Fix concurrent (un)registration

Using registerQueue and delQueue, lists of connectorTokens

app/src/main/java/org/unifiedpush/distributor/nextpush/api/ApiUtils.kt

@@ -22,6 +22,9 @@ import java.util.concurrent.TimeUnit
 
 private const val TAG = "ApiUtils"
 
+val createQueue = emptyList<String>().toMutableList()
+val delQueue = emptyList<String>().toMutableList()
+
 class ApiUtils {
     private lateinit var mApi: ProviderApi
     private lateinit var nextcloudAPI: NextcloudAPI
@@ -187,6 +190,11 @@ class ApiUtils {
                 override fun onNext(response: ApiResponse) {
                     if (response.success) {
                         Log.d(TAG, "App successfully created.")
+                        /**
+                         * Ignore printed error for SQLiteContstraintException.
+                         * It is printed and not thrown by SQLiteDatabase.java
+                         * So we can't catch it
+                         */
                         db.registerApp(appName, connectorToken, response.token)
                     } else {
                         Log.d(TAG, "An error occurred while creating the application.")
@@ -194,24 +202,27 @@ class ApiUtils {
                 }
 
                 override fun onError(e: Throwable) {
+                    createQueue.remove(connectorToken)
                     e.printStackTrace()
                 }
 
                 override fun onComplete() {
+                    createQueue.remove(connectorToken)
                     callback()
                 }
             })
     }
 
-    fun deleteApp(context: Context, appToken: String, callback: ()->Unit) {
+    fun deleteApp(context: Context, connectorToken: String, callback: ()->Unit) {
         cApi(context) {
-            cDeleteApp(appToken) {
+            cDeleteApp(context, connectorToken) {
                 callback()
             }
         }
     }
 
-    private fun cDeleteApp(appToken: String, callback: ()->Unit) {
+    private fun cDeleteApp(context: Context, connectorToken: String, callback: ()->Unit) {
+        val appToken = getDb(context).getAppToken(connectorToken)
         mApi.deleteApp(appToken)
             ?.subscribeOn(Schedulers.newThread())
             ?.observeOn(Schedulers.newThread())
@@ -229,10 +240,12 @@ class ApiUtils {
                 }
 
                 override fun onError(e: Throwable) {
+                    delQueue.remove(connectorToken)
                     e.printStackTrace()
                 }
 
                 override fun onComplete() {
+                    delQueue.remove(connectorToken)
                     callback()
                 }
             })

app/src/main/java/org/unifiedpush/distributor/nextpush/receivers/RegisterBroadcastReceiver.kt

@@ -6,6 +6,8 @@ import android.content.Intent
 import android.util.Log
 import org.unifiedpush.distributor.nextpush.distributor.*
 import org.unifiedpush.distributor.nextpush.api.ApiUtils
+import org.unifiedpush.distributor.nextpush.api.createQueue
+import org.unifiedpush.distributor.nextpush.api.delQueue
 
 /**
  * THIS SERVICE IS USED BY OTHER APPS TO REGISTER
@@ -25,9 +27,18 @@ class RegisterBroadcastReceiver : BroadcastReceiver() {
                     Log.w(TAG,"Trying to register an app without packageName")
                     return
                 }
-                ApiUtils().createApp(context!!.applicationContext, application, connectorToken) {
+                if (connectorToken !in createQueue) {
+                    createQueue.add(connectorToken)
+                    ApiUtils().createApp(
+                        context!!.applicationContext,
+                        application,
+                        connectorToken
+                    ) {
                         sendEndpoint(context.applicationContext, connectorToken)
                     }
+                } else {
+                    Log.d(TAG, "Already registering $connectorToken")
+                }
             }
             ACTION_UNREGISTER ->{
                 Log.i(TAG,"UNREGISTER")
@@ -36,12 +47,16 @@ class RegisterBroadcastReceiver : BroadcastReceiver() {
                 if (application.isBlank()) {
                     return
                 }
+                if (connectorToken !in delQueue) {
+                    delQueue.add(connectorToken)
                     sendUnregistered(context!!.applicationContext, connectorToken)
+                    ApiUtils().deleteApp(context.applicationContext, connectorToken) {
                         val db = getDb(context.applicationContext)
-                val appToken = db.getAppToken(connectorToken)
                         db.unregisterApp(connectorToken)
-                ApiUtils().deleteApp(context.applicationContext, appToken) {
+                        Log.d(TAG, "Unregistration is finished")
-                    Log.d(TAG,"Unregistration is finished")
+                    }
+                } else {
+                    Log.d(TAG, "Already deleting $connectorToken")
                 }
             }
         }