Subject: [PATCH v2 3/4] bulk-checkin: require transaction for index_blob_bulk_checkin()

From: Justin Tobler <[email-masked]>
Date: Thu, 21 Aug 2025 18:22:48 -0500

The bulk-checkin subsystem provides a mechanism to write blobs directly
to a packfile via `index_blob_bulk_checkin()`. If there is an ongoing
transaction when invoked, objects written via this function are stored
in the same packfile. The packfile is not flushed until the transaction
itself is flushed. If there is no transaction, the single object is
written to a packfile and immediately flushed. This complicates
`index_blob_bulk_checkin()` as it cannot reliably use the provided
transaction to get the associated repository.

Update `index_blob_bulk_checkin()` to assume that a valid transaction is
always provided. Callers are now expected to ensure a transaction is set
up beforehand. The single call site in `object-file.c:index_fd()` is
updated accordingly. Due to how `{begin,end}_odb_transaction()` handles
nested transactions, a new transaction is only created and committed if
there is not already an ongoing transaction.

Signed-off-by: Justin Tobler <[email-masked]>
---
 bulk-checkin.c | 15 ++-------------
 bulk-checkin.h |  7 +++++--
 object-file.c  | 21 ++++++++++++++-------
 3 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/bulk-checkin.c b/bulk-checkin.c
index 53a20a2d92f..0e3747640b9 100644
--- a/bulk-checkin.c
+++ b/bulk-checkin.c
@@ -365,19 +365,8 @@ int index_blob_bulk_checkin(struct odb_transaction *transaction,
 			    struct object_id *oid, int fd, size_t size,
 			    const char *path, unsigned flags)
 {
-	int status;
-
-	if (transaction) {
-		status = deflate_blob_to_pack(&transaction->packfile, oid, fd,
-					      size, path, flags);
-	} else {
-		struct bulk_checkin_packfile state = { 0 };
-
-		status = deflate_blob_to_pack(&state, oid, fd, size, path, flags);
-		flush_bulk_checkin_packfile(&state);
-	}
-
-	return status;
+	return deflate_blob_to_pack(&transaction->packfile, oid, fd, size, path,
+				    flags);
 }
 
 struct odb_transaction *begin_odb_transaction(struct object_database *odb)
diff --git a/bulk-checkin.h b/bulk-checkin.h
index 16254ce6a70..ac8887f476b 100644
--- a/bulk-checkin.h
+++ b/bulk-checkin.h
@@ -14,8 +14,11 @@ void fsync_loose_object_bulk_checkin(struct odb_transaction *transaction,
 				     int fd, const char *filename);
 
 /*
- * This creates one packfile per large blob unless bulk-checkin
- * machinery is "plugged".
+ * This writes the specified object to a packfile. Objects written here
+ * during the same transaction are written to the same packfile. The
+ * packfile is not flushed until the transaction is flushed. The caller
+ * is expected to ensure a valid transaction is setup for objects to be
+ * recorded to.
  *
  * This also bypasses the usual "convert-to-git" dance, and that is on
  * purpose. We could write a streaming version of the converting
diff --git a/object-file.c b/object-file.c
index 1740aa2b2e3..bc15af42450 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1253,19 +1253,26 @@ int index_fd(struct index_state *istate, struct object_id *oid,
 	 * Call xsize_t() only when needed to avoid potentially unnecessary
 	 * die() for large files.
 	 */
-	if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
+	if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path)) {
 		ret = index_stream_convert_blob(istate, oid, fd, path, flags);
-	else if (!S_ISREG(st->st_mode))
+	} else if (!S_ISREG(st->st_mode)) {
 		ret = index_pipe(istate, oid, fd, type, path, flags);
-	else if ((st->st_size >= 0 && (size_t) st->st_size <= repo_settings_get_big_file_threshold(istate->repo)) ||
-		 type != OBJ_BLOB ||
-		 (path && would_convert_to_git(istate, path)))
+	} else if ((st->st_size >= 0 &&
+		    (size_t)st->st_size <= repo_settings_get_big_file_threshold(istate->repo)) ||
+		   type != OBJ_BLOB ||
+		   (path && would_convert_to_git(istate, path))) {
 		ret = index_core(istate, oid, fd, xsize_t(st->st_size),
 				 type, path, flags);
-	else
-		ret = index_blob_bulk_checkin(the_repository->objects->transaction,
+	} else {
+		struct odb_transaction *transaction;
+
+		transaction = begin_odb_transaction(the_repository->objects);
+		ret = index_blob_bulk_checkin(transaction,
 					      oid, fd, xsize_t(st->st_size),
 					      path, flags);
+		end_odb_transaction(transaction);
+	}
+
 	close(fd);
 	return ret;
 }
-- 
2.51.0