sync/engine/syncer.h

   1 // Copyright (c) 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_ENGINE_SYNCER_H_
   6 #define SYNC_ENGINE_SYNCER_H_
   7
   8 #include <utility>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/callback.h"
  13 #include "base/gtest_prod_util.h"
  14 #include "base/synchronization/lock.h"
  15 #include "sync/base/sync_export.h"
  16 #include "sync/engine/conflict_resolver.h"
  17 #include "sync/engine/syncer_types.h"
  18 #include "sync/internal_api/public/base/model_type.h"
  19 #include "sync/sessions/sync_session.h"
  20 #include "sync/util/extensions_activity.h"
  21
  22 namespace syncer {
  23
  24 class CancelationSignal;
  25 class CommitProcessor;
  26 class GetUpdatesProcessor;
  27
  28 // A Syncer provides a control interface for driving the sync cycle.  These
  29 // cycles consist of downloading updates, parsing the response (aka. process
  30 // updates), applying updates while resolving conflicts, and committing local
  31 // changes.  Some of these steps may be skipped if they're deemed to be
  32 // unnecessary.
  33 //
  34 // A Syncer instance expects to run on a dedicated thread.  Calls to SyncShare()
  35 // may take an unbounded amount of time because it may block on network I/O, on
  36 // lock contention, or on tasks posted to other threads.
  37 class SYNC_EXPORT_PRIVATE Syncer {
  38  public:
  39   typedef std::vector<int64> UnsyncedMetaHandles;
  40
  41   Syncer(CancelationSignal* cancelation_signal);
  42   virtual ~Syncer();
  43
  44   bool ExitRequested();
  45
  46   // Fetches and applies updates, resolves conflicts and commits local changes
  47   // for |request_types| as necessary until client and server states are in
  48   // sync.  The |nudge_tracker| contains state that describes why the client is
  49   // out of sync and what must be done to bring it back into sync.
  50   virtual bool NormalSyncShare(ModelTypeSet request_types,
  51                                const sessions::NudgeTracker& nudge_tracker,
  52                                sessions::SyncSession* session);
  53
  54   // Performs an initial download for the |request_types|.  It is assumed that
  55   // the specified types have no local state, and that their associated change
  56   // processors are in "passive" mode, so none of the downloaded updates will be
  57   // applied to the model.  The |source| is sent up to the server for debug
  58   // purposes.  It describes the reson for performing this initial download.
  59   virtual bool ConfigureSyncShare(
  60       ModelTypeSet request_types,
  61       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source,
  62       sessions::SyncSession* session);
  63
  64   // Requests to download updates for the |request_types|.  For a well-behaved
  65   // client with a working connection to the invalidations server, this should
  66   // be unnecessary.  It may be invoked periodically to try to keep the client
  67   // in sync despite bugs or transient failures.
  68   virtual bool PollSyncShare(ModelTypeSet request_types,
  69                              sessions::SyncSession* session);
  70
  71  private:
  72   bool DownloadAndApplyUpdates(
  73       ModelTypeSet request_types,
  74       sessions::SyncSession* session,
  75       GetUpdatesProcessor* get_updates_processor,
  76       bool create_mobile_bookmarks_folder);
  77
  78   // This function will commit batches of unsynced items to the server until the
  79   // number of unsynced and ready to commit items reaches zero or an error is
  80   // encountered.  A request to exit early will be treated as an error and will
  81   // abort any blocking operations.
  82   SyncerError BuildAndPostCommits(
  83       ModelTypeSet request_types,
  84       sessions::SyncSession* session,
  85       CommitProcessor* commit_processor);
  86
  87   void HandleCycleBegin(sessions::SyncSession* session);
  88   bool HandleCycleEnd(
  89       sessions::SyncSession* session,
  90       sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
  91
  92   syncer::CancelationSignal* const cancelation_signal_;
  93
  94   friend class SyncerTest;
  95   FRIEND_TEST_ALL_PREFIXES(SyncerTest, NameClashWithResolver);
  96   FRIEND_TEST_ALL_PREFIXES(SyncerTest, IllegalAndLegalUpdates);
  97   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingAndNewParent);
  98   FRIEND_TEST_ALL_PREFIXES(SyncerTest,
  99                            TestCommitListOrderingAndNewParentAndChild);
 100   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingCounterexample);
 101   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNesting);
 102   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNewItems);
 103   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestGetUnsyncedAndSimpleCommit);
 104   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnsynced);
 105   FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnapplied);
 106   FRIEND_TEST_ALL_PREFIXES(SyncerTest, UnappliedUpdateDuringCommit);
 107   FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryInFolder);
 108   FRIEND_TEST_ALL_PREFIXES(SyncerTest,
 109                            LongChangelistCreatesFakeOrphanedEntries);
 110   FRIEND_TEST_ALL_PREFIXES(SyncerTest, QuicklyMergeDualCreatedHierarchy);
 111   FRIEND_TEST_ALL_PREFIXES(SyncerTest, LongChangelistWithApplicationConflict);
 112   FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryWithLocalEdits);
 113   FRIEND_TEST_ALL_PREFIXES(EntryCreatedInNewFolderTest,
 114                            EntryCreatedInNewFolderMidSync);
 115
 116   DISALLOW_COPY_AND_ASSIGN(Syncer);
 117 };
 118
 119 }  // namespace syncer
 120
 121 #endif  // SYNC_ENGINE_SYNCER_H_