sync/internal_api/public/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_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_
   6 #define SYNC_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_
   7
   8 #include "sync/base/sync_export.h"
   9 #include "sync/internal_api/public/base/model_type.h"
  10 #include "sync/internal_api/public/user_share.h"
  11 #include "sync/util/cryptographer.h"
  12
  13 namespace syncer {
  14
  15 namespace syncable {
  16 class BaseTransaction;
  17 class Directory;
  18 }
  19
  20 // Sync API's BaseTransaction, ReadTransaction, and WriteTransaction allow for
  21 // batching of several read and/or write operations.  The read and write
  22 // operations are performed by creating ReadNode and WriteNode instances using
  23 // the transaction. These transaction classes wrap identically named classes in
  24 // syncable, and are used in a similar way. Unlike syncable::BaseTransaction,
  25 // whose construction requires an explicit syncable::Directory, a sync
  26 // API BaseTransaction is created from a UserShare object.
  27 //
  28 // Note, these transactions are not atomic. Individual operations can
  29 // fail. There is no built-in rollback or undo mechanism.
  30 class SYNC_EXPORT BaseTransaction {
  31  public:
  32   // Provide access to the underlying syncable objects from BaseNode.
  33   virtual syncable::BaseTransaction* GetWrappedTrans() const = 0;
  34   Cryptographer* GetCryptographer() const;
  35   ModelTypeSet GetEncryptedTypes() const;
  36
  37   syncable::Directory* GetDirectory() const {
  38     if (!user_share_) {
  39       return NULL;
  40     } else {
  41       return user_share_->directory.get();
  42     }
  43   }
  44
  45   UserShare* GetUserShare() const {
  46     return user_share_;
  47   }
  48
  49  protected:
  50   explicit BaseTransaction(UserShare* share);
  51   virtual ~BaseTransaction();
  52
  53   BaseTransaction() : user_share_(NULL) { }
  54
  55  private:
  56   UserShare* user_share_;
  57
  58   DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
  59 };
  60
  61 }  // namespace syncer
  62
  63 #endif  // SYNC_INTERNAL_API_PUBLIC_BASE_TRANSACTION_H_