Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/src/rocksdb/monitoring/in_memory_stats_history.cc b/src/rocksdb/monitoring/in_memory_stats_history.cc
new file mode 100644
index 000000000..568d8ec13
--- /dev/null
+++ b/src/rocksdb/monitoring/in_memory_stats_history.cc
@@ -0,0 +1,50 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#include "monitoring/in_memory_stats_history.h"
+
+#include "db/db_impl/db_impl.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+InMemoryStatsHistoryIterator::~InMemoryStatsHistoryIterator() {}
+
+bool InMemoryStatsHistoryIterator::Valid() const { return valid_; }
+
+Status InMemoryStatsHistoryIterator::status() const { return status_; }
+
+// Because of garbage collection, the next stats snapshot may or may not be
+// right after the current one. When reading from DBImpl::stats_history_, this
+// call will be protected by DB Mutex so it will not return partial or
+// corrupted results.
+void InMemoryStatsHistoryIterator::Next() {
+  // increment start_time by 1 to avoid infinite loop
+  AdvanceIteratorByTime(GetStatsTime() + 1, end_time_);
+}
+
+uint64_t InMemoryStatsHistoryIterator::GetStatsTime() const { return time_; }
+
+const std::map<std::string, uint64_t>&
+InMemoryStatsHistoryIterator::GetStatsMap() const {
+  return stats_map_;
+}
+
+// advance the iterator to the next time between [start_time, end_time)
+// if success, update time_ and stats_map_ with new_time and stats_map
+void InMemoryStatsHistoryIterator::AdvanceIteratorByTime(uint64_t start_time,
+                                                         uint64_t end_time) {
+  // try to find next entry in stats_history_ map
+  if (db_impl_ != nullptr) {
+    valid_ =
+        db_impl_->FindStatsByTime(start_time, end_time, &time_, &stats_map_);
+  } else {
+    valid_ = false;
+  }
+}
+
+}  // namespace ROCKSDB_NAMESPACE