ceph/src/rocksdb/utilities/transactions/optimistic_transaction.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 #ifndef ROCKSDB_LITE
   9
  10 #include <stack>
  11 #include <string>
  12 #include <unordered_map>
  13 #include <vector>
  14
  15 #include "db/write_callback.h"
  16 #include "rocksdb/db.h"
  17 #include "rocksdb/slice.h"
  18 #include "rocksdb/snapshot.h"
  19 #include "rocksdb/status.h"
  20 #include "rocksdb/types.h"
  21 #include "rocksdb/utilities/transaction.h"
  22 #include "rocksdb/utilities/optimistic_transaction_db.h"
  23 #include "rocksdb/utilities/write_batch_with_index.h"
  24 #include "utilities/transactions/transaction_base.h"
  25 #include "utilities/transactions/transaction_util.h"
  26
  27 namespace rocksdb {
  28
  29 class OptimisticTransaction : public TransactionBaseImpl {
  30  public:
  31   OptimisticTransaction(OptimisticTransactionDB* db,
  32                         const WriteOptions& write_options,
  33                         const OptimisticTransactionOptions& txn_options);
  34
  35   virtual ~OptimisticTransaction();
  36
  37   void Reinitialize(OptimisticTransactionDB* txn_db,
  38                     const WriteOptions& write_options,
  39                     const OptimisticTransactionOptions& txn_options);
  40
  41   Status Prepare() override;
  42
  43   Status Commit() override;
  44
  45   Status Rollback() override;
  46
  47   Status SetName(const TransactionName& name) override;
  48
  49  protected:
  50   Status TryLock(ColumnFamilyHandle* column_family, const Slice& key,
  51                  bool read_only, bool exclusive,
  52                  bool untracked = false) override;
  53
  54  private:
  55   OptimisticTransactionDB* const txn_db_;
  56
  57   friend class OptimisticTransactionCallback;
  58
  59   void Initialize(const OptimisticTransactionOptions& txn_options);
  60
  61   // Returns OK if it is safe to commit this transaction.  Returns Status::Busy
  62   // if there are read or write conflicts that would prevent us from committing
  63   // OR if we can not determine whether there would be any such conflicts.
  64   //
  65   // Should only be called on writer thread.
  66   Status CheckTransactionForConflicts(DB* db);
  67
  68   void Clear() override;
  69
  70   void UnlockGetForUpdate(ColumnFamilyHandle* /* unused */,
  71                           const Slice& /* unused */) override {
  72     // Nothing to unlock.
  73   }
  74
  75   // No copying allowed
  76   OptimisticTransaction(const OptimisticTransaction&);
  77   void operator=(const OptimisticTransaction&);
  78 };
  79
  80 // Used at commit time to trigger transaction validation
  81 class OptimisticTransactionCallback : public WriteCallback {
  82  public:
  83   explicit OptimisticTransactionCallback(OptimisticTransaction* txn)
  84       : txn_(txn) {}
  85
  86   Status Callback(DB* db) override {
  87     return txn_->CheckTransactionForConflicts(db);
  88   }
  89
  90   bool AllowWriteBatching() override { return false; }
  91
  92  private:
  93   OptimisticTransaction* txn_;
  94 };
  95
  96 }  // namespace rocksdb
  97
  98 #endif  // ROCKSDB_LITE