1 files changed, 58 insertions, 0 deletions
diff --git a/src/rocksdb/memory/allocator.h b/src/rocksdb/memory/allocator.h
new file mode 100644
index 000000000..0d7cd60a9
--- /dev/null
+++ b/src/rocksdb/memory/allocator.h
@@ -0,0 +1,58 @@
+//  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.
+//
+// Abstract interface for allocating memory in blocks. This memory is freed
+// when the allocator object is destroyed. See the Arena class for more info.
+
+#pragma once
+#include <cerrno>
+#include <cstddef>
+
+#include "rocksdb/write_buffer_manager.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class Logger;
+
+class Allocator {
+ public:
+  virtual ~Allocator() {}
+
+  virtual char* Allocate(size_t bytes) = 0;
+  virtual char* AllocateAligned(size_t bytes, size_t huge_page_size = 0,
+                                Logger* logger = nullptr) = 0;
+
+  virtual size_t BlockSize() const = 0;
+};
+
+class AllocTracker {
+ public:
+  explicit AllocTracker(WriteBufferManager* write_buffer_manager);
+  // No copying allowed
+  AllocTracker(const AllocTracker&) = delete;
+  void operator=(const AllocTracker&) = delete;
+
+  ~AllocTracker();
+  void Allocate(size_t bytes);
+  // Call when we're finished allocating memory so we can free it from
+  // the write buffer's limit.
+  void DoneAllocating();
+
+  void FreeMem();
+
+  bool is_freed() const { return write_buffer_manager_ == nullptr || freed_; }
+
+ private:
+  WriteBufferManager* write_buffer_manager_;
+  std::atomic<size_t> bytes_allocated_;
+  bool done_allocating_;
+  bool freed_;
+};
+
+}  // namespace ROCKSDB_NAMESPACE