FFI log forwarding

Author: pblazej

Sources/LiveKit/Support/Logger.swift

@@ -16,6 +16,7 @@
 
 import OSLog
 internal import LiveKitWebRTC
+internal import LiveKitFFI
 
 // MARK: - Logger
 
@@ -108,30 +109,36 @@ public struct PrintLogger: Logger {
 /// A logger that logs to OSLog
 /// - Parameter minLevel: The minimum level to log
 /// - Parameter rtc: Whether to log WebRTC output
+/// - Parameter ffi: Whether to log Rust FFI output
 open class OSLogger: Logger, @unchecked Sendable {
     private static let subsystem = "io.livekit.sdk"
 
-    private let queue = DispatchQueue(label: "io.livekit.oslogger", qos: .utility)
+    private static let queue = DispatchQueue(label: "io.livekit.oslogger", qos: .utility)
+
+    private nonisolated(unsafe) static var ffiBootstrapped = false
+
     private var logs: [String: OSLog] = [:]
 
     private lazy var rtcLogger = LKRTCCallbackLogger()
+    private var ffiLogForwardTask: Task<Void, Never>?
 
     private let minLevel: LogLevel
 
-    public init(minLevel: LogLevel = .info, rtc: Bool = false) {
+    public init(minLevel: LogLevel = .info, rtc: Bool = false, ffi: Bool = true) {
         self.minLevel = minLevel
 
-        guard rtc else { return }
+        if rtc {
+            startRTCLogForwarding(minLevel: minLevel)
+        }
 
-        let rtcLog = OSLog(subsystem: Self.subsystem, category: "WebRTC")
-        rtcLogger.severity = minLevel.rtcSeverity
-        rtcLogger.start { message, severity in
-            os_log("%{public}@", log: rtcLog, type: severity.osLogType, message)
+        if ffi {
+            startFFILogForwarding(minLevel: minLevel)
         }
     }
 
     deinit {
         rtcLogger.stop()
+        ffiLogForwardTask?.cancel()
     }
 
     public func log(
@@ -155,7 +162,7 @@ open class OSLogger: Logger, @unchecked Sendable {
 
         let metadata = buildScopedMetadataString()
 
-        queue.async {
+        Self.queue.async {
             func getOSLog(for type: Any.Type) -> OSLog {
                 let typeName = String(describing: type)
 
@@ -171,6 +178,36 @@ open class OSLogger: Logger, @unchecked Sendable {
             os_log("%{public}@", log: getOSLog(for: type), type: level.osLogType, "\(type).\(function) \(message)\(metadata)")
         }
     }
+
+    private func startRTCLogForwarding(minLevel: LogLevel) {
+        let rtcLog = OSLog(subsystem: Self.subsystem, category: "WebRTC")
+
+        rtcLogger.severity = minLevel.rtcSeverity
+        rtcLogger.start { message, severity in
+            os_log("%{public}@", log: rtcLog, type: severity.osLogType, message)
+        }
+    }
+
+    private func startFFILogForwarding(minLevel: LogLevel) {
+        Self.queue.sync {
+            if !Self.ffiBootstrapped {
+                logForwardBootstrap(level: minLevel.logForwardFilter)
+                Self.ffiBootstrapped = true
+            }
+        }
+
+        let ffiLog = OSLog(subsystem: Self.subsystem, category: "FFI")
+
+        ffiLogForwardTask = Task(priority: .utility) {
+            for await entry in AsyncStream(unfolding: logForwardReceive) {
+                guard !Task.isCancelled else { break }
+
+                let message = "\(entry.target) \(entry.message)"
+
+                os_log("%{public}@", log: ffiLog, type: entry.level.osLogType, message)
+            }
+        }
+    }
 }
 
 // MARK: - Loggable
@@ -236,6 +273,15 @@ public enum LogLevel: Int, Sendable, Comparable, CustomStringConvertible {
         }
     }
 
+    var logForwardFilter: LogForwardFilter {
+        switch self {
+        case .debug: .debug
+        case .info: .info
+        case .warning: .warn
+        case .error: .error
+        }
+    }
+
     @inlinable
     public static func < (lhs: LogLevel, rhs: LogLevel) -> Bool {
         lhs.rawValue < rhs.rawValue
@@ -263,3 +309,14 @@ extension LKRTCLoggingSeverity {
         }
     }
 }
+
+extension LogForwardLevel {
+    var osLogType: OSLogType {
+        switch self {
+        case .error: .error
+        case .warn: .default
+        case .info: .info
+        case .debug, .trace: .debug
+        }
+    }
+}