[SyncFS] Add a test to SyncProcessRunner

chrome/browser/sync_file_system/sync_process_runner_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/sync_file_system/sync_process_runner.h"
+
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sync_file_system {
+
+namespace {
+
+class FakeClient : public SyncProcessRunner::Client {
+ public:
+  FakeClient() : service_state_(SYNC_SERVICE_RUNNING) {}
+  virtual ~FakeClient() {}
+
+  virtual SyncServiceState GetSyncServiceState() OVERRIDE {
+    return service_state_;
+  }
+
+  virtual SyncFileSystemService* GetSyncService() OVERRIDE {
+    return NULL;
+  }
+
+  void set_service_state(SyncServiceState service_state) {
+    service_state_ = service_state;
+  }
+
+ private:
+  SyncServiceState service_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeClient);
+};
+
+class FakeTimerHelper : public SyncProcessRunner::TimerHelper {
+ public:
+  FakeTimerHelper() {}
+  virtual ~FakeTimerHelper() {}
+
+  virtual bool IsRunning() OVERRIDE {
+    return !timer_task_.is_null();
+  }
+
+  virtual void Start(const tracked_objects::Location& from_here,
+                     const base::TimeDelta& delay,
+                     const base::Closure& closure) OVERRIDE {
+    scheduled_time_ = current_time_ + delay;
+    timer_task_ = closure;
+  }
+
+  virtual base::TimeTicks Now() const OVERRIDE {
+    return current_time_;
+  }
+
+  void SetCurrentTime(const base::TimeTicks& current_time) {
+    current_time_ = current_time;
+    if (current_time_ < scheduled_time_ || timer_task_.is_null())
+      return;
+
+    base::Closure task = timer_task_;
+    timer_task_.Reset();
+    task.Run();
+  }
+
+  void AdvanceToScheduledTime() {
+    SetCurrentTime(scheduled_time_);
+  }
+
+  int64 GetCurrentDelay() {
+    EXPECT_FALSE(timer_task_.is_null());
+    return (scheduled_time_ - current_time_).InMilliseconds();
+  }
+
+ private:
+  base::TimeTicks current_time_;
+  base::TimeTicks scheduled_time_;
+  base::Closure timer_task_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeTimerHelper);
+};
+
+class FakeSyncProcessRunner : public SyncProcessRunner {
+ public:
+  FakeSyncProcessRunner(SyncProcessRunner::Client* client,
+                        scoped_ptr<TimerHelper> timer_helper,
+                        int max_parallel_task)
+      : SyncProcessRunner("FakeSyncProcess",
+                          client, timer_helper.Pass(),
+                          max_parallel_task) {
+  }
+
+  virtual void StartSync(const SyncStatusCallback& callback) OVERRIDE {
+    EXPECT_TRUE(running_task_.is_null());
+    running_task_ = callback;
+  }
+
+  virtual ~FakeSyncProcessRunner() {
+  }
+
+  void UpdateChanges(int num_changes) {
+    OnChangesUpdated(num_changes);
+  }
+
+  void CompleteTask(SyncStatusCode status) {
+    ASSERT_FALSE(running_task_.is_null());
+    SyncStatusCallback task = running_task_;
+    running_task_.Reset();
+    task.Run(status);
+  }
+
+  bool HasRunningTask() const {
+    return !running_task_.is_null();
+  }
+
+ private:
+  SyncStatusCallback running_task_;
+
+  DISALLOW_COPY_AND_ASSIGN(FakeSyncProcessRunner);
+};
+
+}  // namespace
+
+TEST(SyncProcessRunnerTest, SingleTaskBasicTest) {
+  FakeClient fake_client;
+  FakeTimerHelper* fake_timer = new FakeTimerHelper();
+  FakeSyncProcessRunner fake_runner(
+      &fake_client,
+      scoped_ptr<SyncProcessRunner::TimerHelper>(fake_timer),
+      1 /* max_parallel_task */);
+
+  base::TimeTicks base_time = base::TimeTicks::Now();
+  fake_timer->SetCurrentTime(base_time);
+
+  // SyncProcessRunner is expected not to run a task  initially.
+  EXPECT_FALSE(fake_timer->IsRunning());
+
+  // As soon as SyncProcessRunner gets a new update, it should start running
+  // the timer to run a synchronization task.
+  fake_runner.UpdateChanges(100);
+  EXPECT_TRUE(fake_timer->IsRunning());
+  EXPECT_EQ(SyncProcessRunner::kSyncDelayFastInMilliseconds,
+            fake_timer->GetCurrentDelay());
+
+  // When the time has come, the timer should fire the scheduled task.
+  fake_timer->AdvanceToScheduledTime();
+  EXPECT_FALSE(fake_timer->IsRunning());
+  EXPECT_TRUE(fake_runner.HasRunningTask());
+
+  // Successful completion of the task fires next synchronization task.
+  fake_runner.CompleteTask(SYNC_STATUS_OK);
+  EXPECT_TRUE(fake_timer->IsRunning());
+  EXPECT_FALSE(fake_runner.HasRunningTask());
+  EXPECT_EQ(SyncProcessRunner::kSyncDelayFastInMilliseconds,
+            fake_timer->GetCurrentDelay());
+
+  // Turn |service_state| to TEMPORARY_UNAVAILABLE and let the task fail.
+  // |fake_runner| should schedule following tasks with longer delay.
+  fake_timer->AdvanceToScheduledTime();
+  fake_client.set_service_state(SYNC_SERVICE_TEMPORARY_UNAVAILABLE);
+  fake_runner.CompleteTask(SYNC_STATUS_FAILED);
+  EXPECT_EQ(SyncProcessRunner::kSyncDelaySlowInMilliseconds,
+            fake_timer->GetCurrentDelay());
+
+  // Repeated failure makes the task delay back off.
+  fake_timer->AdvanceToScheduledTime();
+  fake_runner.CompleteTask(SYNC_STATUS_FAILED);
+  EXPECT_EQ(2 * SyncProcessRunner::kSyncDelaySlowInMilliseconds,
+            fake_timer->GetCurrentDelay());
+
+  // After |service_state| gets back to normal state, SyncProcessRunner should
+  // restart rapid task invocation.
+  fake_client.set_service_state(SYNC_SERVICE_RUNNING);
+  fake_timer->AdvanceToScheduledTime();
+  fake_runner.CompleteTask(SYNC_STATUS_OK);
+  EXPECT_EQ(SyncProcessRunner::kSyncDelayFastInMilliseconds,
+            fake_timer->GetCurrentDelay());
+
+  // There's no item to sync anymore, SyncProcessRunner should schedules the
+  // next with the longest delay.
+  fake_runner.UpdateChanges(0);
+  fake_timer->AdvanceToScheduledTime();
+  fake_runner.CompleteTask(SYNC_STATUS_OK);
+  EXPECT_EQ(SyncProcessRunner::kSyncDelayMaxInMilliseconds,
+            fake_timer->GetCurrentDelay());
+}
+
+}  // namespace sync_file_system