feat(api): configure number of task processing threads

komga/src/main/kotlin/org/gotson/komga/application/tasks/TaskEvents.kt

@@ -1,3 +1,4 @@
 package org.gotson.komga.application.tasks
 
 class TaskAddedEvent
+class TaskPoolSizeChangedEvent

komga/src/main/kotlin/org/gotson/komga/application/tasks/TaskProcessor.kt

@@ -1,6 +1,7 @@
 package org.gotson.komga.application.tasks
 
 import mu.KotlinLogging
+import org.gotson.komga.infrastructure.configuration.KomgaSettingsProvider
 import org.springframework.beans.factory.InitializingBean
 import org.springframework.boot.context.event.ApplicationReadyEvent
 import org.springframework.boot.task.TaskExecutorBuilder
@@ -14,12 +15,13 @@ private val logger = KotlinLogging.logger {}
 class TaskProcessor(
   private val tasksRepository: TasksRepository,
   private val taskHandler: TaskHandler,
+  private val settingsProvider: KomgaSettingsProvider,
   taskExecutorBuilder: TaskExecutorBuilder,
 ) : InitializingBean {
   val executor: ThreadPoolTaskExecutor =
     taskExecutorBuilder
       .threadNamePrefix("taskProcessor-")
-      .corePoolSize(8)
+      .corePoolSize(settingsProvider.taskPoolSize)
       .build()
       .apply { initialize() }
 
@@ -32,11 +34,18 @@ class TaskProcessor(
     processTasks = true
   }
 
+  @EventListener(TaskPoolSizeChangedEvent::class)
+  fun taskPoolSizeChanged() {
+    executor.corePoolSize = settingsProvider.taskPoolSize
+  }
+
   @EventListener(TaskAddedEvent::class, ApplicationReadyEvent::class)
   fun processAvailableTask() {
     if (processTasks) {
+      logger.debug { "Active count: ${executor.activeCount}, Core Pool Size: ${executor.corePoolSize}, Pool Size: ${executor.poolSize}" }
+      if (executor.corePoolSize == 1) executor.execute { takeAndProcess() }
       // fan out while threads are available
-      while (tasksRepository.hasAvailable() && executor.activeCount < executor.corePoolSize)
+      else while (tasksRepository.hasAvailable() && executor.activeCount < executor.corePoolSize)
         executor.execute { takeAndProcess() }
     } else {
       logger.debug { "Not processing tasks" }

komga/src/main/kotlin/org/gotson/komga/infrastructure/configuration/KomgaSettingsProvider.kt

@@ -1,8 +1,10 @@
 package org.gotson.komga.infrastructure.configuration
 
 import org.apache.commons.lang3.RandomStringUtils
+import org.gotson.komga.application.tasks.TaskPoolSizeChangedEvent
 import org.gotson.komga.domain.model.ThumbnailSize
 import org.gotson.komga.infrastructure.jooq.main.ServerSettingsDao
+import org.springframework.context.ApplicationEventPublisher
 import org.springframework.stereotype.Service
 import kotlin.time.Duration
 import kotlin.time.Duration.Companion.days
@@ -10,6 +12,7 @@ import kotlin.time.Duration.Companion.days
 @Service
 class KomgaSettingsProvider(
   private val serverSettingsDao: ServerSettingsDao,
+  private val eventPublisher: ApplicationEventPublisher,
 ) {
   var deleteEmptyCollections: Boolean =
     serverSettingsDao.getSettingByKey(Settings.DELETE_EMPTY_COLLECTIONS.name, Boolean::class.java) ?: false
@@ -54,6 +57,14 @@ class KomgaSettingsProvider(
       serverSettingsDao.saveSetting(Settings.THUMBNAIL_SIZE.name, value.name)
       field = value
     }
+
+  var taskPoolSize: Int =
+    serverSettingsDao.getSettingByKey(Settings.TASK_POOL_SIZE.name, Int::class.java) ?: 8
+    set(value) {
+      serverSettingsDao.saveSetting(Settings.TASK_POOL_SIZE.name, value)
+      field = value
+      eventPublisher.publishEvent(TaskPoolSizeChangedEvent())
+    }
 }
 
 private enum class Settings {
@@ -62,4 +73,5 @@ private enum class Settings {
   REMEMBER_ME_KEY,
   REMEMBER_ME_DURATION,
   THUMBNAIL_SIZE,
+  TASK_POOL_SIZE,
 }

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/SettingsController.kt

@@ -32,6 +32,7 @@ class SettingsController(
       komgaSettingsProvider.deleteEmptyReadLists,
       komgaSettingsProvider.rememberMeDuration.inWholeDays,
       komgaSettingsProvider.thumbnailSize.toDto(),
+      komgaSettingsProvider.taskPoolSize,
     )
 
   @PatchMapping
@@ -45,5 +46,6 @@ class SettingsController(
     newSettings.rememberMeDurationDays?.let { komgaSettingsProvider.rememberMeDuration = it.days }
     if (newSettings.renewRememberMeKey == true) komgaSettingsProvider.renewRememberMeKey()
     newSettings.thumbnailSize?.let { komgaSettingsProvider.thumbnailSize = it.toDomain() }
+    newSettings.taskPoolSize?.let { komgaSettingsProvider.taskPoolSize = it }
   }
 }

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/dto/SettingsDto.kt

@@ -5,4 +5,5 @@ data class SettingsDto(
   val deleteEmptyReadLists: Boolean,
   val rememberMeDurationDays: Long,
   val thumbnailSize: ThumbnailSizeDto,
+  val taskPoolSize: Int,
 )

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/dto/SettingsUpdateDto.kt

@@ -9,4 +9,6 @@ data class SettingsUpdateDto(
   val rememberMeDurationDays: Long? = null,
   val renewRememberMeKey: Boolean? = null,
   val thumbnailSize: ThumbnailSizeDto? = null,
+  @get:Positive
+  val taskPoolSize: Int? = null,
 )

komga/src/test/kotlin/org/gotson/komga/interfaces/api/rest/SettingsControllerTest.kt

@@ -53,6 +53,7 @@ class SettingsControllerTest(
     komgaSettingsProvider.deleteEmptyReadLists = false
     komgaSettingsProvider.rememberMeDuration = 5.days
     komgaSettingsProvider.thumbnailSize = ThumbnailSize.LARGE
+    komgaSettingsProvider.taskPoolSize = 4
 
     mockMvc.get("/api/v1/settings")
       .andExpect {
@@ -61,6 +62,7 @@ class SettingsControllerTest(
         jsonPath("deleteEmptyReadLists") { value(false) }
         jsonPath("rememberMeDurationDays") { value(5) }
         jsonPath("thumbnailSize") { value("LARGE") }
+        jsonPath("taskPoolSize") { value(4) }
       }
   }
 
@@ -71,6 +73,7 @@ class SettingsControllerTest(
     komgaSettingsProvider.deleteEmptyReadLists = true
     komgaSettingsProvider.rememberMeDuration = 5.days
     komgaSettingsProvider.thumbnailSize = ThumbnailSize.LARGE
+    komgaSettingsProvider.taskPoolSize = 4
 
     val rememberMeKey = komgaSettingsProvider.rememberMeKey
 
@@ -80,7 +83,8 @@ class SettingsControllerTest(
         "deleteEmptyCollections": false,
         "rememberMeDurationDays": 15,
         "renewRememberMeKey": true,
-        "thumbnailSize": "MEDIUM"
+        "thumbnailSize": "MEDIUM",
+        "taskPoolSize": 8
       }
     """.trimIndent()
 
@@ -97,6 +101,7 @@ class SettingsControllerTest(
     assertThat(komgaSettingsProvider.rememberMeDuration).isEqualTo(15.days)
     assertThat(komgaSettingsProvider.rememberMeKey).isNotEqualTo(rememberMeKey)
     assertThat(komgaSettingsProvider.thumbnailSize).isEqualTo(ThumbnailSize.MEDIUM)
+    assertThat(komgaSettingsProvider.taskPoolSize).isEqualTo(8)
   }
 
   @ParameterizedTest
@@ -107,6 +112,8 @@ class SettingsControllerTest(
       """{"rememberMeDurationDays": 0}""",
       //language=JSON
       """{"thumbnailSize": "HUGE"}""",
+      """{"taskPoolSize": 0}""",
+      """{"taskPoolSize": -15}""",
     ],
   )
   fun `given admin user when updating with invalid settings then returns bad request`(jsonString: String) {