From 38b86e81ae9d3fff3ce300e867f6cd2d1732c998 Mon Sep 17 00:00:00 2001 From: Michael Haggerty Date: Fri, 23 Jun 2017 09:01:35 +0200 Subject: packed_ref_store: support iteration Add the infrastructure to iterate over a `packed_ref_store`. It's a lot of boilerplate, but it's all part of a campaign to make `packed_ref_store` implement `ref_store`. In the future, this iterator will work much differently. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano --- refs/files-backend.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 110 insertions(+), 9 deletions(-) (limited to 'refs/files-backend.c') diff --git a/refs/files-backend.c b/refs/files-backend.c index 185d05e1d..0490cc087 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -1062,10 +1062,102 @@ static int files_peel_ref(struct ref_store *ref_store, return peel_object(base, sha1); } +struct packed_ref_iterator { + struct ref_iterator base; + + struct packed_ref_cache *cache; + struct ref_iterator *iter0; + unsigned int flags; +}; + +static int packed_ref_iterator_advance(struct ref_iterator *ref_iterator) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + int ok; + + while ((ok = ref_iterator_advance(iter->iter0)) == ITER_OK) { + if (iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY && + ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE) + continue; + + 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; + } + + iter->iter0 = NULL; + if (ref_iterator_abort(ref_iterator) != ITER_DONE) + ok = ITER_ERROR; + + return ok; +} + +static int packed_ref_iterator_peel(struct ref_iterator *ref_iterator, + struct object_id *peeled) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + + return ref_iterator_peel(iter->iter0, peeled); +} + +static int packed_ref_iterator_abort(struct ref_iterator *ref_iterator) +{ + struct packed_ref_iterator *iter = + (struct packed_ref_iterator *)ref_iterator; + int ok = ITER_DONE; + + if (iter->iter0) + ok = ref_iterator_abort(iter->iter0); + + release_packed_ref_cache(iter->cache); + base_ref_iterator_free(ref_iterator); + return ok; +} + +static struct ref_iterator_vtable packed_ref_iterator_vtable = { + packed_ref_iterator_advance, + packed_ref_iterator_peel, + packed_ref_iterator_abort +}; + +static struct ref_iterator *packed_ref_iterator_begin( + struct packed_ref_store *refs, + const char *prefix, unsigned int flags) +{ + struct packed_ref_iterator *iter; + struct ref_iterator *ref_iterator; + + iter = xcalloc(1, sizeof(*iter)); + ref_iterator = &iter->base; + base_ref_iterator_init(ref_iterator, &packed_ref_iterator_vtable); + + /* + * Note that get_packed_ref_cache() internally checks whether + * the packed-ref cache is up to date with what is on disk, + * and re-reads it if not. + */ + + iter->cache = get_packed_ref_cache(refs); + acquire_packed_ref_cache(iter->cache); + iter->iter0 = cache_ref_iterator_begin(iter->cache->cache, prefix, 0); + + iter->flags = flags; + + return ref_iterator; +} + struct files_ref_iterator { struct ref_iterator base; - struct packed_ref_cache *packed_ref_cache; struct ref_iterator *iter0; unsigned int flags; }; @@ -1118,7 +1210,6 @@ static int files_ref_iterator_abort(struct ref_iterator *ref_iterator) 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; } @@ -1160,18 +1251,28 @@ static struct ref_iterator *files_ref_iterator_begin( * (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. + * packed_ref_iterator_begin(), which internally checks + * whether the packed-ref cache is up to date with what is on + * disk, and re-reads it if not. */ loose_iter = cache_ref_iterator_begin(get_loose_ref_cache(refs), prefix, 1); - iter->packed_ref_cache = get_packed_ref_cache(refs->packed_ref_store); - acquire_packed_ref_cache(iter->packed_ref_cache); - packed_iter = cache_ref_iterator_begin(iter->packed_ref_cache->cache, - prefix, 0); + /* + * The packed-refs file might contain broken references, for + * example an old version of a reference that points at an + * object that has since been garbage-collected. This is OK as + * long as there is a corresponding loose reference that + * overrides it, and we don't want to emit an error message in + * this case. So ask the packed_ref_store for all of its + * references, and (if needed) do our own check for broken + * ones in files_ref_iterator_advance(), after we have merged + * the packed and loose references. + */ + packed_iter = packed_ref_iterator_begin( + refs->packed_ref_store, prefix, + DO_FOR_EACH_INCLUDE_BROKEN); iter->iter0 = overlay_ref_iterator_begin(loose_iter, packed_iter); iter->flags = flags; -- cgit v1.2.1