1// Copyright (c) 2011 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 CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
6#define CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
7#pragma once
8
9#include <utility>
10#include <vector>
11
12#include "base/basictypes.h"
13#include "base/callback.h"
14#include "base/gtest_prod_util.h"
15#include "base/memory/scoped_ptr.h"
16#include "base/synchronization/lock.h"
17#include "chrome/browser/sync/engine/conflict_resolver.h"
18#include "chrome/browser/sync/engine/syncer_types.h"
19#include "chrome/browser/sync/engine/syncproto.h"
20#include "chrome/browser/sync/sessions/sync_session.h"
21#include "chrome/browser/sync/syncable/directory_event.h"
22#include "chrome/browser/sync/syncable/model_type.h"
23#include "chrome/browser/sync/util/extensions_activity_monitor.h"
24#include "chrome/common/deprecated/event_sys.h"
25#include "chrome/common/deprecated/event_sys-inl.h"
26
27namespace syncable {
28class Directory;
29class DirectoryManager;
30class Entry;
31class Id;
32class MutableEntry;
33class WriteTransaction;
34}  // namespace syncable
35
36namespace browser_sync {
37
38class ModelSafeWorker;
39class ServerConnectionManager;
40class SyncProcessState;
41class URLFactory;
42struct HttpResponse;
43
44enum SyncerStep {
45  SYNCER_BEGIN,
46  CLEANUP_DISABLED_TYPES,
47  DOWNLOAD_UPDATES,
48  PROCESS_CLIENT_COMMAND,
49  VERIFY_UPDATES,
50  PROCESS_UPDATES,
51  STORE_TIMESTAMPS,
52  APPLY_UPDATES,
53  BUILD_COMMIT_REQUEST,
54  POST_COMMIT_MESSAGE,
55  PROCESS_COMMIT_RESPONSE,
56  BUILD_AND_PROCESS_CONFLICT_SETS,
57  RESOLVE_CONFLICTS,
58  APPLY_UPDATES_TO_RESOLVE_CONFLICTS,
59  CLEAR_PRIVATE_DATA,  // TODO(tim): Rename 'private' to 'user'.
60  SYNCER_END
61};
62
63// A Syncer provides a control interface for driving the individual steps
64// of the sync cycle.  Each cycle (hopefully) moves the client into closer
65// synchronization with the server.  The individual steps are modeled
66// as SyncerCommands, and the ordering of the steps is expressed using
67// the SyncerStep enum.
68//
69// A Syncer instance expects to run on a dedicated thread.  Calls
70// to SyncShare() may take an unbounded amount of time, as SyncerCommands
71// may block on network i/o, on lock contention, or on tasks posted to
72// other threads.
73class Syncer {
74 public:
75  typedef std::vector<int64> UnsyncedMetaHandles;
76
77  // The constructor may be called from a thread that is not the Syncer's
78  // dedicated thread, to allow some flexibility in the setup.
79  Syncer();
80  virtual ~Syncer();
81
82  // Called by other threads to tell the syncer to stop what it's doing
83  // and return early from SyncShare, if possible.
84  bool ExitRequested();
85  void RequestEarlyExit();
86
87  // TODO(tim): Deprecated.
88  // Cause one sync cycle to occur.  Like a good parent, it is the caller's
89  // responsibility to clean up after the syncer when it finishes a sync share
90  // operation and honor server mandated throttles.
91  virtual void SyncShare(sessions::SyncSession* session);
92
93  // Like SyncShare() above, but |first_step| and |last_step| are provided to
94  // perform a partial sync cycle, stopping after |last_step| is performed.
95  virtual void SyncShare(sessions::SyncSession* session,
96                         SyncerStep first_step,
97                         SyncerStep last_step);
98
99 private:
100  // Implements the PROCESS_CLIENT_COMMAND syncer step.
101  void ProcessClientCommand(sessions::SyncSession* session);
102
103  bool early_exit_requested_;
104  base::Lock early_exit_requested_lock_;
105
106  ConflictResolver resolver_;
107
108  // A callback hook used in unittests to simulate changes between conflict set
109  // building and conflict resolution.
110  Callback0::Type* pre_conflict_resolution_closure_;
111
112  friend class SyncerTest;
113  FRIEND_TEST_ALL_PREFIXES(SyncerTest, NameClashWithResolver);
114  FRIEND_TEST_ALL_PREFIXES(SyncerTest, IllegalAndLegalUpdates);
115  FRIEND_TEST_ALL_PREFIXES(SusanDeletingTest,
116                           NewServerItemInAFolderHierarchyWeHaveDeleted3);
117  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingAndNewParent);
118  FRIEND_TEST_ALL_PREFIXES(SyncerTest,
119                           TestCommitListOrderingAndNewParentAndChild);
120  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingCounterexample);
121  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNesting);
122  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestCommitListOrderingWithNewItems);
123  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestGetUnsyncedAndSimpleCommit);
124  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnsynced);
125  FRIEND_TEST_ALL_PREFIXES(SyncerTest, TestPurgeWhileUnapplied);
126  FRIEND_TEST_ALL_PREFIXES(SyncerTest, UnappliedUpdateDuringCommit);
127  FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryInFolder);
128  FRIEND_TEST_ALL_PREFIXES(SyncerTest,
129                           LongChangelistCreatesFakeOrphanedEntries);
130  FRIEND_TEST_ALL_PREFIXES(SyncerTest, QuicklyMergeDualCreatedHierarchy);
131  FRIEND_TEST_ALL_PREFIXES(SyncerTest, LongChangelistWithApplicationConflict);
132  FRIEND_TEST_ALL_PREFIXES(SyncerTest, DeletingEntryWithLocalEdits);
133  FRIEND_TEST_ALL_PREFIXES(EntryCreatedInNewFolderTest,
134                           EntryCreatedInNewFolderMidSync);
135
136  DISALLOW_COPY_AND_ASSIGN(Syncer);
137};
138
139// Inline utility functions.
140
141// Given iterator ranges from two collections sorted according to a common
142// strict weak ordering, return true if the two ranges contain any common
143// items, and false if they do not. This function is in this header so that it
144// can be tested.
145template <class Iterator1, class Iterator2>
146bool SortedCollectionsIntersect(Iterator1 begin1, Iterator1 end1,
147                                Iterator2 begin2, Iterator2 end2) {
148  Iterator1 i1 = begin1;
149  Iterator2 i2 = begin2;
150  while (i1 != end1 && i2 != end2) {
151    if (*i1 == *i2)
152      return true;
153    if (*i1 > *i2)
154      ++i2;
155    else
156      ++i1;
157  }
158  return false;
159}
160// Utility function declarations.
161void CopyServerFields(syncable::Entry* src, syncable::MutableEntry* dest);
162void ClearServerData(syncable::MutableEntry* entry);
163
164}  // namespace browser_sync
165
166#endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_H_
167
168