sync/syncable/syncable_base_transaction.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef SYNC_SYNCABLE_SYNCABLE_BASE_TRANSACTION_H_
   6 #define SYNC_SYNCABLE_SYNCABLE_BASE_TRANSACTION_H_
   7
   8 #include "base/location.h"
   9 #include "sync/base/sync_export.h"
  10 #include "sync/syncable/syncable_id.h"
  11
  12 namespace syncer {
  13 namespace syncable {
  14
  15 class Directory;
  16
  17 // A WriteTransaction has a writer tag describing which body of code is doing
  18 // the write. This is defined up here since WriteTransactionInfo also contains
  19 // one.
  20 enum WriterTag {
  21   INVALID,
  22   SYNCER,
  23   AUTHWATCHER,
  24   UNITTEST,
  25   VACUUM_AFTER_SAVE,
  26   HANDLE_SAVE_FAILURE,
  27   PURGE_ENTRIES,
  28   SYNCAPI,
  29 };
  30
  31 // Make sure to update this if you update WriterTag.
  32 std::string WriterTagToString(WriterTag writer_tag);
  33
  34 class SYNC_EXPORT BaseTransaction {
  35  public:
  36   static Id root_id();
  37
  38   Directory* directory() const;
  39
  40   virtual ~BaseTransaction();
  41
  42   // This should be called when a database corruption is detected and there is
  43   // no way for us to recover short of wiping the database clean. When this is
  44   // called we set a bool in the transaction. The caller has to unwind the
  45   // stack. When the destructor for the transaction is called it acts upon the
  46   // bool and calls the Directory to handle the unrecoverable error.
  47   void OnUnrecoverableError(const tracked_objects::Location& location,
  48                             const std::string& message);
  49
  50   bool unrecoverable_error_set() const;
  51
  52  protected:
  53   BaseTransaction(const tracked_objects::Location& from_here,
  54                   const char* name,
  55                   WriterTag writer,
  56                   Directory* directory);
  57
  58   void Lock();
  59   void Unlock();
  60
  61   // This should be called before unlocking because it calls the Direcotry's
  62   // OnUnrecoverableError method which is not protected by locks and could
  63   // be called from any thread. Holding the transaction lock ensures only one
  64   // thread could call the method at a time.
  65   void HandleUnrecoverableErrorIfSet();
  66
  67   const tracked_objects::Location from_here_;
  68   const char* const name_;
  69   WriterTag writer_;
  70   Directory* const directory_;
  71
  72   // Error information.
  73   bool unrecoverable_error_set_;
  74   tracked_objects::Location unrecoverable_error_location_;
  75   std::string unrecoverable_error_msg_;
  76
  77  private:
  78   friend class Entry;
  79   DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
  80 };
  81
  82 }  // namespace syncable
  83 }  // namespace syncer
  84
  85 #endif  // SYNC_SYNCABLE_SYNCABLE_BASE_TRANSACTION_H_