SERVER-8119: add TimerStats class for collecting timing information

1 files changed, 76 insertions, 0 deletions

diff --git a/src/mongo/db/stats/timer_stats.h b/src/mongo/db/stats/timer_stats.h
new file mode 100644
index 00000000000..13b814f89f9
--- /dev/null
+++ b/src/mongo/db/stats/timer_stats.h
@@ -0,0 +1,76 @@
+// timer_stats.h
+
+/*    Copyright 2012 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#pragma once
+
+#include "mongo/db/jsobj.h"
+#include "mongo/util/concurrency/spin_lock.h"
+#include "mongo/util/timer.h"
+
+namespace mongo {
+
+
+    /**
+     * Holds timing information in milliseconds
+     * keeps track of number of times and total milliseconds
+     * so a diff can be computed
+     */
+    class TimerStats {
+    public:
+        void recordMillis( int millis );
+
+        /**
+         * @return number of millis
+         */
+        int record( const Timer& timer );
+
+        BSONObj getReport() const;
+        operator BSONObj() const { return getReport(); }
+
+    private:
+        mutable SpinLock _lock;
+        long long _num;
+        long long _totalMillis;
+    };
+
+    /**
+     * Holds an instance of a Timer such that we the time is recorded
+     * when the TimerHolder goes out of scope
+     */
+    class TimerHolder {
+    public:
+        TimerHolder( TimerStats* stats );
+        ~TimerHolder();
+
+        /**
+         * returns elapsed millis from internal timer
+         */
+        int millis() const { return _t.millis(); }
+
+
+        /**
+         * records the time in the TimerStats and marks that we've
+         * already recorded so the destructor doesn't
+         */
+        int recordMillis();
+
+    private:
+        TimerStats* _stats;
+        bool _recorded;
+        Timer _t;
+    };
+}