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