Home | History | Annotate | Download | only in api 
      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_API_SYNC_CHANGE_H_
      6 #define SYNC_API_SYNC_CHANGE_H_
      7 
      8 #include <iosfwd>
      9 #include <string>
     10 #include <vector>
     11 
     12 #include "base/location.h"
     13 #include "sync/api/sync_data.h"
     14 #include "sync/base/sync_export.h"
     15 
     16 namespace syncer {
     17 
     18 // A SyncChange object reflects a change to a piece of synced data. The change
     19 // can be either a delete, add, or an update. All data relevant to the change
     20 // is encapsulated within the SyncChange, which, once created, is immutable.
     21 // Note: it is safe and cheap to pass these by value or make copies, as they do
     22 // not create deep copies of their internal data.
     23 class SYNC_EXPORT SyncChange {
     24  public:
     25   enum SyncChangeType {
     26     ACTION_INVALID,
     27     ACTION_ADD,
     28     ACTION_UPDATE,
     29     ACTION_DELETE,
     30   };
     31 
     32   // Default constructor creates an invalid change.
     33   SyncChange();
     34   // Create a new change with the specified sync data.
     35   SyncChange(
     36       const tracked_objects::Location& from_here,
     37       SyncChangeType change_type,
     38       const SyncData& sync_data);
     39   ~SyncChange();
     40 
     41   // Copy constructor and assignment operator welcome.
     42 
     43   // Whether this change is valid. This must be true before attempting to access
     44   // the data.
     45   // Deletes: Requires valid tag when going to the syncer. Requires valid
     46   //          specifics when coming from the syncer.
     47   // Adds, Updates: Require valid tag and specifics when going to the syncer.
     48   //                Require only valid specifics when coming from the syncer.
     49   bool IsValid() const;
     50 
     51   // Getters.
     52   SyncChangeType change_type() const;
     53   SyncData sync_data() const;
     54   tracked_objects::Location location() const;
     55 
     56   // Returns a string representation of |change_type|.
     57   static std::string ChangeTypeToString(SyncChangeType change_type);
     58 
     59   // Returns a string representation of the entire object. Used for gmock
     60   // printing method, PrintTo.
     61   std::string ToString() const;
     62 
     63  private:
     64   tracked_objects::Location location_;
     65 
     66   SyncChangeType change_type_;
     67 
     68   // An immutable container for the data of this SyncChange. Whenever
     69   // SyncChanges are copied, they copy references to this data.
     70   SyncData sync_data_;
     71 };
     72 
     73 // gmock printer helper.
     74 SYNC_EXPORT void PrintTo(const SyncChange& sync_change, std::ostream* os);
     75 
     76 }  // namespace syncer
     77 
     78 #endif  // SYNC_API_SYNC_CHANGE_H_
     79