SERVER-29131 Support resumeAfter option to control where to start returning notifications from, which always errors if no entry with the given resumeToken exists

1 files changed, 75 insertions, 0 deletions

diff --git a/src/mongo/db/pipeline/resume_token.h b/src/mongo/db/pipeline/resume_token.h
new file mode 100644
index 00000000000..733e285e599
--- /dev/null
+++ b/src/mongo/db/pipeline/resume_token.h
@@ -0,0 +1,75 @@
+/**
+ * Copyright (C) 2017 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 "mongo/base/string_data.h"
+#include "mongo/bson/bsonobj.h"
+#include "mongo/bson/timestamp.h"
+#include "mongo/db/pipeline/value.h"
+
+namespace mongo {
+/**
+ * A token passed in by the user to indicate where in the oplog we should start for
+ * $changeNotification.
+ */
+class ResumeToken {
+public:
+    /**
+     * The default no-argument constructor is required by the IDL for types used as non-optional
+     * fields.
+     */
+    ResumeToken() = default;
+    explicit ResumeToken(const Value& resumeValue);
+    bool operator==(const ResumeToken&);
+
+    Timestamp getTimestamp() const {
+        return _timestamp;
+    }
+
+    Document toDocument() const;
+
+    BSONObj toBSON() const;
+
+    /**
+     * Parse a resume token from a BSON object; used as an interface to the IDL parser.
+     */
+    static ResumeToken parse(const BSONObj& obj);
+
+private:
+    /**
+     * Construct from a BSON object.
+     * External callers should use the static ResumeToken::parse(const BSONObj&) method instead.
+     */
+    explicit ResumeToken(const BSONObj& resumeBson);
+
+    Timestamp _timestamp;
+    std::string _namespace;
+    Value _documentId;
+};
+}  // namespace mongo