1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef _RESOLVER_STATS_H_ 18 #define _RESOLVER_STATS_H_ 19 20 #include <time.h> 21 22 namespace android { 23 namespace net { 24 25 struct ResolverStats { 26 // Offsets into the per-server resolver stats as encoded in vector<int32_t> stats of 27 // getResolverInfo() of Netd's binder interface. The stats are based on data reported by 28 // android_net_res_stats_get_info_for_net(), the usability is calculated by applying 29 // android_net_res_stats_get_usable_servers() to this data. 30 enum ResolverStatsOffsets { 31 STATS_SUCCESSES = 0, // # successes counted for this server 32 STATS_ERRORS, // # errors 33 STATS_TIMEOUTS, // # timeouts 34 STATS_INTERNAL_ERRORS, // # internal errors 35 STATS_RTT_AVG, // average round-trip-time 36 STATS_LAST_SAMPLE_TIME, // time in s when the last sample was recorded 37 STATS_USABLE, // whether the server is considered usable 38 STATS_COUNT // total count of integers in the per-server data 39 }; 40 41 int successes {-1}; 42 int errors {-1}; 43 int timeouts {-1}; 44 int internal_errors {-1}; 45 int rtt_avg {-1}; 46 time_t last_sample_time {0}; 47 bool usable {false}; 48 49 // Serialize the resolver stats to the end of |out|. 50 void encode(std::vector<int32_t>* out) const; 51 52 // Read the serialized resolverstats starting at |in[ofs]|. 53 ssize_t decode(const std::vector<int32_t>& in, ssize_t ofs); 54 55 // Serialize the contents of |stats| and append them to the end of |out|. Multiple arrays 56 // can be written to the same output vector in sequence, however, the corresponding call 57 // to decodeAll() will return the combined contents in one vector. 58 static void encodeAll(const std::vector<ResolverStats>& stats, std::vector<int32_t>* out); 59 60 // Decodes the serialized ResolverStats from |in| and appends them to stats. 61 static bool decodeAll(const std::vector<int32_t>& in, std::vector<ResolverStats>* stats); 62 }; 63 64 65 inline void ResolverStats::encode(std::vector<int32_t>* out) const { 66 size_t ofs = out->size(); 67 out->resize(ofs + STATS_COUNT); 68 int32_t* cur = &(*out)[ofs]; 69 cur[STATS_SUCCESSES] = successes; 70 cur[STATS_ERRORS] = errors; 71 cur[STATS_TIMEOUTS] = timeouts; 72 cur[STATS_INTERNAL_ERRORS] = internal_errors; 73 cur[STATS_RTT_AVG] = rtt_avg; 74 cur[STATS_LAST_SAMPLE_TIME] = last_sample_time; 75 cur[STATS_USABLE] = usable; 76 } 77 78 // Read the serialized resolverstats starting at |in[ofs]|. 79 inline ssize_t ResolverStats::decode(const std::vector<int32_t>& in, ssize_t ofs) { 80 if (ofs < 0 || static_cast<size_t>(ofs) + STATS_COUNT > in.size()) { 81 return -1; 82 } 83 const int32_t* cur = &in[ofs]; 84 successes = cur[STATS_SUCCESSES]; 85 errors = cur[STATS_ERRORS]; 86 timeouts = cur[STATS_TIMEOUTS]; 87 internal_errors = cur[STATS_INTERNAL_ERRORS]; 88 rtt_avg = cur[STATS_RTT_AVG]; 89 last_sample_time = cur[STATS_LAST_SAMPLE_TIME]; 90 usable = cur[STATS_USABLE]; 91 return ofs + STATS_COUNT; 92 } 93 94 inline void ResolverStats::encodeAll(const std::vector<ResolverStats>& stats, 95 std::vector<int32_t>* out) { 96 for (const auto& s : stats) { 97 s.encode(out); 98 } 99 } 100 101 // TODO: Replace with a better representation, e.g. a Parcelable. 102 inline bool ResolverStats::decodeAll(const std::vector<int32_t>& in, 103 std::vector<ResolverStats>* stats) { 104 ssize_t size = in.size(); 105 if (size % STATS_COUNT) { 106 return false; 107 } 108 stats->resize(size / STATS_COUNT); 109 ssize_t ofs = 0; 110 for (auto& s : *stats) { 111 ofs = s.decode(in, ofs); 112 if (ofs < 0) { 113 return false; 114 } 115 } 116 return true; 117 } 118 119 } // namespace net 120 } // namespace android 121 122 #endif /* _RESOLVER_STATS_H_ */ 123
