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