107 lines
3.6 KiB
C++
107 lines
3.6 KiB
C++
/*
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* Copyright 2019 AT&T Intellectual Property
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* Copyright 2019 Nokia
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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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* This source code is part of the near-RT RIC (RAN Intelligent Controller)
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* platform project (RICP).
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*/
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//
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// Created by adi ENZEL on 8/21/19.
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//
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#ifndef E2_OPENTRACING_H
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#define E2_OPENTRACING_H
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#include <iostream>
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#include <string>
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#include <tracelibcpp/tracelibcpp.hpp>
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#include <opentracing/tracer.h>
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#include <opentracing/propagation.h>
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#include <nlohmann/json.hpp> // use nlohmann json library as an example
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struct RICCarrierWriter : opentracing::TextMapWriter {
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explicit RICCarrierWriter(
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std::unordered_map<std::string, std::string>& data_)
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: data{data_} {}
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opentracing::expected<void> Set(
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opentracing::string_view key,
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opentracing::string_view value) const override {
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// OpenTracing uses opentracing::expected for error handling. This closely
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// follows the expected proposal for the C++ Standard Library. See
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// http://open-std.org/JTC1/SC22/WG21/docs/papers/2017/p0323r3.pdf
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// for more background.
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opentracing::expected<void> result;
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auto was_successful = data.emplace(key, value);
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if (was_successful.second) {
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// Use a default constructed opentracing::expected<void> to indicate
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// success.
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return result;
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} else {
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// `key` clashes with existing data, so the span context can't be encoded
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// successfully; set opentracing::expected<void> to an std::error_code.
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return opentracing::make_unexpected(
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std::make_error_code(std::errc::not_supported));
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}
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}
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std::unordered_map<std::string, std::string>& data;
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};
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struct RICCarrierReader : opentracing::TextMapReader {
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explicit RICCarrierReader(
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const std::unordered_map<std::string, std::string>& data_)
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: data{data_} {}
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using F = std::function<opentracing::expected<void>(
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opentracing::string_view, opentracing::string_view)>;
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opentracing::expected<void> ForeachKey(F f) const override {
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// Iterate through all key-value pairs, the tracer will use the relevant keys
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// to extract a span context.
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for (auto& key_value : data) {
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auto was_successful = f(key_value.first, key_value.second);
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if (!was_successful) {
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// If the callback returns and unexpected value, bail out of the loop.
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return was_successful;
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}
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}
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// Indicate successful iteration.
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return {};
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}
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// Optional, define TextMapReader::LookupKey to allow for faster extraction.
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opentracing::expected<opentracing::string_view> LookupKey(
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opentracing::string_view key) const override {
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auto iter = data.find(key);
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if (iter != data.end()) {
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return opentracing::make_unexpected(opentracing::key_not_found_error);
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}
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return opentracing::string_view{iter->second};
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}
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const std::unordered_map<std::string, std::string>& data;
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};
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#endif //E2_OPENTRACING_H
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