SERVER-2227 Addition of index usage statistics

1 files changed, 70 insertions, 0 deletions

diff --git a/src/mongo/db/collection_index_usage_tracker.cpp b/src/mongo/db/collection_index_usage_tracker.cpp
new file mode 100644
index 00000000000..10894bcfe6e
--- /dev/null
+++ b/src/mongo/db/collection_index_usage_tracker.cpp
@@ -0,0 +1,70 @@
+/**
+ *    Copyright (C) 2014 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.
+ */
+
+#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kStorage
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/collection_index_usage_tracker.h"
+#include "mongo/util/assert_util.h"
+#include "mongo/util/clock_source.h"
+#include "mongo/util/log.h"
+
+namespace mongo {
+
+CollectionIndexUsageTracker::CollectionIndexUsageTracker(ClockSource* clockSource)
+    : _clockSource(clockSource) {
+    invariant(_clockSource);
+}
+
+void CollectionIndexUsageTracker::recordIndexAccess(StringData indexName) {
+    invariant(!indexName.empty());
+    dassert(_indexUsageMap.find(indexName) != _indexUsageMap.end());
+
+    _indexUsageMap[indexName].accesses.fetchAndAdd(1);
+}
+
+void CollectionIndexUsageTracker::registerIndex(StringData indexName) {
+    invariant(!indexName.empty());
+    dassert(_indexUsageMap.find(indexName) == _indexUsageMap.end());
+
+    // Create map entry.
+    _indexUsageMap[indexName] = IndexUsageStats(_clockSource->now());
+}
+
+void CollectionIndexUsageTracker::unregisterIndex(StringData indexName) {
+    invariant(!indexName.empty());
+
+    _indexUsageMap.erase(indexName);
+}
+
+CollectionIndexUsageMap CollectionIndexUsageTracker::getUsageStats() const {
+    return _indexUsageMap;
+}
+
+}  // namespace mongo