add closure-based debug logging instead of autoclosure logging for all levels

Author: jaeopt

DemoSwiftApp/Customization/CustomLogger.swift

@@ -15,9 +15,9 @@ class CustomLogger: OPTLogger {
     required init() {
     }
 
-    public func log(level: OptimizelyLogLevel, message: @autoclosure () -> String) {
+    public func log(level: OptimizelyLogLevel, message: String) {
         if level.rawValue <= CustomLogger.logLevel.rawValue {
-            print("🐱 - [\(level.name)] Kitty - \(message())")
+            print("🐱 - [\(level.name)] Kitty - \(message)")
         }
     }
 }

OptimizelySDK/Customization/DefaultEventDispatcher.swift

@@ -158,7 +158,8 @@ open class DefaultEventDispatcher : BackgroundingCallbacks, OPTEventDispatcher {
                                 self.logger?.e("Removed event different from sent event")
                             }
                             else {
-                                self.logger?.d("Successfully sent event: \(event)")
+                                // avoid event-log-message preparation overheads with closure-logging
+                                self.logger?.d({ "Successfully sent event: \(event)" })
                             }
                         }
                         else {

OptimizelySDK/Customization/DefaultLogger.swift

@@ -33,11 +33,11 @@ open class DefaultLogger : OPTLogger {
     required public init() {
     }
 
-    open func log(level: OptimizelyLogLevel, message: @autoclosure () -> String) {
-        if level.rawValue > DefaultLogger.logLevel.rawValue {
+    open func log(level: OptimizelyLogLevel, message: String) {
+        if level > DefaultLogger.logLevel {
             return
         }
-        let message = "[OPTIMIZELY][" + level.name + "] " + message()
+        let message = "[OPTIMIZELY][" + level.name + "] " + message
 
         NSLog(message)
     }

OptimizelySDK/Customization/Protocols/OPTLogger.swift

@@ -35,7 +35,7 @@ import Foundation
      - Parameter level: The priority level of the log.
      - Parameter message: The message to log.
      */
-    func log(level: OptimizelyLogLevel, message: @autoclosure () -> String)
+    func log(level: OptimizelyLogLevel, message: String)
 
 }
 
@@ -47,6 +47,12 @@ extension OPTLogger {
     func w(_ message: String) { log(level: .warning, message: message) }
     func i(_ message: String) { log(level: .info, message: message) }
     func d(_ message: String) { log(level: .debug, message: message) }
+    // closure-based debug logging:
+    // - we pay overhead for preparing large/complicated log messages only when it's debug level
+    func d(_ message: () -> String) {
+        guard Self.logLevel >= OptimizelyLogLevel.debug else { return }
+        log(level: .debug, message: message())
+    }
 
     // MARK: - Utils for LogMessage
 

OptimizelySDK/Implementation/DefaultDatafileHandler.swift

@@ -126,7 +126,8 @@ class DefaultDatafileHandler : OPTDatafileHandler {
 
                 completionHandler(result)
 
-                //self.logger?.d(response.debugDescription)                
+                // avoid event-log-message preparation overheads with closure-logging
+                self.logger?.d({ response.debugDescription })
             }
 
             task.resume()

OptimizelySDK/Optimizely/OptimizelyLogLevel.swift

@@ -43,3 +43,9 @@ import Foundation
         }
     }
 }
+
+extension OptimizelyLogLevel: Comparable {
+    public static func < (lhs: OptimizelyLogLevel, rhs: OptimizelyLogLevel) -> Bool {
+        return lhs.rawValue < rhs.rawValue
+    }
+}