Further implement JobQueue

SessionMessagingKit/Jobs/JobQueue.swift

@@ -1,3 +1,4 @@
+import SessionUtilities
 
 public final class JobQueue : JobDelegate {
 
@@ -10,12 +11,47 @@ public final class JobQueue : JobDelegate {
     }
 
     public func handleJobSucceeded(_ job: Job) {
-        // Mark the job as succeeded
+        Configuration.shared.storage.withAsync({ transaction in
+            Configuration.shared.storage.markJobAsSucceeded(job, using: transaction)
+        }, completion: {
+            // Do nothing
+        })
     }
 
     public func handleJobFailed(_ job: Job, with error: Error) {
-        // Persist the job
-        // Retry it if the max failure count hasn't been reached
-        // Propagate the error otherwise
+        job.failureCount += 1
+        let storage = Configuration.shared.storage
+        storage.withAsync({ transaction in
+            storage.persist(job, using: transaction)
+        }, completion: { // Intentionally capture self
+            if job.failureCount == type(of: job).maxFailureCount {
+                storage.withAsync({ transaction in
+                    storage.markJobAsFailed(job, using: transaction)
+                }, completion: {
+                    // Do nothing
+                })
+            } else {
+                let retryInterval = self.getRetryInterval(for: job)
+                Timer.weakScheduledTimer(withTimeInterval: retryInterval, target: self, selector: #selector(retry(_:)), userInfo: job, repeats: false)
+            }
+        })
+    }
+
+    private func getRetryInterval(for job: Job) -> TimeInterval {
+        // Arbitrary backoff factor...
+        // try  1 delay:  0.00s
+        // try  2 delay:  0.19s
+        // ...
+        // try  5 delay:  1.30s
+        // ...
+        // try 11 delay: 61.31s
+        let backoffFactor = 1.9
+        let maxBackoff: Double = 60 * 60 * 1000
+        return 0.1 * min(maxBackoff, pow(backoffFactor, Double(job.failureCount)))
+    }
+
+    @objc private func retry(_ job: Any) {
+        guard let job = job as? Job else { return }
+        job.execute()
     }
 }

SessionMessagingKit/Jobs/MessageReceiveJob.swift

@@ -6,7 +6,7 @@ public final class MessageReceiveJob : NSObject, Job,  NSCoding { // NSObject/NS
     public var failureCount: UInt = 0
 
     // MARK: Settings
-    public static let maxFailureCount: UInt = 20
+    public static let maxFailureCount: UInt = 10
 
     // MARK: Initialization
     init(data: Data) {
@@ -45,7 +45,6 @@ public final class MessageReceiveJob : NSObject, Job,  NSCoding { // NSObject/NS
     }
 
     private func handleFailure(error: Error) {
-        self.failureCount += 1
         delegate?.handleJobFailed(self, with: error)
     }
 }

SessionMessagingKit/Jobs/MessageSendJob.swift

@@ -51,7 +51,6 @@ public final class MessageSendJob : NSObject, Job, NSCoding { // NSObject/NSCodi
     }
 
     private func handleFailure(error: Error) {
-        self.failureCount += 1
         delegate?.handleJobFailed(self, with: error)
     }
 }

SessionMessagingKit/Jobs/NotifyPNServerJob.swift

@@ -39,7 +39,6 @@ public final class NotifyPNServerJob : NSObject, Job, NSCoding { // NSObject/NSC
     }
 
     private func handleFailure(error: Error) {
-        self.failureCount += 1
         delegate?.handleJobFailed(self, with: error)
     }
 }

SessionMessagingKit/Storage.swift

@@ -3,10 +3,13 @@ import SessionProtocolKit
 public protocol SessionMessagingKitStorageProtocol {
 
     func with(_ work: (Any) -> Void)
+    func withAsync(_ work: (Any) -> Void, completion: () -> Void)
 
     func getUserPublicKey() -> String?
     func getOrGenerateRegistrationID(using transaction: Any) -> UInt32
     func isClosedGroup(_ publicKey: String) -> Bool
     func getClosedGroupPrivateKey(for publicKey: String) -> String?
     func persist(_ job: Job, using transaction: Any)
+    func markJobAsSucceeded(_ job: Job, using transaction: Any)
+    func markJobAsFailed(_ job: Job, using transaction: Any)
 }