60 lines
2.0 KiB
C++
60 lines
2.0 KiB
C++
// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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#pragma once
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#include <cstdint>
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#include "opentelemetry/context/context.h"
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#include "opentelemetry/nostd/string_view.h"
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#include "opentelemetry/version.h"
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OPENTELEMETRY_BEGIN_NAMESPACE
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namespace context
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{
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namespace propagation
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{
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// TextMapCarrier is the storage medium used by TextMapPropagator.
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class TextMapCarrier
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{
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public:
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// returns the value associated with the passed key.
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virtual nostd::string_view Get(nostd::string_view key) const noexcept = 0;
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// stores the key-value pair.
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virtual void Set(nostd::string_view key, nostd::string_view value) noexcept = 0;
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/* list of all the keys in the carrier.
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By default, it returns true without invoking callback */
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virtual bool Keys(nostd::function_ref<bool(nostd::string_view)> callback) const noexcept
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{
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return true;
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}
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virtual ~TextMapCarrier() = default;
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};
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// The TextMapPropagator class provides an interface that enables extracting and injecting
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// context into carriers that travel in-band across process boundaries. HTTP frameworks and clients
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// can integrate with TextMapPropagator by providing the object containing the
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// headers, and a getter and setter function for the extraction and
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// injection of values, respectively.
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class TextMapPropagator
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{
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public:
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// Returns the context that is stored in the carrier with the TextMapCarrier as extractor.
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virtual context::Context Extract(const TextMapCarrier &carrier,
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context::Context &context) noexcept = 0;
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// Sets the context for carrier with self defined rules.
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virtual void Inject(TextMapCarrier &carrier, const context::Context &context) noexcept = 0;
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// Gets the fields set in the carrier by the `inject` method
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virtual bool Fields(nostd::function_ref<bool(nostd::string_view)> callback) const noexcept = 0;
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virtual ~TextMapPropagator() = default;
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};
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} // namespace propagation
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} // namespace context
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OPENTELEMETRY_END_NAMESPACE
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