diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 3103 |
1 files changed, 3103 insertions, 0 deletions
@@ -0,0 +1,3103 @@ +#include "cache.h" +#include "refs.h" +#include "object.h" +#include "tag.h" +#include "dir.h" +#include "string-list.h" + +/* + * Make sure "ref" 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) + */ + +/* Return true iff ch is not allowed in reference names. */ +static inline int bad_ref_char(int ch) +{ + if (((unsigned) ch) <= ' ' || ch == 0x7f || + ch == '~' || ch == '^' || ch == ':' || ch == '\\') + return 1; + /* 2.13 Pattern Matching Notation */ + if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */ + return 1; + return 0; +} + +/* + * 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. + */ +static int check_refname_component(const char *refname, int flags) +{ + const char *cp; + char last = '\0'; + + for (cp = refname; ; cp++) { + char ch = *cp; + if (ch == '\0' || ch == '/') + break; + if (bad_ref_char(ch)) + return -1; /* Illegal character in refname. */ + if (last == '.' && ch == '.') + return -1; /* Refname contains "..". */ + if (last == '@' && ch == '{') + return -1; /* Refname contains "@{". */ + last = ch; + } + if (cp == refname) + return 0; /* Component has zero length. */ + if (refname[0] == '.') { + if (!(flags & REFNAME_DOT_COMPONENT)) + return -1; /* Component starts with '.'. */ + /* + * Even if leading dots are allowed, don't allow "." + * as a component (".." is prevented by a rule above). + */ + if (refname[1] == '\0') + return -1; /* Component equals ".". */ + } + if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5)) + 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, and REF_ISBROKEN=0x04 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 0x08 + +/* ref_entry represents a directory of references */ +#define REF_DIR 0x10 + +/* + * Entry has not yet been read from disk (used only for REF_DIR + * entries representing loose references) + */ +#define REF_INCOMPLETE 0x20 + +/* + * 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 is_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; +} + +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|REFNAME_DOT_COMPONENT)) + die("Reference has invalid format: '%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; + int retval; + if (prefixcmp(entry->name, data->base)) + return 0; + + if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + !ref_resolves_to_object(entry)) + return 0; + + current_ref = entry; + retval = data->fn(entry->name + data->trim, entry->u.value.sha1, + entry->flag, data->cb_data); + current_ref = NULL; + 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; + } +} + +/* + * Return true iff refname1 and refname2 conflict with each other. + * Two reference names conflict if one of them exactly matches the + * leading components of the other; e.g., "foo/bar" conflicts with + * both "foo" and with "foo/bar/baz" but not with "foo/bar" or + * "foo/barbados". + */ +static int names_conflict(const char *refname1, const char *refname2) +{ + for (; *refname1 && *refname1 == *refname2; refname1++, refname2++) + ; + return (*refname1 == '\0' && *refname2 == '/') + || (*refname1 == '/' && *refname2 == '\0'); +} + +struct name_conflict_cb { + const char *refname; + const char *oldrefname; + const char *conflicting_refname; +}; + +static int name_conflict_fn(struct ref_entry *entry, void *cb_data) +{ + struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; + if (data->oldrefname && !strcmp(data->oldrefname, entry->name)) + return 0; + if (names_conflict(data->refname, entry->name)) { + data->conflicting_refname = entry->name; + return 1; + } + return 0; +} + +/* + * Return true iff a reference named refname could be created without + * conflicting with the name of an existing reference in dir. If + * oldrefname is non-NULL, ignore potential conflicts with oldrefname + * (e.g., because oldrefname is scheduled for deletion in the same + * operation). + */ +static int is_refname_available(const char *refname, const char *oldrefname, + struct ref_dir *dir) +{ + struct name_conflict_cb data; + data.refname = refname; + data.oldrefname = oldrefname; + data.conflicting_refname = NULL; + + sort_ref_dir(dir); + if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) { + error("'%s' exists; cannot create '%s'", + data.conflicting_refname, refname); + return 0; + } + return 1; +} + +/* + * 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 ref_entry *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; + +static void clear_packed_ref_cache(struct ref_cache *refs) +{ + if (refs->packed) { + free_ref_entry(refs->packed); + refs->packed = NULL; + } +} + +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; +} + +void invalidate_ref_cache(const char *submodule) +{ + struct ref_cache *refs = get_ref_cache(submodule); + clear_packed_ref_cache(refs); + clear_loose_ref_cache(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(char *line, unsigned char *sha1) +{ + /* + * 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) + */ + int len = strlen(line) - 42; + + if (len <= 0) + return NULL; + if (get_sha1_hex(line, sha1) < 0) + return NULL; + if (!isspace(line[40])) + return NULL; + line += 41; + if (isspace(*line)) + return NULL; + if (line[len] != '\n') + return NULL; + line[len] = 0; + + return line; +} + +/* + * 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; + char refline[PATH_MAX]; + enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; + + while (fgets(refline, sizeof(refline), f)) { + unsigned char sha1[20]; + const char *refname; + static const char header[] = "# pack-refs with:"; + + if (!strncmp(refline, header, sizeof(header)-1)) { + const char *traits = refline + sizeof(header) - 1; + 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(refline, sha1); + if (refname) { + last = create_ref_entry(refname, sha1, REF_ISPACKED, 1); + if (peeled == PEELED_FULLY || + (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/"))) + last->flag |= REF_KNOWS_PEELED; + add_ref(dir, last); + continue; + } + if (last && + refline[0] == '^' && + strlen(refline) == PEELED_LINE_LENGTH && + refline[PEELED_LINE_LENGTH - 1] == '\n' && + !get_sha1_hex(refline + 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; + } + } +} + +static struct ref_dir *get_packed_refs(struct ref_cache *refs) +{ + if (!refs->packed) { + const char *packed_refs_file; + FILE *f; + + refs->packed = create_dir_entry(refs, "", 0, 0); + if (*refs->name) + packed_refs_file = git_path_submodule(refs->name, "packed-refs"); + else + packed_refs_file = git_path("packed-refs"); + f = fopen(packed_refs_file, "r"); + if (f) { + read_packed_refs(f, get_ref_dir(refs->packed)); + fclose(f); + } + } + return get_ref_dir(refs->packed); +} + +void add_packed_ref(const char *refname, const unsigned char *sha1) +{ + add_ref(get_packed_refs(&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 (has_extension(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, sha1, 1, &flag)) { + hashclr(sha1); + flag |= REF_ISBROKEN; + } + add_entry_to_dir(dir, + create_ref_entry(refname.buf, sha1, flag, 1)); + } + 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 <refname> 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; + + memcpy(sha1, ref->u.value.sha1, 20); + 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); +} + +const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag) +{ + int depth = MAXDEPTH; + ssize_t len; + char buffer[256]; + static char refname_buffer[256]; + + if (flag) + *flag = 0; + + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) + return NULL; + + for (;;) { + char path[PATH_MAX]; + struct stat st; + char *buf; + int fd; + + if (--depth < 0) + return NULL; + + git_snpath(path, sizeof(path), "%s", refname); + + if (lstat(path, &st) < 0) { + struct ref_entry *entry; + + if (errno != ENOENT) + return NULL; + /* + * 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 (flag) + *flag |= REF_ISPACKED; + return refname; + } + /* The reference is not a packed reference, either. */ + if (reading) { + return NULL; + } else { + hashclr(sha1); + 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) + return NULL; + buffer[len] = 0; + if (!prefixcmp(buffer, "refs/") && + !check_refname_format(buffer, 0)) { + strcpy(refname_buffer, buffer); + refname = refname_buffer; + if (flag) + *flag |= REF_ISSYMREF; + 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) + return NULL; + len = read_in_full(fd, buffer, sizeof(buffer)-1); + close(fd); + if (len < 0) + return NULL; + while (len && isspace(buffer[len-1])) + len--; + buffer[len] = '\0'; + + /* + * Is it a symbolic ref? + */ + if (prefixcmp(buffer, "ref:")) + break; + if (flag) + *flag |= REF_ISSYMREF; + buf = buffer + 4; + while (isspace(*buf)) + buf++; + if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) { + if (flag) + *flag |= REF_ISBROKEN; + return NULL; + } + refname = strcpy(refname_buffer, buf); + } + /* 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 (flag) + *flag |= REF_ISBROKEN; + return NULL; + } + return refname; +} + +char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag) +{ + const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag); + return ret ? xstrdup(ret) : NULL; +} + +/* 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, unsigned char *sha1, int reading, int *flags) +{ + if (resolve_ref_unsafe(refname, sha1, reading, flags)) + return 0; + return -1; +} + +int read_ref(const char *refname, unsigned char *sha1) +{ + return read_ref_full(refname, sha1, 1, NULL); +} + +int ref_exists(const char *refname) +{ + unsigned char sha1[20]; + return !!resolve_ref_unsafe(refname, sha1, 1, 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 (fnmatch(filter->pattern, refname, 0)) + 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) + return PEEL_INVALID; + o->type = type; + } + + 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, base, 1, &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 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, junk, 0, NULL); + if (!resolves_to || strcmp(resolves_to, d->refname)) + 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.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 ref_dir *packed_dir = get_packed_refs(refs); + struct ref_dir *loose_dir = get_loose_refs(refs); + int retval = 0; + + if (base && *base) { + packed_dir = find_containing_dir(packed_dir, base, 0); + loose_dir = find_containing_dir(loose_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); + } + + 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; + + 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", sha1, 1, &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, sha1, 1, &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 && prefixcmp(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 + ( + !prefixcmp(name, "refs/heads/") ? 11 : + !prefixcmp(name, "refs/tags/") ? 10 : + !prefixcmp(name, "refs/remotes/") ? 13 : + 0); +} + +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 **rules) +{ + const char **p; + const int abbrev_name_len = strlen(abbrev_name); + + for (p = rules; *p; p++) { + if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) { + return 1; + } + } + + return 0; +} + +static struct ref_lock *verify_lock(struct ref_lock *lock, + const unsigned char *old_sha1, int mustexist) +{ + if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) { + error("Can't verify ref %s", lock->ref_name); + unlock_ref(lock); + 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); + 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; + + strbuf_init(&path, 20); + strbuf_addstr(&path, file); + + result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY); + + strbuf_release(&path); + + 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, &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, this_result, 1, &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++) { + struct stat st; + unsigned char hash[20]; + char path[PATH_MAX]; + const char *ref, *it; + + mksnpath(path, sizeof(path), *p, len, str); + ref = resolve_ref_unsafe(path, hash, 1, NULL); + if (!ref) + continue; + if (!stat(git_path("logs/%s", path), &st) && + S_ISREG(st.st_mode)) + it = path; + else if (strcmp(ref, path) && + !stat(git_path("logs/%s", ref), &st) && + S_ISREG(st.st_mode)) + it = ref; + else + continue; + if (!logs_found++) { + *log = xstrdup(it); + hashcpy(sha1, hash); + } + if (!warn_ambiguous_refs) + break; + } + free(last_branch); + return logs_found; +} + +static struct ref_lock *lock_ref_sha1_basic(const char *refname, + const unsigned char *old_sha1, + int flags, int *type_p) +{ + 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 missing = 0; + + lock = xcalloc(1, sizeof(struct ref_lock)); + lock->lock_fd = -1; + + refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &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; + error("there are still refs under '%s'", orig_refname); + goto error_return; + } + refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type); + } + if (type_p) + *type_p = type; + if (!refname) { + last_errno = errno; + error("unable to resolve reference %s: %s", + orig_refname, strerror(errno)); + goto error_return; + } + missing = is_null_sha1(lock->old_sha1); + /* When the ref did not exist and we are creating it, + * make sure there is no existing ref that is packed + * whose name begins with our refname, nor a ref whose + * name is a proper prefix of our refname. + */ + if (missing && + !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) { + last_errno = ENOTDIR; + goto error_return; + } + + lock->lk = xcalloc(1, sizeof(struct lock_file)); + + lflags = LOCK_DIE_ON_ERROR; + if (flags & REF_NODEREF) { + refname = orig_refname; + lflags |= LOCK_NODEREF; + } + lock->ref_name = xstrdup(refname); + lock->orig_ref_name = xstrdup(orig_refname); + ref_file = git_path("%s", refname); + if (missing) + lock->force_write = 1; + if ((flags & REF_NODEREF) && (type & REF_ISSYMREF)) + lock->force_write = 1; + + if (safe_create_leading_directories(ref_file)) { + last_errno = errno; + error("unable to create directory for %s", ref_file); + goto error_return; + } + + lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags); + return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock; + + error_return: + unlock_ref(lock); + errno = last_errno; + return NULL; +} + +struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1) +{ + char refpath[PATH_MAX]; + if (check_refname_format(refname, 0)) + return NULL; + strcpy(refpath, mkpath("refs/%s", refname)); + return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL); +} + +struct ref_lock *lock_any_ref_for_update(const char *refname, + const unsigned char *old_sha1, int flags) +{ + if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) + return NULL; + return lock_ref_sha1_basic(refname, old_sha1, flags, 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(int fd, char *refname, unsigned char *sha1, + unsigned char *peeled) +{ + char line[PATH_MAX + 100]; + int len; + + len = snprintf(line, sizeof(line), "%s %s\n", + sha1_to_hex(sha1), refname); + /* this should not happen but just being defensive */ + if (len > sizeof(line)) + die("too long a refname '%s'", refname); + write_or_die(fd, line, len); + + if (peeled) { + if (snprintf(line, sizeof(line), "^%s\n", + sha1_to_hex(peeled)) != PEELED_LINE_LENGTH) + die("internal error"); + write_or_die(fd, line, PEELED_LINE_LENGTH); + } +} + +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_to_prune *ref_to_prune; + int fd; +}; + +static int pack_one_ref(struct ref_entry *entry, void *cb_data) +{ + struct pack_refs_cb_data *cb = cb_data; + enum peel_status peel_status; + int is_tag_ref = !prefixcmp(entry->name, "refs/tags/"); + + /* ALWAYS pack refs that were already packed or are tags */ + if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref && + !(entry->flag & REF_ISPACKED)) + return 0; + + /* Do not pack symbolic or broken refs: */ + if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry)) + return 0; + + 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)); + write_packed_entry(cb->fd, entry->name, entry->u.value.sha1, + peel_status == PEEL_PEELED ? + entry->u.value.peeled : NULL); + + /* If the ref was already packed, there is no need to prune it. */ + if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) { + 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_lock *lock = lock_ref_sha1(r->name + 5, r->sha1); + + if (lock) { + unlink_or_warn(git_path("%s", r->name)); + unlock_ref(lock); + try_remove_empty_parents(r->name); + } +} + +static void prune_refs(struct ref_to_prune *r) +{ + while (r) { + prune_ref(r); + r = r->next; + } +} + +static struct lock_file packlock; + +int pack_refs(unsigned int flags) +{ + struct pack_refs_cb_data cbdata; + + memset(&cbdata, 0, sizeof(cbdata)); + cbdata.flags = flags; + + cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), + LOCK_DIE_ON_ERROR); + + write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER)); + + do_for_each_entry(&ref_cache, "", pack_one_ref, &cbdata); + if (commit_lock_file(&packlock) < 0) + die_errno("unable to overwrite old ref-pack file"); + prune_refs(cbdata.ref_to_prune); + return 0; +} + +static int repack_ref_fn(struct ref_entry *entry, void *cb_data) +{ + int *fd = cb_data; + enum peel_status peel_status; + + if (entry->flag & REF_ISBROKEN) { + /* This shouldn't happen to packed refs. */ + error("%s is broken!", entry->name); + return 0; + } + if (!has_sha1_file(entry->u.value.sha1)) { + unsigned char sha1[20]; + int flags; + + if (read_ref_full(entry->name, sha1, 0, &flags)) + /* We should at least have found the packed ref. */ + die("Internal error"); + if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) + /* + * This packed reference is overridden by a + * loose reference, so it is OK that its value + * is no longer valid; for example, it might + * refer to an object that has been garbage + * collected. For this purpose we don't even + * care whether the loose reference itself is + * invalid, broken, symbolic, etc. Silently + * omit the packed reference from the output. + */ + return 0; + /* + * There is no overriding loose reference, so the fact + * that this reference doesn't refer to a valid object + * indicates some kind of repository corruption. + * Report the problem, then omit the reference from + * the output. + */ + error("%s does not point to a valid object!", entry->name); + return 0; + } + + peel_status = peel_entry(entry, 0); + write_packed_entry(*fd, entry->name, entry->u.value.sha1, + peel_status == PEEL_PEELED ? + entry->u.value.peeled : NULL); + + return 0; +} + +static int repack_without_ref(const char *refname) +{ + int fd; + struct ref_dir *packed; + + if (!get_packed_ref(refname)) + return 0; /* refname does not exist in packed refs */ + + fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0); + if (fd < 0) { + unable_to_lock_error(git_path("packed-refs"), errno); + return error("cannot delete '%s' from packed refs", refname); + } + clear_packed_ref_cache(&ref_cache); + packed = get_packed_refs(&ref_cache); + /* Remove refname from the cache. */ + if (remove_entry(packed, refname) == -1) { + /* + * The packed entry disappeared while we were + * acquiring the lock. + */ + rollback_lock_file(&packlock); + return 0; + } + write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER)); + do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd); + return commit_lock_file(&packlock); +} + +int delete_ref(const char *refname, const unsigned char *sha1, int delopt) +{ + struct ref_lock *lock; + int err, i = 0, ret = 0, flag = 0; + + lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag); + if (!lock) + return 1; + if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { + /* loose */ + i = strlen(lock->lk->filename) - 5; /* .lock */ + lock->lk->filename[i] = 0; + err = unlink_or_warn(lock->lk->filename); + if (err && errno != ENOENT) + ret = 1; + + lock->lk->filename[i] = '.'; + } + /* removing the loose one could have resurrected an earlier + * packed one. Also, if it was not loose we need to repack + * without it. + */ + ret |= repack_without_ref(lock->ref_name); + + unlink_or_warn(git_path("logs/%s", lock->ref_name)); + clear_loose_ref_cache(&ref_cache); + unlock_ref(lock); + return ret; +} + +/* + * 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" + +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; + + if (log && S_ISLNK(loginfo.st_mode)) + return error("reflog for %s is a symlink", oldrefname); + + symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &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 (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache))) + return 1; + + if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache))) + 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, sha1, 1, &flag) && + 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 && safe_create_leading_directories(git_path("logs/%s", newrefname))) { + error("unable to create directory for %s", newrefname); + goto rollback; + } + + retry: + if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) { + if (errno==EISDIR || errno==ENOTDIR) { + /* + * 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); + goto rollback; + } + goto retry; + } else { + error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s", + newrefname, strerror(errno)); + goto rollback; + } + } + logmoved = log; + + lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL); + if (!lock) { + error("unable to lock %s for update", newrefname); + goto rollback; + } + lock->force_write = 1; + 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, 0, NULL); + if (!lock) { + error("unable to lock %s for rollback", oldrefname); + goto rollbacklog; + } + + lock->force_write = 1; + 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; +} + +int close_ref(struct ref_lock *lock) +{ + if (close_lock_file(lock->lk)) + return -1; + lock->lock_fd = -1; + return 0; +} + +int commit_ref(struct ref_lock *lock) +{ + if (commit_lock_file(lock->lk)) + return -1; + lock->lock_fd = -1; + return 0; +} + +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); +} + +/* + * 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; +} + +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 && + (!prefixcmp(refname, "refs/heads/") || + !prefixcmp(refname, "refs/remotes/") || + !prefixcmp(refname, "refs/notes/") || + !strcmp(refname, "HEAD"))) { + if (safe_create_leading_directories(logfile) < 0) + return error("unable to create directory for %s", + logfile); + oflags |= O_CREAT; + } + + logfd = open(logfile, oflags, 0666); + if (logfd < 0) { + if (!(oflags & O_CREAT) && errno == ENOENT) + return 0; + + if ((oflags & O_CREAT) && errno == EISDIR) { + if (remove_empty_directories(logfile)) { + return error("There are still logs under '%s'", + logfile); + } + logfd = open(logfile, oflags, 0666); + } + + if (logfd < 0) + return error("Unable to append to %s: %s", + logfile, strerror(errno)); + } + + adjust_shared_perm(logfile); + close(logfd); + 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, written, oflags = O_APPEND | O_WRONLY; + unsigned maxlen, len; + int msglen; + char log_file[PATH_MAX]; + char *logrec; + const char *committer; + + 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; + msglen = msg ? strlen(msg) : 0; + committer = git_committer_info(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(logfd, logrec, len) : -1; + free(logrec); + if (close(logfd) != 0 || written != len) + return error("Unable to append to %s", log_file); + return 0; +} + +static int is_branch(const char *refname) +{ + return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/"); +} + +int write_ref_sha1(struct ref_lock *lock, + const unsigned char *sha1, const char *logmsg) +{ + static char term = '\n'; + struct object *o; + + if (!lock) + return -1; + if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) { + unlock_ref(lock); + return 0; + } + 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); + 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); + 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) { + error("Couldn't write %s", lock->lk->filename); + unlock_ref(lock); + 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", head_sha1, 1, &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; +} + +static char *ref_msg(const char *line, const char *endp) +{ + const char *ep; + line += 82; + ep = memchr(line, '\n', endp - line); + if (!ep) + ep = endp; + return xmemdupz(line, ep - line); +} + +int read_ref_at(const char *refname, unsigned long at_time, int cnt, + unsigned char *sha1, char **msg, + unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt) +{ + const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec; + char *tz_c; + int logfd, tz, reccnt = 0; + struct stat st; + unsigned long date; + unsigned char logged_sha1[20]; + void *log_mapped; + size_t mapsz; + + logfile = git_path("logs/%s", refname); + logfd = open(logfile, O_RDONLY, 0); + if (logfd < 0) + die_errno("Unable to read log '%s'", logfile); + fstat(logfd, &st); + if (!st.st_size) + die("Log %s is empty.", logfile); + mapsz = xsize_t(st.st_size); + log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0); + logdata = log_mapped; + close(logfd); + + lastrec = NULL; + rec = logend = logdata + st.st_size; + while (logdata < rec) { + reccnt++; + if (logdata < rec && *(rec-1) == '\n') + rec--; + lastgt = NULL; + while (logdata < rec && *(rec-1) != '\n') { + rec--; + if (*rec == '>') + lastgt = rec; + } + if (!lastgt) + die("Log %s is corrupt.", logfile); + date = strtoul(lastgt + 1, &tz_c, 10); + if (date <= at_time || cnt == 0) { + tz = strtoul(tz_c, NULL, 10); + if (msg) + *msg = ref_msg(rec, logend); + if (cutoff_time) + *cutoff_time = date; + if (cutoff_tz) + *cutoff_tz = tz; + if (cutoff_cnt) + *cutoff_cnt = reccnt - 1; + if (lastrec) { + if (get_sha1_hex(lastrec, logged_sha1)) + die("Log %s is corrupt.", logfile); + if (get_sha1_hex(rec + 41, sha1)) + die("Log %s is corrupt.", logfile); + if (hashcmp(logged_sha1, sha1)) { + warning("Log %s has gap after %s.", + logfile, show_date(date, tz, DATE_RFC2822)); + } + } + else if (date == at_time) { + if (get_sha1_hex(rec + 41, sha1)) + die("Log %s is corrupt.", logfile); + } + else { + if (get_sha1_hex(rec + 41, logged_sha1)) + die("Log %s is corrupt.", logfile); + if (hashcmp(logged_sha1, sha1)) { + warning("Log %s unexpectedly ended on %s.", + logfile, show_date(date, tz, DATE_RFC2822)); + } + } + munmap(log_mapped, mapsz); + return 0; + } + lastrec = rec; + if (cnt > 0) + cnt--; + } + + rec = logdata; + while (rec < logend && *rec != '>' && *rec != '\n') + rec++; + if (rec == logend || *rec == '\n') + die("Log %s is corrupt.", logfile); + date = strtoul(rec + 1, &tz_c, 10); + tz = strtoul(tz_c, NULL, 10); + if (get_sha1_hex(logdata, sha1)) + die("Log %s is corrupt.", logfile); + if (is_null_sha1(sha1)) { + if (get_sha1_hex(logdata + 41, sha1)) + die("Log %s is corrupt.", logfile); + } + if (msg) + *msg = ref_msg(logdata, logend); + munmap(log_mapped, mapsz); + + if (cutoff_time) + *cutoff_time = date; + if (cutoff_tz) + *cutoff_tz = tz; + if (cutoff_cnt) + *cutoff_cnt = reccnt; + return 1; +} + +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 <email> 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') { + strbuf_splice(&sb, 0, 0, buf, endp - buf); + if (pos) + break; /* need to fill another block */ + scanp = buf - 1; /* leave loop */ + } else { + /* + * (bp + 1) thru endp is the beginning of the + * current line we have in sb + */ + 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; + } + + } + if (!ret && sb.len) + ret = show_one_reflog_ent(&sb, fn, cb_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 (has_extension(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, sha1, 0, 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; +} + +int update_ref(const char *action, const char *refname, + const unsigned char *sha1, const unsigned char *oldval, + int flags, enum action_on_err onerr) +{ + static struct ref_lock *lock; + lock = lock_any_ref_for_update(refname, oldval, flags); + if (!lock) { + const char *str = "Cannot lock the ref '%s'."; + switch (onerr) { + case MSG_ON_ERR: error(str, refname); break; + case DIE_ON_ERR: die(str, refname); break; + case QUIET_ON_ERR: break; + } + return 1; + } + if (write_ref_sha1(lock, sha1, action) < 0) { + const char *str = "Cannot update the ref '%s'."; + switch (onerr) { + case MSG_ON_ERR: error(str, refname); break; + case DIE_ON_ERR: die(str, refname); break; + case QUIET_ON_ERR: break; + } + return 1; + } + return 0; +} + +struct ref *find_ref_by_name(const struct ref *list, const char *name) +{ + for ( ; list; list = list->next) + if (!strcmp(list->name, name)) + return (struct ref *)list; + return NULL; +} + +/* + * generate a format suitable for scanf from a ref_rev_parse_rules + * rule, that is replace the "%.*s" spec with a "%s" spec + */ +static void gen_scanf_fmt(char *scanf_fmt, const char *rule) +{ + char *spec; + + spec = strstr(rule, "%.*s"); + if (!spec || strstr(spec + 4, "%.*s")) + die("invalid rule in ref_rev_parse_rules: %s", rule); + + /* copy all until spec */ + strncpy(scanf_fmt, rule, spec - rule); + scanf_fmt[spec - rule] = '\0'; + /* copy new spec */ + strcat(scanf_fmt, "%s"); + /* copy remaining rule */ + strcat(scanf_fmt, spec + 4); + + return; +} + +char *shorten_unambiguous_ref(const char *refname, int strict) +{ + int i; + static char **scanf_fmts; + static int nr_rules; + char *short_name; + + /* pre generate scanf formats from ref_rev_parse_rules[] */ + if (!nr_rules) { + size_t total_len = 0; + + /* the rule list is NULL terminated, count them first */ + for (; ref_rev_parse_rules[nr_rules]; nr_rules++) + /* no +1 because strlen("%s") < strlen("%.*s") */ + total_len += strlen(ref_rev_parse_rules[nr_rules]); + + scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len); + + total_len = 0; + for (i = 0; i < nr_rules; i++) { + scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + + total_len; + gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]); + total_len += strlen(ref_rev_parse_rules[i]); + } + } + + /* 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 */ + (!prefixcmp(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 (prefixcmp(refname, item->string)) + continue; + len = strlen(item->string); + if (!refname[len] || refname[len] == '/') + return 1; + } + return 0; +} |