SERVER-27437 Add dotted path expansion for Documents.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/mongo/db/pipeline/document_path_support.h b/src/mongo/db/pipeline/document_path_support.h
new file mode 100644
index 00000000000..60020873947
--- /dev/null
+++ b/src/mongo/db/pipeline/document_path_support.h
@@ -0,0 +1,55 @@
+/**
+ * Copyright (C) 2016 MongoDB Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * As a special exception, the copyright holders give permission to link the
+ * code of portions of this program with the OpenSSL library under certain
+ * conditions as described in each individual source file and distribute
+ * linked combinations including the program with the OpenSSL library. You
+ * must comply with the GNU Affero General Public License in all respects
+ * for all of the code used other than as permitted herein. If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so. If you do not
+ * wish to do so, delete this exception statement from your version. If you
+ * delete this exception statement from all source files in the program,
+ * then also delete it in the license file.
+ */
+
+#pragma once
+
+#include <vector>
+
+#include "mongo/db/pipeline/document.h"
+#include "mongo/db/pipeline/expression_context.h"
+#include "mongo/db/pipeline/field_path.h"
+#include "mongo/db/pipeline/value.h"
+#include "mongo/db/pipeline/value_comparator.h"
+#include "mongo/stdx/functional.h"
+
+namespace mongo {
+namespace document_path_support {
+
+/**
+ * Calls 'callback' once for each value found at 'path' in the document 'doc'. If an array value is
+ * found at 'path', it is expanded and 'callback' is invoked once for each value within the array.
+ *
+ * For example, 'callback' will be invoked on the values 1, 1, {a: 1}, 2 and 3 are on the path "x.y"
+ * in the document {x: [{y: 1}, {y: 1}, {y: {a: 1}}, {y: [2, 3]}, 3, 4]}.
+ */
+void visitAllValuesAtPath(Document doc,
+                          const FieldPath& path,
+                          stdx::function<void(const Value&)> callback);
+
+}  // namespace document_path_support
+}  // namespace mongo