bulk-checkin: rebrand plug/unplug APIs as 'odb transactions'

Make it clearer in the naming and documentation of the plug_bulk_checkin
and unplug_bulk_checkin APIs that they can be thought of as
a "transaction" to optimize operations on the object database. These
transactions may be nested so that subsystems like the cache-tree
writing code can optimize their operations without caring whether the
top-level code has a transaction active.

Add a flush_odb_transaction API that will be used in update-index to
make objects visible even if a transaction is active. The flush call may
also be useful in future cases if we hold a transaction active around
calling hooks.

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 22 insertions, 2 deletions

diff --git a/bulk-checkin.h b/bulk-checkin.h
index b26f3dc3b7..ee0832989a 100644
--- a/bulk-checkin.h
+++ b/bulk-checkin.h
@@ -10,7 +10,27 @@ int index_bulk_checkin(struct object_id *oid,
 		       int fd, size_t size, enum object_type type,
 		       const char *path, unsigned flags);
 
-void plug_bulk_checkin(void);
-void unplug_bulk_checkin(void);
+/*
+ * Tell the object database to optimize for adding
+ * multiple objects. end_odb_transaction must be called
+ * to make new objects visible. Transactions can be nested,
+ * and objects are only visible after the outermost transaction
+ * is complete or the transaction is flushed.
+ */
+void begin_odb_transaction(void);
+
+/*
+ * Make any objects that are currently part of a pending object
+ * database transaction visible. It is valid to call this function
+ * even if no transaction is active.
+ */
+void flush_odb_transaction(void);
+
+/*
+ * Tell the object database to make any objects from the
+ * current transaction visible if this is the final nested
+ * transaction.
+ */
+void end_odb_transaction(void);
 
 #endif