diff options
Diffstat (limited to 'refs.c')
| -rw-r--r-- | refs.c | 2415 |
1 files changed, 1824 insertions, 591 deletions
@@ -3,54 +3,261 @@ #include "object.h" #include "tag.h" #include "dir.h" +#include "string-list.h" -/* ISSYMREF=0x01, ISPACKED=0x02 and ISBROKEN=0x04 are public interfaces */ -#define REF_KNOWS_PEELED 0x10 +/* + * 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) + */ -struct ref_entry { - unsigned char flag; /* ISSYMREF? ISPACKED? */ +/* 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; + + 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]; - /* The full name of the reference (e.g., "refs/heads/master"): */ - char name[FLEX_ARRAY]; }; -struct ref_array { +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; - struct ref_entry **refs; + + /* + * 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; }; /* - * 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. + * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, + * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see + * refs.h. */ -static const char *parse_ref_line(char *line, unsigned char *sha1) -{ + +/* + * 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; /* - * 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) + * 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/"): */ - int len = strlen(line) - 42; + char name[FLEX_ARRAY]; +}; - 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; +static void read_loose_refs(const char *dirname, struct ref_dir *dir); - return line; +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, @@ -65,18 +272,73 @@ static struct ref_entry *create_ref_entry(const char *refname, die("Reference has invalid format: '%s'", refname); len = strlen(refname) + 1; ref = xmalloc(sizeof(struct ref_entry) + len); - hashcpy(ref->sha1, sha1); - hashclr(ref->peeled); + hashcpy(ref->u.value.sha1, sha1); + hashclr(ref->u.value.peeled); memcpy(ref->name, refname, len); ref->flag = flag; return ref; } -/* Add a ref_entry to the end of the ref_array (unsorted). */ -static void add_ref(struct ref_array *refs, struct ref_entry *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) { - ALLOC_GROW(refs->refs, refs->nr + 1, refs->alloc); - refs->refs[refs->nr++] = ref; + 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) @@ -86,6 +348,189 @@ static int ref_entry_cmp(const void *a, const void *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 @@ -93,105 +538,374 @@ static int ref_entry_cmp(const void *a, const void *b) */ static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2) { - if (!strcmp(ref1->name, ref2->name)) { - /* Duplicate name; make sure that the SHA1s match: */ - if (hashcmp(ref1->sha1, ref2->sha1)) - die("Duplicated ref, and SHA1s don't match: %s", - ref1->name); - warning("Duplicated ref: %s", ref1->name); - return 1; - } else { + 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; } -static void sort_ref_array(struct ref_array *array) +/* + * 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; - /* Nothing to sort unless there are at least two entries */ - if (array->nr < 2) + /* + * 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(array->refs, array->nr, sizeof(*array->refs), ref_entry_cmp); + qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp); - /* Remove any duplicates from the ref_array */ - i = 0; - for (j = 1; j < array->nr; j++) { - if (is_dup_ref(array->refs[i], array->refs[j])) { - free(array->refs[j]); - continue; - } - array->refs[++i] = array->refs[j]; + /* 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; } - array->nr = i + 1; + dir->sorted = dir->nr = i; } -static struct ref_entry *search_ref_array(struct ref_array *array, const char *refname) +/* 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) { - struct ref_entry *e, **r; - int len; + 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; +} - if (refname == NULL) - return NULL; +/* + * 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; - if (!array->nr) - return NULL; +typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data); - len = strlen(refname) + 1; - e = xmalloc(sizeof(struct ref_entry) + len); - memcpy(e->name, refname, len); +struct ref_entry_cb { + const char *base; + int trim; + int flags; + each_ref_fn *fn; + void *cb_data; +}; - r = bsearch(&e, array->refs, array->nr, sizeof(*array->refs), ref_entry_cmp); +/* + * 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; - free(e); + if (prefixcmp(entry->name, data->base)) + return 0; - if (r == NULL) - return NULL; + if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && + !ref_resolves_to_object(entry)) + return 0; - return *r; + /* 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)); + } +} +/* + * 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; +} + +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; - char did_loose; - char did_packed; - struct ref_array loose; - struct ref_array packed; - /* The submodule name, or "" for the main repo. */ - char name[FLEX_ARRAY]; -} *ref_cache; + 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; -static struct ref_entry *current_ref; +/* Lock used for the main packed-refs file: */ +static struct lock_file packlock; -static struct ref_array extra_refs; +/* + * Increment the reference count of *packed_refs. + */ +static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs) +{ + packed_refs->referrers++; +} -static void clear_ref_array(struct ref_array *array) +/* + * 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) { - int i; - for (i = 0; i < array->nr; i++) - free(array->refs[i]); - free(array->refs); - array->nr = array->alloc = 0; - array->refs = NULL; + 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->did_packed) - clear_ref_array(&refs->packed); - refs->did_packed = 0; + 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->did_loose) - clear_ref_array(&refs->loose); - refs->did_loose = 0; + if (refs->loose) { + free_ref_entry(refs->loose); + refs->loose = NULL; + } } static struct ref_cache *create_ref_cache(const char *submodule) @@ -214,18 +928,18 @@ static struct ref_cache *create_ref_cache(const char *submodule) */ static struct ref_cache *get_ref_cache(const char *submodule) { - struct ref_cache *refs = ref_cache; - if (!submodule) - submodule = ""; - while (refs) { + 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 = refs->next; - } refs = create_ref_cache(submodule); - refs->next = ref_cache; - ref_cache = refs; + refs->next = submodule_ref_caches; + submodule_ref_caches = refs; return refs; } @@ -236,11 +950,81 @@ void invalidate_ref_cache(const char *submodule) clear_loose_ref_cache(refs); } -static void read_packed_refs(FILE *f, struct ref_array *array) +/* 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]; - int flag = REF_ISPACKED; + enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; while (fgets(refline, sizeof(refline), f)) { unsigned char sha1[20]; @@ -249,165 +1033,177 @@ static void read_packed_refs(FILE *f, struct ref_array *array) if (!strncmp(refline, header, sizeof(header)-1)) { const char *traits = refline + sizeof(header) - 1; - if (strstr(traits, " peeled ")) - flag |= REF_KNOWS_PEELED; + 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, flag, 1); - add_ref(array, last); + 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) == 42 && - refline[41] == '\n' && - !get_sha1_hex(refline + 1, sha1)) - hashcpy(last->peeled, sha1); + 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; + } } - sort_ref_array(array); } -void add_extra_ref(const char *refname, const unsigned char *sha1, int flag) +/* + * 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) { - add_ref(&extra_refs, create_ref_entry(refname, sha1, flag, 0)); -} + const char *packed_refs_file; -void clear_extra_refs(void) -{ - clear_ref_array(&extra_refs); -} + if (*refs->name) + packed_refs_file = git_path_submodule(refs->name, "packed-refs"); + else + packed_refs_file = git_path("packed-refs"); -static struct ref_array *get_packed_refs(struct ref_cache *refs) -{ - if (!refs->did_packed) { - const char *packed_refs_file; + if (refs->packed && + !stat_validity_check(&refs->packed->validity, packed_refs_file)) + clear_packed_ref_cache(refs); + + if (!refs->packed) { FILE *f; - if (*refs->name) - packed_refs_file = git_path_submodule(refs->name, "packed-refs"); - else - packed_refs_file = git_path("packed-refs"); + 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) { - read_packed_refs(f, &refs->packed); + stat_validity_update(&refs->packed->validity, fileno(f)); + read_packed_refs(f, get_ref_dir(refs->packed->root)); fclose(f); } - refs->did_packed = 1; } - return &refs->packed; + return refs->packed; } -static void get_ref_dir(struct ref_cache *refs, const char *base, - struct ref_array *array) +static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache) { - DIR *dir; + 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", base); + path = git_path_submodule(refs->name, "%s", dirname); else - path = git_path("%s", base); + path = git_path("%s", dirname); + d = opendir(path); + if (!d) + return; - dir = opendir(path); - - if (dir) { - struct dirent *de; - int baselen = strlen(base); - char *refname = xmalloc(baselen + 257); - - memcpy(refname, base, baselen); - if (baselen && base[baselen-1] != '/') - refname[baselen++] = '/'; + strbuf_init(&refname, dirnamelen + 257); + strbuf_add(&refname, dirname, dirnamelen); - while ((de = readdir(dir)) != NULL) { - unsigned char sha1[20]; - struct stat st; - int flag; - int namelen; - const char *refdir; + while ((de = readdir(d)) != NULL) { + unsigned char sha1[20]; + struct stat st; + int flag; + const char *refdir; - if (de->d_name[0] == '.') - continue; - namelen = strlen(de->d_name); - if (namelen > 255) - continue; - if (has_extension(de->d_name, ".lock")) - continue; - memcpy(refname + baselen, de->d_name, namelen+1); - refdir = *refs->name - ? git_path_submodule(refs->name, "%s", refname) - : git_path("%s", refname); - if (stat(refdir, &st) < 0) - continue; - if (S_ISDIR(st.st_mode)) { - get_ref_dir(refs, refname, array); - continue; - } + 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, sha1) < 0) { + if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) { hashclr(sha1); flag |= REF_ISBROKEN; } - } else if (read_ref_full(refname, sha1, 1, &flag)) { + } else if (read_ref_full(refname.buf, sha1, 1, &flag)) { hashclr(sha1); flag |= REF_ISBROKEN; } - add_ref(array, create_ref_entry(refname, sha1, flag, 1)); + add_entry_to_dir(dir, + create_ref_entry(refname.buf, sha1, flag, 1)); } - free(refname); - closedir(dir); + strbuf_setlen(&refname, dirnamelen); } + strbuf_release(&refname); + closedir(d); } -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); - return 0; -} - -void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname) +static struct ref_dir *get_loose_refs(struct ref_cache *refs) { - 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); -} - -static struct ref_array *get_loose_refs(struct ref_cache *refs) -{ - if (!refs->did_loose) { - get_ref_dir(refs, "refs", &refs->loose); - sort_ref_array(&refs->loose); - refs->did_loose = 1; + 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 &refs->loose; + return get_ref_dir(refs->loose); } /* We allow "recursive" symbolic refs. Only within reason, though */ @@ -423,13 +1219,13 @@ static int resolve_gitlink_packed_ref(struct ref_cache *refs, const char *refname, unsigned char *sha1) { struct ref_entry *ref; - struct ref_array *array = get_packed_refs(refs); + struct ref_dir *dir = get_packed_refs(refs); - ref = search_ref_array(array, refname); + ref = find_ref(dir, refname); if (ref == NULL) return -1; - memcpy(sha1, ref->sha1, 20); + memcpy(sha1, ref->u.value.sha1, 20); return 0; } @@ -491,18 +1287,43 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sh } /* - * Try to read ref from the packed references. On success, set sha1 - * and return 0; otherwise, return -1. + * 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 get_packed_ref(const char *refname, unsigned char *sha1) +static const char *handle_missing_loose_ref(const char *refname, + unsigned char *sha1, + int reading, + int *flag) { - struct ref_array *packed = get_packed_refs(get_ref_cache(NULL)); - struct ref_entry *entry = search_ref_array(packed, refname); + 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->sha1); - return 0; + 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; } - return -1; } const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag) @@ -529,32 +1350,34 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea 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) + if (errno == ENOENT) + return handle_missing_loose_ref(refname, sha1, + reading, flag); + else return NULL; - /* - * The loose reference file does not exist; - * check for a packed reference. - */ - if (!get_packed_ref(refname, 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; + if (len < 0) { + if (errno == ENOENT || errno == EINVAL) + /* inconsistent with lstat; retry */ + goto stat_ref; + else + return NULL; + } buffer[len] = 0; if (!prefixcmp(buffer, "refs/") && !check_refname_format(buffer, 0)) { @@ -577,8 +1400,13 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea * a ref */ fd = open(path, O_RDONLY); - if (fd < 0) - return NULL; + 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); close(fd); if (len < 0) @@ -590,8 +1418,19 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea /* * Is it a symbolic ref? */ - if (prefixcmp(buffer, "ref:")) - break; + if (prefixcmp(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 (flag) + *flag |= REF_ISBROKEN; + return NULL; + } + return refname; + } if (flag) *flag |= REF_ISSYMREF; buf = buffer + 4; @@ -604,13 +1443,6 @@ const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int rea } 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) @@ -638,23 +1470,10 @@ int read_ref(const char *refname, unsigned char *sha1) return read_ref_full(refname, sha1, 1, NULL); } -#define DO_FOR_EACH_INCLUDE_BROKEN 01 -static int do_one_ref(const char *base, each_ref_fn fn, int trim, - int flags, void *cb_data, struct ref_entry *entry) +int ref_exists(const char *refname) { - if (prefixcmp(entry->name, base)) - return 0; - - if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) { - if (entry->flag & REF_ISBROKEN) - return 0; /* ignore broken refs e.g. dangling symref */ - if (!has_sha1_file(entry->sha1)) { - error("%s does not point to a valid object!", entry->name); - return 0; - } - } - current_ref = entry; - return fn(entry->name + trim, entry->sha1, entry->flag, cb_data); + 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, @@ -666,93 +1485,244 @@ static int filter_refs(const char *refname, const unsigned char *sha1, int flags 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]; - struct object *o; if (current_ref && (current_ref->name == refname - || !strcmp(current_ref->name, refname))) { - if (current_ref->flag & REF_KNOWS_PEELED) { - hashcpy(sha1, current_ref->peeled); - return 0; - } - hashcpy(base, current_ref->sha1); - goto fallback; + || !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 ((flag & REF_ISPACKED)) { - struct ref_array *array = get_packed_refs(get_ref_cache(NULL)); - struct ref_entry *r = search_ref_array(array, refname); - - if (r != NULL && r->flag & REF_KNOWS_PEELED) { - hashcpy(sha1, r->peeled); + /* + * 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; } } -fallback: - o = parse_object(base); - if (o && o->type == OBJ_TAG) { - o = deref_tag(o, refname, 0); - if (o) { - hashcpy(sha1, o->sha1); - return 0; - } - } - return -1; + return peel_object(base, sha1); } -static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn, - int trim, int flags, void *cb_data) +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) { - int retval = 0, i, p = 0, l = 0; - struct ref_cache *refs = get_ref_cache(submodule); - struct ref_array *packed = get_packed_refs(refs); - struct ref_array *loose = get_loose_refs(refs); + struct warn_if_dangling_data *d = cb_data; + const char *resolves_to; + unsigned char junk[20]; - struct ref_array *extra = &extra_refs; + if (!(flags & REF_ISSYMREF)) + return 0; - for (i = 0; i < extra->nr; i++) - retval = do_one_ref(base, fn, trim, flags, cb_data, extra->refs[i]); + resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL); + if (!resolves_to || strcmp(resolves_to, d->refname)) + return 0; - while (p < packed->nr && l < loose->nr) { - struct ref_entry *entry; - int cmp = strcmp(packed->refs[p]->name, loose->refs[l]->name); - if (!cmp) { - p++; - continue; - } - if (cmp > 0) { - entry = loose->refs[l++]; - } else { - entry = packed->refs[p++]; - } - retval = do_one_ref(base, fn, trim, flags, cb_data, entry); - if (retval) - goto end_each; - } + fprintf(d->fp, d->msg_fmt, refname); + fputc('\n', d->fp); + return 0; +} - if (l < loose->nr) { - p = l; - packed = loose; - } +void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname) +{ + struct warn_if_dangling_data data; - for (; p < packed->nr; p++) { - retval = do_one_ref(base, fn, trim, flags, cb_data, packed->refs[p]); - if (retval) - goto end_each; - } + data.fp = fp; + data.refname = refname; + data.msg_fmt = msg_fmt; + for_each_rawref(warn_if_dangling_symref, &data); +} -end_each: - current_ref = NULL; +/* + * 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; + + 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) { @@ -784,23 +1754,23 @@ int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data) int for_each_ref(each_ref_fn fn, void *cb_data) { - return do_for_each_ref(NULL, "", fn, 0, 0, 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(submodule, "", fn, 0, 0, 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(NULL, prefix, fn, strlen(prefix), 0, 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(submodule, prefix, fn, strlen(prefix), 0, 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) @@ -835,7 +1805,7 @@ int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *c int for_each_replace_ref(each_ref_fn fn, void *cb_data) { - return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, 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) @@ -858,7 +1828,7 @@ 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(NULL, buf.buf, fn, 0, 0, cb_data); + ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data); strbuf_release(&buf); return ret; } @@ -900,105 +1870,10 @@ int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data) int for_each_rawref(each_ref_fn fn, void *cb_data) { - return do_for_each_ref(NULL, "", fn, 0, + return do_for_each_ref(&ref_cache, "", fn, 0, DO_FOR_EACH_INCLUDE_BROKEN, cb_data); } -/* - * 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 -1; /* 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; - - 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; -} - const char *prettify_refname(const char *name) { return name + ( @@ -1069,35 +1944,6 @@ static int remove_empty_directories(const char *file) } /* - * Return true iff a reference named refname could be created without - * conflicting with the name of an existing reference. 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_array *array) -{ - int i, namlen = strlen(refname); /* e.g. 'foo/bar' */ - for (i = 0; i < array->nr; i++ ) { - struct ref_entry *entry = array->refs[i]; - /* entry->name could be 'foo' or 'foo/bar/baz' */ - if (!oldrefname || strcmp(oldrefname, entry->name)) { - int len = strlen(entry->name); - int cmplen = (namlen < len) ? namlen : len; - const char *lead = (namlen < len) ? entry->name : refname; - if (!strncmp(refname, entry->name, cmplen) && - lead[cmplen] == '/') { - error("'%s' exists; cannot create '%s'", - entry->name, refname); - return 0; - } - } - } - return 1; -} - -/* * *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. @@ -1230,7 +2076,7 @@ static struct ref_lock *lock_ref_sha1_basic(const char *refname, * name is a proper prefix of our refname. */ if (missing && - !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) { + !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) { last_errno = ENOTDIR; goto error_return; } @@ -1282,37 +2128,325 @@ struct ref_lock *lock_any_ref_for_update(const char *refname, return lock_ref_sha1_basic(refname, old_sha1, flags, NULL); } -static struct lock_file packlock; +/* + * 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; -static int repack_without_ref(const char *refname) + 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); + } +} + +/* + * 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) { - struct ref_array *packed; - int fd, i; + int *fd = cb_data; + enum peel_status peel_status = peel_entry(entry, 0); - packed = get_packed_refs(get_ref_cache(NULL)); - if (search_ref_array(packed, refname) == NULL) + 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(*fd, entry->name, entry->u.value.sha1, + peel_status == PEEL_PEELED ? + entry->u.value.peeled : NULL); + return 0; +} + +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; +} + +int commit_packed_refs(void) +{ + struct packed_ref_cache *packed_ref_cache = + get_packed_ref_cache(&ref_cache); + int error = 0; + + if (!packed_ref_cache->lock) + die("internal error: packed-refs not locked"); + write_or_die(packed_ref_cache->lock->fd, + PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER)); + + do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache), + 0, write_packed_entry_fn, + &packed_ref_cache->lock->fd); + if (commit_lock_file(packed_ref_cache->lock)) + error = -1; + packed_ref_cache->lock = NULL; + release_packed_ref_cache(packed_ref_cache); + 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 = !prefixcmp(entry->name, "refs/tags/"); + + /* ALWAYS pack tags */ + if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref) return 0; - fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0); - if (fd < 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_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; + } +} + +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; +} + +/* + * If entry is no longer needed in packed-refs, add it to the string + * list pointed to by cb_data. Reasons for deleting entries: + * + * - Entry is broken. + * - Entry is overridden by a loose ref. + * - Entry does not point at a valid object. + * + * In the first and third cases, also emit an error message because these + * are indications of repository corruption. + */ +static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data) +{ + struct string_list *refs_to_delete = cb_data; + + if (entry->flag & REF_ISBROKEN) { + /* This shouldn't happen to packed refs. */ + error("%s is broken!", entry->name); + string_list_append(refs_to_delete, 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 + * remove the packed reference. + */ + string_list_append(refs_to_delete, entry->name); + 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); + string_list_append(refs_to_delete, entry->name); + return 0; + } + + return 0; +} + +static int repack_without_ref(const char *refname) +{ + struct ref_dir *packed; + struct string_list refs_to_delete = STRING_LIST_INIT_DUP; + struct string_list_item *ref_to_delete; + + if (!get_packed_ref(refname)) + return 0; /* refname does not exist in packed refs */ + + if (lock_packed_refs(0)) { unable_to_lock_error(git_path("packed-refs"), errno); return error("cannot delete '%s' from packed refs", refname); } + packed = get_packed_refs(&ref_cache); - for (i = 0; i < packed->nr; i++) { - char line[PATH_MAX + 100]; - int len; - struct ref_entry *ref = packed->refs[i]; + /* Remove refname from the cache: */ + if (remove_entry(packed, refname) == -1) { + /* + * The packed entry disappeared while we were + * acquiring the lock. + */ + rollback_packed_refs(); + return 0; + } - if (!strcmp(refname, ref->name)) - continue; - len = snprintf(line, sizeof(line), "%s %s\n", - sha1_to_hex(ref->sha1), ref->name); - /* this should not happen but just being defensive */ - if (len > sizeof(line)) - die("too long a refname '%s'", ref->name); - write_or_die(fd, line, len); + /* Remove any other accumulated cruft: */ + do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete); + for_each_string_list_item(ref_to_delete, &refs_to_delete) { + if (remove_entry(packed, ref_to_delete->string) == -1) + die("internal error"); } - return commit_lock_file(&packlock); + + /* Write what remains: */ + return commit_packed_refs(); } int delete_ref(const char *refname, const unsigned char *sha1, int delopt) @@ -1320,35 +2454,27 @@ 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, 0, &flag); + lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag); if (!lock) return 1; if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) { /* loose */ - const char *path; - - if (!(delopt & REF_NODEREF)) { - i = strlen(lock->lk->filename) - 5; /* .lock */ - lock->lk->filename[i] = 0; - path = lock->lk->filename; - } else { - path = git_path("%s", refname); - } - err = unlink_or_warn(path); + 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; - if (!(delopt & REF_NODEREF)) - lock->lk->filename[i] = '.'; + 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(refname); + ret |= repack_without_ref(lock->ref_name); unlink_or_warn(git_path("logs/%s", lock->ref_name)); - invalidate_ref_cache(NULL); + clear_loose_ref_cache(&ref_cache); unlock_ref(lock); return ret; } @@ -1370,7 +2496,6 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms struct stat loginfo; int log = !lstat(git_path("logs/%s", oldrefname), &loginfo); const char *symref = NULL; - struct ref_cache *refs = get_ref_cache(NULL); if (log && S_ISLNK(loginfo.st_mode)) return error("reflog for %s is a symlink", oldrefname); @@ -1382,10 +2507,10 @@ int rename_ref(const char *oldrefname, const char *newrefname, const char *logms if (!symref) return error("refname %s not found", oldrefname); - if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs))) + if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache))) return 1; - if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs))) + 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))) @@ -1641,7 +2766,7 @@ int write_ref_sha1(struct ref_lock *lock, unlock_ref(lock); return -1; } - clear_loose_ref_cache(get_ref_cache(NULL)); + 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)) { @@ -1857,59 +2982,117 @@ int read_ref_at(const char *refname, unsigned long at_time, int cnt, return 1; } -int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data) +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) { - const char *logfile; - FILE *logfp; struct strbuf sb = STRBUF_INIT; - int ret = 0; + FILE *logfp; + long pos; + int ret = 0, at_tail = 1; - logfile = git_path("logs/%s", refname); - logfp = fopen(logfile, "r"); + logfp = fopen(git_path("logs/%s", refname), "r"); if (!logfp) return -1; - if (ofs) { - struct stat statbuf; - if (fstat(fileno(logfp), &statbuf) || - statbuf.st_size < ofs || - fseek(logfp, -ofs, SEEK_END) || - strbuf_getwholeline(&sb, logfp, '\n')) { - fclose(logfp); - strbuf_release(&sb); - 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; } - } - while (!strbuf_getwholeline(&sb, logfp, '\n')) { - 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])) - continue; /* corrupt? */ - email_end[1] = '\0'; - tz = strtol(message + 1, NULL, 10); - if (message[6] != '\t') - message += 6; - else - message += 7; - ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message, - cb_data); - if (ret) - break; } + if (!ret && sb.len) + ret = show_one_reflog_ent(&sb, fn, cb_data); + fclose(logfp); strbuf_release(&sb); return ret; @@ -1917,60 +3100,73 @@ int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data) { - return for_each_recent_reflog_ent(refname, fn, 0, cb_data); -} + FILE *logfp; + struct strbuf sb = STRBUF_INIT; + int ret = 0; -static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data) + 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 *dir = opendir(git_path("logs/%s", base)); + DIR *d = opendir(git_path("logs/%s", name->buf)); int retval = 0; + struct dirent *de; + int oldlen = name->len; - if (dir) { - struct dirent *de; - int baselen = strlen(base); - char *log = xmalloc(baselen + 257); - - memcpy(log, base, baselen); - if (baselen && base[baselen-1] != '/') - log[baselen++] = '/'; + if (!d) + return name->len ? errno : 0; - while ((de = readdir(dir)) != NULL) { - struct stat st; - int namelen; + while ((de = readdir(d)) != NULL) { + struct stat st; - if (de->d_name[0] == '.') - continue; - namelen = strlen(de->d_name); - if (namelen > 255) - continue; - if (has_extension(de->d_name, ".lock")) - continue; - memcpy(log + baselen, de->d_name, namelen+1); - if (stat(git_path("logs/%s", log), &st) < 0) - continue; + 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)) { - retval = do_for_each_reflog(log, fn, cb_data); + strbuf_addch(name, '/'); + retval = do_for_each_reflog(name, fn, cb_data); } else { unsigned char sha1[20]; - if (read_ref_full(log, sha1, 0, NULL)) - retval = error("bad ref for %s", log); + if (read_ref_full(name->buf, sha1, 0, NULL)) + retval = error("bad ref for %s", name->buf); else - retval = fn(log, sha1, 0, cb_data); + retval = fn(name->buf, sha1, 0, cb_data); } if (retval) break; } - free(log); - closedir(dir); + strbuf_setlen(name, oldlen); } - else if (*base) - return errno; + closedir(d); return retval; } int for_each_reflog(each_ref_fn fn, void *cb_data) { - return do_for_each_reflog("", fn, 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, @@ -2000,12 +3196,6 @@ int update_ref(const char *action, const char *refname, return 0; } -int ref_exists(const char *refname) -{ - unsigned char sha1[20]; - return !!resolve_ref_unsafe(refname, sha1, 1, NULL); -} - struct ref *find_ref_by_name(const struct ref *list, const char *name) { for ( ; list; list = list->next) @@ -2123,3 +3313,46 @@ char *shorten_unambiguous_ref(const char *refname, int strict) 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; +} |