Add delay to starting of generation tasks

Add a delay to the starts of the tasks so that they don't all start on the same tick. To completely avoid two tasks being executed on the same tick, the "period" config option should be set to the expected number of tasks or higher.

src/main/kotlin/net/trivernis/chunkmaster/lib/generation/GenerationManager.kt

@@ -2,6 +2,7 @@ package net.trivernis.chunkmaster.lib.generation
 
 import io.papermc.lib.PaperLib
 import net.trivernis.chunkmaster.Chunkmaster
+import org.bukkit.Chunk
 import org.bukkit.Server
 import org.bukkit.World
 
@@ -83,13 +84,14 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
         center: ChunkCoordinates,
         last: ChunkCoordinates,
         id: Int,
-        stopAfter: Int = -1
+        stopAfter: Int = -1,
+        delay: Long = 200L
     ) {
         if (!paused) {
             chunkmaster.logger.info(chunkmaster.langManager.getLocalized("RESUME_FOR_WORLD", world.name))
             val generationTask = createGenerationTask(world, center, last, stopAfter)
             val task = server.scheduler.runTaskTimer(
-                chunkmaster, generationTask, 200,  // 10 sec delay
+                chunkmaster, generationTask, delay,  // 10 sec delay
                 chunkmaster.config.getLong("generation.period")
             )
             tasks.add(RunningTaskEntry(id, task, generationTask))
@@ -149,11 +151,14 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
      * Stops all generation tasks
      */
     fun stopAll() {
-        saveProgress()
         val removalSet = HashSet<RunningTaskEntry>()
         for (task in tasks) {
-            task.generationTask.cancel()
+            val lastChunk = task.generationTask.lastChunkCoords
+            val id = task.id
+            chunkmaster.logger.info(chunkmaster.langManager.getLocalized("SAVING_TASK_PROGRESS", task.id))
+            saveProgressToDatabase(lastChunk, id)
             task.task.cancel()
+            task.generationTask.cancel()
             if (task.task.isCancelled) {
                 removalSet.add(task)
             }
@@ -167,7 +172,9 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
      */
     fun startAll() {
         chunkmaster.sqliteManager.executeStatement("SELECT * FROM generation_tasks", HashMap()) { res ->
+            var count = 0
             while (res.next()) {
+                count++
                 try {
                     val id = res.getInt("id")
                     val world = server.getWorld(res.getString("world"))
@@ -175,7 +182,7 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
                     val last = ChunkCoordinates(res.getInt("last_x"), res.getInt("last_z"))
                     val stopAfter = res.getInt("stop_after")
                     if (this.tasks.find { it.id == id } == null) {
-                        resumeTask(world!!, center, last, id, stopAfter)
+                        resumeTask(world!!, center, last, id, stopAfter, 200L + count)
                     }
                 } catch (error: NullPointerException) {
                     chunkmaster.logger.severe(chunkmaster.langManager.getLocalized("TASK_LOAD_FAILED", res.getInt("id")))
@@ -238,20 +245,27 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
                     speed,
                     genTask.lastChunk.x,
                     genTask.lastChunk.z))
-                chunkmaster.sqliteManager.executeStatement(
+                saveProgressToDatabase(genTask.lastChunkCoords, task.id)
-                    """
-                    UPDATE generation_tasks SET last_x = ?, last_z = ?
-                    WHERE id = ?
-                    """.trimIndent(),
-                    HashMap(mapOf(1 to genTask.lastChunk.x, 2 to genTask.lastChunk.z, 3 to task.id)),
-                    null
-                )
             } catch (error: Exception) {
                 chunkmaster.logger.warning(chunkmaster.langManager.getLocalized("TASK_SAVE_FAILED", error.toString()))
             }
         }
     }
 
+    /**
+     * Saves the generation progress to the database
+     */
+    private fun saveProgressToDatabase(lastChunk: ChunkCoordinates, id: Int) {
+        chunkmaster.sqliteManager.executeStatement(
+            """
+                    UPDATE generation_tasks SET last_x = ?, last_z = ?
+                    WHERE id = ?
+                    """.trimIndent(),
+            HashMap(mapOf(1 to lastChunk.x, 2 to lastChunk.z, 3 to id)),
+            null
+        )
+    }
+
     /**
      * Creates a new generation task. This method is used to create a task depending
      * on the server type (Paper/Spigot).

src/main/kotlin/net/trivernis/chunkmaster/lib/generation/GenerationTask.kt

@@ -17,7 +17,8 @@ abstract class GenerationTask(plugin: Chunkmaster, centerChunk: ChunkCoordinates
     protected val spiral: Spiral =
         Spiral(Pair(centerChunk.x, centerChunk.z), Pair(startChunk.x, startChunk.z))
     protected val loadedChunks: HashSet<Chunk> = HashSet()
-    protected var lastChunkCoords = ChunkCoordinates(startChunk.x, startChunk.z)
+    var lastChunkCoords = ChunkCoordinates(startChunk.x, startChunk.z)
+        protected set
     protected val chunkSkips = plugin.config.getInt("generation.chunk-skips-per-step")
     protected val msptThreshold = plugin.config.getLong("generation.mspt-pause-threshold")
     protected val maxLoadedChunks = plugin.config.getInt("generation.max-loaded-chunks")

src/main/kotlin/net/trivernis/chunkmaster/lib/generation/GenerationTaskSpigot.kt

@@ -2,6 +2,7 @@ package net.trivernis.chunkmaster.lib.generation
 
 import net.trivernis.chunkmaster.Chunkmaster
 import org.bukkit.World
+import java.lang.Exception
 
 class GenerationTaskSpigot(
     private val plugin: Chunkmaster, override val world: World,
@@ -62,7 +63,11 @@ class GenerationTaskSpigot(
     override fun cancel() {
         for (chunk in loadedChunks) {
             if (chunk.isLoaded) {
-                chunk.unload(true)
+                try {
+                    chunk.unload(true)
+                } catch (e: Exception) {
+                    plugin.logger.severe(e.toString())
+                }
             }
         }
     }

src/main/resources/i18n/DEFAULT.i18n.properties

@@ -35,6 +35,7 @@ NO_PERMISSION = §cYou do not have the permission for this command!
 SUBCOMMAND_NOT_FOUND = §cSubcommand §2%s §cnot found!
 
 STOPPING_ALL_TASKS = Stopping all generation tasks...
+SAVING_TASK_PROGRESS = Saving the progress of task #%s to the database...
 DB_INIT = Initializing database...
 DB_INIT_FINISHED = Database fully initialized.
 DB_INIT_EROR = Failed to init database: %s.

src/main/resources/i18n/de.i18n.properties

@@ -35,6 +35,7 @@ NO_PERMISSION = §cDu hast nicht die Rechte für diesen Befehl!
 SUBCOMMAND_NOT_FOUND = §cUnteraktion §2%s §cwurde nicht gefunden!
 
 STOPPING_ALL_TASKS = Stoppt alle Aufgaben...
+SAVING_TASK_PROGRESS = Speichert den Fortschritt der Aufgabe #%s in der Datenbank...
 DB_INIT = Initialisiere Datenbank...
 DB_INIT_FINISHED = Die Datenbank wurde initialisiert.
 DB_INIT_EROR = Fehler beim Initalisieren der Datenbank: %s.

src/main/resources/i18n/en.i18n.properties

@@ -35,6 +35,7 @@ NO_PERMISSION = §cYou do not have the permission for this command!
 SUBCOMMAND_NOT_FOUND = §cSubcommand §2%s §cnot found!
 
 STOPPING_ALL_TASKS = Stopping all generation tasks...
+SAVING_TASK_PROGRESS = Saving the progress of task #%s to the database...
 DB_INIT = Initializing database...
 DB_INIT_FINISHED = Database fully initialized.
 DB_INIT_EROR = Failed to init database: %s.