text: // 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 "storage/browser/fileapi/local_file_stream_reader.h"
  
  #include <stddef.h>
  #include <stdint.h>
  
  #include <memory>
  #include <string>
  
  #include "base/files/file.h"
  #include "base/files/file_path.h"
  #include "base/files/file_util.h"
  #include "base/files/scoped_temp_dir.h"
  #include "base/location.h"
  #include "base/macros.h"
  #include "base/run_loop.h"
  #include "base/single_thread_task_runner.h"
  #include "base/threading/thread.h"
  #include "net/base/io_buffer.h"
  #include "net/base/net_errors.h"
  #include "net/base/test_completion_callback.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  using storage::LocalFileStreamReader;
  
  namespace content {
  
  namespace {
  
  const char kTestData[] = "0123456789";
  const int kTestDataSize = arraysize(kTestData) - 1;
  
  void ReadFromReader(LocalFileStreamReader* reader,
                      std::string* data, size_t size,
                      int* result) {
    ASSERT_TRUE(reader != NULL);
    ASSERT_TRUE(result != NULL);
    *result = net::OK;
    net::TestCompletionCallback callback;
    size_t total_bytes_read = 0;
    while (total_bytes_read < size) {
      scoped_refptr<net::IOBufferWithSize> buf(
          new net::IOBufferWithSize(size - total_bytes_read));
      int rv = reader->Read(buf.get(), buf->size(), callback.callback());
      if (rv == net::ERR_IO_PENDING)
        rv = callback.WaitForResult();
      if (rv < 0)
        *result = rv;
      if (rv <= 0)
        break;
      total_bytes_read += rv;
      data->append(buf->data(), rv);
    }
  }
  
  void NeverCalled(int) { ADD_FAILURE(); }
  void EmptyCallback() {}
  
  void QuitLoop() {
    base::MessageLoop::current()->QuitWhenIdle();
  }
  
  }  // namespace
  
  class LocalFileStreamReaderTest : public testing::Test {
   public:
    LocalFileStreamReaderTest()
        : file_thread_("FileUtilProxyTestFileThread") {}
  
    void SetUp() override {
      ASSERT_TRUE(file_thread_.Start());
      ASSERT_TRUE(dir_.CreateUniqueTempDir());
  
      base::WriteFile(test_path(), kTestData, kTestDataSize);
      base::File::Info info;
      ASSERT_TRUE(base::GetFileInfo(test_path(), &info));
      test_file_modification_time_ = info.last_modified;
    }
  
    void TearDown() override {
      // Give another chance for deleted streams to perform Close.
      base::RunLoop().RunUntilIdle();
      file_thread_.Stop();
      base::RunLoop().RunUntilIdle();
    }
  
   protected:
    LocalFileStreamReader* CreateFileReader(
        const base::FilePath& path,
        int64_t initial_offset,
        const base::Time& expected_modification_time) {
      return new LocalFileStreamReader(
              file_task_runner(),
              path,
              initial_offset,
              expected_modification_time);
    }
  
    void TouchTestFile(base::TimeDelta delta) {
      base::Time new_modified_time = test_file_modification_time() + delta;
      ASSERT_TRUE(base::TouchFile(test_path(),
                                  test_file_modification_time(),
                                  new_modified_time));
    }
  
    base::SingleThreadTaskRunner* file_task_runner() const {
      return file_thread_.task_runner().get();
    }
  
    base::FilePath test_dir() const { return dir_.path(); }
    base::FilePath test_path() const { return dir_.path().AppendASCII("test"); }
    base::Time test_file_modification_time() const {
      return test_file_modification_time_;
    }
  
    void EnsureFileTaskFinished() {
      file_task_runner()->PostTaskAndReply(
          FROM_HERE, base::Bind(&EmptyCallback), base::Bind(&QuitLoop));
      base::MessageLoop::current()->Run();
    }
  
   private:
    base::MessageLoopForIO message_loop_;
    base::Thread file_thread_;
    base::ScopedTempDir dir_;
    base::Time test_file_modification_time_;
  };
  
  TEST_F(LocalFileStreamReaderTest, NonExistent) {
    base::FilePath nonexistent_path = test_dir().AppendASCII("nonexistent");
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(nonexistent_path, 0, base::Time()));
    int result = 0;
    std::string data;
    ReadFromReader(reader.get(), &data, 10, &result);
    ASSERT_EQ(net::ERR_FILE_NOT_FOUND, result);
    ASSERT_EQ(0U, data.size());
  }
  
  TEST_F(LocalFileStreamReaderTest, Empty) {
    base::FilePath empty_path = test_dir().AppendASCII("empty");
    base::File file(empty_path, base::File::FLAG_CREATE | base::File::FLAG_READ);
    ASSERT_TRUE(file.IsValid());
    file.Close();
  
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(empty_path, 0, base::Time()));
    int result = 0;
    std::string data;
    ReadFromReader(reader.get(), &data, 10, &result);
    ASSERT_EQ(net::OK, result);
    ASSERT_EQ(0U, data.size());
  
    net::TestInt64CompletionCallback callback;
    int64_t length_result = reader->GetLength(callback.callback());
    if (length_result == net::ERR_IO_PENDING)
      length_result = callback.WaitForResult();
    ASSERT_EQ(0, result);
  }
  
  TEST_F(LocalFileStreamReaderTest, GetLengthNormal) {
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 0, test_file_modification_time()));
    net::TestInt64CompletionCallback callback;
    int64_t result = reader->GetLength(callback.callback());
    if (result == net::ERR_IO_PENDING)
      result = callback.WaitForResult();
    ASSERT_EQ(kTestDataSize, result);
  }
  
  TEST_F(LocalFileStreamReaderTest, GetLengthAfterModified) {
    // Touch file so that the file's modification time becomes different
    // from what we expect.
    TouchTestFile(base::TimeDelta::FromSeconds(-1));
  
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 0, test_file_modification_time()));
    net::TestInt64CompletionCallback callback;
    int64_t result = reader->GetLength(callback.callback());
    if (result == net::ERR_IO_PENDING)
      result = callback.WaitForResult();
    ASSERT_EQ(net::ERR_UPLOAD_FILE_CHANGED, result);
  
    // With NULL expected modification time this should work.
    reader.reset(CreateFileReader(test_path(), 0, base::Time()));
    result = reader->GetLength(callback.callback());
    if (result == net::ERR_IO_PENDING)
      result = callback.WaitForResult();
    ASSERT_EQ(kTestDataSize, result);
  }
  
  TEST_F(LocalFileStreamReaderTest, GetLengthWithOffset) {
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 3, base::Time()));
    net::TestInt64CompletionCallback callback;
    int64_t result = reader->GetLength(callback.callback());
    if (result == net::ERR_IO_PENDING)
      result = callback.WaitForResult();
    // Initial offset does not affect the result of GetLength.
    ASSERT_EQ(kTestDataSize, result);
  }
  
  TEST_F(LocalFileStreamReaderTest, ReadNormal) {
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 0, test_file_modification_time()));
    int result = 0;
    std::string data;
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    ASSERT_EQ(net::OK, result);
    ASSERT_EQ(kTestData, data);
  }
  
  TEST_F(LocalFileStreamReaderTest, ReadAfterModified) {
    // Touch file so that the file's modification time becomes different
    // from what we expect. Note that the resolution on some filesystems
    // is 1s so we can't test with deltas less than that.
    TouchTestFile(base::TimeDelta::FromSeconds(-1));
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 0, test_file_modification_time()));
    int result = 0;
    std::string data;
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    EXPECT_EQ(net::ERR_UPLOAD_FILE_CHANGED, result);
    EXPECT_EQ(0U, data.size());
  
    // Due to precision loss converting int64_t->double->int64_t (e.g. through
    // Blink) the expected/actual time may vary by microseconds. With
    // modification time delta < 10us this should work.
    TouchTestFile(base::TimeDelta::FromMicroseconds(1));
    data.clear();
    reader.reset(CreateFileReader(test_path(), 0, test_file_modification_time()));
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    EXPECT_EQ(net::OK, result);
    EXPECT_EQ(kTestData, data);
  
    // With matching modification times time this should work.
    TouchTestFile(base::TimeDelta());
    data.clear();
    reader.reset(CreateFileReader(test_path(), 0, test_file_modification_time()));
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    EXPECT_EQ(net::OK, result);
    EXPECT_EQ(kTestData, data);
  
    // And with NULL expected modification time this should work.
    data.clear();
    reader.reset(CreateFileReader(test_path(), 0, base::Time()));
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    EXPECT_EQ(net::OK, result);
    EXPECT_EQ(kTestData, data);
  }
  
  TEST_F(LocalFileStreamReaderTest, ReadWithOffset) {
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 3, base::Time()));
    int result = 0;
    std::string data;
    ReadFromReader(reader.get(), &data, kTestDataSize, &result);
    ASSERT_EQ(net::OK, result);
    ASSERT_EQ(&kTestData[3], data);
  }
  
  TEST_F(LocalFileStreamReaderTest, DeleteWithUnfinishedRead) {
    std::unique_ptr<LocalFileStreamReader> reader(
        CreateFileReader(test_path(), 0, base::Time()));
  
    net::TestCompletionCallback callback;
    scoped_refptr<net::IOBufferWithSize> buf(
        new net::IOBufferWithSize(kTestDataSize));
    int rv = reader->Read(buf.get(), buf->size(), base::Bind(&NeverCalled));
    ASSERT_TRUE(rv == net::ERR_IO_PENDING || rv >= 0);
  
    // Delete immediately.
    // Should not crash; nor should NeverCalled be callback.
    reader.reset();
    EnsureFileTaskFinished();
  }
  
  }  // namespace content
  