ceph/src/rocksdb/include/rocksdb/trace_reader_writer.h

   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:
  22   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:
  34   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