs->packed && !stat_validity_check(&refs->packed->validity, packed_refs_file)) clear_packed_ref_cache(refs); if (!refs->packed) { FILE *f; refs->packed = xcalloc(1, sizeof(*refs->packed)); acquire_packed_ref_cache(refs->packed); refs->packed->root = create_dir_entry(refs, "", 0, 0); f = fopen(packed_refs_file, "r"); if (f) { stat_validity_update(&refs->packed->validity, fileno(f)); read_packed_refs(f, get_ref_dir(refs->packed->root)); fclose(f); } } return refs->packed; } static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) { return get_ref_dir(packed_ref_cache->root); } static struct ref_dir *get_packed_refs(struct ref_cache *refs) { return get_packed_ref_dir(get_packed_ref_cache(refs)); } void add_packed_ref(const char *refname, const unsigned char *sha1) { struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(&ref_cache); if (!packed_ref_cache->lock) die("internal error: packed refs not locked"); add_ref(get_packed_ref_dir(packed_ref_cache), create_ref_entry(refname, sha1, REF_ISPACKED, 1)); } /* * Read the loose references from the namespace dirname into dir * (without recursing). dirname must end with '/'. dir must be the * directory entry corresponding to dirname. */ static void read_loose_refs(const char *dirname, struct ref_dir *dir) { struct ref_cache *refs = dir->ref_cache; DIR *d; const char *path; struct dirent *de; int dirnamelen = strlen(dirname); struct strbuf refname; if (*refs->name) path = git_path_submodule(refs->name, "%s", dirname); else path = git_path("%s", dirname); d = opendir(path); if (!d) return; strbuf_init(&refname, dirnamelen + 257); strbuf_add(&refname, dirname, dirnamelen); while ((de = readdir(d)) != NULL) { unsigned char sha1[20]; struct stat st; int flag; const char *refdir; if (de->d_name[0] == '.') continue; if (ends_with(de->d_name, ".lock")) continue; strbuf_addstr(&refname, de->d_name); refdir = *refs->name ? git_path_submodule(refs->name, "%s", refname.buf) : git_path("%s", refname.buf); if (stat(refdir, &st) < 0) { ; /* silently ignore */ } else if (S_ISDIR(st.st_mode)) { strbuf_addch(&refname, '/'); add_entry_to_dir(dir, create_dir_entry(refs, refname.buf, refname.len, 1)); } else { if (*refs->name) { hashclr(sha1); flag = 0; if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) { hashclr(sha1); flag |= REF_ISBROKEN; } } else if (read_ref_full(refname.buf, RESOLVE_REF_READING, sha1, &flag)) { hashclr(sha1); flag |= REF_ISBROKEN; } if (check_refname_format(refname.buf, REFNAME_ALLOW_ONELEVEL)) { hashclr(sha1); flag |= REF_BAD_NAME | REF_ISBROKEN; } add_entry_to_dir(dir, create_ref_entry(refname.buf, sha1, flag, 0)); } strbuf_setlen(&refname, dirnamelen); } strbuf_release(&refname); closedir(d); } static struct ref_dir *get_loose_refs(struct ref_cache *refs) { if (!refs->loose) { /* * Mark the top-level directory complete because we * are about to read the only subdirectory that can * hold references: */ refs->loose = create_dir_entry(refs, "", 0, 0); /* * Create an incomplete entry for "refs/": */ add_entry_to_dir(get_ref_dir(refs->loose), create_dir_entry(refs, "refs/", 5, 1)); } return get_ref_dir(refs->loose); } /* We allow "recursive" symbolic refs. Only within reason, though */ #define MAXDEPTH 5 #define MAXREFLEN (1024) /* * Called by resolve_gitlink_ref_recursive() after it failed to read * from the loose refs in ref_cache refs. Find in the * packed-refs file for the submodule. */ static int resolve_gitlink_packed_ref(struct ref_cache *refs, const char *refname, unsigned char *sha1) { struct ref_entry *ref; struct ref_dir *dir = get_packed_refs(refs); ref = find_ref(dir, refname); if (ref == NULL) return -1; hashcpy(sha1, ref->u.value.sha1); return 0; } static int resolve_gitlink_ref_recursive(struct ref_cache *refs, const char *refname, unsigned char *sha1, int recursion) { int fd, len; char buffer[128], *p; char *path; if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN) return -1; path = *refs->name ? git_path_submodule(refs->name, "%s", refname) : git_path("%s", refname); fd = open(path, O_RDONLY); if (fd < 0) return resolve_gitlink_packed_ref(refs, refname, sha1); len = read(fd, buffer, sizeof(buffer)-1); close(fd); if (len < 0) return -1; while (len && isspace(buffer[len-1])) len--; buffer[len] = 0; /* Was it a detached head or an old-fashioned symlink? */ if (!get_sha1_hex(buffer, sha1)) return 0; /* Symref? */ if (strncmp(buffer, "ref:", 4)) return -1; p = buffer + 4; while (isspace(*p)) p++; return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1); } int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1) { int len = strlen(path), retval; char *submodule; struct ref_cache *refs; while (len && path[len-1] == '/') len--; if (!len) return -1; submodule = xstrndup(path, len); refs = get_ref_cache(submodule); free(submodule); retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0); return retval; } /* * Return the ref_entry for the given refname from the packed * references. If it does not exist, return NULL. */ static struct ref_entry *get_packed_ref(const char *refname) { return find_ref(get_packed_refs(&ref_cache), refname); } /* * A loose ref file doesn't exist; check for a packed ref. The * options are forwarded from resolve_safe_unsafe(). */ static int resolve_missing_loose_ref(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { struct ref_entry *entry; /* * The loose reference file does not exist; check for a packed * reference. */ entry = get_packed_ref(refname); if (entry) { hashcpy(sha1, entry->u.value.sha1); if (flags) *flags |= REF_ISPACKED; return 0; } /* The reference is not a packed reference, either. */ if (resolve_flags & RESOLVE_REF_READING) { errno = ENOENT; return -1; } else { hashclr(sha1); return 0; } } /* This function needs to return a meaningful errno on failure */ const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { int depth = MAXDEPTH; ssize_t len; char buffer[256]; static char refname_buffer[256]; int bad_name = 0; if (flags) *flags = 0; if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { if (flags) *flags |= REF_BAD_NAME; if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || !refname_is_safe(refname)) { errno = EINVAL; return NULL; } /* * dwim_ref() uses REF_ISBROKEN to distinguish between * missing refs and refs that were present but invalid, * to complain about the latter to stderr. * * We don't know whether the ref exists, so don't set * REF_ISBROKEN yet. */ bad_name = 1; } for (;;) { char path[PATH_MAX]; struct stat st; char *buf; int fd; if (--depth < 0) { errno = ELOOP; return NULL; } git_snpath(path, sizeof(path), "%s", refname); /* * We might have to loop back here to avoid a race * condition: first we lstat() the file, then we try * to read it as a link or as a file. But if somebody * changes the type of the file (file <-> directory * <-> symlink) between the lstat() and reading, then * we don't want to report that as an error but rather * try again starting with the lstat(). */ stat_ref: if (lstat(path, &st) < 0) { if (errno != ENOENT) return NULL; if (resolve_missing_loose_ref(refname, resolve_flags, sha1, flags)) return NULL; if (bad_name) { hashclr(sha1); if (flags) *flags |= REF_ISBROKEN; } return refname; } /* Follow "normalized" - ie "refs/.." symlinks by hand */ if (S_ISLNK(st.st_mode)) { len = readlink(path, buffer, sizeof(buffer)-1); if (len < 0) { if (errno == ENOENT || errno == EINVAL) /* inconsistent with lstat; retry */ goto stat_ref; else return NULL; } buffer[len] = 0; if (starts_with(buffer, "refs/") && !check_refname_format(buffer, 0)) { strcpy(refname_buffer, buffer); refname = refname_buffer; if (flags) *flags |= REF_ISSYMREF; if (resolve_flags & RESOLVE_REF_NO_RECURSE) { hashclr(sha1); return refname; } continue; } } /* Is it a directory? */ if (S_ISDIR(st.st_mode)) { errno = EISDIR; return NULL; } /* * Anything else, just open it and try to use it as * a ref */ fd = open(path, O_RDONLY); if (fd < 0) { if (errno == ENOENT) /* inconsistent with lstat; retry */ goto stat_ref; else return NULL; } len = read_in_full(fd, buffer, sizeof(buffer)-1); if (len < 0) { int save_errno = errno; close(fd); errno = save_errno; return NULL; } close(fd); while (len && isspace(buffer[len-1])) len--; buffer[len] = '\0'; /* * Is it a symbolic ref? */ if (!starts_with(buffer, "ref:")) { /* * Please note that FETCH_HEAD has a second * line containing other data. */ if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) { if (flags) *flags |= REF_ISBROKEN; errno = EINVAL; return NULL; } if (bad_name) { hashclr(sha1); if (flags) *flags |= REF_ISBROKEN; } return refname; } if (flags) *flags |= REF_ISSYMREF; buf = buffer + 4; while (isspace(*buf)) buf++; refname = strcpy(refname_buffer, buf); if (resolve_flags & RESOLVE_REF_NO_RECURSE) { hashclr(sha1); return refname; } if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { if (flags) *flags |= REF_ISBROKEN; if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) || !refname_is_safe(buf)) { errno = EINVAL; return NULL; } bad_name = 1; } } } char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags) { return xstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags)); } /* The argument to filter_refs */ struct ref_filter { const char *pattern; each_ref_fn *fn; void *cb_data; }; int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags) { if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags)) return 0; return -1; } int read_ref(const char *refname, unsigned char *sha1) { return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL); } int ref_exists(const char *refname) { unsigned char sha1[20]; return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL); } static int filter_refs(const char *refname, const unsigned char *sha1, int flags, void *data) { struct ref_filter *filter = (struct ref_filter *)data; if (wildmatch(filter->pattern, refname, 0, NULL)) return 0; return filter->fn(refname, sha1, flags, filter->cb_data); } enum peel_status { /* object was peeled successfully: */ PEEL_PEELED = 0, /* * object cannot be peeled because the named object (or an * object referred to by a tag in the peel chain), does not * exist. */ PEEL_INVALID = -1, /* object cannot be peeled because it is not a tag: */ PEEL_NON_TAG = -2, /* ref_entry contains no peeled value because it is a symref: */ PEEL_IS_SYMREF = -3, /* * ref_entry cannot be peeled because it is broken (i.e., the * symbolic reference cannot even be resolved to an object * name): */ PEEL_BROKEN = -4 }; /* * Peel the named object; i.e., if the object is a tag, resolve the * tag recursively until a non-tag is found. If successful, store the * result to sha1 and return PEEL_PEELED. If the object is not a tag * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively, * and leave sha1 unchanged. */ static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1) { struct object *o = lookup_unknown_object(name); if (o->type == OBJ_NONE) { int type = sha1_object_info(name, NULL); if (type < 0 || !object_as_type(o, type, 0)) return PEEL_INVALID; } if (o->type != OBJ_TAG) return PEEL_NON_TAG; o = deref_tag_noverify(o); if (!o) return PEEL_INVALID; hashcpy(sha1, o->sha1); return PEEL_PEELED; } /* * Peel the entry (if possible) and return its new peel_status. If * repeel is true, re-peel the entry even if there is an old peeled * value that is already stored in it. * * It is OK to call this function with a packed reference entry that * might be stale and might even refer to an object that has since * been garbage-collected. In such a case, if the entry has * REF_KNOWS_PEELED then leave the status unchanged and return * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID. */ static enum peel_status peel_entry(struct ref_entry *entry, int repeel) { enum peel_status status; if (entry->flag & REF_KNOWS_PEELED) { if (repeel) { entry->flag &= ~REF_KNOWS_PEELED; hashclr(entry->u.value.peeled); } else { return is_null_sha1(entry->u.value.peeled) ? PEEL_NON_TAG : PEEL_PEELED; } } if (entry->flag & REF_ISBROKEN) return PEEL_BROKEN; if (entry->flag & REF_ISSYMREF) return PEEL_IS_SYMREF; status = peel_object(entry->u.value.sha1, entry->u.value.peeled); if (status == PEEL_PEELED || status == PEEL_NON_TAG) entry->flag |= REF_KNOWS_PEELED; return status; } int peel_ref(const char *refname, unsigned char *sha1) { int flag; unsigned char base[20]; if (current_ref && (current_ref->name == refname || !strcmp(current_ref->name, refname))) { if (peel_entry(current_ref, 0)) return -1; hashcpy(sha1, current_ref->u.value.peeled); return 0; } if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag)) return -1; /* * If the reference is packed, read its ref_entry from the * cache in the hope that we already know its peeled value. * We only try this optimization on packed references because * (a) forcing the filling of the loose reference cache could * be expensive and (b) loose references anyway usually do not * have REF_KNOWS_PEELED. */ if (flag & REF_ISPACKED) { struct ref_entry *r = get_packed_ref(refname); if (r) { if (peel_entry(r, 0)) return -1; hashcpy(sha1, r->u.value.peeled); return 0; } } return peel_object(base, sha1); } struct warn_if_dangling_data { FILE *fp; const char *refname; const struct string_list *refnames; const char *msg_fmt; }; static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1, int flags, void *cb_data) { struct warn_if_dangling_data *d = cb_data; const char *resolves_to; unsigned char junk[20]; if (!(flags & REF_ISSYMREF)) return 0; resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL); if (!resolves_to || (d->refname ? strcmp(resolves_to, d->refname) : !string_list_has_string(d->refnames, resolves_to))) { return 0; } fprintf(d->fp, d->msg_fmt, refname); fputc('\n', d->fp); return 0; } void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname) { struct warn_if_dangling_data data; data.fp = fp; data.refname = refname; data.refnames = NULL; data.msg_fmt = msg_fmt; for_each_rawref(warn_if_dangling_symref, &data); } void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames) { struct warn_if_dangling_data data; data.fp = fp; data.refname = NULL; data.refnames = refnames; data.msg_fmt = msg_fmt; for_each_rawref(warn_if_dangling_symref, &data); } /* * Call fn for each reference in the specified ref_cache, omitting * references not in the containing_dir of base. fn is called for all * references, including broken ones. If fn ever returns a non-zero * value, stop the iteration and return that value; otherwise, return * 0. */ static int do_for_each_entry(struct ref_cache *refs, const char *base, each_ref_entry_fn fn, void *cb_data) { struct packed_ref_cache *packed_ref_cache; struct ref_dir *loose_dir; struct ref_dir *packed_dir; int retval = 0; /* * We must make sure that all loose refs are read before accessing the * packed-refs file; this avoids a race condition in which loose refs * are migrated to the packed-refs file by a simultaneous process, but * our in-memory view is from before the migration. get_packed_ref_cache() * takes care of making sure our view is up to date with what is on * disk. */ loose_dir = get_loose_refs(refs); if (base && *base) { loose_dir = find_containing_dir(loose_dir, base, 0); } if (loose_dir) prime_ref_dir(loose_dir); packed_ref_cache = get_packed_ref_cache(refs); acquire_packed_ref_cache(packed_ref_cache); packed_dir = get_packed_ref_dir(packed_ref_cache); if (base && *base) { packed_dir = find_containing_dir(packed_dir, base, 0); } if (packed_dir && loose_dir) { sort_ref_dir(packed_dir); sort_ref_dir(loose_dir); retval = do_for_each_entry_in_dirs( packed_dir, loose_dir, fn, cb_data); } else if (packed_dir) { sort_ref_dir(packed_dir); retval = do_for_each_entry_in_dir( packed_dir, 0, fn, cb_data); } else if (loose_dir) { sort_ref_dir(loose_dir); retval = do_for_each_entry_in_dir( loose_dir, 0, fn, cb_data); } release_packed_ref_cache(packed_ref_cache); return retval; } /* * Call fn for each reference in the specified ref_cache for which the * refname begins with base. If trim is non-zero, then trim that many * characters off the beginning of each refname before passing the * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include * broken references in the iteration. If fn ever returns a non-zero * value, stop the iteration and return that value; otherwise, return * 0. */ static int do_for_each_ref(struct ref_cache *refs, const char *base, each_ref_fn fn, int trim, int flags, void *cb_data) { struct ref_entry_cb data; data.base = base; data.trim = trim; data.flags = flags; data.fn = fn; data.cb_data = cb_data; if (ref_paranoia < 0) ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0); if (ref_paranoia) data.flags |= DO_FOR_EACH_INCLUDE_BROKEN; return do_for_each_entry(refs, base, do_one_ref, &data); } static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data) { unsigned char sha1[20]; int flag; if (submodule) { if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0) return fn("HEAD", sha1, 0, cb_data); return 0; } if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag)) return fn("HEAD", sha1, flag, cb_data); return 0; } int head_ref(each_ref_fn fn, void *cb_data) { return do_head_ref(NULL, fn, cb_data); } int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { return do_head_ref(submodule, fn, cb_data); } int for_each_ref(each_ref_fn fn, void *cb_data) { return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data); } int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data); } int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data) { return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data); } int for_each_ref_in_submodule(const char *submodule, const char *prefix, each_ref_fn fn, void *cb_data) { return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data); } int for_each_tag_ref(each_ref_fn fn, void *cb_data) { return for_each_ref_in("refs/tags/", fn, cb_data); } int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data); } int for_each_branch_ref(each_ref_fn fn, void *cb_data) { return for_each_ref_in("refs/heads/", fn, cb_data); } int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data); } int for_each_remote_ref(each_ref_fn fn, void *cb_data) { return for_each_ref_in("refs/remotes/", fn, cb_data); } int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) { return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data); } int for_each_replace_ref(each_ref_fn fn, void *cb_data) { return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data); } int head_ref_namespaced(each_ref_fn fn, void *cb_data) { struct strbuf buf = STRBUF_INIT; int ret = 0; unsigned char sha1[20]; int flag; strbuf_addf(&buf, "%sHEAD", get_git_namespace()); if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag)) ret = fn(buf.buf, sha1, flag, cb_data); strbuf_release(&buf); return ret; } int for_each_namespaced_ref(each_ref_fn fn, void *cb_data) { struct strbuf buf = STRBUF_INIT; int ret; strbuf_addf(&buf, "%srefs/", get_git_namespace()); ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data); strbuf_release(&buf); return ret; } int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, const char *prefix, void *cb_data) { struct strbuf real_pattern = STRBUF_INIT; struct ref_filter filter; int ret; if (!prefix && !starts_with(pattern, "refs/")) strbuf_addstr(&real_pattern, "refs/"); else if (prefix) strbuf_addstr(&real_pattern, prefix); strbuf_addstr(&real_pattern, pattern); if (!has_glob_specials(pattern)) { /* Append implied '/' '*' if not present. */ if (real_pattern.buf[real_pattern.len - 1] != '/') strbuf_addch(&real_pattern, '/'); /* No need to check for '*', there is none. */ strbuf_addch(&real_pattern, '*'); } filter.pattern = real_pattern.buf; filter.fn = fn; filter.cb_data = cb_data; ret = for_each_ref(filter_refs, &filter); strbuf_release(&real_pattern); return ret; } int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data) { return for_each_glob_ref_in(fn, pattern, NULL, cb_data); } int for_each_rawref(each_ref_fn fn, void *cb_data) { return do_for_each_ref(&ref_cache, "", fn, 0, DO_FOR_EACH_INCLUDE_BROKEN, cb_data); } const char *prettify_refname(const char *name) { return name + ( starts_with(name, "refs/heads/") ? 11 : starts_with(name, "refs/tags/") ? 10 : starts_with(name, "refs/remotes/") ? 13 : 0); } static const char *ref_rev_parse_rules[] = { "%.*s", "refs/%.*s", "refs/tags/%.*s", "refs/heads/%.*s", "refs/remotes/%.*s", "refs/remotes/%.*s/HEAD", NULL }; int refname_match(const char *abbrev_name, const char *full_name) { const char **p; const int abbrev_name_len = strlen(abbrev_name); for (p = ref_rev_parse_rules; *p; p++) { if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { return 1; } } return 0; } static void unlock_ref(struct ref_lock *lock) { /* Do not free lock->lk -- atexit() still looks at them */ if (lock->lk) rollback_lock_file(lock->lk); free(lock->ref_name); free(lock->orig_ref_name); free(lock); } /* This function should make sure errno is meaningful on error */ static struct ref_lock *verify_lock(struct ref_lock *lock, const unsigned char *old_sha1, int mustexist) { if (read_ref_full(lock->ref_name, mustexist ? RESOLVE_REF_READING : 0, lock->old_sha1, NULL)) { int save_errno = errno; error("Can't verify ref %s", lock->ref_name); unlock_ref(lock); errno = save_errno; return NULL; } if (hashcmp(lock->old_sha1, old_sha1)) { error("Ref %s is at %s but expected %s", lock->ref_name, sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1)); unlock_ref(lock); errno = EBUSY; return NULL; } return lock; } static int remove_empty_directories(const char *file) { /* we want to create a file but there is a directory there; * if that is an empty directory (or a directory that contains * only empty directories), remove them. */ struct strbuf path; int result, save_errno; strbuf_init(&path, 20); strbuf_addstr(&path, file); result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY); save_errno = errno; strbuf_release(&path); errno = save_errno; return result; } /* * *string and *len will only be substituted, and *string returned (for * later free()ing) if the string passed in is a magic short-hand form * to name a branch. */ static char *substitute_branch_name(const char **string, int *len) { struct strbuf buf = STRBUF_INIT; int ret = interpret_branch_name(*string, *len, &buf); if (ret == *len) { size_t size; *string = strbuf_detach(&buf, &size); *len = size; return (char *)*string; } return NULL; } int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref) { char *last_branch = substitute_branch_name(&str, &len); const char **p, *r; int refs_found = 0; *ref = NULL; for (p = ref_rev_parse_rules; *p; p++) { char fullref[PATH_MAX]; unsigned char sha1_from_ref[20]; unsigned char *this_result; int flag; this_result = refs_found ? sha1_from_ref : sha1; mksnpath(fullref, sizeof(fullref), *p, len, str); r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING, this_result, &flag); if (r) { if (!refs_found++) *ref = xstrdup(r); if (!warn_ambiguous_refs) break; } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) { warning("ignoring dangling symref %s.", fullref); } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) { warning("ignoring broken ref %s.", fullref); } } free(last_branch); return refs_found; } int dwim_log(const char *str, int len, unsigned char *sha1, char **log) { char *last_branch = substitute_branch_name(&str, &len); const char **p; int logs_found = 0; *log = NULL; for (p = ref_rev_parse_rules; *p; p++) { unsigned char hash[20]; char path[PATH_MAX]; const char *ref, *it; mksnpath(path, sizeof(path), *p, len, str); ref = resolve_ref_unsafe(path, RESOLVE_REF_READING, hash, NULL); if (!ref) continue; if (reflog_exists(path)) it = path; else if (strcmp(ref, path) && reflog_exists(ref)) it = ref; else continue; if (!logs_found++) { *log = xstrdup(it); hashcpy(sha1, hash); } if (!warn_ambiguous_refs) break; } free(last_branch); return logs_found; } /* * Locks a ref returning the lock on success and NULL on failure. * On failure errno is set to something meaningful. */ static struct ref_lock *lock_ref_sha1_basic(const char *refname, const unsigned char *old_sha1, const struct string_list *extras, const struct string_list *skip, unsigned int flags, int *type_p, struct strbuf *err) { char *ref_file; const char *orig_refname = refname; struct ref_lock *lock; int last_errno = 0; int type, lflags; int mustexist = (old_sha1 && !is_null_sha1(old_sha1)); int resolve_flags = 0; int attempts_remaining = 3; assert(err); lock = xcalloc(1, sizeof(struct ref_lock)); lock->lock_fd = -1; if (mustexist) resolve_flags |= RESOLVE_REF_READING; if (flags & REF_DELETING) { resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME; if (flags & REF_NODEREF) resolve_flags |= RESOLVE_REF_NO_RECURSE; } refname = resolve_ref_unsafe(refname, resolve_flags, lock->old_sha1, &type); if (!refname && errno == EISDIR) { /* we are trying to lock foo but we used to * have foo/bar which now does not exist; * it is normal for the empty directory 'foo' * to remain. */ ref_file = git_path("%s", orig_refname); if (remove_empty_directories(ref_file)) { last_errno = errno; if (!verify_refname_available(orig_refname, extras, skip, get_loose_refs(&ref_cache), err)) strbuf_addf(err, "there are still refs under '%s'", orig_refname); goto error_return; } refname = resolve_ref_unsafe(orig_refname, resolve_flags, lock->old_sha1, &type); } if (type_p) *type_p = type; if (!refname) { last_errno = errno; if (last_errno != ENOTDIR || !verify_refname_available(orig_refname, extras, skip, get_loose_refs(&ref_cache), err)) strbuf_addf(err, "unable to resolve reference %s: %s", orig_refname, strerror(last_errno)); goto error_return; } /* * If the ref did not exist and we are creating it, make sure * there is no existing packed ref whose name begins with our * refname, nor a packed ref whose name is a proper prefix of * our refname. */ if (is_null_sha1(lock->old_sha1) && verify_refname_available(refname, extras, skip, get_packed_refs(&ref_cache), err)) { last_errno = ENOTDIR; goto error_return; } lock->lk = xcalloc(1, sizeof(struct lock_file)); lflags = 0; if (flags & REF_NODEREF) { refname = orig_refname; lflags |= LOCK_NO_DEREF; } lock->ref_name = xstrdup(refname); lock->orig_ref_name = xstrdup(orig_refname); ref_file = git_path("%s", refname); retry: switch (safe_create_leading_directories(ref_file)) { case SCLD_OK: break; /* success */ case SCLD_VANISHED: if (--attempts_remaining > 0) goto retry; /* fall through */ default: last_errno = errno; strbuf_addf(err, "unable to create directory for %s", ref_file); goto error_return; } lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags); if (lock->lock_fd < 0) { last_errno = errno; if (errno == ENOENT && --attempts_remaining > 0) /* * Maybe somebody just deleted one of the * directories leading to ref_file. Try * again: */ goto retry; else { unable_to_lock_message(ref_file, errno, err); goto error_return; } } return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock; error_return: unlock_ref(lock); errno = last_errno; return NULL; } /* * Write an entry to the packed-refs file for the specified refname. * If peeled is non-NULL, write it as the entry's peeled value. */ static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1, unsigned char *peeled) { fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname); if (peeled) fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled)); } /* * An each_ref_entry_fn that writes the entry to a packed-refs file. */ static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data) { enum peel_status peel_status = peel_entry(entry, 0); if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) error("internal error: %s is not a valid packed reference!", entry->name); write_packed_entry(cb_data, entry->name, entry->u.value.sha1, peel_status == PEEL_PEELED ? entry->u.value.peeled : NULL); return 0; } /* This should return a meaningful errno on failure */ int lock_packed_refs(int flags) { struct packed_ref_cache *packed_ref_cache; if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0) return -1; /* * Get the current packed-refs while holding the lock. If the * packed-refs file has been modified since we last read it, * this will automatically invalidate the cache and re-read * the packed-refs file. */ packed_ref_cache = get_packed_ref_cache(&ref_cache); packed_ref_cache->lock = &packlock; /* Increment the reference count to prevent it from being freed: */ acquire_packed_ref_cache(packed_ref_cache); return 0; } /* * Commit the packed refs changes. * On error we must make sure that errno contains a meaningful value. */ int commit_packed_refs(void) { struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(&ref_cache); int error = 0; int save_errno = 0; FILE *out; if (!packed_ref_cache->lock) die("internal error: packed-refs not locked"); out = fdopen_lock_file(packed_ref_cache->lock, "w"); if (!out) die_errno("unable to fdopen packed-refs descriptor"); fprintf_or_die(out, "%s", PACKED_REFS_HEADER); do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), 0, write_packed_entry_fn, out); if (commit_lock_file(packed_ref_cache->lock)) { save_errno = errno; error = -1; } packed_ref_cache->lock = NULL; release_packed_ref_cache(packed_ref_cache); errno = save_errno; return error; } void rollback_packed_refs(void) { struct packed_ref_cache *packed_ref_cache = get_packed_ref_cache(&ref_cache); if (!packed_ref_cache->lock) die("internal error: packed-refs not locked"); rollback_lock_file(packed_ref_cache->lock); packed_ref_cache->lock = NULL; release_packed_ref_cache(packed_ref_cache); clear_packed_ref_cache(&ref_cache); } struct ref_to_prune { struct ref_to_prune *next; unsigned char sha1[20]; char name[FLEX_ARRAY]; }; struct pack_refs_cb_data { unsigned int flags; struct ref_dir *packed_refs; struct ref_to_prune *ref_to_prune; }; /* * An each_ref_entry_fn that is run over loose references only. If * the loose reference can be packed, add an entry in the packed ref * cache. If the reference should be pruned, also add it to * ref_to_prune in the pack_refs_cb_data. */ static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data) { struct pack_refs_cb_data *cb = cb_data; enum peel_status peel_status; struct ref_entry *packed_entry; int is_tag_ref = starts_with(entry->name, "refs/tags/"); /* ALWAYS pack tags */ if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) return 0; /* Do not pack symbolic or broken refs: */ if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry)) return 0; /* Add a packed ref cache entry equivalent to the loose entry. */ peel_status = peel_entry(entry, 1); if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG) die("internal error peeling reference %s (%s)", entry->name, sha1_to_hex(entry->u.value.sha1)); packed_entry = find_ref(cb->packed_refs, entry->name); if (packed_entry) { /* Overwrite existing packed entry with info from loose entry */ packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED; hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1); } else { packed_entry = create_ref_entry(entry->name, entry->u.value.sha1, REF_ISPACKED | REF_KNOWS_PEELED, 0); add_ref(cb->packed_refs, packed_entry); } hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled); /* Schedule the loose reference for pruning if requested. */ if ((cb->flags & PACK_REFS_PRUNE)) { int namelen = strlen(entry->name) + 1; struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen); hashcpy(n->sha1, entry->u.value.sha1); strcpy(n->name, entry->name); n->next = cb->ref_to_prune; cb->ref_to_prune = n; } return 0; } /* * Remove empty parents, but spare refs/ and immediate subdirs. * Note: munges *name. */ static void try_remove_empty_parents(char *name) { char *p, *q; int i; p = name; for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */ while (*p && *p != '/') p++; /* tolerate duplicate slashes; see check_refname_format() */ while (*p == '/') p++; } for (q = p; *q; q++) ; while (1) { while (q > p && *q != '/') q--; while (q > p && *(q-1) == '/') q--; if (q == p) break; *q = '\0'; if (rmdir(git_path("%s", name))) break; } } /* make sure nobody touched the ref, and unlink */ static void prune_ref(struct ref_to_prune *r) { struct ref_transaction *transaction; struct strbuf err = STRBUF_INIT; if (check_refname_format(r->name, 0)) return; transaction = ref_transaction_begin(&err); if (!transaction || ref_transaction_delete(transaction, r->name, r->sha1, REF_ISPRUNING, NULL, &err) || ref_transaction_commit(transaction, &err)) { ref_transaction_free(transaction); error("%s", err.buf); strbuf_release(&err); return; } ref_transaction_free(transaction); strbuf_release(&err); try_remove_empty_parents(r->name); } static void prune_refs(struct ref_to_prune *r) { while (r) { prune_ref(r); r = r->next; } } int pack_refs(unsigned int flags) { struct pack_refs_cb_data cbdata; memset(&cbdata, 0, sizeof(cbdata)); cbdata.flags = flags; lock_packed_refs(LOCK_DIE_ON_ERROR); cbdata.packed_refs = get_packed_refs(&ref_cache); do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0, pack_if_possible_fn, &cbdata); if (commit_packed_refs()) die_errno("unable to overwrite old ref-pack file"); prune_refs(cbdata.ref_to_prune); return 0; } int repack_without_refs(struct string_list *refnames, struct strbuf *err) { struct ref_dir *packed; struct string_list_item *refname; int ret, needs_repacking = 0, removed = 0; assert(err); /* Look for a packed ref */ for_each_string_list_item(refname, refnames) { if (get_packed_ref(refname->string)) { needs_repacking = 1; break; } } /* Avoid locking if we have nothing to do */ if (!needs_repacking) return 0; /* no refname exists in packed refs */ if (lock_packed_refs(0)) { unable_to_lock_message(git_path("packed-refs"), errno, err); return -1; } packed = get_packed_refs(&ref_cache); /* Remove refnames from the cache */ for_each_string_list_item(refname, refnames) if (remove_entry(packed, refname->string) != -1) removed = 1; if (!removed) { /* * All packed entries disappeared while we were * acquiring the lock. */ rollback_packed_refs(); return 0; } /* Write what remains */ ret = commit_packed_refs(); if (ret) strbuf_addf(err, "unable to overwrite old ref-pack file: %s", strerror(errno)); return ret; } static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err) { assert(err); if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { /* * loose. The loose file name is the same as the * lockfile name, minus ".lock": */ char *loose_filename = get_locked_file_path(lock->lk); int res = unlink_or_msg(loose_filename, err); free(loose_filename); if (res) return 1; } return 0; } int delete_ref(const char *refname, const unsigned char *sha1, unsigned int flags) { struct ref_transaction *transaction; struct strbuf err = STRBUF_INIT; transaction = ref_transaction_begin(&err); if (!transaction || ref_transaction_delete(transaction, refname, (sha1 && !is_null_sha1(sha1)) ? sha1 : NULL, flags, NULL, &err) || ref_transaction_commit(transaction, &err)) { error("%s", err.buf); ref_transaction_free(transaction); strbuf_release(&err); return 1; } ref_transaction_free(transaction); strbuf_release(&err); return 0; } /* * People using contrib's git-new-workdir have .git/logs/refs -> * /some/other/path/.git/logs/refs, and that may live on another device. * * IOW, to avoid cross device rename errors, the temporary renamed log must * live into logs/refs. */ #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log" static int rename_tmp_log(const char *newrefname) { int attempts_remaining = 4; retry: switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) { case SCLD_OK: break; /* success */ case SCLD_VANISHED: if (--attempts_remaining > 0) goto retry; /* fall through */ default: error("unable to create directory for %s", newrefname); return -1; } if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) { if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) { /* * rename(a, b) when b is an existing * directory ought to result in ISDIR, but * Solaris 5.8 gives ENOTDIR. Sheesh. */ if (remove_empty_directories(git_path("logs/%s", newrefname))) { error("Directory not empty: logs/%s", newrefname); return -1; } goto retry; } else if (errno == ENOENT && --attempts_remaining > 0) { /* * Maybe another process just deleted one of * the directories in the path to newrefname. * Try again from the beginning. */ goto retry; } else { error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", newrefname, strerror(errno)); return -1; } } return 0; } static int rename_ref_available(const char *oldname, const char *newname) { struct string_list skip = STRING_LIST_INIT_NODUP; struct strbuf err = STRBUF_INIT; int ret; string_list_insert(&skip, oldname); ret = !verify_refname_available(newname, NULL, &skip, get_packed_refs(&ref_cache), &err) && !verify_refname_available(newname, NULL, &skip, get_loose_refs(&ref_cache), &err); if (!ret) error("%s", err.buf); string_list_clear(&skip, 0); strbuf_release(&err); return ret; } static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *logmsg); int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg) { unsigned char sha1[20], orig_sha1[20]; int flag = 0, logmoved = 0; struct ref_lock *lock; struct stat loginfo; int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); const char *symref = NULL; struct strbuf err = STRBUF_INIT; if (log && S_ISLNK(loginfo.st_mode)) return error("reflog for %s is a symlink", oldrefname); symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, orig_sha1, &flag); if (flag & REF_ISSYMREF) return error("refname %s is a symbolic ref, renaming it is not supported", oldrefname); if (!symref) return error("refname %s not found", oldrefname); if (!rename_ref_available(oldrefname, newrefname)) return 1; if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG))) return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s", oldrefname, strerror(errno)); if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) { error("unable to delete old %s", oldrefname); goto rollback; } if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) && delete_ref(newrefname, sha1, REF_NODEREF)) { if (errno==EISDIR) { if (remove_empty_directories(git_path("%s", newrefname))) { error("Directory not empty: %s", newrefname); goto rollback; } } else { error("unable to delete existing %s", newrefname); goto rollback; } } if (log && rename_tmp_log(newrefname)) goto rollback; logmoved = log; lock = lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, 0, NULL, &err); if (!lock) { error("unable to rename '%s' to '%s': %s", oldrefname, newrefname, err.buf); strbuf_release(&err); goto rollback; } hashcpy(lock->old_sha1, orig_sha1); if (write_ref_sha1(lock, orig_sha1, logmsg)) { error("unable to write current sha1 into %s", newrefname); goto rollback; } return 0; rollback: lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, 0, NULL, &err); if (!lock) { error("unable to lock %s for rollback: %s", oldrefname, err.buf); strbuf_release(&err); goto rollbacklog; } flag = log_all_ref_updates; log_all_ref_updates = 0; if (write_ref_sha1(lock, orig_sha1, NULL)) error("unable to write current sha1 into %s", oldrefname); log_all_ref_updates = flag; rollbacklog: if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname))) error("unable to restore logfile %s from %s: %s", oldrefname, newrefname, strerror(errno)); if (!logmoved && log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname))) error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s", oldrefname, strerror(errno)); return 1; } static int close_ref(struct ref_lock *lock) { if (close_lock_file(lock->lk)) return -1; lock->lock_fd = -1; return 0; } static int commit_ref(struct ref_lock *lock) { if (commit_lock_file(lock->lk)) return -1; lock->lock_fd = -1; return 0; } /* * copy the reflog message msg to buf, which has been allocated sufficiently * large, while cleaning up the whitespaces. Especially, convert LF to space, * because reflog file is one line per entry. */ static int copy_msg(char *buf, const char *msg) { char *cp = buf; char c; int wasspace = 1; *cp++ = '\t'; while ((c = *msg++)) { if (wasspace && isspace(c)) continue; wasspace = isspace(c); if (wasspace) c = ' '; *cp++ = c; } while (buf < cp && isspace(cp[-1])) cp--; *cp++ = '\n'; return cp - buf; } /* This function must set a meaningful errno on failure */ int log_ref_setup(const char *refname, char *logfile, int bufsize) { int logfd, oflags = O_APPEND | O_WRONLY; git_snpath(logfile, bufsize, "logs/%s", refname); if (log_all_ref_updates && (starts_with(refname, "refs/heads/") || starts_with(refname, "refs/remotes/") || starts_with(refname, "refs/notes/") || !strcmp(refname, "HEAD"))) { if (safe_create_leading_directories(logfile) < 0) { int save_errno = errno; error("unable to create directory for %s", logfile); errno = save_errno; return -1; } oflags |= O_CREAT; } logfd = open(logfile, oflags, 0666); if (logfd < 0) { if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR)) return 0; if (errno == EISDIR) { if (remove_empty_directories(logfile)) { int save_errno = errno; error("There are still logs under '%s'", logfile); errno = save_errno; return -1; } logfd = open(logfile, oflags, 0666); } if (logfd < 0) { int save_errno = errno; error("Unable to append to %s: %s", logfile, strerror(errno)); errno = save_errno; return -1; } } adjust_shared_perm(logfile); close(logfd); return 0; } static int log_ref_write_fd(int fd, const unsigned char *old_sha1, const unsigned char *new_sha1, const char *committer, const char *msg) { int msglen, written; unsigned maxlen, len; char *logrec; msglen = msg ? strlen(msg) : 0; maxlen = strlen(committer) + msglen + 100; logrec = xmalloc(maxlen); len = sprintf(logrec, "%s %s %s\n", sha1_to_hex(old_sha1), sha1_to_hex(new_sha1), committer); if (msglen) len += copy_msg(logrec + len - 1, msg) - 1; written = len <= maxlen ? write_in_full(fd, logrec, len) : -1; free(logrec); if (written != len) return -1; return 0; } static int log_ref_write(const char *refname, const unsigned char *old_sha1, const unsigned char *new_sha1, const char *msg) { int logfd, result, oflags = O_APPEND | O_WRONLY; char log_file[PATH_MAX]; if (log_all_ref_updates < 0) log_all_ref_updates = !is_bare_repository(); result = log_ref_setup(refname, log_file, sizeof(log_file)); if (result) return result; logfd = open(log_file, oflags); if (logfd < 0) return 0; result = log_ref_write_fd(logfd, old_sha1, new_sha1, git_committer_info(0), msg); if (result) { int save_errno = errno; close(logfd); error("Unable to append to %s", log_file); errno = save_errno; return -1; } if (close(logfd)) { int save_errno = errno; error("Unable to append to %s", log_file); errno = save_errno; return -1; } return 0; } int is_branch(const char *refname) { return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/"); } /* * Write sha1 into the ref specified by the lock. Make sure that errno * is sane on error. */ static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *logmsg) { static char term = '\n'; struct object *o; o = parse_object(sha1); if (!o) { error("Trying to write ref %s with nonexistent object %s", lock->ref_name, sha1_to_hex(sha1)); unlock_ref(lock); errno = EINVAL; return -1; } if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) { error("Trying to write non-commit object %s to branch %s", sha1_to_hex(sha1), lock->ref_name); unlock_ref(lock); errno = EINVAL; return -1; } if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 || write_in_full(lock->lock_fd, &term, 1) != 1 || close_ref(lock) < 0) { int save_errno = errno; error("Couldn't write %s", lock->lk->filename.buf); unlock_ref(lock); errno = save_errno; return -1; } clear_loose_ref_cache(&ref_cache); if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 || (strcmp(lock->ref_name, lock->orig_ref_name) && log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) { unlock_ref(lock); return -1; } if (strcmp(lock->orig_ref_name, "HEAD") != 0) { /* * Special hack: If a branch is updated directly and HEAD * points to it (may happen on the remote side of a push * for example) then logically the HEAD reflog should be * updated too. * A generic solution implies reverse symref information, * but finding all symrefs pointing to the given branch * would be rather costly for this rare event (the direct * update of a branch) to be worth it. So let's cheat and * check with HEAD only which should cover 99% of all usage * scenarios (even 100% of the default ones). */ unsigned char head_sha1[20]; int head_flag; const char *head_ref; head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING, head_sha1, &head_flag); if (head_ref && (head_flag & REF_ISSYMREF) && !strcmp(head_ref, lock->ref_name)) log_ref_write("HEAD", lock->old_sha1, sha1, logmsg); } if (commit_ref(lock)) { error("Couldn't set %s", lock->ref_name); unlock_ref(lock); return -1; } unlock_ref(lock); return 0; } int create_symref(const char *ref_target, const char *refs_heads_master, const char *logmsg) { const char *lockpath; char ref[1000]; int fd, len, written; char *git_HEAD = git_pathdup("%s", ref_target); unsigned char old_sha1[20], new_sha1[20]; if (logmsg && read_ref(ref_target, old_sha1)) hashclr(old_sha1); if (safe_create_leading_directories(git_HEAD) < 0) return error("unable to create directory for %s", git_HEAD); #ifndef NO_SYMLINK_HEAD if (prefer_symlink_refs) { unlink(git_HEAD); if (!symlink(refs_heads_master, git_HEAD)) goto done; fprintf(stderr, "no symlink - falling back to symbolic ref\n"); } #endif len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master); if (sizeof(ref) <= len) { error("refname too long: %s", refs_heads_master); goto error_free_return; } lockpath = mkpath("%s.lock", git_HEAD); fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666); if (fd < 0) { error("Unable to open %s for writing", lockpath); goto error_free_return; } written = write_in_full(fd, ref, len); if (close(fd) != 0 || written != len) { error("Unable to write to %s", lockpath); goto error_unlink_return; } if (rename(lockpath, git_HEAD) < 0) { error("Unable to create %s", git_HEAD); goto error_unlink_return; } if (adjust_shared_perm(git_HEAD)) { error("Unable to fix permissions on %s", lockpath); error_unlink_return: unlink_or_warn(lockpath); error_free_return: free(git_HEAD); return -1; } #ifndef NO_SYMLINK_HEAD done: #endif if (logmsg && !read_ref(refs_heads_master, new_sha1)) log_ref_write(ref_target, old_sha1, new_sha1, logmsg); free(git_HEAD); return 0; } struct read_ref_at_cb { const char *refname; unsigned long at_time; int cnt; int reccnt; unsigned char *sha1; int found_it; unsigned char osha1[20]; unsigned char nsha1[20]; int tz; unsigned long date; char **msg; unsigned long *cutoff_time; int *cutoff_tz; int *cutoff_cnt; }; static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1, const char *email, unsigned long timestamp, int tz, const char *message, void *cb_data) { struct read_ref_at_cb *cb = cb_data; cb->reccnt++; cb->tz = tz; cb->date = timestamp; if (timestamp <= cb->at_time || cb->cnt == 0) { if (cb->msg) *cb->msg = xstrdup(message); if (cb->cutoff_time) *cb->cutoff_time = timestamp; if (cb->cutoff_tz) *cb->cutoff_tz = tz; if (cb->cutoff_cnt) *cb->cutoff_cnt = cb->reccnt - 1; /* * we have not yet updated cb->[n|o]sha1 so they still * hold the values for the previous record. */ if (!is_null_sha1(cb->osha1)) { hashcpy(cb->sha1, nsha1); if (hashcmp(cb->osha1, nsha1)) warning("Log for ref %s has gap after %s.", cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822)); } else if (cb->date == cb->at_time) hashcpy(cb->sha1, nsha1); else if (hashcmp(nsha1, cb->sha1)) warning("Log for ref %s unexpectedly ended on %s.", cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822)); hashcpy(cb->osha1, osha1); hashcpy(cb->nsha1, nsha1); cb->found_it = 1; return 1; } hashcpy(cb->osha1, osha1); hashcpy(cb->nsha1, nsha1); if (cb->cnt > 0) cb->cnt--; return 0; } static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1, const char *email, unsigned long timestamp, int tz, const char *message, void *cb_data) { struct read_ref_at_cb *cb = cb_data; if (cb->msg) *cb->msg = xstrdup(message); if (cb->cutoff_time) *cb->cutoff_time = timestamp; if (cb->cutoff_tz) *cb->cutoff_tz = tz; if (cb->cutoff_cnt) *cb->cutoff_cnt = cb->reccnt; hashcpy(cb->sha1, osha1); if (is_null_sha1(cb->sha1)) hashcpy(cb->sha1, nsha1); /* We just want the first entry */ return 1; } int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt) { struct read_ref_at_cb cb; memset(&cb, 0, sizeof(cb)); cb.refname = refname; cb.at_time = at_time; cb.cnt = cnt; cb.msg = msg; cb.cutoff_time = cutoff_time; cb.cutoff_tz = cutoff_tz; cb.cutoff_cnt = cutoff_cnt; cb.sha1 = sha1; for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb); if (!cb.reccnt) { if (flags & GET_SHA1_QUIETLY) exit(128); else die("Log for %s is empty.", refname); } if (cb.found_it) return 0; for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb); return 1; } int reflog_exists(const char *refname) { struct stat st; return !lstat(git_path("logs/%s", refname), &st) && S_ISREG(st.st_mode); } int delete_reflog(const char *refname) { return remove_path(git_path("logs/%s", refname)); } static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data) { unsigned char osha1[20], nsha1[20]; char *email_end, *message; unsigned long timestamp; int tz; /* old SP new SP name SP time TAB msg LF */ if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' || get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' || get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' || !(email_end = strchr(sb->buf + 82, '>')) || email_end[1] != ' ' || !(timestamp = strtoul(email_end + 2, &message, 10)) || !message || message[0] != ' ' || (message[1] != '+' && message[1] != '-') || !isdigit(message[2]) || !isdigit(message[3]) || !isdigit(message[4]) || !isdigit(message[5])) return 0; /* corrupt? */ email_end[1] = '\0'; tz = strtol(message + 1, NULL, 10); if (message[6] != '\t') message += 6; else message += 7; return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data); } static char *find_beginning_of_line(char *bob, char *scan) { while (bob < scan && *(--scan) != '\n') ; /* keep scanning backwards */ /* * Return either beginning of the buffer, or LF at the end of * the previous line. */ return scan; } int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data) { struct strbuf sb = STRBUF_INIT; FILE *logfp; long pos; int ret = 0, at_tail = 1; logfp = fopen(git_path("logs/%s", refname), "r"); if (!logfp) return -1; /* Jump to the end */ if (fseek(logfp, 0, SEEK_END) < 0) return error("cannot seek back reflog for %s: %s", refname, strerror(errno)); pos = ftell(logfp); while (!ret && 0 < pos) { int cnt; size_t nread; char buf[BUFSIZ]; char *endp, *scanp; /* Fill next block from the end */ cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos; if (fseek(logfp, pos - cnt, SEEK_SET)) return error("cannot seek back reflog for %s: %s", refname, strerror(errno)); nread = fread(buf, cnt, 1, logfp); if (nread != 1) return error("cannot read %d bytes from reflog for %s: %s", cnt, refname, strerror(errno)); pos -= cnt; scanp = endp = buf + cnt; if (at_tail && scanp[-1] == '\n') /* Looking at the final LF at the end of the file */ scanp--; at_tail = 0; while (buf < scanp) { /* * terminating LF of the previous line, or the beginning * of the buffer. */ char *bp; bp = find_beginning_of_line(buf, scanp); if (*bp == '\n') { /* * The newline is the end of the previous line, * so we know we have complete line starting * at (bp + 1). Prefix it onto any prior data * we collected for the line and process it. */ strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1)); scanp = bp; endp = bp + 1; ret = show_one_reflog_ent(&sb, fn, cb_data); strbuf_reset(&sb); if (ret) break; } else if (!pos) { /* * We are at the start of the buffer, and the * start of the file; there is no previous * line, and we have everything for this one. * Process it, and we can end the loop. */ strbuf_splice(&sb, 0, 0, buf, endp - buf); ret = show_one_reflog_ent(&sb, fn, cb_data); strbuf_reset(&sb); break; } if (bp == buf) { /* * We are at the start of the buffer, and there * is more file to read backwards. Which means * we are in the middle of a line. Note that we * may get here even if *bp was a newline; that * just means we are at the exact end of the * previous line, rather than some spot in the * middle. * * Save away what we have to be combined with * the data from the next read. */ strbuf_splice(&sb, 0, 0, buf, endp - buf); break; } } } if (!ret && sb.len) die("BUG: reverse reflog parser had leftover data"); fclose(logfp); strbuf_release(&sb); return ret; } int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data) { FILE *logfp; struct strbuf sb = STRBUF_INIT; int ret = 0; logfp = fopen(git_path("logs/%s", refname), "r"); if (!logfp) return -1; while (!ret && !strbuf_getwholeline(&sb, logfp, '\n')) ret = show_one_reflog_ent(&sb, fn, cb_data); fclose(logfp); strbuf_release(&sb); return ret; } /* * Call fn for each reflog in the namespace indicated by name. name * must be empty or end with '/'. Name will be used as a scratch * space, but its contents will be restored before return. */ static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data) { DIR *d = opendir(git_path("logs/%s", name->buf)); int retval = 0; struct dirent *de; int oldlen = name->len; if (!d) return name->len ? errno : 0; while ((de = readdir(d)) != NULL) { struct stat st; if (de->d_name[0] == '.') continue; if (ends_with(de->d_name, ".lock")) continue; strbuf_addstr(name, de->d_name); if (stat(git_path("logs/%s", name->buf), &st) < 0) { ; /* silently ignore */ } else { if (S_ISDIR(st.st_mode)) { strbuf_addch(name, '/'); retval = do_for_each_reflog(name, fn, cb_data); } else { unsigned char sha1[20]; if (read_ref_full(name->buf, 0, sha1, NULL)) retval = error("bad ref for %s", name->buf); else retval = fn(name->buf, sha1, 0, cb_data); } if (retval) break; } strbuf_setlen(name, oldlen); } closedir(d); return retval; } int for_each_reflog(each_ref_fn fn, void *cb_data) { int retval; struct strbuf name; strbuf_init(&name, PATH_MAX); retval = do_for_each_reflog(&name, fn, cb_data); strbuf_release(&name); return retval; } /** * Information needed for a single ref update. Set new_sha1 to the new * value or to null_sha1 to delete the ref. To check the old value * while the ref is locked, set (flags & REF_HAVE_OLD) and set * old_sha1 to the old value, or to null_sha1 to ensure the ref does * not exist before update. */ struct ref_update { /* * If (flags & REF_HAVE_NEW), set the reference to this value: */ unsigned char new_sha1[20]; /* * If (flags & REF_HAVE_OLD), check that the reference * previously had this value: */ unsigned char old_sha1[20]; /* * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF, * REF_DELETING, and REF_ISPRUNING: */ unsigned int flags; struct ref_lock *lock; int type; char *msg; const char refname[FLEX_ARRAY]; }; /* * Transaction states. * OPEN: The transaction is in a valid state and can accept new updates. * An OPEN transaction can be committed. * CLOSED: A closed transaction is no longer active and no other operations * than free can be used on it in this state. * A transaction can either become closed by successfully committing * an active transaction or if there is a failure while building * the transaction thus rendering it failed/inactive. */ enum ref_transaction_state { REF_TRANSACTION_OPEN = 0, REF_TRANSACTION_CLOSED = 1 }; /* * Data structure for holding a reference transaction, which can * consist of checks and updates to multiple references, carried out * as atomically as possible. This structure is opaque to callers. */ struct ref_transaction { struct ref_update **updates; size_t alloc; size_t nr; enum ref_transaction_state state; }; struct ref_transaction *ref_transaction_begin(struct strbuf *err) { assert(err); return xcalloc(1, sizeof(struct ref_transaction)); } void ref_transaction_free(struct ref_transaction *transaction) { int i; if (!transaction) return; for (i = 0; i < transaction->nr; i++) { free(transaction->updates[i]->msg); free(transaction->updates[i]); } free(transaction->updates); free(transaction); } static struct ref_update *add_update(struct ref_transaction *transaction, const char *refname) { size_t len = strlen(refname); struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1); strcpy((char *)update->refname, refname); ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc); transaction->updates[transaction->nr++] = update; return update; } int ref_transaction_update(struct ref_transaction *transaction, const char *refname, const unsigned char *new_sha1, const unsigned char *old_sha1, unsigned int flags, const char *msg, struct strbuf *err) { struct ref_update *update; assert(err); if (transaction->state != REF_TRANSACTION_OPEN) die("BUG: update called for transaction that is not open"); if (new_sha1 && !is_null_sha1(new_sha1) && check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) { strbuf_addf(err, "refusing to update ref with bad name %s", refname); return -1; } update = add_update(transaction, refname); if (new_sha1) { hashcpy(update->new_sha1, new_sha1); flags |= REF_HAVE_NEW; } if (old_sha1) { hashcpy(update->old_sha1, old_sha1); flags |= REF_HAVE_OLD; } update->flags = flags; if (msg) update->msg = xstrdup(msg); return 0; } int ref_transaction_create(struct ref_transaction *transaction, const char *refname, const unsigned char *new_sha1, unsigned int flags, const char *msg, struct strbuf *err) { if (!new_sha1 || is_null_sha1(new_sha1)) die("BUG: create called without valid new_sha1"); return ref_transaction_update(transaction, refname, new_sha1, null_sha1, flags, msg, err); } int ref_transaction_delete(struct ref_transaction *transaction, const char *refname, const unsigned char *old_sha1, unsigned int flags, const char *msg, struct strbuf *err) { if (old_sha1 && is_null_sha1(old_sha1)) die("BUG: delete called with old_sha1 set to zeros"); return ref_transaction_update(transaction, refname, null_sha1, old_sha1, flags, msg, err); } int ref_transaction_verify(struct ref_transaction *transaction, const char *refname, const unsigned char *old_sha1, unsigned int flags, struct strbuf *err) { if (!old_sha1) die("BUG: verify called with old_sha1 set to NULL"); return ref_transaction_update(transaction, refname, NULL, old_sha1, flags, NULL, err); } int update_ref(const char *msg, const char *refname, const unsigned char *new_sha1, const unsigned char *old_sha1, unsigned int flags, enum action_on_err onerr) { struct ref_transaction *t; struct strbuf err = STRBUF_INIT; t = ref_transaction_begin(&err); if (!t || ref_transaction_update(t, refname, new_sha1, old_sha1, flags, msg, &err) || ref_transaction_commit(t, &err)) { const char *str = "update_ref failed for ref '%s': %s"; ref_transaction_free(t); switch (onerr) { case UPDATE_REFS_MSG_ON_ERR: error(str, refname, err.buf); break; case UPDATE_REFS_DIE_ON_ERR: die(str, refname, err.buf); break; case UPDATE_REFS_QUIET_ON_ERR: break; } strbuf_release(&err); return 1; } strbuf_release(&err); ref_transaction_free(t); return 0; } static int ref_update_reject_duplicates(struct string_list *refnames, struct strbuf *err) { int i, n = refnames->nr; assert(err); for (i = 1; i < n; i++) if (!strcmp(refnames->items[i - 1].string, refnames->items[i].string)) { strbuf_addf(err, "Multiple updates for ref '%s' not allowed.", refnames->items[i].string); return 1; } return 0; } int ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err) { int ret = 0, i; int n = transaction->nr; struct ref_update **updates = transaction->updates; struct string_list refs_to_delete = STRING_LIST_INIT_NODUP; struct string_list_item *ref_to_delete; struct string_list affected_refnames = STRING_LIST_INIT_NODUP; assert(err); if (transaction->state != REF_TRANSACTION_OPEN) die("BUG: commit called for transaction that is not open"); if (!n) { transaction->state = REF_TRANSACTION_CLOSED; return 0; } /* Fail if a refname appears more than once in the transaction: */ for (i = 0; i < n; i++) string_list_append(&affected_refnames, updates[i]->refname); string_list_sort(&affected_refnames); if (ref_update_reject_duplicates(&affected_refnames, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } /* Acquire all locks while verifying old values */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; unsigned int flags = update->flags; if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) flags |= REF_DELETING; update->lock = lock_ref_sha1_basic( update->refname, ((update->flags & REF_HAVE_OLD) ? update->old_sha1 : NULL), &affected_refnames, NULL, flags, &update->type, err); if (!update->lock) { char *reason; ret = (errno == ENOTDIR) ? TRANSACTION_NAME_CONFLICT : TRANSACTION_GENERIC_ERROR; reason = strbuf_detach(err, NULL); strbuf_addf(err, "Cannot lock ref '%s': %s", update->refname, reason); free(reason); goto cleanup; } } /* Perform updates first so live commits remain referenced */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; int flags = update->flags; if ((flags & REF_HAVE_NEW) && !is_null_sha1(update->new_sha1)) { int overwriting_symref = ((update->type & REF_ISSYMREF) && (update->flags & REF_NODEREF)); if (!overwriting_symref && !hashcmp(update->lock->old_sha1, update->new_sha1)) { /* * The reference already has the desired * value, so we don't need to write it. */ unlock_ref(update->lock); update->lock = NULL; } else if (write_ref_sha1(update->lock, update->new_sha1, update->msg)) { update->lock = NULL; /* freed by write_ref_sha1 */ strbuf_addf(err, "Cannot update the ref '%s'.", update->refname); ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } else { /* freed by write_ref_sha1(): */ update->lock = NULL; } } } /* Perform deletes now that updates are safely completed */ for (i = 0; i < n; i++) { struct ref_update *update = updates[i]; int flags = update->flags; if ((flags & REF_HAVE_NEW) && is_null_sha1(update->new_sha1)) { if (delete_ref_loose(update->lock, update->type, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } if (!(flags & REF_ISPRUNING)) string_list_append(&refs_to_delete, update->lock->ref_name); } } if (repack_without_refs(&refs_to_delete, err)) { ret = TRANSACTION_GENERIC_ERROR; goto cleanup; } for_each_string_list_item(ref_to_delete, &refs_to_delete) unlink_or_warn(git_path("logs/%s", ref_to_delete->string)); clear_loose_ref_cache(&ref_cache); cleanup: transaction->state = REF_TRANSACTION_CLOSED; for (i = 0; i < n; i++) if (updates[i]->lock) unlock_ref(updates[i]->lock); string_list_clear(&refs_to_delete, 0); string_list_clear(&affected_refnames, 0); return ret; } char *shorten_unambiguous_ref(const char *refname, int strict) { int i; static char **scanf_fmts; static int nr_rules; char *short_name; if (!nr_rules) { /* * Pre-generate scanf formats from ref_rev_parse_rules[]. * Generate a format suitable for scanf from a * ref_rev_parse_rules rule by interpolating "%s" at the * location of the "%.*s". */ size_t total_len = 0; size_t offset = 0; /* the rule list is NULL terminated, count them first */ for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++) /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */ total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1; scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len); offset = 0; for (i = 0; i < nr_rules; i++) { assert(offset < total_len); scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset; offset += snprintf(scanf_fmts[i], total_len - offset, ref_rev_parse_rules[i], 2, "%s") + 1; } } /* bail out if there are no rules */ if (!nr_rules) return xstrdup(refname); /* buffer for scanf result, at most refname must fit */ short_name = xstrdup(refname); /* skip first rule, it will always match */ for (i = nr_rules - 1; i > 0 ; --i) { int j; int rules_to_fail = i; int short_name_len; if (1 != sscanf(refname, scanf_fmts[i], short_name)) continue; short_name_len = strlen(short_name); /* * in strict mode, all (except the matched one) rules * must fail to resolve to a valid non-ambiguous ref */ if (strict) rules_to_fail = nr_rules; /* * check if the short name resolves to a valid ref, * but use only rules prior to the matched one */ for (j = 0; j < rules_to_fail; j++) { const char *rule = ref_rev_parse_rules[j]; char refname[PATH_MAX]; /* skip matched rule */ if (i == j) continue; /* * the short name is ambiguous, if it resolves * (with this previous rule) to a valid ref * read_ref() returns 0 on success */ mksnpath(refname, sizeof(refname), rule, short_name_len, short_name); if (ref_exists(refname)) break; } /* * short name is non-ambiguous if all previous rules * haven't resolved to a valid ref */ if (j == rules_to_fail) return short_name; } free(short_name); return xstrdup(refname); } static struct string_list *hide_refs; int parse_hide_refs_config(const char *var, const char *value, const char *section) { if (!strcmp("transfer.hiderefs", var) || /* NEEDSWORK: use parse_config_key() once both are merged */ (starts_with(var, section) && var[strlen(section)] == '.' && !strcmp(var + strlen(section), ".hiderefs"))) { char *ref; int len; if (!value) return config_error_nonbool(var); ref = xstrdup(value); len = strlen(ref); while (len && ref[len - 1] == '/') ref[--len] = '\0'; if (!hide_refs) { hide_refs = xcalloc(1, sizeof(*hide_refs)); hide_refs->strdup_strings = 1; } string_list_append(hide_refs, ref); } return 0; } int ref_is_hidden(const char *refname) { struct string_list_item *item; if (!hide_refs) return 0; for_each_string_list_item(item, hide_refs) { int len; if (!starts_with(refname, item->string)) continue; len = strlen(item->string); if (!refname[len] || refname[len] == '/') return 1; } return 0; } struct expire_reflog_cb { unsigned int flags; reflog_expiry_should_prune_fn *should_prune_fn; void *policy_cb; FILE *newlog; unsigned char last_kept_sha1[20]; }; static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1, const char *email, unsigned long timestamp, int tz, const char *message, void *cb_data) { struct expire_reflog_cb *cb = cb_data; struct expire_reflog_policy_cb *policy_cb = cb->policy_cb; if (cb->flags & EXPIRE_REFLOGS_REWRITE) osha1 = cb->last_kept_sha1; if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz, message, policy_cb)) { if (!cb->newlog) printf("would prune %s", message); else if (cb->flags & EXPIRE_REFLOGS_VERBOSE) printf("prune %s", message); } else { if (cb->newlog) { fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s", sha1_to_hex(osha1), sha1_to_hex(nsha1), email, timestamp, tz, message); hashcpy(cb->last_kept_sha1, nsha1); } if (cb->flags & EXPIRE_REFLOGS_VERBOSE) printf("keep %s", message); } return 0; } int reflog_expire(const char *refname, const unsigned char *sha1, unsigned int flags, reflog_expiry_prepare_fn prepare_fn, reflog_expiry_should_prune_fn should_prune_fn, reflog_expiry_cleanup_fn cleanup_fn, void *policy_cb_data) { static struct lock_file reflog_lock; struct expire_reflog_cb cb; struct ref_lock *lock; char *log_file; int status = 0; int type; struct strbuf err = STRBUF_INIT; memset(&cb, 0, sizeof(cb)); cb.flags = flags; cb.policy_cb = policy_cb_data; cb.should_prune_fn = should_prune_fn; /* * The reflog file is locked by holding the lock on the * reference itself, plus we might need to update the * reference if --updateref was specified: */ lock = lock_ref_sha1_basic(refname, sha1, NULL, NULL, 0, &type, &err); if (!lock) { error("cannot lock ref '%s': %s", refname, err.buf); strbuf_release(&err); return -1; } if (!reflog_exists(refname)) { unlock_ref(lock); return 0; } log_file = git_pathdup("logs/%s", refname); if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { /* * Even though holding $GIT_DIR/logs/$reflog.lock has * no locking implications, we use the lock_file * machinery here anyway because it does a lot of the * work we need, including cleaning up if the program * exits unexpectedly. */ if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) { struct strbuf err = STRBUF_INIT; unable_to_lock_message(log_file, errno, &err); error("%s", err.buf); strbuf_release(&err); goto failure; } cb.newlog = fdopen_lock_file(&reflog_lock, "w"); if (!cb.newlog) { error("cannot fdopen %s (%s)", reflog_lock.filename.buf, strerror(errno)); goto failure; } } (*prepare_fn)(refname, sha1, cb.policy_cb); for_each_reflog_ent(refname, expire_reflog_ent, &cb); (*cleanup_fn)(cb.policy_cb); if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) { /* * It doesn't make sense to adjust a reference pointed * to by a symbolic ref based on expiring entries in * the symbolic reference's reflog. Nor can we update * a reference if there are no remaining reflog * entries. */ int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) && !(type & REF_ISSYMREF) && !is_null_sha1(cb.last_kept_sha1); if (close_lock_file(&reflog_lock)) { status |= error("couldn't write %s: %s", log_file, strerror(errno)); } else if (update && (write_in_full(lock->lock_fd, sha1_to_hex(cb.last_kept_sha1), 40) != 40 || write_str_in_full(lock->lock_fd, "\n") != 1 || close_ref(lock) < 0)) { status |= error("couldn't write %s", lock->lk->filename.buf); rollback_lock_file(&reflog_lock); } else if (commit_lock_file(&reflog_lock)) { status |= error("unable to commit reflog '%s' (%s)", log_file, strerror(errno)); } else if (update && commit_ref(lock)) { status |= error("couldn't set %s", lock->ref_name); } } free(log_file); unlock_ref(lock); return status; failure: rollback_lock_file(&reflog_lock); free(log_file); unlock_ref(lock); return -1; }