User service is now non blocking

api/src/extensions/Coroutines.kt

@@ -6,3 +6,8 @@ import kotlinx.coroutines.*
 fun <T> ioAsync(block: suspend CoroutineScope.() -> T): Deferred<T> {
     return CoroutineScope(Dispatchers.IO).async(block = block)
 }
+
+suspend inline fun <T> launchIo(crossinline block: () -> T): T =
+    withContext(Dispatchers.IO) {
+        block()
+    }

api/src/services/UserService.kt

@@ -1,7 +1,10 @@
 package be.vandewalleh.services
 
 import be.vandewalleh.entities.User
+import be.vandewalleh.extensions.ioAsync
+import be.vandewalleh.extensions.launchIo
 import be.vandewalleh.tables.Users
+import kotlinx.coroutines.Deferred
 import me.liuwj.ktorm.database.*
 import me.liuwj.ktorm.dsl.*
 import me.liuwj.ktorm.entity.*
@@ -20,8 +23,8 @@ class UserService(override val kodein: Kodein) : KodeinAware {
     /**
      * returns a user ID if present or null
      */
-    fun getUserId(userEmail: String): Int? {
-        return db.from(Users)
+    suspend fun getUserId(userEmail: String): Int? = launchIo {
+        db.from(Users)
             .select(Users.id)
             .where { Users.email eq userEmail }
             .map { it[Users.id] }
@@ -31,8 +34,8 @@ class UserService(override val kodein: Kodein) : KodeinAware {
     /**
      * returns a user email and password from it's username if found or null
      */
-    fun getFromUsername(username: String): User? {
-        return db.from(Users)
+    suspend fun getFromUsername(username: String): User? = launchIo {
+        db.from(Users)
             .select(Users.email, Users.password, Users.id)
             .where { Users.username eq username }
             .map { row ->
@@ -41,22 +44,22 @@ class UserService(override val kodein: Kodein) : KodeinAware {
             .firstOrNull()
     }
 
-    fun userExists(username: String, email: String): Boolean {
-        return db.from(Users)
+    suspend fun userExists(username: String, email: String): Boolean = launchIo {
+        db.from(Users)
             .select(Users.id)
             .where { (Users.username eq username) or (Users.email eq email) }
             .firstOrNull() != null
     }
 
-    fun userExists(userId: Int): Boolean {
-        return db.from(Users)
+    suspend fun userExists(userId: Int): Boolean = launchIo {
+        db.from(Users)
             .select(Users.id)
             .where { Users.id eq userId }
             .firstOrNull() != null
     }
 
-    fun getUserInfo(id: Int): User? {
-        return db.from(Users)
+    suspend fun getUserInfo(id: Int): User? = launchIo {
+        db.from(Users)
             .select(Users.email, Users.username)
             .where { Users.id eq id }
             .map { Users.createEntity(it) }
@@ -67,25 +70,27 @@ class UserService(override val kodein: Kodein) : KodeinAware {
      * create a new user
      * password should already be hashed
      */
-    fun createUser(username: String, email: String, hashedPassword: String): User? {
-        try {
-            db.useTransaction {
-                val newUser = User {
-                    this.username = username
-                    this.email = email
-                    this.password = hashedPassword
-                    this.createdAt = LocalDateTime.now()
-                }
+    suspend fun createUser(username: String, email: String, hashedPassword: String): User? {
+        val newUser = User {
+            this.username = username
+            this.email = email
+            password = hashedPassword
+            createdAt = LocalDateTime.now()
+        }
 
-                db.sequenceOf(Users).add(newUser)
-                return newUser
+        return try {
+            launchIo {
+                db.useTransaction {
+                    db.sequenceOf(Users).add(newUser)
+                    newUser
+                }
             }
         } catch (e: SQLIntegrityConstraintViolationException) {
-            return null
+            null
         }
     }
 
-    fun updateUser(userId: Int, username: String, email: String, hashedPassword: String) {
+    suspend fun updateUser(userId: Int, username: String, email: String, hashedPassword: String): Unit = launchIo {
         db.useTransaction {
             db.update(Users) {
                 it.username to username
@@ -98,14 +103,17 @@ class UserService(override val kodein: Kodein) : KodeinAware {
         }
     }
 
-    fun deleteUser(userId: Int): Boolean {
+    suspend fun deleteUser(userId: Int): Boolean = launchIo {
         db.useTransaction {
-            return when (db.delete(Users) { it.id eq userId }) {
-                1 -> true
-                0 -> false
-                else -> error("??")
-            }
+            db.delete(Users) { it.id eq userId }
+        }
+    }.let {
+        when (it) {
+            1 -> true
+            0 -> false
+            else -> error("??")
         }
     }
+
 }