pack-bitmap.c: make object filtering functions generic

In 4f3bd5606a (pack-bitmap: implement BLOB_NONE filtering, 2020-02-14),
filtering support for bitmaps was added for the 'LOFC_BLOB_NONE' filter.

In the future, we would like to add support for filters that behave as
if they exclude a certain type of object, for e.g., the tree depth
filter with depth 0.

To prepare for this, make some of the functions used for filtering more
generic, such as 'find_tip_blobs' and 'filter_bitmap_blob_none' so that
they can work over arbitrary object types.

To that end, create 'find_tip_objects' and
'filter_bitmap_exclude_type', and redefine the aforementioned functions
in terms of those.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/pack-bitmap.c b/pack-bitmap.c
index 49a8d10d0cf99716ea37b78bec578ca96c17de20..3693c9e62fa168645419bbd11a73619861ec6a55 100644 (file)
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -715,8 +715,9 @@ static int in_bitmapped_pack(struct bitmap_index *bitmap_git,
        return 0;
 }
 
-static struct bitmap *find_tip_blobs(struct bitmap_index *bitmap_git,
-                                    struct object_list *tip_objects)
+static struct bitmap *find_tip_objects(struct bitmap_index *bitmap_git,
+                                      struct object_list *tip_objects,
+                                      enum object_type type)
 {
        struct bitmap *result = bitmap_new();
        struct object_list *p;
@@ -724,7 +725,7 @@ static struct bitmap *find_tip_blobs(struct bitmap_index *bitmap_git,
        for (p = tip_objects; p; p = p->next) {
                int pos;
 
-               if (p->item->type != OBJ_BLOB)
+               if (p->item->type != type)
                        continue;
 
                pos = bitmap_position(bitmap_git, &p->item->oid);
@@ -737,9 +738,10 @@ static struct bitmap *find_tip_blobs(struct bitmap_index *bitmap_git,
        return result;
 }
 
-static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
-                                   struct object_list *tip_objects,
-                                   struct bitmap *to_filter)
+static void filter_bitmap_exclude_type(struct bitmap_index *bitmap_git,
+                                      struct object_list *tip_objects,
+                                      struct bitmap *to_filter,
+                                      enum object_type type)
 {
        struct eindex *eindex = &bitmap_git->ext_index;
        struct bitmap *tips;
@@ -747,18 +749,21 @@ static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
        eword_t mask;
        uint32_t i;
 
+       if (type != OBJ_BLOB)
+               BUG("filter_bitmap_exclude_type: unsupported type '%d'", type);
+
        /*
         * The non-bitmap version of this filter never removes
-        * blobs which the other side specifically asked for,
+        * objects which the other side specifically asked for,
         * so we must match that behavior.
         */
-       tips = find_tip_blobs(bitmap_git, tip_objects);
+       tips = find_tip_objects(bitmap_git, tip_objects, type);
 
        /*
         * We can use the blob type-bitmap to work in whole words
         * for the objects that are actually in the bitmapped packfile.
         */
-       for (i = 0, init_type_iterator(&it, bitmap_git, OBJ_BLOB);
+       for (i = 0, init_type_iterator(&it, bitmap_git, type);
             i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);
             i++) {
                if (i < tips->word_alloc)
@@ -773,7 +778,7 @@ static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
         */
        for (i = 0; i < eindex->count; i++) {
                uint32_t pos = i + bitmap_git->pack->num_objects;
-               if (eindex->objects[i]->type == OBJ_BLOB &&
+               if (eindex->objects[i]->type == type &&
                    bitmap_get(to_filter, pos) &&
                    !bitmap_get(tips, pos))
                        bitmap_unset(to_filter, pos);
@@ -782,6 +787,14 @@ static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
        bitmap_free(tips);
 }
 
+static void filter_bitmap_blob_none(struct bitmap_index *bitmap_git,
+                                   struct object_list *tip_objects,
+                                   struct bitmap *to_filter)
+{
+       filter_bitmap_exclude_type(bitmap_git, tip_objects, to_filter,
+                                  OBJ_BLOB);
+}
+
 static unsigned long get_size_by_pos(struct bitmap_index *bitmap_git,
                                     uint32_t pos)
 {
@@ -820,7 +833,7 @@ static void filter_bitmap_blob_limit(struct bitmap_index *bitmap_git,
        eword_t mask;
        uint32_t i;
 
-       tips = find_tip_blobs(bitmap_git, tip_objects);
+       tips = find_tip_objects(bitmap_git, tip_objects, OBJ_BLOB);
 
        for (i = 0, init_type_iterator(&it, bitmap_git, OBJ_BLOB);
             i < to_filter->word_alloc && ewah_iterator_next(&mask, &it);