mojo/tools/message_generator.cc

   1 // Copyright 2014 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/file_util.h"
   6 #include "base/files/file_path.h"
   7 #include "base/strings/string_util.h"
   8 #include "base/strings/stringprintf.h"
   9 #include "mojo/public/cpp/bindings/lib/message_builder.h"
  10 #include "mojo/public/cpp/bindings/lib/message_internal.h"
  11 #include "mojo/public/cpp/bindings/message.h"
  12
  13 // This file is used to generate various files corresponding to mojo
  14 // messages. The various binding implementations can parse these to verify they
  15 // correctly decode messages.
  16 //
  17 // The output consists of each byte of the message encoded in a hex string with
  18 // a newline after it.
  19 namespace mojo {
  20 namespace {
  21
  22 std::string BinaryToHex(const base::StringPiece& piece) {
  23   std::string result("// File generated by mojo_message_generator.\n");;
  24   result.reserve(result.size() + (piece.size() * 5));
  25   for (size_t i = 0; i < piece.size(); ++i)
  26     base::StringAppendF(&result, "0X%.2X\n", static_cast<int>(piece.data()[i]));
  27   return result;
  28 }
  29
  30 void WriteMessageToFile(const Message& message, const base::FilePath& path) {
  31   const std::string hex_message(BinaryToHex(
  32       base::StringPiece(reinterpret_cast<const char*>(message.data()),
  33                         message.data_num_bytes())));
  34   CHECK_EQ(static_cast<int>(hex_message.size()),
  35            base::WriteFile(path, hex_message.data(),
  36                            static_cast<int>(hex_message.size())));
  37 }
  38
  39 // Generates a message of type MessageData. The message uses the name 21,
  40 // with 4 bytes of payload: 0x9, 0x8, 0x7, 0x6.
  41 void GenerateMessageDataMessage() {
  42   internal::MessageBuilder builder(static_cast<uint32_t>(21),
  43                                    static_cast<size_t>(4));
  44   char* data = static_cast<char*>(builder.buffer()->Allocate(4));
  45   DCHECK(data);
  46   data[0] = 9;
  47   data[1] = 8;
  48   data[2] = 7;
  49   data[3] = 6;
  50
  51   Message message;
  52   builder.Finish(&message);
  53   WriteMessageToFile(message,
  54                      base::FilePath(FILE_PATH_LITERAL("message_data")));
  55 }
  56
  57 }  // namespace
  58 }  // namespace mojo
  59
  60 int main(int argc, char** argv) {
  61   mojo::GenerateMessageDataMessage();
  62   return 0;
  63 }