CDRIVER-465: Add mongoc_client_kill_cursor()

A good samaritan should clean after himself using
mongoc_cursor_destroy(cursor), but you may not always have the cursor instance.
You are just trying to cleanup after a broken process, and all you got is
the cursorid, which you retrieved from db.currentOp()

Closes #121

Author: bjori

src/mongoc/mongoc-client.c

@@ -1257,6 +1257,30 @@ mongoc_client_command_simple (mongoc_client_t           *client,
    return ret;
 }
 
+void
+mongoc_client_kill_cursor (mongoc_client_t *client,
+                           int64_t          cursor_id)
+{
+   mongoc_rpc_t rpc = {{ 0 }};
+
+   ENTRY;
+
+   bson_return_if_fail(client);
+   bson_return_if_fail(cursor_id);
+
+   rpc.kill_cursors.msg_len = 0;
+   rpc.kill_cursors.request_id = 0;
+   rpc.kill_cursors.response_to = 0;
+   rpc.kill_cursors.opcode = MONGOC_OPCODE_KILL_CURSORS;
+   rpc.kill_cursors.zero = 0;
+   rpc.kill_cursors.cursors = &cursor_id;
+   rpc.kill_cursors.n_cursors = 1;
+
+   _mongoc_client_sendv (client, &rpc, 1, 0, NULL, NULL, NULL);
+
+   EXIT;
+}
+
 
 char **
 mongoc_client_get_database_names (mongoc_client_t *client,

src/mongoc/mongoc-client.h

@@ -92,6 +92,8 @@ mongoc_cursor_t               *mongoc_client_command              (mongoc_client
                                                                    const bson_t                 *query,
                                                                    const bson_t                 *fields,
                                                                    const mongoc_read_prefs_t    *read_prefs);
+void                           mongoc_client_kill_cursor          (mongoc_client_t *client,
+                                                                   int64_t          cursor_id);
 bool                           mongoc_client_command_simple       (mongoc_client_t              *client,
                                                                    const char                   *db_name,
                                                                    const bson_t                 *command,

src/mongoc/mongoc-cursor.c

@@ -318,31 +318,6 @@ _mongoc_cursor_new (mongoc_client_t           *client,
 }
 
 
-static void
-_mongoc_cursor_kill_cursor (mongoc_cursor_t *cursor,
-                            int64_t     cursor_id)
-{
-   mongoc_rpc_t rpc = {{ 0 }};
-
-   ENTRY;
-
-   bson_return_if_fail(cursor);
-   bson_return_if_fail(cursor_id);
-
-   rpc.kill_cursors.msg_len = 0;
-   rpc.kill_cursors.request_id = 0;
-   rpc.kill_cursors.response_to = 0;
-   rpc.kill_cursors.opcode = MONGOC_OPCODE_KILL_CURSORS;
-   rpc.kill_cursors.zero = 0;
-   rpc.kill_cursors.cursors = &cursor_id;
-   rpc.kill_cursors.n_cursors = 1;
-
-   _mongoc_client_sendv (cursor->client, &rpc, 1, 0, NULL, NULL, NULL);
-
-   EXIT;
-}
-
-
 void
 mongoc_cursor_destroy (mongoc_cursor_t *cursor)
 {
@@ -373,7 +348,7 @@ _mongoc_cursor_destroy (mongoc_cursor_t *cursor)
             &cursor->client->cluster.nodes[cursor->hint - 1]);
       }
    } else if (cursor->rpc.reply.cursor_id) {
-      _mongoc_cursor_kill_cursor(cursor, cursor->rpc.reply.cursor_id);
+      mongoc_client_kill_cursor(cursor->client, cursor->rpc.reply.cursor_id);
    }
 
    if (cursor->reader) {
@@ -1079,3 +1054,4 @@ mongoc_cursor_get_hint (const mongoc_cursor_t *cursor)
 
    return cursor->hint;
 }
+