blob: e267e5036dd617cd29ae56a17a4312cecc320edf [file] [log] [blame]
/**
* Copyright (c) 2020, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <climits>
#include <mutex>
#include <string>
#include <string_view>
#include <unordered_map>
#include <android-base/thread_annotations.h>
#include <netdutils/DumpWriter.h>
namespace android::net {
// TODO: Add some way to update the stored experiment flags periodically.
// TODO: Refactor this class and make things easier. (e.g. remove string map.)
class Experiments {
public:
using GetExperimentFlagIntFunction = std::function<int(const std::string&, int)>;
static Experiments* getInstance();
int getFlag(std::string_view key, int defaultValue) const EXCLUDES(mMutex);
void update();
void dump(netdutils::DumpWriter& dw) const EXCLUDES(mMutex);
Experiments(Experiments const&) = delete;
void operator=(Experiments const&) = delete;
private:
explicit Experiments(GetExperimentFlagIntFunction getExperimentFlagIntFunction);
Experiments() = delete;
void updateInternal() EXCLUDES(mMutex);
mutable std::mutex mMutex;
std::unordered_map<std::string_view, int> mFlagsMapInt GUARDED_BY(mMutex);
// TODO: Migrate other experiment flags to here.
// (retry_count, retransmission_time_interval, dot_connect_timeout_ms)
static constexpr const char* const kExperimentFlagKeyList[] = {
"keep_listening_udp", "parallel_lookup", "parallel_lookup_sleep_time",
"sort_nameservers"};
// This value is used in updateInternal as the default value if any flags can't be found.
static constexpr int kFlagIntDefault = INT_MIN;
// For testing.
friend class ExperimentsTest;
const GetExperimentFlagIntFunction mGetExperimentFlagIntFunction;
};
} // namespace android::net