Fixes and readme update

- fixed stop and resuming on player join/leave
- fixed stop command

README.md

@@ -1,5 +1,18 @@
 # chunkmaster
 
-Work in Progress. Wait for first release.
+This plugin can be used to pre-generate the region of a world around the spawn chunk. The plugin provides the commands
 
-Goal is a plugin that pregenerates chunks around the world spawn.
+- /generate - Pre-generates chunks in the current world
+- /listgentasks - Lists all running generation tasks (and their ids)
+- /removegentask - Removes a generation task (stops it permanently)
+
+The generation automatically pauses when a player joins the server (assuming the server was empty before)
+and resumes when the server is empty again. The generation also auto-resumes after a server
+restart. The plugin tracks the ticks per second and pauses the generation when the tps
+is lower than 2.
+
+## Future Features
+
+- pause generation tasks until restarted by command
+- configure the tps pause limit
+- specify how many chunks to generate for a task

src/main/kotlin/net/trivernis/chunkmaster/Chunkmaster.kt

@@ -2,9 +2,11 @@ package net.trivernis.chunkmaster
 
 import net.trivernis.chunkmaster.commands.CommandGenerate
 import net.trivernis.chunkmaster.commands.CommandListGenTasks
+import net.trivernis.chunkmaster.commands.CommandRemoveGenTask
 import net.trivernis.chunkmaster.lib.GenerationManager
 import net.trivernis.chunkmaster.lib.Spiral
 import org.bukkit.plugin.java.JavaPlugin
+import org.bukkit.scheduler.BukkitTask
 import java.lang.Exception
 import java.sql.Connection
 import java.sql.DriverManager
@@ -14,7 +16,13 @@ class Chunkmaster: JavaPlugin() {
     lateinit var sqliteConnection: Connection
     var dbname: String? = null
     lateinit var generationManager: GenerationManager
+    private lateinit var tpsTask: BukkitTask
+    var mspt = 50L      // keep track of the milliseconds per tick
+        get() = field
 
+    /**
+     * On enable of the plugin
+     */
     override fun onEnable() {
         configure()
         initDatabase()
@@ -22,15 +30,28 @@ class Chunkmaster: JavaPlugin() {
         generationManager.init()
         getCommand("generate")?.setExecutor(CommandGenerate(this))
         getCommand("listgentasks")?.setExecutor(CommandListGenTasks(this))
+        getCommand("removegentask")?.setExecutor(CommandRemoveGenTask(this))
         server.pluginManager.registerEvents(ChunkmasterEvents(this, server), this)
+        tpsTask = server.scheduler.runTaskTimer(this, Runnable {
+            val start = System.currentTimeMillis()
+            server.scheduler.runTaskLater(this, Runnable {
+                mspt = System.currentTimeMillis() - start
+            }, 1)
+        }, 1, 300)
     }
 
+    /**
+     * Stop all tasks and close database connection on disable
+     */
     override fun onDisable() {
         logger.info("Stopping all generation tasks...")
         generationManager.stopAll()
         sqliteConnection.close()
     }
 
+    /**
+     * Cofigure the config file
+     */
     private fun configure() {
         dataFolder.mkdir()
         config.options().copyDefaults(true)
@@ -52,7 +73,8 @@ class Chunkmaster: JavaPlugin() {
                     center_z integer NOT NULL DEFAULT 0,
                     last_x integer NOT NULL DEFAULT 0,
                     last_z integer NOT NULL DEFAULT 0,
-                    world text UNIQUE NOT NULL DEFAULT 'world'
+                    world text UNIQUE NOT NULL DEFAULT 'world',
+                    autostart integer DEFAULT 1
                 );
             """.trimIndent())
             createTableStatement.execute()

src/main/kotlin/net/trivernis/chunkmaster/ChunkmasterEvents.kt

@@ -1,6 +1,7 @@
 package net.trivernis.chunkmaster
 
 import org.bukkit.Server
+import org.bukkit.event.EventHandler
 import org.bukkit.event.Listener
 import org.bukkit.event.player.PlayerJoinEvent
 import org.bukkit.event.player.PlayerQuitEvent
@@ -10,7 +11,7 @@ class ChunkmasterEvents(private val chunkmaster: Chunkmaster, private val server
     /**
      * Autostart generation tasks
      */
-    fun onPlayerQuit(event: PlayerQuitEvent) {
+    @EventHandler fun onPlayerQuit(event: PlayerQuitEvent) {
         if (server.onlinePlayers.size == 1 && server.onlinePlayers.contains(event.player) ||
                 server.onlinePlayers.isEmpty()) {
             chunkmaster.generationManager.startAll()
@@ -21,7 +22,7 @@ class ChunkmasterEvents(private val chunkmaster: Chunkmaster, private val server
     /**
      * Autostop generation tasks
      */
-    fun onPlayerJoin(event: PlayerJoinEvent) {
+    @EventHandler fun onPlayerJoin(event: PlayerJoinEvent) {
         if (server.onlinePlayers.size == 1 || server.onlinePlayers.isEmpty()) {
             chunkmaster.generationManager.stopAll()
             chunkmaster.logger.info("Stopping generation tasks because of player join.")

src/main/kotlin/net/trivernis/chunkmaster/commands/CommandListGenTasks.kt

@@ -15,7 +15,7 @@ class CommandListGenTasks(private val chunkmaster: Chunkmaster): CommandExecutor
         val runningTasks = chunkmaster.generationManager.tasks
         val response = ComponentBuilder("Currently running generation tasks").color(ChatColor.BLUE)
         for (task in runningTasks) {
-            response.append("\n - #${task.id}: ${task.generationTask.world}, Progress ${task.generationTask.count}")
+            response.append("\n - #${task.id}: ${task.generationTask.world.name}, Progress ${task.generationTask.count}")
         }
         response.color(ChatColor.GREEN)
         sender.spigot().sendMessage(*response.create())

src/main/kotlin/net/trivernis/chunkmaster/commands/CommandRemoveGenTask.kt

@@ -0,0 +1,19 @@
+package net.trivernis.chunkmaster.commands
+
+import net.trivernis.chunkmaster.Chunkmaster
+import org.bukkit.command.Command
+import org.bukkit.command.CommandExecutor
+import org.bukkit.command.CommandSender
+
+class CommandRemoveGenTask(private val chunkmaster: Chunkmaster): CommandExecutor {
+    override fun onCommand(sender: CommandSender, command: Command, label: String, args: Array<out String>): Boolean {
+        return if (command.testPermission(sender) && args.size == 1) {
+            chunkmaster.generationManager.removeTask(args[1].toInt())
+            sender.sendMessage("Task ${args[1].toInt()} canceled.")
+            true
+        } else {
+            sender.sendMessage("Invalid argument.")
+            false
+        }
+    }
+}

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

@@ -47,13 +47,33 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
     /**
      * Resumes a generation task
      */
-    fun resumeTask(world: World, center: Chunk, last: Chunk, id: Int) {
+    private fun resumeTask(world: World, center: Chunk, last: Chunk, id: Int) {
         chunkmaster.logger.info("Resuming chunk generation task for world \"${world.name}\"")
         val generationTask = GenerationTask(chunkmaster, world, center, last)
         val task = server.scheduler.runTaskTimer(chunkmaster, generationTask, 10, 2)
         tasks.add(TaskEntry(id, task, generationTask))
     }
 
+    /**
+     * Stops a running generation task.
+     */
+    fun removeTask(id: Int) {
+        val taskEntry = this.tasks.find {it.id == id}
+        if (taskEntry != null) {
+            taskEntry.generationTask.cancel()
+            taskEntry.task.cancel()
+            if (taskEntry.task.isCancelled) {
+                tasks.remove(taskEntry)
+            }
+            val setAutostart = chunkmaster.sqliteConnection.prepareStatement("""
+                UPDATE TABLE generation_tasks SET autostart = 0 WHERE id = ?
+            """.trimIndent())
+            setAutostart.setInt(1, id)
+            setAutostart.execute()
+            setAutostart.close()
+        }
+    }
+
     /**
      * Init
      * Loads tasks from the database and resumes them
@@ -75,6 +95,10 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
         for (task in tasks) {
             task.generationTask.cancel()
             task.task.cancel()
+            if (task.task.isCancelled) {
+                tasks.remove(task)
+            }
+            chunkmaster.logger.info("Canceled task #${task.id}")
         }
     }
 
@@ -88,11 +112,15 @@ class GenerationManager(private val chunkmaster: Chunkmaster, private val server
         val res = savedTasksStatement.resultSet
         while (res.next()) {
             try {
+                if (res.getBoolean("autostart")) {
                     val id = res.getInt("id")
                     val world = server.getWorld(res.getString("world"))
                     val center = world!!.getChunkAt(res.getInt("center_x"), res.getInt("center_z"))
                     val last = world.getChunkAt(res.getInt("last_x"), res.getInt("last_z"))
+                    if (this.tasks.find {it.id == id} == null) {
                         resumeTask(world, center, last, id)
+                    }
+                }
             } catch (error: NullPointerException) {
                 server.consoleSender.sendMessage("Failed to load Task ${res.getInt("id")}.")
             }

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

@@ -15,7 +15,12 @@ class GenerationTask(private val plugin: Chunkmaster, val world: World,
     var lastChunk: Chunk = startChunk
         get() = field
 
+    /**
+     * Runs the generation task. Every Iteration the next chunk will be generated if
+     * it hasn't been generated already.
+     */
     override fun run() {
+        if (plugin.mspt < 500L) {    // pause when tps < 2
             if (loadedChunks.size > 10) {
                 for (chunk in loadedChunks) {
                     if (chunk.isLoaded) {
@@ -34,7 +39,12 @@ class GenerationTask(private val plugin: Chunkmaster, val world: World,
                 count++
             }
         }
+    }
 
+    /**
+     * Cancels the generation task.
+     * This unloads all chunks that were generated but not unloaded yet.
+     */
     fun cancel() {
         for (chunk in loadedChunks) {
             if (chunk.isLoaded) {

src/main/kotlin/net/trivernis/chunkmaster/lib/Spiral.kt

@@ -2,7 +2,7 @@ package net.trivernis.chunkmaster.lib
 
 import kotlin.math.abs
 
-class Spiral(private val center: Pair<Int, Int>, private val start: Pair<Int, Int>) {
+class Spiral(private val center: Pair<Int, Int>, start: Pair<Int, Int>) {
     var currentPos = start
     var direction = 0
     var count = 0
@@ -12,15 +12,12 @@ class Spiral(private val center: Pair<Int, Int>, private val start: Pair<Int, In
      */
     fun next(): Pair<Int, Int> {
         if (count == 0 && currentPos != center) {
-            val distances = getDistances(center, currentPos)
-
-            if (distances.second < distances.first && distances.first > 0) {
-                direction = 1
-            } else if (distances.first > distances.second && distances.second < 0) {
-                direction = 2
-            } else if (distances.second > distances.first && distances.first < 0) {
-                direction = 3
-            }
+            // simulate the spiral to get the correct direction
+            // TODO: Improve performance of this workaround (replace it with acutal stuff)
+            val simSpiral = Spiral(center, center)
+            while (simSpiral.next() != currentPos);
+            direction = simSpiral.direction
+            count = simSpiral.count
         }
         if (count == 1) {   // because of the center behaviour
             count ++

src/main/resources/plugin.yml

@@ -14,12 +14,19 @@ commands:
     description: Lists all generation tasks
     permission: chunkmaster.listgentasks
     usage: /listgentasks
+  removegentask:
+    description: Removes the generation task with the specified id
+    permission: chunkmaster.removegentask
+    usage: /removegentask {task-id}
 permissions:
   cunkmaster.generate:
-    description: Allows generate command
+    description: Allows generate command.
     default: op
   chunkmaster.listgentasks:
-    description: Lists all generation tasks
+    description: Allows the listgentask command.
+    default: op
+  chunkmaster.removegentask:
+    description: Allows the removegentask command.
     default: op
   chunkmaster.*:
     description: Wildcard permission
@@ -27,3 +34,4 @@ permissions:
     children:
       - chunkmaster.generate
       - chunkmaster.listgentasks
+      - chunkmaster.removegentask