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| 1 | +#pragma once |
| 2 | + |
| 3 | +#include "kafka/Project.h" |
| 4 | + |
| 5 | +// https://github.com/Tencent/rapidjson/releases/tag/v1.1.0 |
| 6 | +#include "rapidjson/document.h" |
| 7 | +#include "rapidjson/stringbuffer.h" |
| 8 | +#include "rapidjson/writer.h" |
| 9 | + |
| 10 | +#include <algorithm> |
| 11 | +#include <iostream> |
| 12 | +#include <sstream> |
| 13 | +#include <stdexcept> |
| 14 | +#include <string> |
| 15 | +#include <utility> |
| 16 | +#include <vector> |
| 17 | + |
| 18 | + |
| 19 | +namespace KAFKA_API { |
| 20 | + |
| 21 | +/** |
| 22 | + * \brief Helps to parse the metrics string with JSON format. |
| 23 | + */ |
| 24 | +class KafkaMetrics |
| 25 | +{ |
| 26 | +public: |
| 27 | + /** |
| 28 | + * \brief Initilize with the metrics string. |
| 29 | + */ |
| 30 | + explicit KafkaMetrics(std::string jsonMetrics); |
| 31 | + |
| 32 | + static const constexpr char* WILDCARD = "*"; |
| 33 | + |
| 34 | + using KeysType = std::vector<std::string>; |
| 35 | + |
| 36 | + /** |
| 37 | + * \brief The matched keys (for wildcards) and the value. |
| 38 | + */ |
| 39 | + template<typename ValueType> |
| 40 | + using ResultsType = std::vector<std::pair<KeysType, ValueType>>; |
| 41 | + |
| 42 | + /** |
| 43 | + * \brief Get integer value(s) for the specified metrics. |
| 44 | + * Note: the wildcard ("*") is supported. |
| 45 | + */ |
| 46 | + ResultsType<std::int64_t> getInt(const KeysType& keys) { return get<std::int64_t>(keys); } |
| 47 | + |
| 48 | + /** |
| 49 | + * \brief Get string value(s) for the specified metrics. |
| 50 | + * Note: the wildcard ("*") is supported. |
| 51 | + */ |
| 52 | + ResultsType<std::string> getString(const KeysType& keys) { return get<std::string>(keys); } |
| 53 | + |
| 54 | + static std::string toString(const KafkaMetrics::KeysType& keys); |
| 55 | + |
| 56 | + template<typename ValueType> |
| 57 | + static std::string toString(const KafkaMetrics::ResultsType<ValueType>& results); |
| 58 | + |
| 59 | +private: |
| 60 | + template<typename ValueType> |
| 61 | + ResultsType<ValueType> get(const KeysType& keys); |
| 62 | + |
| 63 | + template<typename ValueType> |
| 64 | + void getResults(ResultsType<ValueType>& results, |
| 65 | + KeysType& keysForWildcards, |
| 66 | + rapidjson::Value::ConstMemberIterator iter, |
| 67 | + KeysType::const_iterator keysToParse, |
| 68 | + KeysType::const_iterator keysEnd); |
| 69 | + |
| 70 | + template<typename ValueType> |
| 71 | + static ValueType getValue(rapidjson::Value::ConstMemberIterator iter); |
| 72 | + |
| 73 | +#if COMPILER_SUPPORTS_CPP_17 |
| 74 | + std::string _decodeBuf; |
| 75 | +#else |
| 76 | + std::vector<char> _decodeBuf; |
| 77 | +#endif |
| 78 | + rapidjson::Document _jsonDoc; |
| 79 | +}; |
| 80 | + |
| 81 | +inline |
| 82 | +KafkaMetrics::KafkaMetrics(std::string jsonMetrics) |
| 83 | +#if COMPILER_SUPPORTS_CPP_17 |
| 84 | + : _decodeBuf(std::move(jsonMetrics)) |
| 85 | +#else |
| 86 | + : _decodeBuf(jsonMetrics.cbegin(), jsonMetrics.cend() + 1) |
| 87 | +#endif |
| 88 | +{ |
| 89 | + if (_jsonDoc.ParseInsitu(_decodeBuf.data()).HasParseError()) |
| 90 | + { |
| 91 | + throw std::runtime_error("Failed to parse string with JSON format!"); |
| 92 | + } |
| 93 | +} |
| 94 | + |
| 95 | +template<> |
| 96 | +inline std::int64_t |
| 97 | +KafkaMetrics::getValue<std::int64_t>(rapidjson::Value::ConstMemberIterator iter) |
| 98 | +{ |
| 99 | + return iter->value.GetInt(); |
| 100 | +} |
| 101 | + |
| 102 | +template<> |
| 103 | +inline std::string |
| 104 | +KafkaMetrics::getValue<std::string>(rapidjson::Value::ConstMemberIterator iter) |
| 105 | +{ |
| 106 | + return iter->value.GetString(); |
| 107 | +} |
| 108 | + |
| 109 | +template<typename ValueType> |
| 110 | +inline KafkaMetrics::ResultsType<ValueType> |
| 111 | +KafkaMetrics::get(const KeysType& keys) |
| 112 | +{ |
| 113 | + if (keys.empty()) throw std::invalid_argument("Input keys cannot be empty!"); |
| 114 | + if (keys.front() == WILDCARD) throw std::invalid_argument("The first key cannot be wildcard!"); |
| 115 | + if (keys.back() == WILDCARD) throw std::invalid_argument("The last key cannot be wildcard!"); |
| 116 | + |
| 117 | + ResultsType<ValueType> results; |
| 118 | + |
| 119 | + rapidjson::Value::ConstMemberIterator iter = _jsonDoc.FindMember(keys.front().c_str()); |
| 120 | + if (iter == _jsonDoc.MemberEnd()) return results; |
| 121 | + |
| 122 | + if (keys.size() == 1) |
| 123 | + { |
| 124 | + if (std::is_same<ValueType, std::string>::value ? iter->value.IsString() : iter->value.IsInt()) |
| 125 | + { |
| 126 | + results.emplace_back(KeysType{}, getValue<ValueType>(iter)); |
| 127 | + } |
| 128 | + |
| 129 | + return results; |
| 130 | + } |
| 131 | + |
| 132 | + KeysType keysForWildcards; |
| 133 | + |
| 134 | + getResults(results, keysForWildcards, iter, keys.cbegin() + 1, keys.cend()); |
| 135 | + return results; |
| 136 | +} |
| 137 | + |
| 138 | +template<typename ValueType> |
| 139 | +inline void |
| 140 | +KafkaMetrics::getResults(KafkaMetrics::ResultsType<ValueType>& results, |
| 141 | + KeysType& keysForWildcards, |
| 142 | + rapidjson::Value::ConstMemberIterator iter, |
| 143 | + KeysType::const_iterator keysToParse, |
| 144 | + KeysType::const_iterator keysEnd) |
| 145 | +{ |
| 146 | + if (!iter->value.IsObject()) return; |
| 147 | + |
| 148 | + const auto& key = *(keysToParse++); |
| 149 | + const bool isTheEnd = (keysToParse == keysEnd); |
| 150 | + |
| 151 | + if (key == WILDCARD) |
| 152 | + { |
| 153 | + for (rapidjson::Value::ConstMemberIterator subIter = iter->value.MemberBegin(); subIter != iter->value.MemberEnd(); ++subIter) |
| 154 | + { |
| 155 | + KeysType newKeysForWildcards = keysForWildcards; |
| 156 | + newKeysForWildcards.emplace_back(subIter->name.GetString()); |
| 157 | + |
| 158 | + getResults(results, newKeysForWildcards, subIter, keysToParse, keysEnd); |
| 159 | + } |
| 160 | + } |
| 161 | + else |
| 162 | + { |
| 163 | + rapidjson::Value::ConstMemberIterator subIter = iter->value.FindMember(key.c_str()); |
| 164 | + if (subIter == iter->value.MemberEnd()) return; |
| 165 | + |
| 166 | + if (!isTheEnd) |
| 167 | + { |
| 168 | + getResults(results, keysForWildcards, subIter, keysToParse, keysEnd); |
| 169 | + } |
| 170 | + else if (std::is_same<ValueType, std::string>::value ? subIter->value.IsString() : subIter->value.IsInt()) |
| 171 | + { |
| 172 | + results.emplace_back(keysForWildcards, getValue<ValueType>(subIter)); |
| 173 | + } |
| 174 | + } |
| 175 | +} |
| 176 | + |
| 177 | +inline std::string |
| 178 | +KafkaMetrics::toString(const KafkaMetrics::KeysType& keys) |
| 179 | +{ |
| 180 | + std::string ret; |
| 181 | + |
| 182 | + std::for_each(keys.cbegin(), keys.cend(), |
| 183 | + [&ret](const auto& key){ ret.append((ret.empty() ? std::string() : std::string(", ")) + "\"" + key + "\""); }); |
| 184 | + |
| 185 | + return ret; |
| 186 | +} |
| 187 | + |
| 188 | +template<typename ValueType> |
| 189 | +inline std::string |
| 190 | +KafkaMetrics::toString(const KafkaMetrics::ResultsType<ValueType>& results) |
| 191 | +{ |
| 192 | + std::ostringstream oss; |
| 193 | + bool isTheFirstOne = true; |
| 194 | + |
| 195 | + std::for_each(results.cbegin(), results.cend(), |
| 196 | + [&oss, &isTheFirstOne](const auto& result) { |
| 197 | + const auto keysString = toString(result.first); |
| 198 | + |
| 199 | + oss << (isTheFirstOne ? (isTheFirstOne = false, "") : ", ") |
| 200 | + << (keysString.empty() ? "" : (std::string("[") + keysString + "]:")); |
| 201 | + oss << (std::is_same<ValueType, std::string>::value ? "\"" : "") << result.second << (std::is_same<ValueType, std::string>::value ? "\"" : ""); |
| 202 | + }); |
| 203 | + |
| 204 | + return oss.str(); |
| 205 | +} |
| 206 | + |
| 207 | +} // end of KAFKA_API |
| 208 | + |
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