[#1013] - Enable more granular control over logging behavior (#1014)

* Add new model for logging configuration

* Fix the example app and update the changelog

CHANGELOG.md

@@ -1,3 +1,14 @@
+### [#1013] Enable more granular control over logging behavior
+
+Now the SDK allows for more fine-tuning of its logging behavior. The `LoggingPolicy` enum
+provides for three options: `.default(OSLogger.LogLevel)` wherein the SDK will use its own logger, with the option
+to customize the log level by passing an `OSLogger.LogLevel` to the enum case. 
+`custom` allows one to pass a custom `Logger` implementation for completely customized logging.
+Lastly, `noLogging` disables logging entirely.
+
+To utilize this new configuration option, pass a `loggingPolicy` into the `Initializer`. If unspecified, the SDK
+will utilize an internal `Logger` implementation with an `OSLogger.LogLevel` of `.debug`
+
 # 0.21.0-beta
 
 New checkpoints

Example/ZcashLightClientSample/ZcashLightClientSample.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -5,8 +5,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/grpc/grpc-swift.git",
       "state" : {
-        "revision" : "783ed8ddcde07ac0332a5ec4647b665f82e95b78",
-        "version" : "1.14.0"
+        "revision" : "130467153ff0acd642d2f098b69c1ac33373b24e",
+        "version" : "1.15.0"
       }
     },
     {
@@ -68,8 +68,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-atomics.git",
       "state" : {
-        "revision" : "ff3d2212b6b093db7f177d0855adbc4ef9c5f036",
-        "version" : "1.0.3"
+        "revision" : "6c89474e62719ddcc1e9614989fff2f68208fe10",
+        "version" : "1.1.0"
       }
     },
     {
@@ -104,8 +104,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-nio.git",
       "state" : {
-        "revision" : "45167b8006448c79dda4b7bd604e07a034c15c49",
-        "version" : "2.48.0"
+        "revision" : "d1690f85419fdac8d54e350fb6d2ab9fd95afd75",
+        "version" : "2.51.1"
       }
     },
     {
@@ -113,8 +113,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-nio-extras.git",
       "state" : {
-        "revision" : "f73ca5ee9c6806800243f1ac415fcf82de9a4c91",
-        "version" : "1.10.2"
+        "revision" : "0e0d0aab665ff1a0659ce75ac003081f2b1c8997",
+        "version" : "1.19.0"
       }
     },
     {
@@ -122,8 +122,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-nio-http2.git",
       "state" : {
-        "revision" : "22757ac305f3d44d2b99ba541193ff1d64e77d00",
-        "version" : "1.24.1"
+        "revision" : "6d021a48483dbb273a9be43f65234bdc9185b364",
+        "version" : "1.26.0"
       }
     },
     {
@@ -131,8 +131,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-nio-ssl.git",
       "state" : {
-        "revision" : "4fb7ead803e38949eb1d6fabb849206a72c580f3",
-        "version" : "2.23.0"
+        "revision" : "e866a626e105042a6a72a870c88b4c531ba05f83",
+        "version" : "2.24.0"
       }
     },
     {
@@ -140,8 +140,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-nio-transport-services.git",
       "state" : {
-        "revision" : "c0d9a144cfaec8d3d596aadde3039286a266c15c",
-        "version" : "1.15.0"
+        "revision" : "41f4098903878418537020075a4d8a6e20a0b182",
+        "version" : "1.17.0"
       }
     },
     {
@@ -149,8 +149,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-protobuf.git",
       "state" : {
-        "revision" : "ab3a58b7209a17d781c0d1dbb3e1ff3da306bae8",
-        "version" : "1.20.3"
+        "revision" : "0af9125c4eae12a4973fb66574c53a54962a9e1e",
+        "version" : "1.21.0"
       }
     },
     {
@@ -158,8 +158,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/zcash-hackworks/zcash-light-client-ffi",
       "state" : {
-        "revision" : "bf5992c2e53749ad11c1e85ad5d9c63e39bdf3cc",
-        "version" : "0.3.0"
+        "revision" : "75821e2b859600707318e4a788abbe27e6615833",
+        "version" : "0.3.1"
       }
     }
   ],

Example/ZcashLightClientSample/ZcashLightClientSample/Sync Blocks/SyncBlocksListViewController.swift

@@ -114,7 +114,7 @@ class SyncBlocksListViewController: UIViewController {
             outputParamsURL: try! outputParamsURLHelper(),
             saplingParamsSourceURL: SaplingParamsSourceURL.default,
             alias: data.alias,
-            logLevel: .debug
+            loggingPolicy: .default(.debug)
         )
 
         return SDKSynchronizer(initializer: initializer)

README.md

@@ -71,9 +71,15 @@ public protocol Logger {
     
 }
 ```
-To enable logging you need to do 2 simple steps:
-1. have one class conform the `Logger` protocol
-2. inject that logger when creating the `Initializer`
+
+You have a few different options when it comes to logging:
+1. Leave it to the SDK. It will use its own `Logger` with sensible defaults. For this option, simply omit the `loggingPolicy` parameter when creating the `Initializer`
+
+2. Provide a custom logger. For this option, do the following:
+    a). have one class conform to the `Logger` protocol
+    b). inject that logger when creating the `Initializer` by passing a `loggingPolicy` of `.custom(yourLogger)`
+
+3. No logging. The SDK will not log any events. For this option, pass a `loggingPolicy` of `.noLogging` when creating the `Initializer` 
 
 For more details look the Sample App's `AppDelegate` code.
 

Sources/ZcashLightClientKit/Initializer.swift

@@ -98,6 +98,12 @@ public class Initializer {
         case success
         case seedRequired
     }
+    
+    public enum LoggingPolicy {
+        case `default`(OSLogger.LogLevel)
+        case custom(Logger)
+        case noLogging
+    }
 
     // This is used to uniquely identify instance of the SDKSynchronizer. It's used when checking if the Alias is already used or not.
     let id = UUID()
@@ -152,7 +158,7 @@ public class Initializer {
         outputParamsURL: URL,
         saplingParamsSourceURL: SaplingParamsSourceURL,
         alias: ZcashSynchronizerAlias = .default,
-        logLevel: OSLogger.LogLevel = .debug
+        loggingPolicy: LoggingPolicy = .default(.debug)
     ) {
         let urls = URLs(
             fsBlockDbRoot: fsBlockDbRoot,
@@ -166,7 +172,16 @@ public class Initializer {
         // from constructor. So `parsingError` is just stored in initializer and `SDKSynchronizer.prepare()` throw this error if it exists.
         let (updatedURLs, parsingError) = Self.tryToUpdateURLs(with: alias, urls: urls)
 
-        let logger = OSLogger(logLevel: logLevel, alias: alias)
+        let logger: Logger
+        switch loggingPolicy {
+        case let .default(logLevel):
+            logger = OSLogger(logLevel: logLevel, alias: alias)
+        case let .custom(customLogger):
+            logger = customLogger
+        case .noLogging:
+            logger = NullLogger()
+        }
+        
         let rustBackend = ZcashRustBackend(
             dbData: updatedURLs.dataDbURL,
             fsBlockDbRoot: updatedURLs.fsBlockDbRoot,

Sources/ZcashLightClientKit/Utils/LoggingProxy.swift

@@ -43,3 +43,14 @@ extension Logger {
         error(message, file: file, function: function, line: line)
     }
 }
+
+/**
+A concrete logger implementation that logs nothing at all
+ */
+struct NullLogger: Logger {
+    func debug(_ message: String, file: StaticString, function: StaticString, line: Int) {}
+    func info(_ message: String, file: StaticString, function: StaticString, line: Int) {}
+    func event(_ message: String, file: StaticString, function: StaticString, line: Int) {}
+    func warn(_ message: String, file: StaticString, function: StaticString, line: Int) {}
+    func error(_ message: String, file: StaticString, function: StaticString, line: Int) {}
+}

Tests/OfflineTests/InitializerOfflineTests.swift

@@ -36,7 +36,7 @@ class InitializerOfflineTests: XCTestCase {
             outputParamsURL: outputParamsURL,
             saplingParamsSourceURL: .default,
             alias: alias,
-            logLevel: .debug
+            loggingPolicy: .default(.debug)
         )
     }
 

Tests/OfflineTests/SynchronizerOfflineTests.swift

@@ -249,7 +249,7 @@ class SynchronizerOfflineTests: XCTestCase {
             outputParamsURL: validFileURL,
             saplingParamsSourceURL: .default,
             alias: .default,
-            logLevel: .debug
+            loggingPolicy: .default(.debug)
         )
 
         XCTAssertNotNil(initializer.urlsParsingError)
@@ -290,7 +290,7 @@ class SynchronizerOfflineTests: XCTestCase {
             outputParamsURL: validFileURL,
             saplingParamsSourceURL: .default,
             alias: .default,
-            logLevel: .debug
+            loggingPolicy: .default(.debug)
         )
 
         XCTAssertNotNil(initializer.urlsParsingError)

Tests/PerformanceTests/SynchronizerTests.swift

@@ -79,7 +79,7 @@ class SynchronizerTests: XCTestCase {
                 outputParamsURL: try __outputParamsURL(),
                 saplingParamsSourceURL: SaplingParamsSourceURL.tests,
                 alias: .default,
-                logLevel: .debug
+                loggingPolicy: .default(.debug)
             )
             
             try? FileManager.default.removeItem(at: databases.fsCacheDbRoot)

Tests/TestUtils/TestCoordinator.swift

@@ -77,7 +77,7 @@ class TestCoordinator {
             outputParamsURL: try __outputParamsURL(),
             saplingParamsSourceURL: SaplingParamsSourceURL.tests,
             alias: alias,
-            logLevel: .debug
+            loggingPolicy: .default(.debug)
         )
 
         let derivationTool = DerivationTool(networkType: network.networkType)