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| 1 | +/* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */ |
| 2 | +/* |
| 3 | + * Copyright 2021 Couchbase, Inc. |
| 4 | + * |
| 5 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | + * you may not use this file except in compliance with the License. |
| 7 | + * You may obtain a copy of the License at |
| 8 | + * |
| 9 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | + * |
| 11 | + * Unless required by applicable law or agreed to in writing, software |
| 12 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | + * See the License for the specific language governing permissions and |
| 15 | + * limitations under the License. |
| 16 | + */ |
| 17 | + |
| 18 | +#pragma once |
| 19 | + |
| 20 | +#include "otel_meter.hxx" |
| 21 | + |
| 22 | +#include <couchbase/metrics/meter.hxx> |
| 23 | + |
| 24 | +#include <opentelemetry/metrics/meter_provider.h> |
| 25 | +#include <opentelemetry/metrics/provider.h> |
| 26 | + |
| 27 | +#include <algorithm> |
| 28 | +#include <iostream> |
| 29 | +#include <thread> |
| 30 | +#include <utility> |
| 31 | + |
| 32 | +namespace couchbase::core::metrics |
| 33 | +{ |
| 34 | +namespace |
| 35 | +{ |
| 36 | +class otel_sync_histogram |
| 37 | +{ |
| 38 | +public: |
| 39 | + otel_sync_histogram( |
| 40 | + opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Histogram<std::uint64_t>> |
| 41 | + histogram_counter) |
| 42 | + : histogram_counter_(histogram_counter) |
| 43 | + { |
| 44 | + } |
| 45 | + |
| 46 | + void record(std::uint64_t value, |
| 47 | + const opentelemetry::common::KeyValueIterable& tags, |
| 48 | + opentelemetry::context::Context& ctx) |
| 49 | + { |
| 50 | + histogram_counter_->Record(value, tags, ctx); |
| 51 | + } |
| 52 | + |
| 53 | +private: |
| 54 | + opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Histogram<std::uint64_t>> |
| 55 | + histogram_counter_; |
| 56 | + std::mutex mutex_; |
| 57 | +}; |
| 58 | + |
| 59 | +class otel_value_recorder : public couchbase::metrics::value_recorder |
| 60 | +{ |
| 61 | +public: |
| 62 | + explicit otel_value_recorder( |
| 63 | + nostd::shared_ptr<metrics_api::Histogram<std::uint64_t>> histogram_counter, |
| 64 | + const std::map<std::string, std::string>& tags) |
| 65 | + : histogram_counter_(histogram_counter) |
| 66 | + , tags_(tags) |
| 67 | + { |
| 68 | + } |
| 69 | + void record_value(std::int64_t value) override |
| 70 | + { |
| 71 | + value = std::max<int64_t>(value, 0); |
| 72 | + auto uvalue = static_cast<std::uint64_t>(value); |
| 73 | + histogram_counter_->Record( |
| 74 | + uvalue, opentelemetry::common::KeyValueIterableView<decltype(tags_)>{ tags_ }, context_); |
| 75 | + } |
| 76 | + |
| 77 | + auto tags() -> const std::map<std::string, std::string> |
| 78 | + { |
| 79 | + return tags_; |
| 80 | + } |
| 81 | + |
| 82 | + auto histogram_counter() |
| 83 | + -> opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Histogram<std::uint64_t>> |
| 84 | + { |
| 85 | + return histogram_counter_; |
| 86 | + } |
| 87 | + |
| 88 | +private: |
| 89 | + opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Histogram<std::uint64_t>> |
| 90 | + histogram_counter_; |
| 91 | + const std::map<std::string, std::string> tags_; |
| 92 | + opentelemetry::context::Context context_{}; |
| 93 | + std::mutex mutex_; |
| 94 | +}; |
| 95 | +} // namespace |
| 96 | + |
| 97 | +class otel_meter_impl |
| 98 | +{ |
| 99 | + friend otel_meter; |
| 100 | + |
| 101 | +public: |
| 102 | + explicit otel_meter_impl(opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter> meter) |
| 103 | + : meter_(meter) |
| 104 | + { |
| 105 | + } |
| 106 | + |
| 107 | +private: |
| 108 | + opentelemetry::nostd::shared_ptr<opentelemetry::metrics::Meter> meter_; |
| 109 | + std::mutex mutex_; |
| 110 | + std::multimap<std::string, std::shared_ptr<otel_value_recorder>> recorders_; |
| 111 | +}; |
| 112 | + |
| 113 | +auto |
| 114 | +otel_meter::get_value_recorder(const std::string& name, |
| 115 | + const std::map<std::string, std::string>& tags) |
| 116 | + -> std::shared_ptr<couchbase::metrics::value_recorder> |
| 117 | +{ |
| 118 | + // first look up the histogram, in case we already have it... |
| 119 | + std::scoped_lock<std::mutex> lock(mutex_); |
| 120 | + auto it = recorders_.equal_range(name); |
| 121 | + if (it.first == it.second) { |
| 122 | + // this name isn't associated with any histogram, so make one and return it. |
| 123 | + // Note we'd like to make one with more buckets than default, given the range of |
| 124 | + // response times we'd like to display (queries vs kv for instance), but otel |
| 125 | + // api doesn't seem to allow this. |
| 126 | + return recorders_ |
| 127 | + .insert({ name, |
| 128 | + std::make_shared<otel_value_recorder>(meter_->CreateUInt64Histogram(name, "", "us"), |
| 129 | + tags) }) |
| 130 | + ->second; |
| 131 | + } |
| 132 | + // so it is already, lets see if we already have one with those tags, or need |
| 133 | + // to make a new one (using the histogram we already have). |
| 134 | + for (auto itr = it.first; itr != it.second; itr++) { |
| 135 | + if (tags == itr->second->tags()) { |
| 136 | + return itr->second; |
| 137 | + } |
| 138 | + } |
| 139 | + // if you are here, we need to add one with these tags and the histogram associated with the |
| 140 | + // name. |
| 141 | + return recorders_ |
| 142 | + .insert( |
| 143 | + { name, std::make_shared<otel_value_recorder>(it.first->second->histogram_counter(), tags) }) |
| 144 | + ->second; |
| 145 | +} |
| 146 | +} // namespace couchbase::core::metrics |
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