text: // Copyright (c) 2011 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/protocol/message_decoder.h"
  
  #include <stdint.h>
  
  #include <list>
  #include <memory>
  #include <string>
  
  #include "base/macros.h"
  #include "base/strings/string_number_conversions.h"
  #include "remoting/proto/event.pb.h"
  #include "remoting/proto/internal.pb.h"
  #include "remoting/protocol/message_serialization.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  namespace remoting {
  namespace protocol {
  
  static const unsigned int kTestKey = 142;
  
  static void AppendMessage(const EventMessage& msg,
                            std::string* buffer) {
    // Contains one encoded message.
    scoped_refptr<net::IOBufferWithSize> encoded_msg;
    encoded_msg = SerializeAndFrameMessage(msg);
    buffer->append(encoded_msg->data(), encoded_msg->size());
  }
  
  // Construct and prepare data in the |output_stream|.
  static void PrepareData(uint8_t** buffer, int* size) {
    // Contains all encoded messages.
    std::string encoded_data;
  
    // Then append 10 update sequences to the data.
    for (int i = 0; i < 10; ++i) {
      EventMessage msg;
      msg.set_timestamp(i);
      msg.mutable_key_event()->set_usb_keycode(kTestKey + i);
      msg.mutable_key_event()->set_pressed((i % 2) != 0);
      AppendMessage(msg, &encoded_data);
    }
  
    *size = encoded_data.length();
    *buffer = new uint8_t[*size];
    memcpy(*buffer, encoded_data.c_str(), *size);
  }
  
  void SimulateReadSequence(const int read_sequence[], int sequence_size) {
    // Prepare encoded data for testing.
    int size;
    uint8_t* test_data;
    PrepareData(&test_data, &size);
    std::unique_ptr<uint8_t[]> memory_deleter(test_data);
  
    // Then simulate using MessageDecoder to decode variable
    // size of encoded data.
    // The first thing to do is to generate a variable size of data. This is done
    // by iterating the following array for read sizes.
    MessageDecoder decoder;
  
    // Then feed the protocol decoder using the above generated data and the
    // read pattern.
    std::list<std::unique_ptr<EventMessage>> message_list;
    for (int pos = 0; pos < size;) {
      SCOPED_TRACE("Input position: " + base::IntToString(pos));
  
      // First generate the amount to feed the decoder.
      int read = std::min(size - pos, read_sequence[pos % sequence_size]);
  
      // And then prepare an IOBuffer for feeding it.
      scoped_refptr<net::IOBuffer> buffer(new net::IOBuffer(read));
      memcpy(buffer->data(), test_data + pos, read);
      decoder.AddData(buffer, read);
      while (true) {
        std::unique_ptr<CompoundBuffer> message(decoder.GetNextMessage());
        if (!message.get())
          break;
  
        std::unique_ptr<EventMessage> event = std::make_unique<EventMessage>();
        CompoundBufferInputStream stream(message.get());
        ASSERT_TRUE(event->ParseFromZeroCopyStream(&stream));
        message_list.push_back(std::move(event));
      }
      pos += read;
    }
  
    // Then verify the decoded messages.
    EXPECT_EQ(10u, message_list.size());
  
    unsigned int index = 0;
    for (const auto& message : message_list) {
      SCOPED_TRACE("Message " + base::UintToString(index));
  
      // Partial update stream.
      EXPECT_TRUE(message->has_key_event());
  
      // TODO(sergeyu): Don't use index here. Instead store the expected values
      // in an array.
      EXPECT_EQ(kTestKey + index, message->key_event().usb_keycode());
      EXPECT_EQ((index % 2) != 0, message->key_event().pressed());
      ++index;
    }
  }
  
  TEST(MessageDecoderTest, SmallReads) {
    const int kReads[] = {1, 2, 3, 1};
    SimulateReadSequence(kReads, arraysize(kReads));
  }
  
  TEST(MessageDecoderTest, LargeReads) {
    const int kReads[] = {50, 50, 5};
    SimulateReadSequence(kReads, arraysize(kReads));
  }
  
  TEST(MessageDecoderTest, EmptyReads) {
    const int kReads[] = {4, 0, 50, 0};
    SimulateReadSequence(kReads, arraysize(kReads));
  }
  
  }  // namespace protocol
  }  // namespace remoting
  