1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/**
* 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 <map>
#include <mutex>
#include <string>
#include <string_view>
#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::map<std::string_view, int> mFlagsMapInt GUARDED_BY(mMutex);
// TODO: Migrate other experiment flags to here.
// (retry_count, retransmission_time_interval)
static constexpr const char* const kExperimentFlagKeyList[] = {
"keep_listening_udp",
"parallel_lookup_release",
"parallel_lookup_sleep_time",
"sort_nameservers",
"dot_async_handshake",
"dot_connect_timeout_ms",
"dot_maxtries",
"dot_revalidation_threshold",
"dot_xport_unusable_threshold",
"dot_query_timeout_ms",
"dot_validation_latency_factor",
"dot_validation_latency_offset_ms",
"doh",
"doh_query_timeout_ms",
"doh_probe_timeout_ms",
"doh_idle_timeout_ms",
"doh_session_resumption",
"mdns_resolution",
};
// 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
|
