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authorJunio C Hamano <gitster@pobox.com>2016-07-25 14:13:33 -0700
committerJunio C Hamano <gitster@pobox.com>2016-07-25 14:13:33 -0700
commit87492cb24d9d8be8e18217b89ae5f090089ff31d (patch)
treeb517e8efaa98fa713d8b6286ed6ee1c08c385a2e /refs
parent702ebbf4e2937accbac8184f87932f961e626a63 (diff)
parent2880d16f09635f9d43247b27fd7e6508b992e599 (diff)
downloadgit-87492cb24d9d8be8e18217b89ae5f090089ff31d.tar.gz
git-87492cb24d9d8be8e18217b89ae5f090089ff31d.tar.xz
Merge branch 'mh/ref-iterators'
The API to iterate over all the refs (i.e. for_each_ref(), etc.) has been revamped. * mh/ref-iterators: for_each_reflog(): reimplement using iterators dir_iterator: new API for iterating over a directory tree for_each_reflog(): don't abort for bad references do_for_each_ref(): reimplement using reference iteration refs: introduce an iterator interface ref_resolves_to_object(): new function entry_resolves_to_object(): rename function from ref_resolves_to_object() get_ref_cache(): only create an instance if there is a submodule remote rm: handle symbolic refs correctly delete_refs(): add a flags argument refs: use name "prefix" consistently do_for_each_ref(): move docstring to the header file refs: remove unnecessary "extern" keywords
Diffstat (limited to 'refs')
-rw-r--r--refs/files-backend.c631
-rw-r--r--refs/iterator.c384
-rw-r--r--refs/refs-internal.h226
3 files changed, 987 insertions, 254 deletions
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 1bf643025..12290d249 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1,6 +1,8 @@
#include "../cache.h"
#include "../refs.h"
#include "refs-internal.h"
+#include "../iterator.h"
+#include "../dir-iterator.h"
#include "../lockfile.h"
#include "../object.h"
#include "../dir.h"
@@ -513,68 +515,36 @@ static void sort_ref_dir(struct ref_dir *dir)
}
/*
- * 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.
+ * Return true if refname, which has the specified oid and flags, can
+ * be resolved to an object in the database. If the referred-to object
+ * does not exist, emit a warning and return false.
*/
-static int ref_resolves_to_object(struct ref_entry *entry)
+static int ref_resolves_to_object(const char *refname,
+ const struct object_id *oid,
+ unsigned int flags)
{
- if (entry->flag & REF_ISBROKEN)
+ if (flags & REF_ISBROKEN)
return 0;
- if (!has_sha1_file(entry->u.value.oid.hash)) {
- error("%s does not point to a valid object!", entry->name);
+ if (!has_sha1_file(oid->hash)) {
+ error("%s does not point to a valid object!", refname);
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.
+ * Return true if the reference described by entry can be resolved to
+ * an object in the database; otherwise, emit a warning and return
+ * false.
*/
-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)
+static int entry_resolves_to_object(struct ref_entry *entry)
{
- struct ref_entry_cb *data = cb_data;
- struct ref_entry *old_current_ref;
- int retval;
-
- if (!starts_with(entry->name, data->base))
- return 0;
-
- if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
- !ref_resolves_to_object(entry))
- return 0;
-
- /* Store the old value, in case this is a recursive call: */
- old_current_ref = current_ref;
- current_ref = entry;
- retval = data->fn(entry->name + data->trim, &entry->u.value.oid,
- entry->flag, data->cb_data);
- current_ref = old_current_ref;
- return retval;
+ return ref_resolves_to_object(entry->name,
+ &entry->u.value.oid, entry->flag);
}
+typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
+
/*
* Call fn for each reference in dir that has index in the range
* offset <= index < dir->nr. Recurse into subdirectories that are in
@@ -604,78 +574,6 @@ static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
}
/*
- * 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
@@ -691,6 +589,153 @@ static void prime_ref_dir(struct ref_dir *dir)
}
}
+/*
+ * A level in the reference hierarchy that is currently being iterated
+ * through.
+ */
+struct cache_ref_iterator_level {
+ /*
+ * The ref_dir being iterated over at this level. The ref_dir
+ * is sorted before being stored here.
+ */
+ struct ref_dir *dir;
+
+ /*
+ * The index of the current entry within dir (which might
+ * itself be a directory). If index == -1, then the iteration
+ * hasn't yet begun. If index == dir->nr, then the iteration
+ * through this level is over.
+ */
+ int index;
+};
+
+/*
+ * Represent an iteration through a ref_dir in the memory cache. The
+ * iteration recurses through subdirectories.
+ */
+struct cache_ref_iterator {
+ struct ref_iterator base;
+
+ /*
+ * The number of levels currently on the stack. This is always
+ * at least 1, because when it becomes zero the iteration is
+ * ended and this struct is freed.
+ */
+ size_t levels_nr;
+
+ /* The number of levels that have been allocated on the stack */
+ size_t levels_alloc;
+
+ /*
+ * A stack of levels. levels[0] is the uppermost level that is
+ * being iterated over in this iteration. (This is not
+ * necessary the top level in the references hierarchy. If we
+ * are iterating through a subtree, then levels[0] will hold
+ * the ref_dir for that subtree, and subsequent levels will go
+ * on from there.)
+ */
+ struct cache_ref_iterator_level *levels;
+};
+
+static int cache_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct cache_ref_iterator *iter =
+ (struct cache_ref_iterator *)ref_iterator;
+
+ while (1) {
+ struct cache_ref_iterator_level *level =
+ &iter->levels[iter->levels_nr - 1];
+ struct ref_dir *dir = level->dir;
+ struct ref_entry *entry;
+
+ if (level->index == -1)
+ sort_ref_dir(dir);
+
+ if (++level->index == level->dir->nr) {
+ /* This level is exhausted; pop up a level */
+ if (--iter->levels_nr == 0)
+ return ref_iterator_abort(ref_iterator);
+
+ continue;
+ }
+
+ entry = dir->entries[level->index];
+
+ if (entry->flag & REF_DIR) {
+ /* push down a level */
+ ALLOC_GROW(iter->levels, iter->levels_nr + 1,
+ iter->levels_alloc);
+
+ level = &iter->levels[iter->levels_nr++];
+ level->dir = get_ref_dir(entry);
+ level->index = -1;
+ } else {
+ iter->base.refname = entry->name;
+ iter->base.oid = &entry->u.value.oid;
+ iter->base.flags = entry->flag;
+ return ITER_OK;
+ }
+ }
+}
+
+static enum peel_status peel_entry(struct ref_entry *entry, int repeel);
+
+static int cache_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ struct cache_ref_iterator *iter =
+ (struct cache_ref_iterator *)ref_iterator;
+ struct cache_ref_iterator_level *level;
+ struct ref_entry *entry;
+
+ level = &iter->levels[iter->levels_nr - 1];
+
+ if (level->index == -1)
+ die("BUG: peel called before advance for cache iterator");
+
+ entry = level->dir->entries[level->index];
+
+ if (peel_entry(entry, 0))
+ return -1;
+ hashcpy(peeled->hash, entry->u.value.peeled.hash);
+ return 0;
+}
+
+static int cache_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct cache_ref_iterator *iter =
+ (struct cache_ref_iterator *)ref_iterator;
+
+ free(iter->levels);
+ base_ref_iterator_free(ref_iterator);
+ return ITER_DONE;
+}
+
+static struct ref_iterator_vtable cache_ref_iterator_vtable = {
+ cache_ref_iterator_advance,
+ cache_ref_iterator_peel,
+ cache_ref_iterator_abort
+};
+
+static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir)
+{
+ struct cache_ref_iterator *iter;
+ struct ref_iterator *ref_iterator;
+ struct cache_ref_iterator_level *level;
+
+ iter = xcalloc(1, sizeof(*iter));
+ ref_iterator = &iter->base;
+ base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable);
+ ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
+
+ iter->levels_nr = 1;
+ level = &iter->levels[0];
+ level->index = -1;
+ level->dir = dir;
+
+ return ref_iterator;
+}
+
struct nonmatching_ref_data {
const struct string_list *skip;
const char *conflicting_refname;
@@ -954,15 +999,26 @@ static struct ref_cache *lookup_ref_cache(const char *submodule)
/*
* 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.
+ * the main repository, use submodule==NULL; such a call cannot fail.
+ * For a submodule, the submodule must exist and be a nonbare
+ * repository, otherwise return 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 = lookup_ref_cache(submodule);
- if (!refs)
- refs = create_ref_cache(submodule);
+
+ if (!refs) {
+ struct strbuf submodule_sb = STRBUF_INIT;
+
+ strbuf_addstr(&submodule_sb, submodule);
+ if (is_nonbare_repository_dir(&submodule_sb))
+ refs = create_ref_cache(submodule);
+ strbuf_release(&submodule_sb);
+ }
+
return refs;
}
@@ -1341,13 +1397,10 @@ int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sh
return -1;
strbuf_add(&submodule, path, len);
- refs = lookup_ref_cache(submodule.buf);
+ refs = get_ref_cache(submodule.buf);
if (!refs) {
- if (!is_nonbare_repository_dir(&submodule)) {
- strbuf_release(&submodule);
- return -1;
- }
- refs = create_ref_cache(submodule.buf);
+ strbuf_release(&submodule);
+ return -1;
}
strbuf_release(&submodule);
@@ -1790,11 +1843,12 @@ 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))
+ if (current_ref_iter && current_ref_iter->refname == refname) {
+ struct object_id peeled;
+
+ if (ref_iterator_peel(current_ref_iter, &peeled))
return -1;
- hashcpy(sha1, current_ref->u.value.peeled.hash);
+ hashcpy(sha1, peeled.hash);
return 0;
}
@@ -1822,90 +1876,137 @@ int peel_ref(const char *refname, unsigned char *sha1)
return peel_object(base, sha1);
}
-/*
- * 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 files_ref_iterator {
+ struct ref_iterator base;
+
struct packed_ref_cache *packed_ref_cache;
- struct ref_dir *loose_dir;
- struct ref_dir *packed_dir;
- int retval = 0;
+ struct ref_iterator *iter0;
+ unsigned int flags;
+};
- /*
- * 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);
+static int files_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
+ int ok;
- 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);
+ while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ if (!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
+ !ref_resolves_to_object(iter->iter0->refname,
+ iter->iter0->oid,
+ iter->iter0->flags))
+ continue;
+
+ iter->base.refname = iter->iter0->refname;
+ iter->base.oid = iter->iter0->oid;
+ iter->base.flags = iter->iter0->flags;
+ return ITER_OK;
}
- release_packed_ref_cache(packed_ref_cache);
- return retval;
+ iter->iter0 = NULL;
+ if (ref_iterator_abort(ref_iterator) != ITER_DONE)
+ ok = ITER_ERROR;
+
+ return ok;
}
-/*
- * 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.
- */
-int do_for_each_ref(const char *submodule, const char *base,
- each_ref_fn fn, int trim, int flags, void *cb_data)
+static int files_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
{
- struct ref_entry_cb data;
- struct ref_cache *refs;
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
- refs = get_ref_cache(submodule);
- data.base = base;
- data.trim = trim;
- data.flags = flags;
- data.fn = fn;
- data.cb_data = cb_data;
+ return ref_iterator_peel(iter->iter0, peeled);
+}
+
+static int files_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct files_ref_iterator *iter =
+ (struct files_ref_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->iter0)
+ ok = ref_iterator_abort(iter->iter0);
+
+ release_packed_ref_cache(iter->packed_ref_cache);
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable files_ref_iterator_vtable = {
+ files_ref_iterator_advance,
+ files_ref_iterator_peel,
+ files_ref_iterator_abort
+};
+
+struct ref_iterator *files_ref_iterator_begin(
+ const char *submodule,
+ const char *prefix, unsigned int flags)
+{
+ struct ref_cache *refs = get_ref_cache(submodule);
+ struct ref_dir *loose_dir, *packed_dir;
+ struct ref_iterator *loose_iter, *packed_iter;
+ struct files_ref_iterator *iter;
+ struct ref_iterator *ref_iterator;
+
+ if (!refs)
+ return empty_ref_iterator_begin();
if (ref_paranoia < 0)
ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
if (ref_paranoia)
- data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;
+ flags |= DO_FOR_EACH_INCLUDE_BROKEN;
+
+ iter = xcalloc(1, sizeof(*iter));
+ ref_iterator = &iter->base;
+ base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);
+
+ /*
+ * We must make sure that all loose refs are read before
+ * accessing the packed-refs file; this avoids a race
+ * condition if loose refs are migrated to the packed-refs
+ * file by a simultaneous process, but our in-memory view is
+ * from before the migration. We ensure this as follows:
+ * First, we call prime_ref_dir(), which pre-reads the loose
+ * references for the subtree into the cache. (If they've
+ * already been read, that's OK; we only need to guarantee
+ * that they're read before the packed refs, not *how much*
+ * before.) After that, we call get_packed_ref_cache(), which
+ * internally checks whether the packed-ref cache is up to
+ * date with what is on disk, and re-reads it if not.
+ */
+
+ loose_dir = get_loose_refs(refs);
+
+ if (prefix && *prefix)
+ loose_dir = find_containing_dir(loose_dir, prefix, 0);
- return do_for_each_entry(refs, base, do_one_ref, &data);
+ if (loose_dir) {
+ prime_ref_dir(loose_dir);
+ loose_iter = cache_ref_iterator_begin(loose_dir);
+ } else {
+ /* There's nothing to iterate over. */
+ loose_iter = empty_ref_iterator_begin();
+ }
+
+ iter->packed_ref_cache = get_packed_ref_cache(refs);
+ acquire_packed_ref_cache(iter->packed_ref_cache);
+ packed_dir = get_packed_ref_dir(iter->packed_ref_cache);
+
+ if (prefix && *prefix)
+ packed_dir = find_containing_dir(packed_dir, prefix, 0);
+
+ if (packed_dir) {
+ packed_iter = cache_ref_iterator_begin(packed_dir);
+ } else {
+ /* There's nothing to iterate over. */
+ packed_iter = empty_ref_iterator_begin();
+ }
+
+ iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter);
+ iter->flags = flags;
+
+ return ref_iterator;
}
/*
@@ -2226,7 +2327,7 @@ static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
return 0;
/* Do not pack symbolic or broken refs: */
- if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
+ if ((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))
return 0;
/* Add a packed ref cache entry equivalent to the loose entry. */
@@ -2412,7 +2513,7 @@ static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
return 0;
}
-int delete_refs(struct string_list *refnames)
+int delete_refs(struct string_list *refnames, unsigned int flags)
{
struct strbuf err = STRBUF_INIT;
int i, result = 0;
@@ -2441,7 +2542,7 @@ int delete_refs(struct string_list *refnames)
for (i = 0; i < refnames->nr; i++) {
const char *refname = refnames->items[i].string;
- if (delete_ref(refname, NULL, 0))
+ if (delete_ref(refname, NULL, flags))
result |= error(_("could not remove reference %s"), refname);
}
@@ -3191,60 +3292,88 @@ int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_dat
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;
+struct files_reflog_iterator {
+ struct ref_iterator base;
- while ((de = readdir(d)) != NULL) {
- struct stat st;
+ struct dir_iterator *dir_iterator;
+ struct object_id oid;
+};
- if (de->d_name[0] == '.')
+static int files_reflog_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct files_reflog_iterator *iter =
+ (struct files_reflog_iterator *)ref_iterator;
+ struct dir_iterator *diter = iter->dir_iterator;
+ int ok;
+
+ while ((ok = dir_iterator_advance(diter)) == ITER_OK) {
+ int flags;
+
+ if (!S_ISREG(diter->st.st_mode))
continue;
- if (ends_with(de->d_name, ".lock"))
+ if (diter->basename[0] == '.')
+ continue;
+ if (ends_with(diter->basename, ".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 {
- struct object_id oid;
- if (read_ref_full(name->buf, 0, oid.hash, NULL))
- retval = error("bad ref for %s", name->buf);
- else
- retval = fn(name->buf, &oid, 0, cb_data);
- }
- if (retval)
- break;
+ if (read_ref_full(diter->relative_path, 0,
+ iter->oid.hash, &flags)) {
+ error("bad ref for %s", diter->path.buf);
+ continue;
}
- strbuf_setlen(name, oldlen);
+
+ iter->base.refname = diter->relative_path;
+ iter->base.oid = &iter->oid;
+ iter->base.flags = flags;
+ return ITER_OK;
}
- closedir(d);
- return retval;
+
+ iter->dir_iterator = NULL;
+ if (ref_iterator_abort(ref_iterator) == ITER_ERROR)
+ ok = ITER_ERROR;
+ return ok;
+}
+
+static int files_reflog_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ die("BUG: ref_iterator_peel() called for reflog_iterator");
+}
+
+static int files_reflog_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct files_reflog_iterator *iter =
+ (struct files_reflog_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->dir_iterator)
+ ok = dir_iterator_abort(iter->dir_iterator);
+
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable files_reflog_iterator_vtable = {
+ files_reflog_iterator_advance,
+ files_reflog_iterator_peel,
+ files_reflog_iterator_abort
+};
+
+struct ref_iterator *files_reflog_iterator_begin(void)
+{
+ struct files_reflog_iterator *iter = xcalloc(1, sizeof(*iter));
+ struct ref_iterator *ref_iterator = &iter->base;
+
+ base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);
+ iter->dir_iterator = dir_iterator_begin(git_path("logs"));
+ return ref_iterator;
}
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;
+ return do_for_each_ref_iterator(files_reflog_iterator_begin(),
+ fn, cb_data);
}
static int ref_update_reject_duplicates(struct string_list *refnames,
diff --git a/refs/iterator.c b/refs/iterator.c
new file mode 100644
index 000000000..bce1f192f
--- /dev/null
+++ b/refs/iterator.c
@@ -0,0 +1,384 @@
+/*
+ * Generic reference iterator infrastructure. See refs-internal.h for
+ * documentation about the design and use of reference iterators.
+ */
+
+#include "cache.h"
+#include "refs.h"
+#include "refs/refs-internal.h"
+#include "iterator.h"
+
+int ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ return ref_iterator->vtable->advance(ref_iterator);
+}
+
+int ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ return ref_iterator->vtable->peel(ref_iterator, peeled);
+}
+
+int ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ return ref_iterator->vtable->abort(ref_iterator);
+}
+
+void base_ref_iterator_init(struct ref_iterator *iter,
+ struct ref_iterator_vtable *vtable)
+{
+ iter->vtable = vtable;
+ iter->refname = NULL;
+ iter->oid = NULL;
+ iter->flags = 0;
+}
+
+void base_ref_iterator_free(struct ref_iterator *iter)
+{
+ /* Help make use-after-free bugs fail quickly: */
+ iter->vtable = NULL;
+ free(iter);
+}
+
+struct empty_ref_iterator {
+ struct ref_iterator base;
+};
+
+static int empty_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ return ref_iterator_abort(ref_iterator);
+}
+
+static int empty_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ die("BUG: peel called for empty iterator");
+}
+
+static int empty_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ base_ref_iterator_free(ref_iterator);
+ return ITER_DONE;
+}
+
+static struct ref_iterator_vtable empty_ref_iterator_vtable = {
+ empty_ref_iterator_advance,
+ empty_ref_iterator_peel,
+ empty_ref_iterator_abort
+};
+
+struct ref_iterator *empty_ref_iterator_begin(void)
+{
+ struct empty_ref_iterator *iter = xcalloc(1, sizeof(*iter));
+ struct ref_iterator *ref_iterator = &iter->base;
+
+ base_ref_iterator_init(ref_iterator, &empty_ref_iterator_vtable);
+ return ref_iterator;
+}
+
+int is_empty_ref_iterator(struct ref_iterator *ref_iterator)
+{
+ return ref_iterator->vtable == &empty_ref_iterator_vtable;
+}
+
+struct merge_ref_iterator {
+ struct ref_iterator base;
+
+ struct ref_iterator *iter0, *iter1;
+
+ ref_iterator_select_fn *select;
+ void *cb_data;
+
+ /*
+ * A pointer to iter0 or iter1 (whichever is supplying the
+ * current value), or NULL if advance has not yet been called.
+ */
+ struct ref_iterator **current;
+};
+
+static int merge_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct merge_ref_iterator *iter =
+ (struct merge_ref_iterator *)ref_iterator;
+ int ok;
+
+ if (!iter->current) {
+ /* Initialize: advance both iterators to their first entries */
+ if ((ok = ref_iterator_advance(iter->iter0)) != ITER_OK) {
+ iter->iter0 = NULL;
+ if (ok == ITER_ERROR)
+ goto error;
+ }
+ if ((ok = ref_iterator_advance(iter->iter1)) != ITER_OK) {
+ iter->iter1 = NULL;
+ if (ok == ITER_ERROR)
+ goto error;
+ }
+ } else {
+ /*
+ * Advance the current iterator past the just-used
+ * entry:
+ */
+ if ((ok = ref_iterator_advance(*iter->current)) != ITER_OK) {
+ *iter->current = NULL;
+ if (ok == ITER_ERROR)
+ goto error;
+ }
+ }
+
+ /* Loop until we find an entry that we can yield. */
+ while (1) {
+ struct ref_iterator **secondary;
+ enum iterator_selection selection =
+ iter->select(iter->iter0, iter->iter1, iter->cb_data);
+
+ if (selection == ITER_SELECT_DONE) {
+ return ref_iterator_abort(ref_iterator);
+ } else if (selection == ITER_SELECT_ERROR) {
+ ref_iterator_abort(ref_iterator);
+ return ITER_ERROR;
+ }
+
+ if ((selection & ITER_CURRENT_SELECTION_MASK) == 0) {
+ iter->current = &iter->iter0;
+ secondary = &iter->iter1;
+ } else {
+ iter->current = &iter->iter1;
+ secondary = &iter->iter0;
+ }
+
+ if (selection & ITER_SKIP_SECONDARY) {
+ if ((ok = ref_iterator_advance(*secondary)) != ITER_OK) {
+ *secondary = NULL;
+ if (ok == ITER_ERROR)
+ goto error;
+ }
+ }
+
+ if (selection & ITER_YIELD_CURRENT) {
+ iter->base.refname = (*iter->current)->refname;
+ iter->base.oid = (*iter->current)->oid;
+ iter->base.flags = (*iter->current)->flags;
+ return ITER_OK;
+ }
+ }
+
+error:
+ ref_iterator_abort(ref_iterator);
+ return ITER_ERROR;
+}
+
+static int merge_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ struct merge_ref_iterator *iter =
+ (struct merge_ref_iterator *)ref_iterator;
+
+ if (!iter->current) {
+ die("BUG: peel called before advance for merge iterator");
+ }
+ return ref_iterator_peel(*iter->current, peeled);
+}
+
+static int merge_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct merge_ref_iterator *iter =
+ (struct merge_ref_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->iter0) {
+ if (ref_iterator_abort(iter->iter0) != ITER_DONE)
+ ok = ITER_ERROR;
+ }
+ if (iter->iter1) {
+ if (ref_iterator_abort(iter->iter1) != ITER_DONE)
+ ok = ITER_ERROR;
+ }
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable merge_ref_iterator_vtable = {
+ merge_ref_iterator_advance,
+ merge_ref_iterator_peel,
+ merge_ref_iterator_abort
+};
+
+struct ref_iterator *merge_ref_iterator_begin(
+ struct ref_iterator *iter0, struct ref_iterator *iter1,
+ ref_iterator_select_fn *select, void *cb_data)
+{
+ struct merge_ref_iterator *iter = xcalloc(1, sizeof(*iter));
+ struct ref_iterator *ref_iterator = &iter->base;
+
+ /*
+ * We can't do the same kind of is_empty_ref_iterator()-style
+ * optimization here as overlay_ref_iterator_begin() does,
+ * because we don't know the semantics of the select function.
+ * It might, for example, implement "intersect" by passing
+ * references through only if they exist in both iterators.
+ */
+
+ base_ref_iterator_init(ref_iterator, &merge_ref_iterator_vtable);
+ iter->iter0 = iter0;
+ iter->iter1 = iter1;
+ iter->select = select;
+ iter->cb_data = cb_data;
+ iter->current = NULL;
+ return ref_iterator;
+}
+
+/*
+ * A ref_iterator_select_fn that overlays the items from front on top
+ * of those from back (like loose refs over packed refs). See
+ * overlay_ref_iterator_begin().
+ */
+static enum iterator_selection overlay_iterator_select(
+ struct ref_iterator *front, struct ref_iterator *back,
+ void *cb_data)
+{
+ int cmp;
+
+ if (!back)
+ return front ? ITER_SELECT_0 : ITER_SELECT_DONE;
+ else if (!front)
+ return ITER_SELECT_1;
+
+ cmp = strcmp(front->refname, back->refname);
+
+ if (cmp < 0)
+ return ITER_SELECT_0;
+ else if (cmp > 0)
+ return ITER_SELECT_1;
+ else
+ return ITER_SELECT_0_SKIP_1;
+}
+
+struct ref_iterator *overlay_ref_iterator_begin(
+ struct ref_iterator *front, struct ref_iterator *back)
+{
+ /*
+ * Optimization: if one of the iterators is empty, return the
+ * other one rather than incurring the overhead of wrapping
+ * them.
+ */
+ if (is_empty_ref_iterator(front)) {
+ ref_iterator_abort(front);
+ return back;
+ } else if (is_empty_ref_iterator(back)) {
+ ref_iterator_abort(back);
+ return front;
+ }
+
+ return merge_ref_iterator_begin(front, back,
+ overlay_iterator_select, NULL);
+}
+
+struct prefix_ref_iterator {
+ struct ref_iterator base;
+
+ struct ref_iterator *iter0;
+ char *prefix;
+ int trim;
+};
+
+static int prefix_ref_iterator_advance(struct ref_iterator *ref_iterator)
+{
+ struct prefix_ref_iterator *iter =
+ (struct prefix_ref_iterator *)ref_iterator;
+ int ok;
+
+ while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) {
+ if (!starts_with(iter->iter0->refname, iter->prefix))
+ continue;
+
+ iter->base.refname = iter->iter0->refname + iter->trim;
+ iter->base.oid = iter->iter0->oid;
+ iter->base.flags = iter->iter0->flags;
+ return ITER_OK;
+ }
+
+ iter->iter0 = NULL;
+ if (ref_iterator_abort(ref_iterator) != ITER_DONE)
+ return ITER_ERROR;
+ return ok;
+}
+
+static int prefix_ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled)
+{
+ struct prefix_ref_iterator *iter =
+ (struct prefix_ref_iterator *)ref_iterator;
+
+ return ref_iterator_peel(iter->iter0, peeled);
+}
+
+static int prefix_ref_iterator_abort(struct ref_iterator *ref_iterator)
+{
+ struct prefix_ref_iterator *iter =
+ (struct prefix_ref_iterator *)ref_iterator;
+ int ok = ITER_DONE;
+
+ if (iter->iter0)
+ ok = ref_iterator_abort(iter->iter0);
+ free(iter->prefix);
+ base_ref_iterator_free(ref_iterator);
+ return ok;
+}
+
+static struct ref_iterator_vtable prefix_ref_iterator_vtable = {
+ prefix_ref_iterator_advance,
+ prefix_ref_iterator_peel,
+ prefix_ref_iterator_abort
+};
+
+struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
+ const char *prefix,
+ int trim)
+{
+ struct prefix_ref_iterator *iter;
+ struct ref_iterator *ref_iterator;
+
+ if (!*prefix && !trim)
+ return iter0; /* optimization: no need to wrap iterator */
+
+ iter = xcalloc(1, sizeof(*iter));
+ ref_iterator = &iter->base;
+
+ base_ref_iterator_init(ref_iterator, &prefix_ref_iterator_vtable);
+
+ iter->iter0 = iter0;
+ iter->prefix = xstrdup(prefix);
+ iter->trim = trim;
+
+ return ref_iterator;
+}
+
+struct ref_iterator *current_ref_iter = NULL;
+
+int do_for_each_ref_iterator(struct ref_iterator *iter,
+ each_ref_fn fn, void *cb_data)
+{
+ int retval = 0, ok;
+ struct ref_iterator *old_ref_iter = current_ref_iter;
+
+ current_ref_iter = iter;
+ while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
+ retval = fn(iter->refname, iter->oid, iter->flags, cb_data);
+ if (retval) {
+ /*
+ * If ref_iterator_abort() returns ITER_ERROR,
+ * we ignore that error in deference to the
+ * callback function's return value.
+ */
+ ref_iterator_abort(iter);
+ goto out;
+ }
+ }
+
+out:
+ current_ref_iter = old_ref_iter;
+ if (ok == ITER_ERROR)
+ return -1;
+ return retval;
+}
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 1bb3d87dc..efe584701 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -249,10 +249,230 @@ int rename_ref_available(const char *oldname, const char *newname);
#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
/*
- * The common backend for the for_each_*ref* functions
+ * Reference iterators
+ *
+ * A reference iterator encapsulates the state of an in-progress
+ * iteration over references. Create an instance of `struct
+ * ref_iterator` via one of the functions in this module.
+ *
+ * A freshly-created ref_iterator doesn't yet point at a reference. To
+ * advance the iterator, call ref_iterator_advance(). If successful,
+ * this sets the iterator's refname, oid, and flags fields to describe
+ * the next reference and returns ITER_OK. The data pointed at by
+ * refname and oid belong to the iterator; if you want to retain them
+ * after calling ref_iterator_advance() again or calling
+ * ref_iterator_abort(), you must make a copy. When the iteration has
+ * been exhausted, ref_iterator_advance() releases any resources
+ * assocated with the iteration, frees the ref_iterator object, and
+ * returns ITER_DONE. If you want to abort the iteration early, call
+ * ref_iterator_abort(), which also frees the ref_iterator object and
+ * any associated resources. If there was an internal error advancing
+ * to the next entry, ref_iterator_advance() aborts the iteration,
+ * frees the ref_iterator, and returns ITER_ERROR.
+ *
+ * The reference currently being looked at can be peeled by calling
+ * ref_iterator_peel(). This function is often faster than peel_ref(),
+ * so it should be preferred when iterating over references.
+ *
+ * Putting it all together, a typical iteration looks like this:
+ *
+ * int ok;
+ * struct ref_iterator *iter = ...;
+ *
+ * while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
+ * if (want_to_stop_iteration()) {
+ * ok = ref_iterator_abort(iter);
+ * break;
+ * }
+ *
+ * // Access information about the current reference:
+ * if (!(iter->flags & REF_ISSYMREF))
+ * printf("%s is %s\n", iter->refname, oid_to_hex(&iter->oid));
+ *
+ * // If you need to peel the reference:
+ * ref_iterator_peel(iter, &oid);
+ * }
+ *
+ * if (ok != ITER_DONE)
+ * handle_error();
+ */
+struct ref_iterator {
+ struct ref_iterator_vtable *vtable;
+ const char *refname;
+ const struct object_id *oid;
+ unsigned int flags;
+};
+
+/*
+ * Advance the iterator to the first or next item and return ITER_OK.
+ * If the iteration is exhausted, free the resources associated with
+ * the ref_iterator and return ITER_DONE. On errors, free the iterator
+ * resources and return ITER_ERROR. It is a bug to use ref_iterator or
+ * call this function again after it has returned ITER_DONE or
+ * ITER_ERROR.
+ */
+int ref_iterator_advance(struct ref_iterator *ref_iterator);
+
+/*
+ * If possible, peel the reference currently being viewed by the
+ * iterator. Return 0 on success.
+ */
+int ref_iterator_peel(struct ref_iterator *ref_iterator,
+ struct object_id *peeled);
+
+/*
+ * End the iteration before it has been exhausted, freeing the
+ * reference iterator and any associated resources and returning
+ * ITER_DONE. If the abort itself failed, return ITER_ERROR.
+ */
+int ref_iterator_abort(struct ref_iterator *ref_iterator);
+
+/*
+ * An iterator over nothing (its first ref_iterator_advance() call
+ * returns ITER_DONE).
+ */
+struct ref_iterator *empty_ref_iterator_begin(void);
+
+/*
+ * Return true iff ref_iterator is an empty_ref_iterator.
+ */
+int is_empty_ref_iterator(struct ref_iterator *ref_iterator);
+
+/*
+ * A callback function used to instruct merge_ref_iterator how to
+ * interleave the entries from iter0 and iter1. The function should
+ * return one of the constants defined in enum iterator_selection. It
+ * must not advance either of the iterators itself.
+ *
+ * The function must be prepared to handle the case that iter0 and/or
+ * iter1 is NULL, which indicates that the corresponding sub-iterator
+ * has been exhausted. Its return value must be consistent with the
+ * current states of the iterators; e.g., it must not return
+ * ITER_SKIP_1 if iter1 has already been exhausted.
+ */
+typedef enum iterator_selection ref_iterator_select_fn(
+ struct ref_iterator *iter0, struct ref_iterator *iter1,
+ void *cb_data);
+
+/*
+ * Iterate over the entries from iter0 and iter1, with the values
+ * interleaved as directed by the select function. The iterator takes
+ * ownership of iter0 and iter1 and frees them when the iteration is
+ * over.
+ */
+struct ref_iterator *merge_ref_iterator_begin(
+ struct ref_iterator *iter0, struct ref_iterator *iter1,
+ ref_iterator_select_fn *select, void *cb_data);
+
+/*
+ * An iterator consisting of the union of the entries from front and
+ * back. If there are entries common to the two sub-iterators, use the
+ * one from front. Each iterator must iterate over its entries in
+ * strcmp() order by refname for this to work.
+ *
+ * The new iterator takes ownership of its arguments and frees them
+ * when the iteration is over. As a convenience to callers, if front
+ * or back is an empty_ref_iterator, then abort that one immediately
+ * and return the other iterator directly, without wrapping it.
+ */
+struct ref_iterator *overlay_ref_iterator_begin(
+ struct ref_iterator *front, struct ref_iterator *back);
+
+/*
+ * Wrap iter0, only letting through the references whose names start
+ * with prefix. If trim is set, set iter->refname to the name of the
+ * reference with that many characters trimmed off the front;
+ * otherwise set it to the full refname. The new iterator takes over
+ * ownership of iter0 and frees it when iteration is over. It makes
+ * its own copy of prefix.
+ *
+ * As an convenience to callers, if prefix is the empty string and
+ * trim is zero, this function returns iter0 directly, without
+ * wrapping it.
+ */
+struct ref_iterator *prefix_ref_iterator_begin(struct ref_iterator *iter0,
+ const char *prefix,
+ int trim);
+
+/*
+ * Iterate over the packed and loose references in the specified
+ * submodule that are within find_containing_dir(prefix). If prefix is
+ * NULL or the empty string, iterate over all references in the
+ * submodule.
+ */
+struct ref_iterator *files_ref_iterator_begin(const char *submodule,
+ const char *prefix,
+ unsigned int flags);
+
+/*
+ * Iterate over the references in the main ref_store that have a
+ * reflog. The paths within a directory are iterated over in arbitrary
+ * order.
+ */
+struct ref_iterator *files_reflog_iterator_begin(void);
+
+/* Internal implementation of reference iteration: */
+
+/*
+ * Base class constructor for ref_iterators. Initialize the
+ * ref_iterator part of iter, setting its vtable pointer as specified.
+ * This is meant to be called only by the initializers of derived
+ * classes.
+ */
+void base_ref_iterator_init(struct ref_iterator *iter,
+ struct ref_iterator_vtable *vtable);
+
+/*
+ * Base class destructor for ref_iterators. Destroy the ref_iterator
+ * part of iter and shallow-free the object. This is meant to be
+ * called only by the destructors of derived classes.
+ */
+void base_ref_iterator_free(struct ref_iterator *iter);
+
+/* Virtual function declarations for ref_iterators: */
+
+typedef int ref_iterator_advance_fn(struct ref_iterator *ref_iterator);
+
+typedef int ref_iterator_peel_fn(struct ref_iterator *ref_iterator,
+ struct object_id *peeled);
+
+/*
+ * Implementations of this function should free any resources specific
+ * to the derived class, then call base_ref_iterator_free() to clean
+ * up and free the ref_iterator object.
+ */
+typedef int ref_iterator_abort_fn(struct ref_iterator *ref_iterator);
+
+struct ref_iterator_vtable {
+ ref_iterator_advance_fn *advance;
+ ref_iterator_peel_fn *peel;
+ ref_iterator_abort_fn *abort;
+};
+
+/*
+ * current_ref_iter is a performance hack: when iterating over
+ * references using the for_each_ref*() functions, current_ref_iter is
+ * set to the reference iterator 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 one referred to by
+ * the iterator (it usually is) and if so, asks the iterator for the
+ * peeled version of the reference if it is available. This avoids a
+ * refname lookup in a common case. current_ref_iter is set to NULL
+ * when the iteration is over.
+ */
+extern struct ref_iterator *current_ref_iter;
+
+/*
+ * The common backend for the for_each_*ref* functions. Call fn for
+ * each reference in iter. If the iterator itself ever returns
+ * ITER_ERROR, return -1. If fn ever returns a non-zero value, stop
+ * the iteration and return that value. Otherwise, return 0. In any
+ * case, free the iterator when done. This function is basically an
+ * adapter between the callback style of reference iteration and the
+ * iterator style.
*/
-int do_for_each_ref(const char *submodule, const char *base,
- each_ref_fn fn, int trim, int flags, void *cb_data);
+int do_for_each_ref_iterator(struct ref_iterator *iter,
+ each_ref_fn fn, void *cb_data);
/*
* Read the specified reference from the filesystem or packed refs