[PATCH v2] lib: add return status to database close and destroy

[Jani Nikula <jani@nikula.org>]

notmuch_database_close may fail in Xapian ->flush() or ->close(), so
report the status. Similarly for notmuch_database_destroy which calls
close.

This is required for notmuch insert to report error status if message
indexing failed.

---

v2 of
id:29b808bb6bf051fe21b6a72f12bb4ad1badfbf97.1385903109.git.jani@nikula.org
picked out of the series.
---
 lib/database.cc | 30 ++++++++++++++++++++++++------
 lib/notmuch.h   | 15 +++++++++++++--
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index f395061..46a9a8f 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -767,14 +767,17 @@ notmuch_database_open (const char *path,
     return status;
 }
 
-void
+notmuch_status_t
 notmuch_database_close (notmuch_database_t *notmuch)
 {
+    notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
+
     try {
 	if (notmuch->xapian_db != NULL &&
 	    notmuch->mode == NOTMUCH_DATABASE_MODE_READ_WRITE)
 	    (static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db))->flush ();
     } catch (const Xapian::Error &error) {
+	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 	if (! notmuch->exception_reported) {
 	    fprintf (stderr, "Error: A Xapian exception occurred flushing database: %s\n",
 		     error.get_msg().c_str());
@@ -788,7 +791,9 @@ notmuch_database_close (notmuch_database_t *notmuch)
 	try {
 	    notmuch->xapian_db->close();
 	} catch (const Xapian::Error &error) {
-	    /* do nothing */
+	    /* don't clobber previous error status */
+	    if (status == NOTMUCH_STATUS_SUCCESS)
+		status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
 	}
     }
 
@@ -802,6 +807,8 @@ notmuch_database_close (notmuch_database_t *notmuch)
     notmuch->value_range_processor = NULL;
     delete notmuch->date_range_processor;
     notmuch->date_range_processor = NULL;
+
+    return status;
 }
 
 #if HAVE_XAPIAN_COMPACT
@@ -965,8 +972,15 @@ notmuch_database_compact (const char *path,
     }
 
   DONE:
-    if (notmuch)
-	notmuch_database_destroy (notmuch);
+    if (notmuch) {
+	notmuch_status_t ret2;
+
+	ret2 = notmuch_database_destroy (notmuch);
+
+	/* don't clobber previous error status */
+	if (ret == NOTMUCH_STATUS_SUCCESS && ret2 != NOTMUCH_STATUS_SUCCESS)
+	    ret = ret2;
+    }
 
     talloc_free (local);
 
@@ -984,11 +998,15 @@ notmuch_database_compact (unused (const char *path),
 }
 #endif
 
-void
+notmuch_status_t
 notmuch_database_destroy (notmuch_database_t *notmuch)
 {
-    notmuch_database_close (notmuch);
+    notmuch_status_t status;
+
+    status = notmuch_database_close (notmuch);
     talloc_free (notmuch);
+
+    return status;
 }
 
 const char *
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 02604c5..7ac7118 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -287,8 +287,16 @@ notmuch_database_open (const char *path,
  *
  * notmuch_database_close can be called multiple times.  Later calls
  * have no effect.
+ *
+ * Return value:
+ *
+ * NOTMUCH_STATUS_SUCCESS: Successfully closed the database.
+ *
+ * NOTMUCH_STATUS_XAPIAN_EXCEPTION: A Xapian exception occurred; the
+ *	database has been closed but there are no guarantees the
+ *	changes to the database, if any, have been flushed to disk.
  */
-void
+notmuch_status_t
 notmuch_database_close (notmuch_database_t *database);
 
 /**
@@ -317,8 +325,11 @@ notmuch_database_compact (const char* path,
 /**
  * Destroy the notmuch database, closing it if necessary and freeing
  * all associated resources.
+ *
+ * Return value as in notmuch_database_close if the database was open;
+ * notmuch_database_destroy itself has no failure modes.
  */
-void
+notmuch_status_t
 notmuch_database_destroy (notmuch_database_t *database);
 
 /**
-- 
1.8.5.2