packfile: use object_id in find_pack_entry_one()

The main function we use to search a pack index for an object is
find_pack_entry_one(). That function still takes a bare pointer to the
hash, despite the fact that its underlying bsearch_pack() function needs
an object_id struct. And so we end up making an extra copy of the hash
into the struct just to do a lookup.

As it turns out, all callers but one already have such an object_id. So
we can just take a pointer to that struct and use it directly. This
avoids the extra copy and provides a more type-safe interface.

The one exception is get_delta_base() in packfile.c, when we are chasing
a REF_DELTA from inside the pack (and thus we have a pointer directly to
the mmap'd pack memory, not a struct). We can just bump the hashcpy()
from inside find_pack_entry_one() to this one caller that needs it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

builtin/pack-objects.c

@@ -1556,7 +1556,7 @@ static int want_object_in_pack_one(struct packed_git *p,
 	if (p == *found_pack)
 		offset = *found_offset;
 	else
-		offset = find_pack_entry_one(oid->hash, p);
+		offset = find_pack_entry_one(oid, p);
 
 	if (offset) {
 		if (!*found_pack) {
@@ -3984,7 +3984,7 @@ static int has_sha1_pack_kept_or_nonlocal(const struct object_id *oid)
 	while (p) {
 		if ((!p->pack_local || p->pack_keep ||
 				p->pack_keep_in_core) &&
-			find_pack_entry_one(oid->hash, p)) {
+			find_pack_entry_one(oid, p)) {
 			last_found = p;
 			return 1;
 		}

connected.c

@@ -78,7 +78,7 @@ int check_connected(oid_iterate_fn fn, void *cb_data,
 			for (p = get_all_packs(the_repository); p; p = p->next) {
 				if (!p->pack_promisor)
 					continue;
-				if (find_pack_entry_one(oid->hash, p))
+				if (find_pack_entry_one(oid, p))
 					goto promisor_pack_found;
 			}
 			/*
@@ -144,7 +144,7 @@ no_promisor_pack_found:
 		 * are sure the ref is good and not sending it to
 		 * rev-list for verification.
 		 */
-		if (new_pack && find_pack_entry_one(oid->hash, new_pack))
+		if (new_pack && find_pack_entry_one(oid, new_pack))
 			continue;
 
 		if (fprintf(rev_list_in, "%s\n", oid_to_hex(oid)) < 0)

midx.c

@@ -987,7 +987,7 @@ int verify_midx_file(struct repository *r, const char *object_dir, unsigned flag
 		}
 
 		m_offset = e.offset;
-		p_offset = find_pack_entry_one(oid.hash, e.p);
+		p_offset = find_pack_entry_one(&oid, e.p);
 
 		if (m_offset != p_offset)
 			midx_report(_("incorrect object offset for oid[%d] = %s: %"PRIx64" != %"PRIx64),

pack-bitmap.c

@@ -935,7 +935,7 @@ static inline int bitmap_position_packfile(struct bitmap_index *bitmap_git,
 					   const struct object_id *oid)
 {
 	uint32_t pos;
-	off_t offset = find_pack_entry_one(oid->hash, bitmap_git->pack);
+	off_t offset = find_pack_entry_one(oid, bitmap_git->pack);
 	if (!offset)
 		return -1;
 
@@ -1609,7 +1609,7 @@ static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
 			if (bsearch_midx(&object->oid, bitmap_git->midx, NULL))
 				return 1;
 		} else {
-			if (find_pack_entry_one(object->oid.hash, bitmap_git->pack) > 0)
+			if (find_pack_entry_one(&object->oid, bitmap_git->pack) > 0)
 				return 1;
 		}
 	}

packfile.c

@@ -1239,7 +1239,9 @@ off_t get_delta_base(struct packed_git *p,
 		*curpos += used;
 	} else if (type == OBJ_REF_DELTA) {
 		/* The base entry _must_ be in the same pack */
-		base_offset = find_pack_entry_one(base_info, p);
+		struct object_id oid;
+		hashcpy(oid.hash, base_info, the_repository->hash_algo);
+		base_offset = find_pack_entry_one(&oid, p);
 		*curpos += the_hash_algo->rawsz;
 	} else
 		die("I am totally screwed");
@@ -1971,11 +1973,10 @@ off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
 	}
 }
 
-off_t find_pack_entry_one(const unsigned char *sha1,
-				  struct packed_git *p)
+off_t find_pack_entry_one(const struct object_id *oid,
+			  struct packed_git *p)
 {
 	const unsigned char *index = p->index_data;
-	struct object_id oid;
 	uint32_t result;
 
 	if (!index) {
@@ -1983,8 +1984,7 @@ off_t find_pack_entry_one(const unsigned char *sha1,
 			return 0;
 	}
 
-	hashcpy(oid.hash, sha1, the_repository->hash_algo);
-	if (bsearch_pack(&oid, p, &result))
+	if (bsearch_pack(oid, p, &result))
 		return nth_packed_object_offset(p, result);
 	return 0;
 }
@@ -2016,7 +2016,7 @@ struct packed_git *find_oid_pack(const struct object_id *oid,
 	struct packed_git *p;
 
 	for (p = packs; p; p = p->next) {
-		if (find_pack_entry_one(oid->hash, p))
+		if (find_pack_entry_one(oid, p))
 			return p;
 	}
 	return NULL;
@@ -2033,7 +2033,7 @@ static int fill_pack_entry(const struct object_id *oid,
 	    oidset_contains(&p->bad_objects, oid))
 		return 0;
 
-	offset = find_pack_entry_one(oid->hash, p);
+	offset = find_pack_entry_one(oid, p);
 	if (!offset)
 		return 0;
 

packfile.h

@@ -154,10 +154,10 @@ int nth_packed_object_id(struct object_id *, struct packed_git *, uint32_t n);
 off_t nth_packed_object_offset(const struct packed_git *, uint32_t n);
 
 /*
- * If the object named sha1 is present in the specified packfile,
+ * If the object named by oid is present in the specified packfile,
  * return its offset within the packfile; otherwise, return 0.
  */
-off_t find_pack_entry_one(const unsigned char *sha1, struct packed_git *);
+off_t find_pack_entry_one(const struct object_id *oid, struct packed_git *);
 
 int is_pack_valid(struct packed_git *);
 void *unpack_entry(struct repository *r, struct packed_git *, off_t, enum object_type *, unsigned long *);

t/helper/test-find-pack.c

@@ -40,7 +40,7 @@ int cmd__find_pack(int argc, const char **argv)
 		die("cannot parse %s as an object name", argv[0]);
 
 	for (p = get_all_packs(the_repository); p; p = p->next)
-		if (find_pack_entry_one(oid.hash, p)) {
+		if (find_pack_entry_one(&oid, p)) {
 			printf("%s\n", p->pack_name);
 			actual_count++;
 		}