base/files/important_file_writer_unittest.cc

   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 #include "base/files/important_file_writer.h"
   6
   7 #include "base/bind.h"
   8 #include "base/compiler_specific.h"
   9 #include "base/files/file_path.h"
  10 #include "base/files/file_util.h"
  11 #include "base/files/scoped_temp_dir.h"
  12 #include "base/location.h"
  13 #include "base/logging.h"
  14 #include "base/run_loop.h"
  15 #include "base/single_thread_task_runner.h"
  16 #include "base/thread_task_runner_handle.h"
  17 #include "base/threading/thread.h"
  18 #include "base/time/time.h"
  19 #include "testing/gtest/include/gtest/gtest.h"
  20
  21 namespace base {
  22
  23 namespace {
  24
  25 std::string GetFileContent(const FilePath& path) {
  26   std::string content;
  27   if (!ReadFileToString(path, &content)) {
  28     NOTREACHED();
  29   }
  30   return content;
  31 }
  32
  33 class DataSerializer : public ImportantFileWriter::DataSerializer {
  34  public:
  35   explicit DataSerializer(const std::string& data) : data_(data) {
  36   }
  37
  38   bool SerializeData(std::string* output) override {
  39     output->assign(data_);
  40     return true;
  41   }
  42
  43  private:
  44   const std::string data_;
  45 };
  46
  47 class SuccessfulWriteObserver {
  48  public:
  49   SuccessfulWriteObserver() : successful_write_observed_(false) {}
  50
  51   // Register on_successful_write() to be called on the next successful write
  52   // of |writer|.
  53   void ObserveNextSuccessfulWrite(ImportantFileWriter* writer);
  54
  55   // Returns true if a successful write was observed via on_successful_write()
  56   // and resets the observation state to false regardless.
  57   bool GetAndResetObservationState();
  58
  59  private:
  60   void on_successful_write() {
  61     EXPECT_FALSE(successful_write_observed_);
  62     successful_write_observed_ = true;
  63   }
  64
  65   bool successful_write_observed_;
  66
  67   DISALLOW_COPY_AND_ASSIGN(SuccessfulWriteObserver);
  68 };
  69
  70 void SuccessfulWriteObserver::ObserveNextSuccessfulWrite(
  71     ImportantFileWriter* writer) {
  72   writer->RegisterOnNextSuccessfulWriteCallback(base::Bind(
  73       &SuccessfulWriteObserver::on_successful_write, base::Unretained(this)));
  74 }
  75
  76 bool SuccessfulWriteObserver::GetAndResetObservationState() {
  77   bool was_successful_write_observed = successful_write_observed_;
  78   successful_write_observed_ = false;
  79   return was_successful_write_observed;
  80 }
  81
  82 }  // namespace
  83
  84 class ImportantFileWriterTest : public testing::Test {
  85  public:
  86   ImportantFileWriterTest() { }
  87   void SetUp() override {
  88     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
  89     file_ = temp_dir_.path().AppendASCII("test-file");
  90   }
  91
  92  protected:
  93   SuccessfulWriteObserver successful_write_observer_;
  94   FilePath file_;
  95   MessageLoop loop_;
  96
  97  private:
  98   ScopedTempDir temp_dir_;
  99 };
 100
 101 TEST_F(ImportantFileWriterTest, Basic) {
 102   ImportantFileWriter writer(file_, ThreadTaskRunnerHandle::Get());
 103   EXPECT_FALSE(PathExists(writer.path()));
 104   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 105   writer.WriteNow(make_scoped_ptr(new std::string("foo")));
 106   RunLoop().RunUntilIdle();
 107
 108   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 109   ASSERT_TRUE(PathExists(writer.path()));
 110   EXPECT_EQ("foo", GetFileContent(writer.path()));
 111 }
 112
 113 TEST_F(ImportantFileWriterTest, BasicWithSuccessfulWriteObserver) {
 114   ImportantFileWriter writer(file_, ThreadTaskRunnerHandle::Get());
 115   EXPECT_FALSE(PathExists(writer.path()));
 116   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 117   successful_write_observer_.ObserveNextSuccessfulWrite(&writer);
 118   writer.WriteNow(make_scoped_ptr(new std::string("foo")));
 119   RunLoop().RunUntilIdle();
 120
 121   // Confirm that the observer is invoked.
 122   EXPECT_TRUE(successful_write_observer_.GetAndResetObservationState());
 123   ASSERT_TRUE(PathExists(writer.path()));
 124   EXPECT_EQ("foo", GetFileContent(writer.path()));
 125
 126   // Confirm that re-installing the observer works for another write.
 127   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 128   successful_write_observer_.ObserveNextSuccessfulWrite(&writer);
 129   writer.WriteNow(make_scoped_ptr(new std::string("bar")));
 130   RunLoop().RunUntilIdle();
 131
 132   EXPECT_TRUE(successful_write_observer_.GetAndResetObservationState());
 133   ASSERT_TRUE(PathExists(writer.path()));
 134   EXPECT_EQ("bar", GetFileContent(writer.path()));
 135
 136   // Confirm that writing again without re-installing the observer doesn't
 137   // result in a notification.
 138   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 139   writer.WriteNow(make_scoped_ptr(new std::string("baz")));
 140   RunLoop().RunUntilIdle();
 141
 142   EXPECT_FALSE(successful_write_observer_.GetAndResetObservationState());
 143   ASSERT_TRUE(PathExists(writer.path()));
 144   EXPECT_EQ("baz", GetFileContent(writer.path()));
 145 }
 146
 147 TEST_F(ImportantFileWriterTest, ScheduleWrite) {
 148   ImportantFileWriter writer(file_, ThreadTaskRunnerHandle::Get());
 149   writer.set_commit_interval(TimeDelta::FromMilliseconds(25));
 150   EXPECT_FALSE(writer.HasPendingWrite());
 151   DataSerializer serializer("foo");
 152   writer.ScheduleWrite(&serializer);
 153   EXPECT_TRUE(writer.HasPendingWrite());
 154   ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 155       FROM_HERE, MessageLoop::QuitWhenIdleClosure(),
 156       TimeDelta::FromMilliseconds(100));
 157   MessageLoop::current()->Run();
 158   EXPECT_FALSE(writer.HasPendingWrite());
 159   ASSERT_TRUE(PathExists(writer.path()));
 160   EXPECT_EQ("foo", GetFileContent(writer.path()));
 161 }
 162
 163 TEST_F(ImportantFileWriterTest, DoScheduledWrite) {
 164   ImportantFileWriter writer(file_, ThreadTaskRunnerHandle::Get());
 165   EXPECT_FALSE(writer.HasPendingWrite());
 166   DataSerializer serializer("foo");
 167   writer.ScheduleWrite(&serializer);
 168   EXPECT_TRUE(writer.HasPendingWrite());
 169   writer.DoScheduledWrite();
 170   ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 171       FROM_HERE, MessageLoop::QuitWhenIdleClosure(),
 172       TimeDelta::FromMilliseconds(100));
 173   MessageLoop::current()->Run();
 174   EXPECT_FALSE(writer.HasPendingWrite());
 175   ASSERT_TRUE(PathExists(writer.path()));
 176   EXPECT_EQ("foo", GetFileContent(writer.path()));
 177 }
 178
 179 TEST_F(ImportantFileWriterTest, BatchingWrites) {
 180   ImportantFileWriter writer(file_, ThreadTaskRunnerHandle::Get());
 181   writer.set_commit_interval(TimeDelta::FromMilliseconds(25));
 182   DataSerializer foo("foo"), bar("bar"), baz("baz");
 183   writer.ScheduleWrite(&foo);
 184   writer.ScheduleWrite(&bar);
 185   writer.ScheduleWrite(&baz);
 186   ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 187       FROM_HERE, MessageLoop::QuitWhenIdleClosure(),
 188       TimeDelta::FromMilliseconds(100));
 189   MessageLoop::current()->Run();
 190   ASSERT_TRUE(PathExists(writer.path()));
 191   EXPECT_EQ("baz", GetFileContent(writer.path()));
 192 }
 193
 194 }  // namespace base