packfile: introduce function to iterate through objects

Introduce a new function `packfile_store_for_each_object()`. This
function is equivalent to `odb_source_loose_for_each_object()`, except
that it:

  - Works on a single packfile store instead of working on the object
    database level. Consequently, it will only yield packed objects of a
    single object database source.

  - Passes a `struct object_info` to the callback function.

As such, it provides the same callback interface as we already provide
for loose objects now. These functions will be used in a subsequent step
to implement `odb_for_each_object()`.

The `for_each_packed_object()` function continues to exist for now, but
it will be removed at the end of this patch series.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/packfile.h b/packfile.h
index 447c44c4a7..b7964f0289 100644
--- a/packfile.h
+++ b/packfile.h
@@ -343,6 +343,21 @@ int for_each_object_in_pack(struct packed_git *p,
 int for_each_packed_object(struct repository *repo, each_packed_object_fn cb,
 			   void *data, unsigned flags);
 
+/*
+ * Iterate through all packed objects in the given packfile store and invoke
+ * the callback function for each of them. If an object info request is given,
+ * then the object info will be read for every individual object and passed to
+ * the callback as if `packfile_store_read_object_info()` was called for the
+ * object.
+ *
+ * The flags parameter is a combination of `odb_for_each_object_flags`.
+ */
+int packfile_store_for_each_object(struct packfile_store *store,
+				   const struct object_info *request,
+				   odb_for_each_object_cb cb,
+				   void *cb_data,
+				   unsigned flags);
+
 /* A hook to report invalid files in pack directory */
 #define PACKDIR_FILE_PACK 1
 #define PACKDIR_FILE_IDX 2