in_place_span.hpp

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#pragma once
 
/// @file userver/tracing/in_place_span.hpp
/// @brief @copybrief tracing::InPlaceSpan
 
#include <string>
 
#include <userver/tracing/span.hpp>
#include <userver/utils/fast_pimpl.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace tracing {
 
/// @brief Avoids an extra allocation by storing tracing::Span data in-place
/// @warning Never put InPlaceSpan on the stack! It has a large size and can
/// cause stack overflow.
class InPlaceSpan final {
public:
    struct DetachedTag {};
 
    explicit InPlaceSpan(
        std::string&& name,
        const utils::impl::SourceLocation& source_location = utils::impl::SourceLocation::Current()
    );
 
    explicit InPlaceSpan(
        std::string&& name,
        std::string_view trace_id,
        std::string_view parent_span_id,
        const utils::impl::SourceLocation& source_location = utils::impl::SourceLocation::Current()
    );
 
    explicit InPlaceSpan(
        std::string&& name,
        DetachedTag,
        const utils::impl::SourceLocation& source_location = utils::impl::SourceLocation::Current()
    );
 
    InPlaceSpan(InPlaceSpan&&) = delete;
    InPlaceSpan& operator=(InPlaceSpan&&) = delete;
    ~InPlaceSpan();
 
    const tracing::Span& Get() const noexcept;
 
    tracing::Span& Get() noexcept;
 
private:
    struct Impl;
    utils::FastPimpl<Impl, 4392, 8> impl_;
};
 
}  // namespace tracing
 
USERVER_NAMESPACE_END