Release/5.2.0

CHANGELOG

@@ -1,3 +1,9 @@
+Version 5.2.0 (2023-06-02)
+--------------------------
+Add a filter API to plugins to decide whether to track an event or not (#783)
+Add version to default remote configuration and don't update unless remote configuration is newer (#779)
+Handle unprotected access to sending state in Emitter from concurrent threads (#774)
+
 Version 5.1.0 (2023-05-11)
 --------------------------
 Track new properties in platform context version 1-0-3 and make it configurable which properties to track (#771)

SnowplowTracker.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
     s.name             = "SnowplowTracker"
-    s.version          = "5.1.0"
+    s.version          = "5.2.0"
     s.summary          = "Snowplow event tracker for iOS, macOS, tvOS, watchOS for apps and games."
     s.description      = <<-DESC
     Snowplow is a mobile and event analytics platform with a difference: rather than tell our users how they should analyze their data, we deliver their event-level data in their own data warehouse, on their own Amazon Redshift or Postgres database, so they can analyze it any way they choose. Snowplow mobile is used by data-savvy games companies and app developers to better understand their users and how they engage with their games and applications. Snowplow is open source using the business-friendly Apache License, Version 2.0 and scales horizontally to many billions of events.

Sources/Core/Emitter/Emitter.swift

@@ -19,12 +19,12 @@ let POST_WRAPPER_BYTES = 88
 class Emitter: NSObject, EmitterEventProcessing {
 
     private var timer: Timer?
-    /// Whether the emitter is currently sending.
-    private(set) var isSending = false
     private var dataOperationQueue: OperationQueue = OperationQueue()
     private var builderFinished = false
-
-    private var pausedEmit = false
+
+    private var sendingCheck = SendingCheck()
+    /// Whether the emitter is currently sending.
+    var isSending: Bool { return sendingCheck.sending }
 
     private var _urlEndpoint: String?
     /// Collector endpoint.
@@ -330,29 +330,22 @@ class Emitter: NSObject, EmitterEventProcessing {
 
     /// Allows sending events to collector.
     func resumeEmit() {
-        pausedEmit = false
+        sendingCheck.pausedEmit = false
         flush()
     }
 
     /// Suspends sending events to collector.
     func pauseEmit() {
-        pausedEmit = true
+        sendingCheck.pausedEmit = true
     }
 
     /// Insert a Payload object into the buffer to be sent to collector.
     /// This method will add the payload to the database and flush (send all events).
     /// - Parameter eventPayload: A Payload containing a completed event to be added into the buffer.
     func addPayload(toBuffer eventPayload: Payload) {
-        weak var weakSelf = self
-
-        DispatchQueue.global(qos: .default).async {
-            let strongSelf = weakSelf
-            if strongSelf == nil {
-                return
-            }
-
-            strongSelf?.eventStore?.addEvent(eventPayload)
-            strongSelf?.flush()
+        DispatchQueue.global(qos: .default).async { [weak self] in
+            self?.eventStore?.addEvent(eventPayload)
+            self?.flush()
         }
     }
 
@@ -369,23 +362,19 @@ class Emitter: NSObject, EmitterEventProcessing {
 
     // MARK: - Control methods
 
-    func sendGuard() {
-        if isSending || pausedEmit {
-            return
-        }
-        objc_sync_enter(self)
-        if !isSending && !pausedEmit {
-            isSending = true
+    private func sendGuard() {
+        if sendingCheck.requestToStartSending() {
+            objc_sync_enter(self)
             attemptEmit()
+            objc_sync_exit(self)
+            sendingCheck.sending = false
         }
-        objc_sync_exit(self)
     }
-
-    func attemptEmit() {
+    
+    private func attemptEmit() {
         guard let eventStore = eventStore else { return }
         if eventStore.count() == 0 {
             logDebug(message: "Database empty. Returning.")
-            isSending = false
             return
         }
 
@@ -435,14 +424,13 @@ class Emitter: NSObject, EmitterEventProcessing {
         if failedWillRetryCount > 0 && successCount == 0 {
             logDebug(message: "Ending emitter run as all requests failed.")
             Thread.sleep(forTimeInterval: 5)
-            isSending = false
             return
         } else {
             self.attemptEmit()
         }
     }
 
-    func buildRequests(fromEvents events: [EmitterEvent]) -> [Request] {
+    private func buildRequests(fromEvents events: [EmitterEvent]) -> [Request] {
         var requests: [Request] = []
         guard let networkConnection = networkConnection else { return requests }
 
@@ -503,16 +491,16 @@ class Emitter: NSObject, EmitterEventProcessing {
         return requests
     }
 
-    func isOversize(_ payload: Payload) -> Bool {
+    private func isOversize(_ payload: Payload) -> Bool {
         return isOversize(payload, previousPayloads: [])
     }
 
-    func isOversize(_ payload: Payload, previousPayloads: [Payload]) -> Bool {
+    private func isOversize(_ payload: Payload, previousPayloads: [Payload]) -> Bool {
         let byteLimit = networkConnection?.httpMethod == .get ? byteLimitGet : byteLimitPost
         return isOversize(payload, byteLimit: byteLimit, previousPayloads: previousPayloads)
     }
 
-    func isOversize(_ payload: Payload, byteLimit: Int, previousPayloads: [Payload]) -> Bool {
+    private func isOversize(_ payload: Payload, byteLimit: Int, previousPayloads: [Payload]) -> Bool {
         var totalByteSize = payload.byteSize
         for previousPayload in previousPayloads {
             totalByteSize += previousPayload.byteSize
@@ -529,3 +517,42 @@ class Emitter: NSObject, EmitterEventProcessing {
         pauseTimer()
     }
 }
+
+fileprivate class SendingCheck {
+    private var _sending = false
+    var sending: Bool {
+        get {
+            return lock { return _sending }
+        }
+        set {
+            lock { _sending = newValue }
+        }
+    }
+
+    private var _pausedEmit = false
+    var pausedEmit: Bool {
+        get {
+            return lock { return _pausedEmit }
+        }
+        set {
+            lock { _pausedEmit = newValue }
+        }
+    }
+
+    func requestToStartSending() -> Bool {
+        return lock {
+            if !_sending && !_pausedEmit {
+                _sending = true
+                return true
+            } else {
+                return false
+            }
+        }
+    }
+
+    private func lock<T>(closure: () -> T) -> T {
+        objc_sync_enter(self)
+        defer { objc_sync_exit(self) }
+        return closure()
+    }
+}

Sources/Core/GlobalContexts/GlobalContextPluginConfiguration.swift

@@ -13,10 +13,9 @@
 
 import Foundation
 
-class GlobalContextPluginConfiguration: ConfigurationProtocol, PluginConfigurationProtocol {
+class GlobalContextPluginConfiguration: ConfigurationProtocol, PluginIdentifiable, PluginEntitiesCallable {
     private(set) var identifier: String
     private(set) var globalContext: GlobalContext
-    private(set) var afterTrackConfiguration: PluginAfterTrackConfiguration? = nil
     private(set) var entitiesConfiguration: PluginEntitiesConfiguration?
 
     init(identifier: String, globalContext: GlobalContext) {

Sources/Core/RemoteConfiguration/ConfigurationCache.swift

@@ -19,94 +19,93 @@ class ConfigurationCache: NSObject {
 
     init(remoteConfiguration: RemoteConfiguration) {
         super.init()
-        #if !(os(tvOS)) && !(os(watchOS))
+#if !(os(tvOS)) && !(os(watchOS))
         createCachePath(with: remoteConfiguration)
-        #endif
+#endif
     }
-
+    
     func read() -> FetchedConfigurationBundle? {
-        objc_sync_enter(self)
-        defer { objc_sync_exit(self) }
-        #if !(os(tvOS)) && !(os(watchOS))
-        if let configuration = configuration {
+        return lock {
+#if !(os(tvOS)) && !(os(watchOS))
+            if let configuration = configuration {
+                return configuration
+            }
+            load()
+#endif
             return configuration
         }
-        load()
-        #endif
-        return configuration
     }
-
+    
     func write(_ configuration: FetchedConfigurationBundle) {
-        objc_sync_enter(self)
-        self.configuration = configuration
-        #if !(os(tvOS)) && !(os(watchOS))
-        store()
-        #endif
-        objc_sync_exit(self)
+        lock {
+            self.configuration = configuration
+#if !(os(tvOS)) && !(os(watchOS))
+            store()
+#endif
+        }
     }
-
+    
     func clear() {
-        objc_sync_enter(self)
-        defer { objc_sync_exit(self) }
-        configuration = nil
-        #if !(os(tvOS)) && !(os(watchOS))
-        if let cacheFileUrl = cacheFileUrl {
-            do {
-                try FileManager.default.removeItem(at: cacheFileUrl)
-            } catch let error {
-                logError(message: String(format: "Error on clearing configuration from cache: %@", error.localizedDescription))
+        lock {
+            configuration = nil
+#if !(os(tvOS)) && !(os(watchOS))
+            if let cacheFileUrl = cacheFileUrl {
+                do {
+                    try FileManager.default.removeItem(at: cacheFileUrl)
+                } catch let error {
+                    logError(message: String(format: "Error on clearing configuration from cache: %@", error.localizedDescription))
+                }
             }
+#endif
         }
-        #endif
     }
-
+    
     // Private method
-
+    
     func load() {
-        objc_sync_enter(self)
-        defer { objc_sync_exit(self) }
-        guard let cacheFileUrl = cacheFileUrl,
-              let data = try? Data(contentsOf: cacheFileUrl) else { return }
-        if #available(iOS 12, tvOS 12, watchOS 5, macOS 10.14, *) {
-            do {
-                configuration = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? FetchedConfigurationBundle
-            } catch let error {
-                logError(message: String(format: "Exception on getting configuration from cache: %@", error.localizedDescription))
-                configuration = nil
+        lock {
+            guard let cacheFileUrl = cacheFileUrl,
+                  let data = try? Data(contentsOf: cacheFileUrl) else { return }
+            if #available(iOS 12, tvOS 12, watchOS 5, macOS 10.14, *) {
+                do {
+                    configuration = try NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? FetchedConfigurationBundle
+                } catch let error {
+                    logError(message: String(format: "Exception on getting configuration from cache: %@", error.localizedDescription))
+                    configuration = nil
+                }
+            } else {
+                let unarchiver = NSKeyedUnarchiver(forReadingWith: data)
+                configuration = unarchiver.decodeObject() as? FetchedConfigurationBundle
+                unarchiver.finishDecoding()
             }
-        } else {
-            let unarchiver = NSKeyedUnarchiver(forReadingWith: data)
-            configuration = unarchiver.decodeObject() as? FetchedConfigurationBundle
-            unarchiver.finishDecoding()
         }
     }
 
     func store() {
         _ = DispatchQueue.global(qos: .default)
-        objc_sync_enter(self)
-        defer { objc_sync_exit(self) }
-
-        guard let configuration = configuration,
-              let cacheFileUrl = cacheFileUrl else { return }
-
-        do {
-            var data = Data()
-            var archiver: NSKeyedArchiver?
+        lock {
+            guard let configuration = configuration,
+                  let cacheFileUrl = cacheFileUrl else { return }
 
-            if #available(iOS 12, tvOS 12, watchOS 5, macOS 10.14, *) {
-                archiver = NSKeyedArchiver(requiringSecureCoding: true)
-                archiver?.encode(configuration, forKey: "root")
-                if let encodedData = archiver?.encodedData {
-                    data = encodedData
+            do {
+                var data = Data()
+                var archiver: NSKeyedArchiver?
+
+                if #available(iOS 12, tvOS 12, watchOS 5, macOS 10.14, *) {
+                    archiver = NSKeyedArchiver(requiringSecureCoding: true)
+                    archiver?.encode(configuration, forKey: "root")
+                    if let encodedData = archiver?.encodedData {
+                        data = encodedData
+                    }
+                } else {
+                    archiver = NSKeyedArchiver(forWritingWith: data as! NSMutableData)
+                    archiver?.encode(configuration)
+                    archiver?.finishEncoding()
                 }
-            } else {
-                archiver = NSKeyedArchiver(forWritingWith: data as! NSMutableData)
-                archiver?.encode(configuration)
-                archiver?.finishEncoding()
+                try data.write(to: cacheFileUrl, options: .atomic)
+            } catch let error {
+                logError(message: String(format: "Error on caching configuration: %@", error.localizedDescription))
             }
-            try data.write(to: cacheFileUrl, options: .atomic)
-        } catch let error {
-            logError(message: String(format: "Error on caching configuration: %@", error.localizedDescription))
         }
     }
 
@@ -126,4 +125,10 @@ class ConfigurationCache: NSObject {
             cacheFileUrl = url
         }
     }
+
+    private func lock<T>(closure: () -> T) -> T {
+        objc_sync_enter(self)
+        defer { objc_sync_exit(self) }
+        return closure()
+    }
 }