Re: [PATCH v7 05/13] pack-objects: move in_pack_pos out of struct object_entry

[Jeff King]

On Sat, Mar 24, 2018 at 07:33:45AM +0100, Nguyễn Thái Ngọc Duy wrote:

> This field is only need for pack-bitmap, which is an optional
> feature. Move it to a separate array that is only allocated when
> pack-bitmap is used (it's not freed in the same way that objects[] is
> not).

I had trouble parsing the parenthetical in the last sentence. It does
make sense if you read it hard enough, but maybe:

  (like objects[], it is not freed, since we need it until the end of
  the process)

would be more clear?

The patch itself seems OK.

-Peff

[PATCH v7 05/13] pack-objects: move in_pack_pos out of struct object_entry

[Nguyễn Thái Ngọc Duy]

This field is only need for pack-bitmap, which is an optional
feature. Move it to a separate array that is only allocated when
pack-bitmap is used (it's not freed in the same way that objects[] is
not).

Signed-off-by: Nguyễn Thái Ngọc Duy 
---
 builtin/pack-objects.c |  3 ++-
 pack-bitmap-write.c|  8 +---
 pack-bitmap.c  |  2 +-
 pack-bitmap.h  |  4 +++-
 pack-objects.h | 16 +++-
 5 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 205e1f646c..e1244918a5 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -879,7 +879,8 @@ static void write_pack_file(void)
 
if (write_bitmap_index) {
bitmap_writer_set_checksum(oid.hash);
-   bitmap_writer_build_type_index(written_list, 
nr_written);
+   bitmap_writer_build_type_index(
+   _pack, written_list, nr_written);
}
 
finish_tmp_packfile(, pack_tmp_name,
diff --git a/pack-bitmap-write.c b/pack-bitmap-write.c
index fd11f08940..f7c897515b 100644
--- a/pack-bitmap-write.c
+++ b/pack-bitmap-write.c
@@ -48,7 +48,8 @@ void bitmap_writer_show_progress(int show)
 /**
  * Build the initial type index for the packfile
  */
-void bitmap_writer_build_type_index(struct pack_idx_entry **index,
+void bitmap_writer_build_type_index(struct packing_data *to_pack,
+   struct pack_idx_entry **index,
uint32_t index_nr)
 {
uint32_t i;
@@ -57,12 +58,13 @@ void bitmap_writer_build_type_index(struct pack_idx_entry 
**index,
writer.trees = ewah_new();
writer.blobs = ewah_new();
writer.tags = ewah_new();
+   ALLOC_ARRAY(to_pack->in_pack_pos, to_pack->nr_objects);
 
for (i = 0; i < index_nr; ++i) {
struct object_entry *entry = (struct object_entry *)index[i];
enum object_type real_type;
 
-   entry->in_pack_pos = i;
+   oe_set_in_pack_pos(to_pack, entry, i);
 
switch (oe_type(entry)) {
case OBJ_COMMIT:
@@ -147,7 +149,7 @@ static uint32_t find_object_pos(const unsigned char *sha1)
"(object %s is missing)", sha1_to_hex(sha1));
}
 
-   return entry->in_pack_pos;
+   return oe_in_pack_pos(writer.to_pack, entry);
 }
 
 static void show_object(struct object *object, const char *name, void *data)
diff --git a/pack-bitmap.c b/pack-bitmap.c
index 9270983e5f..865d9ecc4e 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -1032,7 +1032,7 @@ int rebuild_existing_bitmaps(struct packing_data *mapping,
oe = packlist_find(mapping, sha1, NULL);
 
if (oe)
-   reposition[i] = oe->in_pack_pos + 1;
+   reposition[i] = oe_in_pack_pos(mapping, oe) + 1;
}
 
rebuild = bitmap_new();
diff --git a/pack-bitmap.h b/pack-bitmap.h
index 3742a00e14..5ded2f139a 100644
--- a/pack-bitmap.h
+++ b/pack-bitmap.h
@@ -44,7 +44,9 @@ int rebuild_existing_bitmaps(struct packing_data *mapping, 
khash_sha1 *reused_bi
 
 void bitmap_writer_show_progress(int show);
 void bitmap_writer_set_checksum(unsigned char *sha1);
-void bitmap_writer_build_type_index(struct pack_idx_entry **index, uint32_t 
index_nr);
+void bitmap_writer_build_type_index(struct packing_data *to_pack,
+   struct pack_idx_entry **index,
+   uint32_t index_nr);
 void bitmap_writer_reuse_bitmaps(struct packing_data *to_pack);
 void bitmap_writer_select_commits(struct commit **indexed_commits,
unsigned int indexed_commits_nr, int max_bitmaps);
diff --git a/pack-objects.h b/pack-objects.h
index 59407aae3c..4a11653657 100644
--- a/pack-objects.h
+++ b/pack-objects.h
@@ -79,7 +79,6 @@ struct object_entry {
unsigned in_pack_type:TYPE_BITS; /* could be delta */
unsigned type_valid:1;
uint32_t hash;  /* name hint hash */
-   unsigned int in_pack_pos;
unsigned char in_pack_header_size;
unsigned preferred_base:1; /*
* we do not pack this, but is available
@@ -99,6 +98,8 @@ struct packing_data {
 
int32_t *index;
uint32_t index_size;
+
+   unsigned int *in_pack_pos;
 };
 
 struct object_entry *packlist_alloc(struct packing_data *pdata,
@@ -144,4 +145,17 @@ static inline void oe_set_type(struct object_entry *e,
e->type_ = (unsigned)type;
 }
 
+static inline unsigned int oe_in_pack_pos(const struct packing_data *pack,
+ const struct object_entry *e)
+{
+   return pack->in_pack_pos[e - pack->objects];
+}
+
+static inline void oe_set_in_pack_pos(const struct packing_data *pack,
+