message_filter_router.cc 2.8 KB

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  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. #include "ipc/message_filter_router.h"
  5. #include <stddef.h>
  6. #include <stdint.h>
  7. #include "ipc/ipc_message_macros.h"
  8. #include "ipc/ipc_message_start.h"
  9. #include "ipc/ipc_message_utils.h"
  10. #include "ipc/message_filter.h"
  11. namespace IPC {
  12. namespace {
  13. bool TryFiltersImpl(MessageFilterRouter::MessageFilters& filters,
  14. const IPC::Message& message) {
  15. for (size_t i = 0; i < filters.size(); ++i) {
  16. if (filters[i]->OnMessageReceived(message)) {
  17. return true;
  18. }
  19. }
  20. return false;
  21. }
  22. bool RemoveFilterImpl(MessageFilterRouter::MessageFilters& filters,
  23. MessageFilter* filter) {
  24. MessageFilterRouter::MessageFilters::iterator it =
  25. std::remove(filters.begin(), filters.end(), filter);
  26. if (it == filters.end())
  27. return false;
  28. filters.erase(it, filters.end());
  29. return true;
  30. }
  31. bool ValidMessageClass(int message_class) {
  32. return message_class >= 0 && message_class < LastIPCMsgStart;
  33. }
  34. } // namespace
  35. MessageFilterRouter::MessageFilterRouter() = default;
  36. MessageFilterRouter::~MessageFilterRouter() = default;
  37. void MessageFilterRouter::AddFilter(MessageFilter* filter) {
  38. // Determine if the filter should be applied to all messages, or only
  39. // messages of a certain class.
  40. std::vector<uint32_t> supported_message_classes;
  41. if (filter->GetSupportedMessageClasses(&supported_message_classes)) {
  42. for (size_t i = 0; i < supported_message_classes.size(); ++i) {
  43. const int message_class = supported_message_classes[i];
  44. DCHECK(ValidMessageClass(message_class));
  45. // Safely ignore repeated subscriptions to a given message class for the
  46. // current filter being added.
  47. if (!message_class_filters_[message_class].empty() &&
  48. message_class_filters_[message_class].back() == filter) {
  49. continue;
  50. }
  51. message_class_filters_[message_class].push_back(filter);
  52. }
  53. } else {
  54. global_filters_.push_back(filter);
  55. }
  56. }
  57. void MessageFilterRouter::RemoveFilter(MessageFilter* filter) {
  58. if (RemoveFilterImpl(global_filters_, filter))
  59. return;
  60. for (size_t i = 0; i < std::size(message_class_filters_); ++i)
  61. RemoveFilterImpl(message_class_filters_[i], filter);
  62. }
  63. bool MessageFilterRouter::TryFilters(const Message& message) {
  64. if (TryFiltersImpl(global_filters_, message))
  65. return true;
  66. const int message_class = IPC_MESSAGE_CLASS(message);
  67. if (!ValidMessageClass(message_class))
  68. return false;
  69. return TryFiltersImpl(message_class_filters_[message_class], message);
  70. }
  71. void MessageFilterRouter::Clear() {
  72. global_filters_.clear();
  73. for (size_t i = 0; i < std::size(message_class_filters_); ++i)
  74. message_class_filters_[i].clear();
  75. }
  76. } // namespace IPC