sync_client.h revision 116680a4aac90f2aa7413d9095a592090648e557 
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 CHROME_BROWSER_CHROMEOS_DRIVE_SYNC_CLIENT_H_
6#define CHROME_BROWSER_CHROMEOS_DRIVE_SYNC_CLIENT_H_
7
8#include <map>
9#include <string>
10#include <vector>
11
12#include "base/callback.h"
13#include "base/memory/scoped_ptr.h"
14#include "base/memory/weak_ptr.h"
15#include "base/time/time.h"
16#include "chrome/browser/chromeos/drive/file_errors.h"
17#include "chrome/browser/chromeos/drive/job_scheduler.h"
18#include "chrome/browser/chromeos/drive/resource_metadata.h"
19
20namespace base {
21class SequencedTaskRunner;
22}
23
24namespace drive {
25
26class FileCacheEntry;
27class JobScheduler;
28class ResourceEntry;
29struct ClientContext;
30
31namespace file_system {
32class DownloadOperation;
33class OperationObserver;
34}
35
36namespace internal {
37
38class ChangeListLoader;
39class EntryUpdatePerformer;
40class FileCache;
41class LoaderController;
42class ResourceMetadata;
43
44// The SyncClient is used to synchronize pinned files on Drive and the
45// cache on the local drive.
46//
47// If the user logs out before fetching of the pinned files is complete, this
48// client resumes fetching operations next time the user logs in, based on
49// the states left in the cache.
50class SyncClient {
51 public:
52  SyncClient(base::SequencedTaskRunner* blocking_task_runner,
53             file_system::OperationObserver* observer,
54             JobScheduler* scheduler,
55             ResourceMetadata* metadata,
56             FileCache* cache,
57             LoaderController* loader_controller,
58             const base::FilePath& temporary_file_directory);
59  virtual ~SyncClient();
60
61  // Adds a fetch task.
62  void AddFetchTask(const std::string& local_id);
63
64  // Removes a fetch task.
65  void RemoveFetchTask(const std::string& local_id);
66
67  // Adds a update task.
68  void AddUpdateTask(const ClientContext& context, const std::string& local_id);
69
70  // Starts processing the backlog (i.e. pinned-but-not-filed files and
71  // dirty-but-not-uploaded files). Kicks off retrieval of the local
72  // IDs of these files, and then starts the sync loop.
73  void StartProcessingBacklog();
74
75  // Starts checking the existing pinned files to see if these are
76  // up-to-date. If stale files are detected, the local IDs of these files
77  // are added and the sync loop is started.
78  void StartCheckingExistingPinnedFiles();
79
80  // Sets a delay for testing.
81  void set_delay_for_testing(const base::TimeDelta& delay) {
82    delay_ = delay;
83  }
84
85  // Starts the sync loop if it's not running.
86  void StartSyncLoop();
87
88 private:
89  // Types of sync tasks.
90  enum SyncType {
91    FETCH,  // Fetch a file from the Drive server.
92    UPDATE,  // Updates an entry's metadata or content on the Drive server.
93  };
94
95  // States of sync tasks.
96  enum SyncState {
97    SUSPENDED,  // Task is currently inactive.
98    PENDING,  // Task is going to run.
99    RUNNING,  // Task is running.
100  };
101
102  typedef std::pair<SyncType, std::string> SyncTaskKey;
103
104  struct SyncTask {
105    SyncTask();
106    ~SyncTask();
107    SyncState state;
108    ClientContext context;
109    base::Callback<base::Closure(const ClientContext& context)> task;
110    bool should_run_again;
111    base::Closure cancel_closure;
112    std::vector<SyncTaskKey> dependent_tasks;
113  };
114
115  typedef std::map<SyncTaskKey, SyncTask> SyncTasks;
116
117  // Performs a FETCH task.
118  base::Closure PerformFetchTask(const std::string& local_id,
119                                 const ClientContext& context);
120
121  // Adds a FETCH task.
122  void AddFetchTaskInternal(const std::string& local_id,
123                            const base::TimeDelta& delay);
124
125  // Performs a UPDATE task.
126  base::Closure PerformUpdateTask(const std::string& local_id,
127                                  const ClientContext& context);
128
129  // Adds a UPDATE task.
130  void AddUpdateTaskInternal(const ClientContext& context,
131                             const std::string& local_id,
132                             const base::TimeDelta& delay);
133
134  // Adds the given task. If the same task is found, does nothing.
135  void AddTask(const SyncTasks::key_type& key,
136               const SyncTask& task,
137               const base::TimeDelta& delay);
138
139  // Called when a task is ready to start.
140  void StartTask(const SyncTasks::key_type& key);
141  void StartTaskAfterGetParentResourceEntry(const SyncTasks::key_type& key,
142                                            const ResourceEntry* parent,
143                                            FileError error);
144
145  // Called when the local IDs of files in the backlog are obtained.
146  void OnGetLocalIdsOfBacklog(const std::vector<std::string>* to_fetch,
147                              const std::vector<std::string>* to_update);
148
149  // Adds fetch tasks.
150  void AddFetchTasks(const std::vector<std::string>* local_ids);
151
152  // Called when a task is completed.
153  void OnTaskComplete(SyncType type,
154                      const std::string& local_id,
155                      FileError error);
156
157  // Called when the file for |local_id| is fetched.
158  void OnFetchFileComplete(const std::string& local_id,
159                           FileError error,
160                           const base::FilePath& local_path,
161                           scoped_ptr<ResourceEntry> entry);
162
163  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
164  file_system::OperationObserver* operation_observer_;
165  ResourceMetadata* metadata_;
166  FileCache* cache_;
167
168  // Used to fetch pinned files.
169  scoped_ptr<file_system::DownloadOperation> download_operation_;
170
171  // Used to update entry metadata.
172  scoped_ptr<EntryUpdatePerformer> entry_update_performer_;
173
174  // Sync tasks to be processed.
175  SyncTasks tasks_;
176
177  // The delay is used for delaying processing tasks in AddTask().
178  base::TimeDelta delay_;
179
180  // The delay is used for delaying retry of tasks on server errors.
181  base::TimeDelta long_delay_;
182
183  // Note: This should remain the last member so it'll be destroyed and
184  // invalidate its weak pointers before any other members are destroyed.
185  base::WeakPtrFactory<SyncClient> weak_ptr_factory_;
186
187  DISALLOW_COPY_AND_ASSIGN(SyncClient);
188};
189
190}  // namespace internal
191}  // namespace drive
192
193#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_SYNC_CLIENT_H_
194