ipc/message_filter_router.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 "ipc/message_filter_router.h"
   6
   7 #include <stdint.h>
   8
   9 #include "ipc/ipc_message_macros.h"
  10 #include "ipc/ipc_message_utils.h"
  11 #include "ipc/message_filter.h"
  12
  13 namespace IPC {
  14
  15 namespace {
  16
  17 bool TryFiltersImpl(MessageFilterRouter::MessageFilters& filters,
  18                     const IPC::Message& message) {
  19   for (size_t i = 0; i < filters.size(); ++i) {
  20     if (filters[i]->OnMessageReceived(message)) {
  21       return true;
  22     }
  23   }
  24   return false;
  25 }
  26
  27 bool RemoveFilterImpl(MessageFilterRouter::MessageFilters& filters,
  28                       MessageFilter* filter) {
  29   MessageFilterRouter::MessageFilters::iterator it =
  30       std::remove(filters.begin(), filters.end(), filter);
  31   if (it == filters.end())
  32     return false;
  33
  34   filters.erase(it, filters.end());
  35   return true;
  36 }
  37
  38 bool ValidMessageClass(int message_class) {
  39   return message_class >= 0 && message_class < LastIPCMsgStart;
  40 }
  41
  42 }  // namespace
  43
  44 MessageFilterRouter::MessageFilterRouter() {}
  45 MessageFilterRouter::~MessageFilterRouter() {}
  46
  47 void MessageFilterRouter::AddFilter(MessageFilter* filter) {
  48   // Determine if the filter should be applied to all messages, or only
  49   // messages of a certain class.
  50   std::vector<uint32_t> supported_message_classes;
  51   if (filter->GetSupportedMessageClasses(&supported_message_classes)) {
  52     DCHECK(!supported_message_classes.empty());
  53     for (size_t i = 0; i < supported_message_classes.size(); ++i) {
  54       const int message_class = supported_message_classes[i];
  55       DCHECK(ValidMessageClass(message_class));
  56       // Safely ignore repeated subscriptions to a given message class for the
  57       // current filter being added.
  58       if (!message_class_filters_[message_class].empty() &&
  59           message_class_filters_[message_class].back() == filter) {
  60         continue;
  61       }
  62       message_class_filters_[message_class].push_back(filter);
  63     }
  64   } else {
  65     global_filters_.push_back(filter);
  66   }
  67 }
  68
  69 void MessageFilterRouter::RemoveFilter(MessageFilter* filter) {
  70   if (RemoveFilterImpl(global_filters_, filter))
  71     return;
  72
  73   for (size_t i = 0; i < arraysize(message_class_filters_); ++i)
  74     RemoveFilterImpl(message_class_filters_[i], filter);
  75 }
  76
  77 bool MessageFilterRouter::TryFilters(const Message& message) {
  78   if (TryFiltersImpl(global_filters_, message))
  79     return true;
  80
  81   const int message_class = IPC_MESSAGE_CLASS(message);
  82   if (!ValidMessageClass(message_class))
  83     return false;
  84
  85   return TryFiltersImpl(message_class_filters_[message_class], message);
  86 }
  87
  88 void MessageFilterRouter::Clear() {
  89   global_filters_.clear();
  90   for (size_t i = 0; i < arraysize(message_class_filters_); ++i)
  91     message_class_filters_[i].clear();
  92 }
  93
  94 }  // namespace IPC