1 files changed, 50 insertions, 0 deletions
diff --git a/src/rocksdb/include/rocksdb/utilities/memory_util.h b/src/rocksdb/include/rocksdb/utilities/memory_util.h
new file mode 100644
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+++ b/src/rocksdb/include/rocksdb/utilities/memory_util.h
@@ -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).
+
+#ifndef ROCKSDB_LITE
+
+#pragma once
+
+#include <map>
+#include <string>
+#include <unordered_set>
+#include <vector>
+
+#include "rocksdb/cache.h"
+#include "rocksdb/db.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+// Returns the current memory usage of the specified DB instances.
+class MemoryUtil {
+ public:
+  enum UsageType : int {
+    // Memory usage of all the mem-tables.
+    kMemTableTotal = 0,
+    // Memory usage of those un-flushed mem-tables.
+    kMemTableUnFlushed = 1,
+    // Memory usage of all the table readers.
+    kTableReadersTotal = 2,
+    // Memory usage by Cache.
+    kCacheTotal = 3,
+    kNumUsageTypes = 4
+  };
+
+  // Returns the approximate memory usage of different types in the input
+  // list of DBs and Cache set.  For instance, in the output map
+  // usage_by_type, usage_by_type[kMemTableTotal] will store the memory
+  // usage of all the mem-tables from all the input rocksdb instances.
+  //
+  // Note that for memory usage inside Cache class, we will
+  // only report the usage of the input "cache_set" without
+  // including those Cache usage inside the input list "dbs"
+  // of DBs.
+  static Status GetApproximateMemoryUsageByType(
+      const std::vector<DB*>& dbs,
+      const std::unordered_set<const Cache*> cache_set,
+      std::map<MemoryUtil::UsageType, uint64_t>* usage_by_type);
+};
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // !ROCKSDB_LITE