ceph/src/rocksdb/db/transaction_log_impl.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 #pragma once
   6
   7 #ifndef ROCKSDB_LITE
   8 #include <vector>
   9
  10 #include "db/log_reader.h"
  11 #include "db/version_set.h"
  12 #include "options/db_options.h"
  13 #include "port/port.h"
  14 #include "rocksdb/env.h"
  15 #include "rocksdb/options.h"
  16 #include "rocksdb/transaction_log.h"
  17 #include "rocksdb/types.h"
  18 #include "util/filename.h"
  19
  20 namespace rocksdb {
  21
  22 class LogFileImpl : public LogFile {
  23  public:
  24   LogFileImpl(uint64_t logNum, WalFileType logType, SequenceNumber startSeq,
  25               uint64_t sizeBytes) :
  26     logNumber_(logNum),
  27     type_(logType),
  28     startSequence_(startSeq),
  29     sizeFileBytes_(sizeBytes) {
  30   }
  31
  32   std::string PathName() const override {
  33     if (type_ == kArchivedLogFile) {
  34       return ArchivedLogFileName("", logNumber_);
  35     }
  36     return LogFileName("", logNumber_);
  37   }
  38
  39   uint64_t LogNumber() const override { return logNumber_; }
  40
  41   WalFileType Type() const override { return type_; }
  42
  43   SequenceNumber StartSequence() const override { return startSequence_; }
  44
  45   uint64_t SizeFileBytes() const override { return sizeFileBytes_; }
  46
  47   bool operator < (const LogFile& that) const {
  48     return LogNumber() < that.LogNumber();
  49   }
  50
  51  private:
  52   uint64_t logNumber_;
  53   WalFileType type_;
  54   SequenceNumber startSequence_;
  55   uint64_t sizeFileBytes_;
  56
  57 };
  58
  59 class TransactionLogIteratorImpl : public TransactionLogIterator {
  60  public:
  61   TransactionLogIteratorImpl(
  62       const std::string& dir, const ImmutableDBOptions* options,
  63       const TransactionLogIterator::ReadOptions& read_options,
  64       const EnvOptions& soptions, const SequenceNumber seqNum,
  65       std::unique_ptr<VectorLogPtr> files, VersionSet const* const versions,
  66       const bool seq_per_batch);
  67
  68   virtual bool Valid() override;
  69
  70   virtual void Next() override;
  71
  72   virtual Status status() override;
  73
  74   virtual BatchResult GetBatch() override;
  75
  76  private:
  77   const std::string& dir_;
  78   const ImmutableDBOptions* options_;
  79   const TransactionLogIterator::ReadOptions read_options_;
  80   const EnvOptions& soptions_;
  81   SequenceNumber startingSequenceNumber_;
  82   std::unique_ptr<VectorLogPtr> files_;
  83   bool started_;
  84   bool isValid_;  // not valid when it starts of.
  85   Status currentStatus_;
  86   size_t currentFileIndex_;
  87   std::unique_ptr<WriteBatch> currentBatch_;
  88   unique_ptr<log::Reader> currentLogReader_;
  89   Status OpenLogFile(const LogFile* logFile,
  90                      unique_ptr<SequentialFileReader>* file);
  91
  92   struct LogReporter : public log::Reader::Reporter {
  93     Env* env;
  94     Logger* info_log;
  95     virtual void Corruption(size_t bytes, const Status& s) override {
  96       ROCKS_LOG_ERROR(info_log, "dropping %" ROCKSDB_PRIszt " bytes; %s", bytes,
  97                       s.ToString().c_str());
  98     }
  99     virtual void Info(const char* s) { ROCKS_LOG_INFO(info_log, "%s", s); }
 100   } reporter_;
 101
 102   SequenceNumber currentBatchSeq_; // sequence number at start of current batch
 103   SequenceNumber currentLastSeq_; // last sequence in the current batch
 104   // Used only to get latest seq. num
 105   // TODO(icanadi) can this be just a callback?
 106   VersionSet const* const versions_;
 107   const bool seq_per_batch_;
 108   // Reads from transaction log only if the writebatch record has been written
 109   bool RestrictedRead(Slice* record, std::string* scratch);
 110   // Seeks to startingSequenceNumber reading from startFileIndex in files_.
 111   // If strict is set,then must get a batch starting with startingSequenceNumber
 112   void SeekToStartSequence(uint64_t startFileIndex = 0, bool strict = false);
 113   // Implementation of Next. SeekToStartSequence calls it internally with
 114   // internal=true to let it find next entry even if it has to jump gaps because
 115   // the iterator may start off from the first available entry but promises to
 116   // be continuous after that
 117   void NextImpl(bool internal = false);
 118   // Check if batch is expected, else return false
 119   bool IsBatchExpected(const WriteBatch* batch, SequenceNumber expectedSeq);
 120   // Update current batch if a continuous batch is found, else return false
 121   void UpdateCurrentWriteBatch(const Slice& record);
 122   Status OpenLogReader(const LogFile* file);
 123 };
 124 }  //  namespace rocksdb
 125 #endif  // ROCKSDB_LITE