diff mbox series

[2/4] pack-bitmap.c: make object filtering functions generic

Message ID b43a12894e7edf7d54ce2e9679f8db7dabec23e0.1588633810.git.me@ttaylorr.com (mailing list archive)
State New, archived
Headers show
Series pack-bitmap: use bitmaps for traversals with '--filter=tree:0' | expand

Commit Message

Taylor Blau May 4, 2020, 11:12 p.m. UTC 
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>
---
 pack-bitmap.c | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

Comments

Junio C Hamano May 5, 2020, 5:12 a.m. UTC | #1 
Taylor Blau <me@ttaylorr.com> writes:

> 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.

OK, so instead of blobs at the tip, we find objects of requested
type at the tip, which makes sense.

Similarly, blob_none filter used to exclude blobs at the tip, but a
more generic form is to exclude objects of requested type at the
tip.

And these "more generic" variants are named quite intuitively.

Then the blob_none filter becomes a thin wrapper of the more generic
one, with hardcoded OBJ_BLOB type.

Nicely done.
diff mbox series

Patch

diff --git a/pack-bitmap.c b/pack-bitmap.c
index 49a8d10d0c..3693c9e62f 100644
--- 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);