Convert hashtable usage over to khash

This updates khash.h with some extra features (like error checking
on allocations, ability to use wrapped malloc, foreach calls, etc),
creates two high-level wrappers around khash: `git_khash_str` and
`git_khash_oid` for string-to-void-ptr and oid-to-void-ptr tables,
then converts all of the old usage of `git_hashtable` over to use
these new hashtables.

For `git_khash_str`, I've tried to create a set of macros that
yield an API not too unlike the old `git_hashtable` API.  Since
the oid hashtable is only used in one file, I haven't bother to
set up all those macros and just use the khash APIs directly for
now.

1 files changed, 45 insertions, 27 deletions

diff --git a/src/refs.c b/src/refs.c
index 447f3a7b6..7050b4af9 100644
--- a/src/refs.c
+++ b/src/refs.c
@@ -15,6 +15,8 @@
 #include <git2/tag.h>
 #include <git2/object.h>
 
+GIT_KHASH_STR__IMPLEMENTATION;
+
 #define DEFAULT_NESTING_LEVEL	5
 #define MAX_NESTING_LEVEL		10
 
@@ -30,8 +32,6 @@ struct packref {
 	char name[GIT_FLEX_ARRAY];
 };
 
-static const int default_table_size = 32;
-
 static int reference_read(
 	git_buf *file_content,
 	time_t *mtime,
@@ -423,9 +423,7 @@ static int packed_load(git_repository *repo)
 
 	/* First we make sure we have allocated the hash table */
 	if (ref_cache->packfile == NULL) {
-		ref_cache->packfile = git_hashtable_alloc(
-			default_table_size, git_hash__strhash_cb, git_hash__strcmp_cb);
-
+		ref_cache->packfile = git_khash_str_alloc();
 		GITERR_CHECK_ALLOC(ref_cache->packfile);
 	}
 
@@ -440,7 +438,7 @@ static int packed_load(git_repository *repo)
 	 * refresh the packed refs.
 	 */
 	if (result == GIT_ENOTFOUND) {
-		git_hashtable_clear(ref_cache->packfile);
+		git_khash_str_clear(ref_cache->packfile);
 		return 0;
 	}
 
@@ -454,7 +452,7 @@ static int packed_load(git_repository *repo)
 	 * At this point, we want to refresh the packed refs. We already
 	 * have the contents in our buffer.
 	 */
-	git_hashtable_clear(ref_cache->packfile);
+	git_khash_str_clear(ref_cache->packfile);
 
 	buffer_start = (const char *)packfile.ptr;
 	buffer_end = (const char *)(buffer_start) + packfile.size;
@@ -468,6 +466,7 @@ static int packed_load(git_repository *repo)
 	}
 
 	while (buffer_start < buffer_end) {
+		int err;
 		struct packref *ref = NULL;
 
 		if (packed_parse_oid(&ref, &buffer_start, buffer_end) < 0)
@@ -478,15 +477,16 @@ static int packed_load(git_repository *repo)
 				goto parse_failed;
 		}
 
-		if (git_hashtable_insert(ref_cache->packfile, ref->name, ref) < 0)
-			return -1;
+		git_khash_str_insert(ref_cache->packfile, ref->name, ref, err);
+		if (err < 0)
+			goto parse_failed;
 	}
 
 	git_buf_free(&packfile);
 	return 0;
 
 parse_failed:
-	git_hashtable_free(ref_cache->packfile);
+	git_khash_str_free(ref_cache->packfile);
 	ref_cache->packfile = NULL;
 	git_buf_free(&packfile);
 	return -1;
@@ -512,7 +512,7 @@ static int _dirent_loose_listall(void *_data, git_buf *full_path)
 
 	/* do not add twice a reference that exists already in the packfile */
 	if ((data->list_flags & GIT_REF_PACKED) != 0 &&
-		git_hashtable_lookup(data->repo->references.packfile, file_path) != NULL)
+		git_khash_str_exists(data->repo->references.packfile, file_path))
 		return 0;
 
 	if (data->list_flags != GIT_REF_LISTALL) {
@@ -529,6 +529,7 @@ static int _dirent_loose_load(void *data, git_buf *full_path)
 	void *old_ref = NULL;
 	struct packref *ref;
 	const char *file_path;
+	int err;
 
 	if (git_path_isdir(full_path->ptr) == true)
 		return git_path_direach(full_path, _dirent_loose_load, repository);
@@ -538,8 +539,9 @@ static int _dirent_loose_load(void *data, git_buf *full_path)
 	if (loose_lookup_to_packfile(&ref, repository, file_path) < 0)
 		return -1;
 
-	if (git_hashtable_insert2(repository->references.packfile,
-			ref->name, ref, &old_ref) < 0) {
+	git_khash_str_insert2(
+		repository->references.packfile, ref->name, ref, old_ref, err);
+	if (err < 0) {
 		git__free(ref);
 		return -1;
 	}
@@ -734,7 +736,8 @@ static int packed_write(git_repository *repo)
 
 	assert(repo && repo->references.packfile);
 
-	total_refs = (unsigned int)repo->references.packfile->key_count;
+	total_refs =
+		(unsigned int)git_khash_str_num_entries(repo->references.packfile);
 
 	if (git_vector_init(&packing_list, total_refs, packed_sort) < 0)
 		return -1;
@@ -743,10 +746,10 @@ static int packed_write(git_repository *repo)
 	{
 		struct packref *reference;
 
-		GIT_HASHTABLE_FOREACH_VALUE(repo->references.packfile, reference,
-			/* cannot fail: vector already has the right size */
+		/* cannot fail: vector already has the right size */
+		git_khash_str_foreach_value(repo->references.packfile, reference, {
 			git_vector_insert(&packing_list, reference);
-		);
+		});
 	}
 
 	/* sort the vector so the entries appear sorted on the packfile */
@@ -870,7 +873,8 @@ static int reference_exists(int *exists, git_repository *repo, const char *ref_n
 		return -1;
 
 	if (git_path_isfile(ref_path.ptr) == true ||
-		git_hashtable_lookup(repo->references.packfile, ref_path.ptr) != NULL) {
+		git_khash_str_exists(repo->references.packfile, ref_path.ptr))
+	{
 		*exists = 1;
 	} else {
 		*exists = 0;
@@ -936,6 +940,8 @@ static int reference_can_write(
 static int packed_lookup(git_reference *ref)
 {
 	struct packref *pack_ref = NULL;
+	git_khash_str *packfile_refs;
+	khiter_t pos;
 
 	if (packed_load(ref->owner) < 0)
 		return -1;
@@ -952,12 +958,15 @@ static int packed_lookup(git_reference *ref)
 	}
 
 	/* Look up on the packfile */
-	pack_ref = git_hashtable_lookup(ref->owner->references.packfile, ref->name);
-	if (pack_ref == NULL) {
+	packfile_refs = ref->owner->references.packfile;
+	pos = git_khash_str_lookup_index(packfile_refs, ref->name);
+	if (!git_khash_str_valid_index(packfile_refs, pos)) {
 		giterr_set(GITERR_REFERENCE, "Reference '%s' not found", ref->name);
 		return GIT_ENOTFOUND;
 	}
 
+	pack_ref = git_khash_str_value_at(packfile_refs, pos);
+
 	ref->flags = GIT_REF_OID | GIT_REF_PACKED;
 	ref->mtime = ref->owner->references.packfile_time;
 	git_oid_cpy(&ref->target.oid, &pack_ref->oid);
@@ -1002,18 +1011,25 @@ static int reference_delete(git_reference *ref)
 	 * We need to reload the packfile, remove the reference from the
 	 * packing list, and repack */
 	if (ref->flags & GIT_REF_PACKED) {
+		git_khash_str *packfile_refs;
 		struct packref *packref;
+		khiter_t pos;
+
 		/* load the existing packfile */
 		if (packed_load(ref->owner) < 0)
 			return -1;
 
-		if (git_hashtable_remove2(ref->owner->references.packfile,
-				ref->name, (void **) &packref) < 0) {
+		packfile_refs = ref->owner->references.packfile;
+		pos = git_khash_str_lookup_index(packfile_refs, ref->name);
+		if (!git_khash_str_valid_index(packfile_refs, pos)) {
 			giterr_set(GITERR_REFERENCE,
 				"Reference %s stopped existing in the packfile", ref->name);
 			return -1;
 		}
 
+		packref = git_khash_str_value_at(packfile_refs, pos);
+		git_khash_str_delete_at(packfile_refs, pos);
+
 		git__free(packref);
 		if (packed_write(ref->owner) < 0)
 			return -1;
@@ -1467,14 +1483,15 @@ int git_reference_foreach(
 	/* list all the packed references first */
 	if (list_flags & GIT_REF_PACKED) {
 		const char *ref_name;
+		void *ref;
 
 		if (packed_load(repo) < 0)
 			return -1;
 
-		GIT_HASHTABLE_FOREACH_KEY(repo->references.packfile, ref_name,
+		git_khash_str_foreach(repo->references.packfile, ref_name, ref, {
 			if (callback(ref_name, payload) < 0)
 				return 0;
-		);
+		});
 	}
 
 	/* now list the loose references, trying not to
@@ -1538,10 +1555,11 @@ void git_repository__refcache_free(git_refcache *refs)
 	if (refs->packfile) {
 		struct packref *reference;
 
-		GIT_HASHTABLE_FOREACH_VALUE(
-			refs->packfile, reference, git__free(reference));
+		git_khash_str_foreach_value(refs->packfile, reference, {
+			git__free(reference);
+		});
 
-		git_hashtable_free(refs->packfile);
+		git_khash_str_free(refs->packfile);
 	}
 }