[PATCH v4 5/7] bulk-checkin: introduce `index_blob_bulk_checkin_incore()`

[Taylor Blau <me@ttaylorr.com>]

Now that we have factored out many of the common routines necessary to
index a new object into a pack created by the bulk-checkin machinery, we
can introduce a variant of `index_blob_bulk_checkin()` that acts on
blobs whose contents we can fit in memory.

This will be useful in a couple of more commits in order to provide the
`merge-tree` builtin with a mechanism to create a new pack containing
any objects it created during the merge, instead of storing those
objects individually as loose.

Similar to the existing `index_blob_bulk_checkin()` function, the
entrypoint delegates to `deflate_obj_to_pack_incore()`. That function in
turn delegates to deflate_obj_to_pack(), which is responsible for
formatting the pack header and then deflating the contents into the
pack.

Consistent with the rest of the bulk-checkin mechanism, there are no
direct tests here. In future commits when we expose this new
functionality via the `merge-tree` builtin, we will test it indirectly
there.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 bulk-checkin.c | 29 +++++++++++++++++++++++++++++
 bulk-checkin.h |  4 ++++
 2 files changed, 33 insertions(+)

diff --git a/bulk-checkin.c b/bulk-checkin.c
index 60361b3e2e..655a583b06 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -368,6 +368,23 @@ static int deflate_obj_to_pack(struct bulk_checkin_packfile *state,
 	return 0;
 }
 
+static int deflate_obj_to_pack_incore(struct bulk_checkin_packfile *state,
+				       struct object_id *result_oid,
+				       const void *buf, size_t size,
+				       const char *path, enum object_type type,
+				       unsigned flags)
+{
+	struct bulk_checkin_source source = {
+		.type = SOURCE_INCORE,
+		.buf = buf,
+		.size = size,
+		.read = 0,
+		.path = path,
+	};
+
+	return deflate_obj_to_pack(state, result_oid, &source, type, 0, flags);
+}
+
 static int deflate_blob_to_pack(struct bulk_checkin_packfile *state,
 				struct object_id *result_oid,
 				int fd, size_t size,
@@ -431,6 +448,18 @@ int index_blob_bulk_checkin(struct object_id *oid,
 	return status;
 }
 
+int index_blob_bulk_checkin_incore(struct object_id *oid,
+				   const void *buf, size_t size,
+				   const char *path, unsigned flags)
+{
+	int status = deflate_obj_to_pack_incore(&bulk_checkin_packfile, oid,
+						buf, size, path, OBJ_BLOB,
+						flags);
+	if (!odb_transaction_nesting)
+		flush_bulk_checkin_packfile(&bulk_checkin_packfile);
+	return status;
+}
+
 void begin_odb_transaction(void)
 {
 	odb_transaction_nesting += 1;
diff --git a/bulk-checkin.h b/bulk-checkin.h
index aa7286a7b3..1b91daeaee 100644
--- a/bulk-checkin.h
+++ b/bulk-checkin.h
@@ -13,6 +13,10 @@ int index_blob_bulk_checkin(struct object_id *oid,
 			    int fd, size_t size,
 			    const char *path, unsigned flags);
 
+int index_blob_bulk_checkin_incore(struct object_id *oid,
+				   const void *buf, size_t size,
+				   const char *path, unsigned flags);
+
 /*
  * Tell the object database to optimize for adding
  * multiple objects. end_odb_transaction must be called
-- 
2.42.0.405.g86fe3250c2