1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
2 //  This source code is licensed under both the GPLv2 (found in the
3 //  COPYING file in the root directory) and Apache 2.0 License
4 //  (found in the LICENSE.Apache file in the root directory).
5 
6 #pragma once
7 
8 #include "rocksdb/env.h"
9 
10 namespace ROCKSDB_NAMESPACE {
11 
12 // Allow custom implementations of TraceWriter and TraceReader.
13 // By default, RocksDB provides a way to capture the traces to a file using the
14 // factory NewFileTraceWriter(). But users could also choose to export traces to
15 // any other system by providing custom implementations of TraceWriter and
16 // TraceReader.
17 
18 // TraceWriter allows exporting RocksDB traces to any system, one operation at
19 // a time.
20 class TraceWriter {
21  public:
TraceWriter()22   TraceWriter() {}
~TraceWriter()23   virtual ~TraceWriter() {}
24 
25   virtual Status Write(const Slice& data) = 0;
26   virtual Status Close() = 0;
27   virtual uint64_t GetFileSize() = 0;
28 };
29 
30 // TraceReader allows reading RocksDB traces from any system, one operation at
31 // a time. A RocksDB Replayer could depend on this to replay opertions.
32 class TraceReader {
33  public:
TraceReader()34   TraceReader() {}
~TraceReader()35   virtual ~TraceReader() {}
36 
37   virtual Status Read(std::string* data) = 0;
38   virtual Status Close() = 0;
39 };
40 
41 // Factory methods to read/write traces from/to a file.
42 Status NewFileTraceWriter(Env* env, const EnvOptions& env_options,
43                           const std::string& trace_filename,
44                           std::unique_ptr<TraceWriter>* trace_writer);
45 Status NewFileTraceReader(Env* env, const EnvOptions& env_options,
46                           const std::string& trace_filename,
47                           std::unique_ptr<TraceReader>* trace_reader);
48 }  // namespace ROCKSDB_NAMESPACE
49