Adding the message writing class used for remote_security_key STDOUT communication.

remoting/host/security_key/remote_security_key_message_writer_unittest.cc

Index: remoting/host/security_key/remote_security_key_message_writer_unittest.cc
diff --git a/remoting/host/security_key/remote_security_key_message_writer_unittest.cc b/remoting/host/security_key/remote_security_key_message_writer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..07ec3a21de3a4b1df4b0355dd2def6abd375e28c
--- /dev/null
+++ b/remoting/host/security_key/remote_security_key_message_writer_unittest.cc
@@ -0,0 +1,189 @@
+// Copyright 2016 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 "remoting/host/security_key/remote_security_key_message_writer.h"
+
+#include <stdint.h>
+
+#include <utility>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/stl_util.h"
+#include "remoting/host/security_key/security_key_message.h"
+#include "remoting/host/setup/test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+const uint8_t kTestMessageType = 42;
+const char kTestMessageTypeChar = static_cast<char>(kTestMessageType);
+const char kTestMessagePayload[] = "Super-test-payload!";
+const unsigned int kBufferSizeBytes = 40000;
+}  // namespace
+
+namespace remoting {
+
+class RemoteSecurityKeyMessageWriterTest : public testing::Test {
+ public:
+  RemoteSecurityKeyMessageWriterTest();
+  ~RemoteSecurityKeyMessageWriterTest() override;
+
+ protected:
+  // testing::Test interface.
+  void SetUp() override;
+
+  scoped_ptr<RemoteSecurityKeyMessageWriter> writer_;
+  base::File read_file_;
+  base::File write_file_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RemoteSecurityKeyMessageWriterTest);
+};
+
+RemoteSecurityKeyMessageWriterTest::RemoteSecurityKeyMessageWriterTest() {}
+
+RemoteSecurityKeyMessageWriterTest::~RemoteSecurityKeyMessageWriterTest() {}
+
+void RemoteSecurityKeyMessageWriterTest::SetUp() {
+  ASSERT_TRUE(MakePipe(&read_file_, &write_file_, kBufferSizeBytes));

[Sergey Ulanov, 2016/03/28 18:26:43]

Why do you need to set buffer size for this pipe?

[joedow, 2016/03/29 22:14:14]

The short version is that the buffer size can vary and the writer blocks when
the pipe is full.  I initially wanted to avoid introducing a thread to use for
the read operation and a message loop/run loop mechanism for the writer, but it
seems like the better long term approach and is closer to how the writer will be
used IRL.

+  writer_.reset(new RemoteSecurityKeyMessageWriter(std::move(write_file_)));
+}
+
+TEST_F(RemoteSecurityKeyMessageWriterTest, WriteMessageWithoutPayload) {
+  ASSERT_TRUE(writer_->WriteMessage(
+      static_cast<RemoteSecurityKeyMessageType>(kTestMessageType)));
+
+  // Retrieve and verify the message header.
+  uint32_t length;
+  int bytes_read =
+      read_file_.ReadAtCurrentPos(reinterpret_cast<char*>(&length), 4);
+  ASSERT_EQ(4, bytes_read);
+  ASSERT_EQ(sizeof(kTestMessageType), length);
+
+  // Retrieve and verify the message type.
+  std::string message_type(length, '\0');
+  bytes_read =
+      read_file_.ReadAtCurrentPos(string_as_array(&message_type), length);
+  ASSERT_EQ(static_cast<int>(length), bytes_read);
+  ASSERT_EQ(message_type, std::string(&kTestMessageTypeChar, 1));
+
+  // Destroy the writer and verify the other end of the pipe is clean.
+  writer_.reset();
+  char unused;
+  ASSERT_LE(read_file_.ReadAtCurrentPos(&unused, 1), 0);
+}
+
+TEST_F(RemoteSecurityKeyMessageWriterTest, WriteMessageWithPayload) {
+  std::string test_message_payload(kTestMessagePayload);
+  ASSERT_TRUE(writer_->WriteMessage(
+      static_cast<RemoteSecurityKeyMessageType>(kTestMessageType),
+      test_message_payload));
+
+  // Retrieve and verify the message header.
+  uint32_t total_length;
+  int bytes_read =
+      read_file_.ReadAtCurrentPos(reinterpret_cast<char*>(&total_length), 4);
+  ASSERT_EQ(4, bytes_read);
+  ASSERT_EQ(sizeof(kTestMessageType) + test_message_payload.size(),
+            total_length);
+
+  // Retrieve and verify the message type.
+  int message_type_length = 1;
+  std::string message_type(message_type_length, '\0');
+  bytes_read = read_file_.ReadAtCurrentPos(string_as_array(&message_type),
+                                           message_type_length);
+  ASSERT_EQ(message_type_length, bytes_read);
+  ASSERT_EQ(message_type, std::string(&kTestMessageTypeChar, 1));
+
+  // Retrieve and verify the message payload.
+  int message_payload_length = total_length - message_type_length;
+  std::string message_payload(message_payload_length, '\0');
+  bytes_read = read_file_.ReadAtCurrentPos(string_as_array(&message_payload),
+                                           message_payload_length);
+  ASSERT_EQ(message_payload_length, bytes_read);
+  ASSERT_EQ(message_payload, test_message_payload);
+
+  // Destroy the writer and verify the other end of the pipe is clean.
+  writer_.reset();
+  char unused;
+  ASSERT_LE(read_file_.ReadAtCurrentPos(&unused, 1), 0);
+}
+
+TEST_F(RemoteSecurityKeyMessageWriterTest, WriteMessageWithLargePayload) {
+  std::string test_message_payload(kBufferSizeBytes -
+                                       sizeof(RemoteSecurityKeyMessageType) -
+                                       SecurityKeyMessage::kHeaderSizeBytes,

[Sergey Ulanov, 2016/03/28 18:26:43]

What if the message is larger than the buffer? I think the writer should still
be able to handle this case.

[joedow, 2016/03/29 22:14:14]

Done.

+                                   'Y');
+  ASSERT_TRUE(writer_->WriteMessage(
+      static_cast<RemoteSecurityKeyMessageType>(kTestMessageType),
+      test_message_payload));
+
+  // Retrieve and verify the message header.
+  uint32_t total_length;
+  int bytes_read =
+      read_file_.ReadAtCurrentPos(reinterpret_cast<char*>(&total_length), 4);
+  ASSERT_EQ(4, bytes_read);
+  ASSERT_EQ(sizeof(kTestMessageType) + test_message_payload.size(),
+            total_length);
+
+  // Retrieve and verify the message type.
+  int message_type_length = 1;
+  std::string message_type(message_type_length, '\0');
+  bytes_read = read_file_.ReadAtCurrentPos(string_as_array(&message_type),
+                                           message_type_length);
+  ASSERT_EQ(message_type_length, bytes_read);
+  ASSERT_EQ(message_type, std::string(&kTestMessageTypeChar, 1));
+
+  // Retrieve and verify the message payload.
+  int message_payload_length = total_length - message_type_length;
+  std::string message_payload(message_payload_length, '\0');
+  bytes_read = read_file_.ReadAtCurrentPos(string_as_array(&message_payload),
+                                           message_payload_length);
+  ASSERT_EQ(message_payload_length, bytes_read);
+  ASSERT_EQ(message_payload, test_message_payload);
+
+  // Destroy the writer and verify the other end of the pipe is clean.
+  writer_.reset();
+  char unused;
+  ASSERT_LE(read_file_.ReadAtCurrentPos(&unused, 1), 0);
+}
+
+TEST_F(RemoteSecurityKeyMessageWriterTest, WriteMultipleMessages) {
+  int total_messages_to_write = 10;
+  for (int i = 0; i < total_messages_to_write; i++) {
+    ASSERT_TRUE(writer_->WriteMessage(
+        static_cast<RemoteSecurityKeyMessageType>(kTestMessageType + i)));
+  }
+
+  for (int i = 0; i < total_messages_to_write; i++) {
+    // Retrieve and verify the message header.
+    uint32_t length;
+    int bytes_read =
+        read_file_.ReadAtCurrentPos(reinterpret_cast<char*>(&length), 4);
+    ASSERT_EQ(4, bytes_read);
+    ASSERT_EQ(sizeof(kTestMessageType), length);
+
+    // Retrieve and verify the message type.
+    std::string message_type(length, '\0');
+    bytes_read =
+        read_file_.ReadAtCurrentPos(string_as_array(&message_type), length);
+    ASSERT_EQ(static_cast<int>(length), bytes_read);
+    char current_char = kTestMessageType + i;
+    ASSERT_EQ(message_type, std::string(&current_char, 1));
+  }
+
+  // Destroy the writer and verify the other end of the pipe is clean.
+  writer_.reset();
+  char unused;
+  ASSERT_LE(read_file_.ReadAtCurrentPos(&unused, 1), 0);
+}
+
+TEST_F(RemoteSecurityKeyMessageWriterTest, EnsureWriteFailsWhenPipeClosed) {
+  // Close the read end so that writing fails immediately.
+  read_file_.Close();
+
+  EXPECT_FALSE(writer_->WriteMessage(
+      static_cast<RemoteSecurityKeyMessageType>(kTestMessageType)));
+}
+
+}  // namespace remoting