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// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include <iterator>
#include <type_traits>
#include <utility>
#include "opentelemetry/common/key_value_iterable_view.h"
#include "opentelemetry/nostd/function_ref.h"
#include "opentelemetry/nostd/span.h"
#include "opentelemetry/nostd/string_view.h"
#include "opentelemetry/nostd/utility.h"
#include "opentelemetry/trace/span_context.h"
#include "opentelemetry/trace/span_context_kv_iterable.h"
#include "opentelemetry/version.h"
OPENTELEMETRY_BEGIN_NAMESPACE
namespace trace
{
// NOTE - code within `detail` namespace implements internal details, and not part
// of the public interface.
namespace detail
{
template <class T>
inline void take_span_context_kv(SpanContext, opentelemetry::common::KeyValueIterableView<T>)
{}
template <class T, nostd::enable_if_t<common::detail::is_key_value_iterable<T>::value> * = nullptr>
inline void take_span_context_kv(SpanContext, T &)
{}
inline void take_span_context_kv(
SpanContext,
std::initializer_list<std::pair<nostd::string_view, common::AttributeValue>>)
{}
template <class T>
auto is_span_context_kv_iterable_impl(T iterable)
-> decltype(take_span_context_kv(std::begin(iterable)->first, std::begin(iterable)->second),
nostd::size(iterable),
std::true_type{});
std::false_type is_span_context_kv_iterable_impl(...);
template <class T>
struct is_span_context_kv_iterable
{
static const bool value =
decltype(detail::is_span_context_kv_iterable_impl(std::declval<T>()))::value;
};
} // namespace detail
template <class T>
class SpanContextKeyValueIterableView final : public SpanContextKeyValueIterable
{
static_assert(detail::is_span_context_kv_iterable<T>::value,
"Must be a context/key-value iterable");
public:
explicit SpanContextKeyValueIterableView(const T &links) noexcept : container_{&links} {}
bool ForEachKeyValue(nostd::function_ref<bool(SpanContext, const common::KeyValueIterable &)>
callback) const noexcept override
{
auto iter = std::begin(*container_);
auto last = std::end(*container_);
for (; iter != last; ++iter)
{
if (!this->do_callback(iter->first, iter->second, callback))
{
return false;
}
}
return true;
}
size_t size() const noexcept override { return nostd::size(*container_); }
private:
const T *container_;
bool do_callback(SpanContext span_context,
const common::KeyValueIterable &attributes,
nostd::function_ref<bool(SpanContext, const common::KeyValueIterable &)>
callback) const noexcept
{
if (!callback(span_context, attributes))
{
return false;
}
return true;
}
template <class U,
nostd::enable_if_t<common::detail::is_key_value_iterable<U>::value> * = nullptr>
bool do_callback(SpanContext span_context,
const U &attributes,
nostd::function_ref<bool(SpanContext, const common::KeyValueIterable &)>
callback) const noexcept
{
return do_callback(span_context, common::KeyValueIterableView<U>(attributes), callback);
}
bool do_callback(
SpanContext span_context,
std::initializer_list<std::pair<nostd::string_view, common::AttributeValue>> attributes,
nostd::function_ref<bool(SpanContext, const common::KeyValueIterable &)> callback)
const noexcept
{
return do_callback(span_context,
nostd::span<const std::pair<nostd::string_view, common::AttributeValue>>{
attributes.begin(), attributes.end()},
callback);
}
};
} // namespace trace
OPENTELEMETRY_END_NAMESPACE