Revert "Revert "SERVER-28562 Move LogicalTime HMAC computation outside collection lock""

This reverts commit b7c013aa097b2d999ad3f942cdfce130558ef40f.

1 files changed, 75 insertions, 0 deletions

diff --git a/src/mongo/db/logical_time_validator.h b/src/mongo/db/logical_time_validator.h
new file mode 100644
index 00000000000..74bf93077bf
--- /dev/null
+++ b/src/mongo/db/logical_time_validator.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 <memory>
+
+#include "mongo/db/signed_logical_time.h"
+#include "mongo/db/time_proof_service.h"
+#include "mongo/stdx/mutex.h"
+
+namespace mongo {
+
+class OperationContext;
+class ServiceContext;
+
+/**
+ * This is responsible for signing logical times that can be used to sent to other servers and
+ * verifying signatures of signed logical times.
+ */
+class LogicalTimeValidator {
+public:
+    // Decorate ServiceContext with LogicalTimeValidator instance.
+    static LogicalTimeValidator* get(ServiceContext* service);
+    static LogicalTimeValidator* get(OperationContext* ctx);
+    static void set(ServiceContext* service, std::unique_ptr<LogicalTimeValidator> validator);
+
+    /**
+     * Returns the newTime with a valid signature.
+     */
+    SignedLogicalTime signLogicalTime(const LogicalTime& newTime);
+
+    /**
+     * Returns true if the signature of newTime is valid.
+     */
+    Status validate(const SignedLogicalTime& newTime);
+
+    /**
+     * Saves the newTime if it is newer than the last seen valid LogicalTime without performing
+     * validation.
+     */
+    void updateCacheTrustedSource(const SignedLogicalTime& newTime);
+
+private:
+    stdx::mutex _mutex;
+    SignedLogicalTime _lastSeenValidTime;
+    TimeProofService _timeProofService;
+};
+
+}  // namespace mongo