HTTPClient+tracing.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the AsyncHTTPClient open source project
//
// Copyright (c) 2021 Apple Inc. and the AsyncHTTPClient project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of AsyncHTTPClient project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//

import NIOHTTP1
import Tracing

@available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
extension HTTPClient {
    @inlinable
    func withRequestSpan(
        _ request: HTTPClientRequest,
        _ body: () async throws -> HTTPClientResponse
    ) async rethrows -> HTTPClientResponse {
        guard let tracer = self.tracer else {
            return try await body()
        }

        return try await tracer.withSpan(request.method.rawValue, ofKind: .client) { span in
            let keys = self.configuration.tracing.attributeKeys
            span.attributes[keys.requestMethod] = request.method.rawValue

            // set url attributes
            if let deconstructedURL = try? DeconstructedURL(url: request.url) {
                span.attributes[keys.urlScheme] = deconstructedURL.scheme.rawValue
                span.attributes[keys.urlPath] = deconstructedURL.uri
                span.attributes[keys.serverHostname] = deconstructedURL.connectionTarget.host
                span.attributes[keys.serverPort] = deconstructedURL.connectionTarget.port
            }

            let response = try await body()

            // set response span attributes
            TracingSupport.handleResponseStatusCode(span, response.status, keys: tracing.attributeKeys)
            
            // set network protocol version
            span.attributes[keys.networkProtocolVersion] = "\(response.version.major).\(response.version.minor)"

            return response
        }
    }
}