[PATCH 12/17] lib: Wrap notmuch_database_add_message in an atomic section.

[Austin Clements]

Adding a message may involve changes to multiple database documents,
and thus needs to be done in a transaction.  This makes add_message
(and, I think, the whole library) atomicity-safe: library callers only
needs to use atomic sections if they needs atomicity across multiple
library calls.
---
 lib/database.cc |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index daa619d..f963964 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -1601,7 +1601,7 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
 {
     notmuch_message_file_t *message_file;
     notmuch_message_t *message = NULL;
-    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
+    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS, ret2;
     notmuch_private_status_t private_status;
 
     const char *date, *header;
@@ -1619,6 +1619,12 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
     if (message_file == NULL)
 	return NOTMUCH_STATUS_FILE_ERROR;
 
+    /* Adding a message may change many documents.  Do this all
+     * atomically. */
+    ret = notmuch_database_begin_atomic (notmuch);
+    if (ret)
+	goto DONE;
+
     notmuch_message_file_restrict_headers (message_file,
 					   "date",
 					   "from",
@@ -1740,6 +1746,12 @@ notmuch_database_add_message (notmuch_database_t *notmuch,
     if (message_file)
 	notmuch_message_file_close (message_file);
 
+    ret2 = notmuch_database_end_atomic (notmuch);
+    if ((ret == NOTMUCH_STATUS_SUCCESS ||
+	 ret == NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID) &&
+	ret2 != NOTMUCH_STATUS_SUCCESS)
+	ret = ret2;
+
     return ret;
 }
 
-- 
1.7.5.1