Logging.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift Cluster Membership open source project
//
// Copyright (c) 2020 Apple Inc. and the Swift Cluster Membership project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of Swift Cluster Membership project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//

import ClusterMembership
import Logging
import NIO
import SWIM

// ==== ----------------------------------------------------------------------------------------------------------------
// MARK: Tracelog: SWIM [tracelog:SWIM]

extension SWIMNIOShell {
    /// Optional "dump all messages" logging.
    ///
    /// Enabled by `SWIM.Settings.traceLogLevel` or `-DTRACELOG_SWIM`
    func tracelog(
        _ type: TraceLogType,
        message: @autoclosure () -> String,
        file: String = #file,
        function: String = #function,
        line: UInt = #line
    ) {
        if let level = self.settings.swim.traceLogLevel {
            self.log.log(
                level: level,
                "[\(self.myself.node)] \(type.description) :: \(message())",
                metadata: self.swim.metadata,
                file: file,
                function: function,
                line: line
            )
        }
    }

    internal enum TraceLogType: CustomStringConvertible {
        case send(to: SWIMAddressablePeer)
        case reply(to: SWIMAddressablePeer)
        case receive(pinged: SWIMAddressablePeer?)

        static var receive: TraceLogType {
            .receive(pinged: nil)
        }

        var description: String {
            switch self {
            case .send(let to):
                return "SEND(to:\(to.swimNode))"
            case .receive(nil):
                return "RECV"
            case .receive(let .some(pinged)):
                return "RECV(pinged:\(pinged.swimNode))"
            case .reply(let to):
                return "REPL(to:\(to.swimNode))"
            }
        }
    }
}