[PATCH 11/17] lib: Add an API to find a message by filename.

[Austin Clements <amdragon@MIT.EDU>]

notmuch_database_find_message_by_filename is mostly stolen from
notmuch_database_remove_message, so this patch also vastly simplfies
the latter using the former.

This API is also useful in its own right and will be used in a later
patch for eager maildir flag synchronization.
---
 lib/database.cc |   49 ++++++++++++++++++++++++++-----------------------
 lib/notmuch.h   |   16 ++++++++++++++++
 2 files changed, 42 insertions(+), 23 deletions(-)

diff --git a/lib/database.cc b/lib/database.cc
index 9886622..daa619d 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -1747,57 +1747,60 @@ notmuch_status_t
 notmuch_database_remove_message (notmuch_database_t *notmuch,
 				 const char *filename)
 {
+    notmuch_message_t *message =
+	notmuch_database_find_message_by_filename (notmuch, filename);
+    notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;
+
+    if (message) {
+	    status = _notmuch_message_remove_filename (message, filename);
+	    if (status == NOTMUCH_STATUS_SUCCESS)
+		_notmuch_message_delete (message);
+	    else if (status == NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID)
+		_notmuch_message_sync (message);
+    }
+
+    return status;
+}
+
+notmuch_message_t *
+notmuch_database_find_message_by_filename (notmuch_database_t *notmuch,
+					   const char *filename)
+{
     void *local;
     const char *prefix = _find_prefix ("file-direntry");
     char *direntry, *term;
     Xapian::PostingIterator i, end;
-    Xapian::Document document;
+    notmuch_message_t *message = NULL;
     notmuch_status_t status;
 
-    status = _notmuch_database_ensure_writable (notmuch);
-    if (status)
-	return status;
-
     local = talloc_new (notmuch);
 
     try {
-
 	status = _notmuch_database_filename_to_direntry (local, notmuch,
 							 filename, &direntry);
 	if (status)
-	    return status;
+	    return NULL;
 
 	term = talloc_asprintf (local, "%s%s", prefix, direntry);
 
 	find_doc_ids_for_term (notmuch, term, &i, &end);
 
-	for ( ; i != end; i++) {
-	    Xapian::TermIterator j;
-	    notmuch_message_t *message;
+	if (i != end) {
 	    notmuch_private_status_t private_status;
 
-	    message = _notmuch_message_create (local, notmuch,
+	    message = _notmuch_message_create (notmuch, notmuch,
 					       *i, &private_status);
-	    if (message == NULL)
-		return COERCE_STATUS (private_status,
-				      "Inconsistent document ID in datbase.");
-
-	    status = _notmuch_message_remove_filename (message, filename);
-	    if (status == NOTMUCH_STATUS_SUCCESS)
-		_notmuch_message_delete (message);
-	    else if (status == NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID)
-		_notmuch_message_sync (message);
 	}
     } catch (const Xapian::Error &error) {
-	fprintf (stderr, "Error: A Xapian exception occurred removing message: %s\n",
+	fprintf (stderr, "Error: A Xapian exception occurred finding message by filename: %s\n",
 		 error.get_msg().c_str());
 	notmuch->exception_reported = TRUE;
-	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
+	message = NULL;
     }
 
     talloc_free (local);
 
-    return status;
+    return message;
 }
 
 notmuch_string_list_t *
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 830aa41..9ae260e 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -356,6 +356,22 @@ notmuch_message_t *
 notmuch_database_find_message (notmuch_database_t *database,
 			       const char *message_id);
 
+/* Find a message with the given filename.
+ *
+ * If the database contains a message with the given filename, then a
+ * new notmuch_message_t object is returned.  The caller should call 
+ * notmuch_message_destroy when done with the message.
+ *
+ * This function returns NULL in the following situations:
+ *
+ *	* No message is found with the given filename
+ *	* An out-of-memory situation occurs
+ *	* A Xapian exception occurs
+ */
+notmuch_message_t *
+notmuch_database_find_message_by_filename (notmuch_database_t *notmuch,
+					   const char *filename);
+
 /* Return a list of all tags found in the database.
  *
  * This function creates a list of all tags found in the database. The
-- 
1.7.5.1