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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ipc/message_filter_router.h"
#include <stddef.h>
#include <stdint.h>
#include "ipc/ipc_message_macros.h"
#include "ipc/ipc_message_start.h"
#include "ipc/ipc_message_utils.h"
#include "ipc/message_filter.h"
namespace IPC {
namespace {
bool TryFiltersImpl(MessageFilterRouter::MessageFilters& filters,
const IPC::Message& message) {
for (size_t i = 0; i < filters.size(); ++i) {
if (filters[i]->OnMessageReceived(message)) {
return true;
}
}
return false;
}
bool RemoveFilterImpl(MessageFilterRouter::MessageFilters& filters,
MessageFilter* filter) {
MessageFilterRouter::MessageFilters::iterator it =
std::remove(filters.begin(), filters.end(), filter);
if (it == filters.end())
return false;
filters.erase(it, filters.end());
return true;
}
bool ValidMessageClass(int message_class) {
return message_class >= 0 && message_class < LastIPCMsgStart;
}
} // namespace
MessageFilterRouter::MessageFilterRouter() = default;
MessageFilterRouter::~MessageFilterRouter() = default;
void MessageFilterRouter::AddFilter(MessageFilter* filter) {
// Determine if the filter should be applied to all messages, or only
// messages of a certain class.
std::vector<uint32_t> supported_message_classes;
if (filter->GetSupportedMessageClasses(&supported_message_classes)) {
for (size_t i = 0; i < supported_message_classes.size(); ++i) {
const int message_class = supported_message_classes[i];
DCHECK(ValidMessageClass(message_class));
// Safely ignore repeated subscriptions to a given message class for the
// current filter being added.
if (!message_class_filters_[message_class].empty() &&
message_class_filters_[message_class].back() == filter) {
continue;
}
message_class_filters_[message_class].push_back(filter);
}
} else {
global_filters_.push_back(filter);
}
}
void MessageFilterRouter::RemoveFilter(MessageFilter* filter) {
if (RemoveFilterImpl(global_filters_, filter))
return;
for (size_t i = 0; i < std::size(message_class_filters_); ++i)
RemoveFilterImpl(message_class_filters_[i], filter);
}
bool MessageFilterRouter::TryFilters(const Message& message) {
if (TryFiltersImpl(global_filters_, message))
return true;
const int message_class = IPC_MESSAGE_CLASS(message);
if (!ValidMessageClass(message_class))
return false;
return TryFiltersImpl(message_class_filters_[message_class], message);
}
void MessageFilterRouter::Clear() {
global_filters_.clear();
for (size_t i = 0; i < std::size(message_class_filters_); ++i)
message_class_filters_[i].clear();
}
} // namespace IPC