Files services library: Add an "output stream" file impl helper class.

mojo/services/files/public/cpp/tests/output_stream_file_unittest.cc

+// Copyright 2015 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 "files/public/cpp/output_stream_file.h"
+
+#include <string.h>
+
+#include <memory>
+#include <string>
+
+#include "files/public/interfaces/files.mojom.h"
+#include "files/public/interfaces/types.mojom.h"
+#include "mojo/public/cpp/application/application_test_base.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/system/macros.h"
+#include "mojo/public/cpp/utility/run_loop.h"
+
+namespace files_impl {
+namespace {
+
+using OutputStreamFileTest = mojo::test::ApplicationTestBase;
+
+void QuitMessageLoop() {
+  mojo::RunLoop::current()->Quit();
+}
+
+void RunMessageLoop() {
+  mojo::RunLoop::current()->Run();
+}
+
+void RunMessageLoopUntilIdle() {
+  mojo::RunLoop::current()->RunUntilIdle();
+}
+
+// Converts a string to a |mojo::Array<uint8_t>| (not in
+mojo::Array<uint8_t> StringToArray(const std::string& s) {
+  auto rv = mojo::Array<uint8_t>::New(s.size());
+  if (s.size())
+    memcpy(&rv[0], &s[0], s.size());
+  return rv;
+}
+
+class TestClient : public OutputStreamFile::Client {
+ public:
+  TestClient() { Reset(); }
+  ~TestClient() override {}
+
+  void Reset() {
+    got_on_data_received_ = false;
+    data_ = std::string();
+    got_on_closed_ = false;
+  }
+
+  bool got_on_data_received() const { return got_on_data_received_; }
+  const std::string& data() const { return data_; }
+  bool got_on_closed() const { return got_on_closed_; }
+
+ private:
+  // |OutputStreamFile::Client|:
+  void OnDataReceived(const void* bytes, size_t num_bytes) override {
+    got_on_data_received_ = true;
+    data_ = std::string(static_cast<const char*>(bytes), num_bytes);
+    QuitMessageLoop();
+  }
+  void OnClosed() override {
+    got_on_closed_ = true;
+    QuitMessageLoop();
+  }
+
+  bool got_on_data_received_;
+  std::string data_;
+  bool got_on_closed_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(TestClient);
+};
+
+void TestWrite(mojo::files::File* file,
+               TestClient* client,
+               const std::string& s) {
+  bool write_cb_called = false;
+  mojo::files::Error error = mojo::files::ERROR_INTERNAL;
+  uint32_t num_bytes_written = 0;
+  file->Write(StringToArray(s), 0, mojo::files::WHENCE_FROM_CURRENT,
+              [&write_cb_called, &error, &num_bytes_written](
+                  mojo::files::Error e, uint32_t n) {
+                write_cb_called = true;
+                error = e;
+                num_bytes_written = n;
+                QuitMessageLoop();
+              });
+  if (client) {
+    // If there's a client, since we're running everything on one thread, the
+    // impl (which will call the client, which will quit the message loop) will
+    // get called before the callback.
+    client->Reset();
+    RunMessageLoop();
+    EXPECT_TRUE(client->got_on_data_received());
+    EXPECT_EQ(s, client->data());
+    EXPECT_FALSE(client->got_on_closed());
+    EXPECT_FALSE(write_cb_called);
+    // Spin the message loop again to get the callback.
+    client->Reset();
+    RunMessageLoop();
+    EXPECT_FALSE(client->got_on_data_received());
+    EXPECT_FALSE(client->got_on_closed());
+  } else {
+    // Otherwise, only the write callback will be called and quit the message
+    // loop.
+    RunMessageLoop();
+  }
+  EXPECT_TRUE(write_cb_called);
+  EXPECT_EQ(mojo::files::ERROR_OK, error);
+  EXPECT_EQ(s.size(), num_bytes_written);
+}
+
+void TestClose(mojo::files::File* file, TestClient* client) {
+  bool close_cb_called = false;
+  mojo::files::Error error = mojo::files::ERROR_INTERNAL;
+  file->Close([&close_cb_called, &error](mojo::files::Error e) {
+    close_cb_called = true;
+    error = e;
+    QuitMessageLoop();
+  });
+  // (This is analogous to |TestWrite()|.)
+  if (client) {
+    client->Reset();
+    RunMessageLoop();
+    EXPECT_FALSE(client->got_on_data_received());
+    EXPECT_TRUE(client->got_on_closed());
+    EXPECT_FALSE(close_cb_called);
+    client->Reset();
+    RunMessageLoop();
+    EXPECT_FALSE(client->got_on_data_received());
+    EXPECT_FALSE(client->got_on_closed());
+  } else {
+    RunMessageLoop();
+  }
+  EXPECT_TRUE(close_cb_called);
+  EXPECT_EQ(mojo::files::ERROR_OK, error);
+}
+
+TEST_F(OutputStreamFileTest, Basic) {
+  mojo::files::FilePtr file;
+  TestClient client;
+  std::unique_ptr<OutputStreamFile> file_impl =
+      OutputStreamFile::Create(&client, GetProxy(&file));
+
+  TestWrite(file.get(), &client, "hello");
+  TestWrite(file.get(), &client, "world");
+  TestClose(file.get(), &client);
+}
+
+TEST_F(OutputStreamFileTest, SetClient) {
+  mojo::files::FilePtr file;
+  TestClient client1;
+  std::unique_ptr<OutputStreamFile> file_impl =
+      OutputStreamFile::Create(&client1, GetProxy(&file));
+
+  TestWrite(file.get(), &client1, "hello");
+
+  TestClient client2;
+  file_impl->set_client(&client2);
+  TestWrite(file.get(), &client2, "world");
+
+  file_impl->set_client(&client1);
+  TestWrite(file.get(), &client1, "!");
+  TestClose(file.get(), &client1);
+}
+
+TEST_F(OutputStreamFileTest, NullClient) {
+  mojo::files::FilePtr file;
+  std::unique_ptr<OutputStreamFile> file_impl =
+      OutputStreamFile::Create(nullptr, GetProxy(&file));
+
+  TestWrite(file.get(), nullptr, "hello");
+
+  TestClient client;
+  file_impl->set_client(&client);
+  TestWrite(file.get(), &client, "world");
+
+  file_impl->set_client(nullptr);
+  client.Reset();
+  TestWrite(file.get(), nullptr, "!");
+  TestClose(file.get(), nullptr);
+  EXPECT_FALSE(client.got_on_data_received());
+  EXPECT_FALSE(client.got_on_closed());
+}
+
+TEST_F(OutputStreamFileTest, ImplOnlyClosesMessagePipeOnDestruction) {
+  mojo::files::FilePtr file;
+  std::unique_ptr<OutputStreamFile> file_impl =
+      OutputStreamFile::Create(nullptr, GetProxy(&file));
+  bool got_connection_error = false;
+  file.set_connection_error_handler([&got_connection_error]() {
+    got_connection_error = true;
+    QuitMessageLoop();
+  });
+
+  TestClose(file.get(), nullptr);
+  // The impl should only close its end when it's destroyed (even if |Close()|
+  // has been called).
+  RunMessageLoopUntilIdle();
+  EXPECT_FALSE(got_connection_error);
+  file_impl.reset();
+  RunMessageLoop();
+  EXPECT_TRUE(got_connection_error);
+}
+
+TEST_F(OutputStreamFileTest, ClosingMessagePipeCausesOnClosed) {
+  mojo::files::FilePtr file;
+  TestClient client;
+  std::unique_ptr<OutputStreamFile> file_impl =
+      OutputStreamFile::Create(&client, GetProxy(&file));
+
+  file.reset();
+  RunMessageLoop();
+  EXPECT_FALSE(client.got_on_data_received());
+  EXPECT_TRUE(client.got_on_closed());
+}
+
+// Clients may own the impl (and this is a typical pattern). This client will
+// own/destroy its impl on any |Client| call (and we'll test that this doesn't
+// result in any additional calls to the client).
+class TestClientDestroysImplClient : public OutputStreamFile::Client {
+ public:
+  explicit TestClientDestroysImplClient(
+      mojo::InterfaceRequest<mojo::files::File> request)
+      : file_impl_(OutputStreamFile::Create(this, request.Pass())) {}
+  ~TestClientDestroysImplClient() override {}
+
+ private:
+  // OutputStreamFile::Client|:
+  void OnDataReceived(const void* /*bytes*/, size_t /*num_bytes*/) override {
+    // We reset the impl on any call, and afterwards it shouldn't call us.
+    EXPECT_TRUE(file_impl_);
+    file_impl_.reset();
+  }
+  void OnClosed() override {
+    // We reset the impl on any call, and afterwards it shouldn't call us.
+    EXPECT_TRUE(file_impl_);
+    file_impl_.reset();
+  }
+
+  std::unique_ptr<OutputStreamFile> file_impl_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(TestClientDestroysImplClient);
+};
+
+TEST_F(OutputStreamFileTest, ClientDestroysImpl) {
+  // Test destruction due to writing.
+  {
+    mojo::files::FilePtr file;
+    TestClientDestroysImplClient client(GetProxy(&file));
+    bool got_connection_error = false;
+    file.set_connection_error_handler([&got_connection_error]() {
+      got_connection_error = true;
+      QuitMessageLoop();
+    });
+    // |TestClientDestroysImplClient| doesn't quit the message loop, so it
+    // behaves like a null client.
+    TestWrite(file.get(), nullptr, "hello");
+    // The connection error may be called immediately after the write callback,
+    // in which case we have to spin the message loop again.
+    if (!got_connection_error)
+      RunMessageLoop();
+    EXPECT_TRUE(got_connection_error);
+  }
+
+  // Test destruction due to closing.
+  {
+    mojo::files::FilePtr file;
+    TestClientDestroysImplClient client(GetProxy(&file));
+    bool got_connection_error = false;
+    file.set_connection_error_handler([&got_connection_error]() {
+      got_connection_error = true;
+      QuitMessageLoop();
+    });
+    TestClose(file.get(), nullptr);
+    if (!got_connection_error)
+      RunMessageLoop();
+    EXPECT_TRUE(got_connection_error);
+  }
+}
+
+}  // namespace
+}  // namespace files_impl