SellyCloudSDK_demo/Example/Pods/CocoaLumberjack/Sources/CocoaLumberjackSwift/DDLog+Combine.swift

113 lines
3.9 KiB
Swift

// Software License Agreement (BSD License)
//
// Copyright (c) 2010-2021, Deusty, LLC
// All rights reserved.
//
// Redistribution and use of this software in source and binary forms,
// with or without modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Neither the name of Deusty nor the names of its contributors may be used
// to endorse or promote products derived from this software without specific
// prior written permission of Deusty, LLC.
#if arch(arm64) || arch(x86_64)
#if canImport(Combine)
import Combine
#if SWIFT_PACKAGE
import CocoaLumberjack
import CocoaLumberjackSwiftSupport
#endif
@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
extension DDLog {
/**
* Creates a message publisher.
*
* The publisher will add and remove loggers as subscriptions are added and removed.
*
* The level that you provide here is a preemptive filter (for performance).
* That is, the level specified here will be used to filter out logMessages so that
* the logger is never even invoked for the messages.
*
* More information:
* See -[DDLog addLogger:with:]
*
* - Parameter logLevel: preemptive filter of the message returned by the publisher. All levels are sent by default
* - Returns: A MessagePublisher that emits LogMessages filtered by the specified logLevel
**/
public func messagePublisher(with logLevel: DDLogLevel = .all) -> MessagePublisher {
return MessagePublisher(log: self, with: logLevel)
}
// MARK: - MessagePublisher
@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
public struct MessagePublisher: Combine.Publisher {
public typealias Output = DDLogMessage
public typealias Failure = Never
private let log: DDLog
private let logLevel: DDLogLevel
public init(log: DDLog, with logLevel: DDLogLevel) {
self.log = log
self.logLevel = logLevel
}
public func receive<S>(subscriber: S) where S: Subscriber, S.Failure == Failure, S.Input == Output {
let subscription = Subscription(log: log, with: logLevel, subscriber: subscriber)
subscriber.receive(subscription: subscription)
}
}
// MARK: - Subscription
private final class Subscription<S: Subscriber>: NSObject, DDLogger, Combine.Subscription where S.Input == DDLogMessage {
private var subscriber: S?
private weak var log: DDLog?
//Not used but DDLogger requires it. The preferred way to achieve this is to use the `map()` Combine operator of the publisher.
//ie:
// DDLog.sharedInstance.messagePublisher()
// .map { [format log message] }
// .sink(receiveValue: { [process log message] })
//
var logFormatter: DDLogFormatter?
init(log: DDLog, with logLevel: DDLogLevel, subscriber: S) {
self.subscriber = subscriber
self.log = log
super.init()
log.add(self, with: logLevel)
}
func request(_ demand: Subscribers.Demand) {
//The log messages are endless until canceled, so we won't do any demand management.
//Combine operators can be used to deal with it as needed.
}
func cancel() {
log?.remove(self)
subscriber = nil
}
func log(message logMessage: DDLogMessage) {
_ = subscriber?.receive(logMessage)
}
}
}
@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
extension Publisher where Output == DDLogMessage {
public func formatted(with formatter: DDLogFormatter) -> Publishers.CompactMap<Self, String> {
return compactMap { formatter.format(message: $0) }
}
}
#endif
#endif