Code cleanup, readme, creative common segment

Author: fruitcoder

Example/main.swift

@@ -8,6 +8,8 @@ let semaphore = DispatchSemaphore(value: 0)
 do {
 	try server.start(9080, forceIPv4: true)
 	print("Server has started ( port = \(try server.port()) ). Try to connect now...")
+	print("Check out \(server.livestreamUrl!.absoluteString)")
+
 	semaphore.wait()
 } catch {
 	print("Server start error: \(error)")

Package.swift

@@ -5,6 +5,12 @@ import PackageDescription
 
 let package = Package(
 	name: "SwifterHlsMock",
+	platforms: [
+		.iOS(.v10),
+		.macOS(.v10_12),
+		.tvOS(.v10),
+		.watchOS(.v3)
+	],
 	products: [
 		.library(
 			name: "SwifterHlsMock",

README.md

@@ -1,2 +1,11 @@
 # SwiftHlsMock
-A little mock server to simulate hls locally based on Swifter
+A little mock server to simulate hls locally based on Swifter.
+
+##### Why?
+
+You can use this package to have better control over your UITests by just starting the server and giving your player the localhost url. The server always streams the same segment (the 10 segments are identical) from [bensound](https://www.bensound.com/royalty-free-music/track/ukulele).
+
+##### Try it
+
+To try it out I'd recommend checking out the project and starting the Sample executable. 
+

Sources/SwifterHlsMock/Resources/segments/BipPop.ts

@@ -1,34 +1,24 @@
 import Foundation
+import os.log
 import Swifter
 
 public final class HlsServer: HttpServer {
-	var targetSegmentLength: Int = 3
-	let segmentLength: TimeInterval = 2.9866666
-	let seekingWindowInSeconds: TimeInterval = 18_000 // 5h
-	let skippableSegments = 6
-	var isStale: Bool = false {
-		didSet {
-			guard isStale != oldValue else { return }
-
-			if isStale {
-				stopScheduledPlaylistUpdates()
-			} else {
-				startScheduledPlaylistUpdates()
-			}
-		}
-	}
-	let path: String
-	let segmentsPath: String = "segments"
-	let livestreamPlaylistFilename = "main-ios.m3u8"
-	let livestreamVariantFilename = "main-128000-ios.m3u8"
-	var livestreamUrl: URL? {
+	public var isStale: Bool = false
+	public let livestreamPlaylistFilename: String
+	public var livestreamUrl: URL? {
 		guard
 			let port = try? self.port()
 		else {
 			return nil
 		}
 		return URL(string: "http://localhost:\(port)/\(path)/\(livestreamPlaylistFilename)")
 	}
+	public var now: Date {
+		Date().addingTimeInterval(-serverToNowDifference)
+	}
+	public let path: String
+	public let seekingWindowInSeconds: TimeInterval
+	public let segmentLength: TimeInterval
 
 	/// The difference in seconds between the server time and the client time.
 	///
@@ -61,20 +51,127 @@ public final class HlsServer: HttpServer {
 	/// )
 	/// ```
 	/// This way the time passes in realtime relative to a fixed start date.
-	let serverToNowDifference: TimeInterval
-	var now: Date {
-		Date().addingTimeInterval(-serverToNowDifference)
+	public let serverToNowDifference: TimeInterval
+
+	public let skippableSegments: Int
+	public let targetSegmentLength: Int
+
+	/// Creates an `HlsServer` instance.
+	/// - Parameters:
+	///   - livestreamPlaylistFilename: The name of the playlist. Defaults to `main-ios.m3u8`.
+	///   - path: The path to register for hls. Defaults to `mockServer`.
+	///   - seekingWindowInSeconds: The seeking in window in seconds. Defaults to five hours.
+	///   - segmentLength: The actual segment length in seconds. Defaults to `2.9866666`.
+	///   - skippableSegments: This value + 1 determines the number of segments returned for delta updates. Defaults to `6`.
+	///   - targetSegmentLength: The target duration of a segment (`#EXT-X-TARGETDURATION`). Defaults to `3`.
+	///   - serverToNowDifference: The time difference between the client and the server. Defaults to `0`. See ``serverToNowDifference``.
+	public init(livestreamPlaylistFilename: String = "main-ios.m3u8",
+							path: String = "mockServer",
+							seekingWindowInSeconds: TimeInterval = 18_000,
+							segmentLength: TimeInterval = 2.9866666,
+							skippableSegments: Int = 6,
+							targetSegmentLength: Int = 3,
+							serverToNowDifference: TimeInterval = 0) {
+		self.livestreamPlaylistFilename = livestreamPlaylistFilename
+		self.path = path
+		self.seekingWindowInSeconds = seekingWindowInSeconds
+		self.segmentLength = segmentLength
+		self.skippableSegments = skippableSegments
+		self.targetSegmentLength = targetSegmentLength
+		self.serverToNowDifference = serverToNowDifference
+
+		super.init()
+
+		startScheduledPlaylistUpdates()
+
+		// segments
+		self["/\(path)/\(segmentsPath)/:segmentName"] = { request in
+			os_log("request path is %{public}@", log: log, type: .info, request.path)
+
+			let filePath = Bundle.module.resourcePath! + "/segments/sample\(self.segmentFileIndex).ts"
+
+			os_log("streaming file from %{public}@", log: log, type: .info, filePath)
+
+			if let file = try? filePath.openForReading() {
+				var responseHeader: [String: String] = ["Content-Type": "video/mp2t"]
+
+				if let attr = try? FileManager.default.attributesOfItem(atPath: filePath),
+					 let fileSize = attr[FileAttributeKey.size] as? UInt64 {
+					responseHeader["Content-Length"] = String(fileSize)
+				}
+
+				return .raw(200, "OK", responseHeader, { writer in
+					try? writer.write(file)
+					file.close()
+				})
+			}
+			return .notFound
+		}
+
+		self["/\(path)/\(livestreamPlaylistFilename)"] = { request in
+			os_log("request main playlist", log: log, type: .info)
+
+			return .ok(
+				.data("""
+					#EXTM3U
+					#EXT-X-VERSION:9
+					#EXT-X-ALLOW-CACHE:NO
+					## Created with Z/IPStream R/2 v1.08.09
+					#EXT-X-STREAM-INF:BANDWIDTH=137557,CODECS="mp4a.40.2"
+					\(self.livestreamVariantFilename)
+					""".data(using: .utf8)!,
+							contentType: "application/vnd.apple.mpegurl"
+				)
+			)
+		}
+
+		self["/\(path)/\(livestreamVariantFilename)"] = { [weak self] request in
+			guard let self = self else { return .internalServerError }
+
+			if request.queryParams.contains(where: { (key, value) in key == "_HLS_skip" && value == "YES" }) {
+				os_log("requesting delta variant playlist", log: log, type: .info)
+				return .ok(.data(self.currentDeltaPlaylist.data(using: .utf8)!, contentType: "application/vnd.apple.mpegurl"))
+			} else {
+				os_log("requesting variant playlist", log: log, type: .info)
+				return .ok(.data(self.currentPlaylist.data(using: .utf8)!, contentType: "application/vnd.apple.mpegurl"))
+			}
+		}
 	}
 
-	private var segmentCount: Int { Int(seekingWindowInSeconds / Double(targetSegmentLength)) }
+	deinit {
+		timer.setEventHandler {}
+		timer.cancel()
+
+		// If the timer is suspended, calling cancel without resuming triggers a crash.
+		// This is documented here https://forums.developer.apple.com/thread/15902
+		startScheduledPlaylistUpdates()
+	}
+
+	private var currentDeltaPlaylist: String = ""
+	private var currentPlaylist: String = ""
+
+	private lazy var dateFormatter: DateFormatter = {
+		let formatter = DateFormatter()
+		formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
+		formatter.locale = Locale(identifier: "en_US_POSIX")
+		formatter.timeZone = TimeZone(secondsFromGMT: 0)
+		return formatter
+	}()
+
 	private let initialMediaSequence = 1_000_000
+	private var isTimerSuspended = true
+
+	private let livestreamVariantFilename = "main-128000-ios.m3u8"
 	private var numberOfPlaylistUpdates = 0
-	private var currentPlaylist: String = ""
-	private var currentDeltaPlaylist: String = ""
+	private var previousSegmentIndex = 0
+	private var segmentCount: Int { Int(seekingWindowInSeconds / Double(targetSegmentLength)) }
 
-	private var previousDeltaPlaylistResponse: String?
-	private var previousPlaylistResponse: String?
-	private var previousDate: Date?
+	private var segmentFileIndex: Int {
+		defer { previousSegmentIndex = (previousSegmentIndex + 1) % segmentIndices.count }
+		return segmentIndices[previousSegmentIndex]
+	}
+	private var segmentIndices = Array(0...9)
+	private let segmentsPath = "segments"
 
 	private lazy var timer: DispatchSourceTimer = {
 		let t = DispatchSource.makeTimerSource()
@@ -84,39 +181,25 @@ public final class HlsServer: HttpServer {
 		})
 		return t
 	}()
-	private var isTimerSuspended = true
-
-	private lazy var dateFormatter: DateFormatter = {
-		let formatter = DateFormatter()
-		formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
-		formatter.locale = Locale(identifier: "en_US_POSIX")
-		formatter.timeZone = TimeZone(secondsFromGMT: 0)
-		return formatter
-	}()
 
 	@objc private func updatePlaylist() {
+		guard !isStale else { return }
 
-//		if currentMediaSequence >= 1_000_010 {
-//			print("playlist is stale now")
-//			return
-//		}
-
-		// simulate one segment length latency to the live time
-		let mostRecentSegmentPDT = now.addingTimeInterval(-segmentLength)
+		let mostRecentSegmentPDT = now
 
 		// this is constant since segments are removed from the top and added to the bottom (5993 in our case)
 		let skippedSegments = segmentCount-skippableSegments-1
 
 		var fullPlaylist = """
 			#EXTM3U
-			#EXT-X-VERSION:3
+			#EXT-X-VERSION:9
 			#EXT-X-MEDIA-SEQUENCE:\(initialMediaSequence + numberOfPlaylistUpdates)
 			#EXT-X-TARGETDURATION:\(targetSegmentLength)
 			#EXT-X-SERVER-CONTROL:CAN-SKIP-UNTIL=\(skippableSegments * targetSegmentLength)
 			"""
 
 		var deltaPlayist = fullPlaylist
-		deltaPlayist += "\n#EXT-X-SKIP:SKIPPED-SEGMENTS=\(skippedSegments)\n" // this is the total number of skipped segments
+		deltaPlayist += "\n#EXT-X-SKIP:SKIPPED-SEGMENTS=\(skippedSegments)" // this is the total number of skipped segments
 
 		for segmentIndex in numberOfPlaylistUpdates ..< segmentCount + numberOfPlaylistUpdates {
 			let inverseIndex = segmentCount + numberOfPlaylistUpdates - segmentIndex - 1
@@ -145,19 +228,10 @@ public final class HlsServer: HttpServer {
 		numberOfPlaylistUpdates += 1
 	}
 
-	deinit {
-		timer.setEventHandler {}
-		timer.cancel()
-
-		// If the timer is suspended, calling cancel without resuming triggers a crash.
-		// This is documented here https://forums.developer.apple.com/thread/15902
-		startScheduledPlaylistUpdates()
-	}
-
 	private func startScheduledPlaylistUpdates() {
 		guard isTimerSuspended else { return }
 
-		print("playlist timer update started")
+		os_log("playlist timer update started", log: log, type: .info)
 
 		timer.resume()
 		isTimerSuspended.toggle()
@@ -166,73 +240,9 @@ public final class HlsServer: HttpServer {
 	private func stopScheduledPlaylistUpdates() {
 		guard !isTimerSuspended else { return }
 
-		print("playlist timer update stopped")
+		os_log("playlist timer update stopped", log: log, type: .info)
 		timer.suspend()
 	}
-
-	public init(path: String = "mockServer",
-							serverToNowDifference: TimeInterval = 0) {
-		self.path = path
-		self.serverToNowDifference = serverToNowDifference
-
-		super.init()
-
-		startScheduledPlaylistUpdates()
-
-		// segments
-		self["/\(path)/\(segmentsPath)/:segmentName"] = { request in
-			print("request path is \(request.path)")
-
-			let filePath = Bundle.module.resourcePath! + "/segments/sample.ts"
-
-			if let file = try? filePath.openForReading() {
-				var responseHeader: [String: String] = ["Content-Type": "video/mp2t"]
-
-				if let attr = try? FileManager.default.attributesOfItem(atPath: filePath),
-					 let fileSize = attr[FileAttributeKey.size] as? UInt64 {
-					responseHeader["Content-Length"] = String(fileSize)
-				}
-
-				return .raw(200, "OK", responseHeader, { writer in
-					try? writer.write(file)
-					file.close()
-				})
-			}
-			return .notFound
-		}
-
-		self["/\(path)/\(livestreamPlaylistFilename)"] = { request in
-			return .ok(
-				.data("""
-					#EXTM3U
-					#EXT-X-VERSION:3
-					#EXT-X-ALLOW-CACHE:NO
-					## Created with Z/IPStream R/2 v1.08.09
-					#EXT-X-STREAM-INF:BANDWIDTH=137557,CODECS="mp4a.40.2"
-					\(self.livestreamVariantFilename)
-					""".data(using: .utf8)!,
-					contentType: "application/vnd.apple.mpegurl"
-				)
-			)
-		}
-
-		self["/\(path)/\(livestreamVariantFilename)"] = { [weak self] request in
-			guard let self = self else { return .internalServerError }
-
-			if request.queryParams.contains(where: { (key, value) in key == "_HLS_skip" && value == "YES" }) {
-				let response = self.currentDeltaPlaylist
-				self.previousDeltaPlaylistResponse = response
-				return .ok(.data(response.data(using: .utf8)!, contentType: "application/vnd.apple.mpegurl"))
-			} else {
-				let response = self.currentPlaylist
-				self.previousPlaylistResponse = response
-				return .ok(.data(response.data(using: .utf8)!, contentType: "application/vnd.apple.mpegurl"))
-			}
-		}
-
-		self.notFoundHandler = { request in
-			print("Not found handler called \(dump(request))")
-			return .notFound
-		}
-	}
 }
+
+private let log = OSLog(subsystem: "de.fruitco.hlsmock", category: "server")