Option to slowdown downloads and configure parallelism

app/src/main/java/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -141,6 +141,12 @@ class AppSettings(context: Context) {
 			}
 		}
 
+	val isDownloadsSlowdownEnabled: Boolean
+		get() = prefs.getBoolean(KEY_DOWNLOADS_SLOWDOWN, false)
+
+	val downloadsParallelism: Int
+		get() = prefs.getInt(KEY_DOWNLOADS_PARALLELISM, 2)
+
 	val isSuggestionsEnabled: Boolean
 		get() = prefs.getBoolean(KEY_SUGGESTIONS, false)
 
@@ -261,6 +267,8 @@ class AppSettings(context: Context) {
 		const val KEY_SUGGESTIONS_EXCLUDE_NSFW = "suggestions_exclude_nsfw"
 		const val KEY_SUGGESTIONS_EXCLUDE_TAGS = "suggestions_exclude_tags"
 		const val KEY_SEARCH_SINGLE_SOURCE = "search_single_source"
+		const val KEY_DOWNLOADS_PARALLELISM = "downloads_parallelism"
+		const val KEY_DOWNLOADS_SLOWDOWN = "downloads_slowdown"
 
 		// About
 		const val KEY_APP_UPDATE = "app_update"

app/src/main/java/org/koitharu/kotatsu/download/domain/DownloadManager.kt

@@ -17,6 +17,7 @@ import org.koitharu.kotatsu.BuildConfig
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.core.network.CommonHeaders
 import org.koitharu.kotatsu.core.parser.MangaRepository
+import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.local.data.PagesCache
 import org.koitharu.kotatsu.local.domain.CbzMangaOutput
 import org.koitharu.kotatsu.local.domain.LocalMangaRepository
@@ -30,8 +31,8 @@ import org.koitharu.kotatsu.utils.progress.ProgressJob
 import java.io.File
 
 private const val MAX_DOWNLOAD_ATTEMPTS = 3
-private const val MAX_PARALLEL_DOWNLOADS = 2
 private const val DOWNLOAD_ERROR_DELAY = 500L
+private const val SLOWDOWN_DELAY = 200L
 
 class DownloadManager(
 	private val coroutineScope: CoroutineScope,
@@ -40,9 +41,10 @@ class DownloadManager(
 	private val okHttp: OkHttpClient,
 	private val cache: PagesCache,
 	private val localMangaRepository: LocalMangaRepository,
+	private val settings: AppSettings,
 ) {
 
-	private val connectivityManager = context.applicationContext.getSystemService(
+	private val connectivityManager = context.getSystemService(
 		Context.CONNECTIVITY_SERVICE
 	) as ConnectivityManager
 	private val coverWidth = context.resources.getDimensionPixelSize(
@@ -51,7 +53,7 @@ class DownloadManager(
 	private val coverHeight = context.resources.getDimensionPixelSize(
 		androidx.core.R.dimen.compat_notification_large_icon_max_height
 	)
-	private val semaphore = Semaphore(MAX_PARALLEL_DOWNLOADS)
+	private val semaphore = Semaphore(settings.downloadsParallelism)
 
 	fun downloadManga(
 		manga: Manga,
@@ -141,6 +143,10 @@ class DownloadManager(
 						totalPages = pages.size,
 						currentPage = pageIndex,
 					)
+
+					if (settings.isDownloadsSlowdownEnabled) {
+						delay(SLOWDOWN_DELAY)
+					}
 				}
 			}
 			outState.value = DownloadState.PostProcessing(startId, data, cover)
@@ -206,4 +212,24 @@ class DownloadManager(
 				error = throwable,
 			)
 		}
+
+	class Factory(
+		private val context: Context,
+		private val imageLoader: ImageLoader,
+		private val okHttp: OkHttpClient,
+		private val cache: PagesCache,
+		private val localMangaRepository: LocalMangaRepository,
+		private val settings: AppSettings,
+	) {
+
+		fun create(coroutineScope: CoroutineScope) = DownloadManager(
+			coroutineScope = coroutineScope,
+			context = context,
+			imageLoader = imageLoader,
+			okHttp = okHttp,
+			cache = cache,
+			localMangaRepository = localMangaRepository,
+			settings = settings,
+		)
+	}
 }

app/src/main/java/org/koitharu/kotatsu/download/ui/service/DownloadService.kt

@@ -49,13 +49,8 @@ class DownloadService : BaseService() {
 		notificationSwitcher = ForegroundNotificationSwitcher(this)
 		val wakeLock = (getSystemService(Context.POWER_SERVICE) as PowerManager)
 			.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "kotatsu:downloading")
-		downloadManager = DownloadManager(
+		downloadManager = get<DownloadManager.Factory>().create(
 			coroutineScope = lifecycleScope + WakeLockNode(wakeLock, TimeUnit.HOURS.toMillis(1)),
-			context = this,
-			imageLoader = get(),
-			okHttp = get(),
-			cache = get(),
-			localMangaRepository = get(),
 		)
 		DownloadNotification.createChannel(this)
 		registerReceiver(controlReceiver, IntentFilter(ACTION_DOWNLOAD_CANCEL))

app/src/main/java/org/koitharu/kotatsu/local/LocalModule.kt

@@ -3,6 +3,7 @@ package org.koitharu.kotatsu.local
 import org.koin.android.ext.koin.androidContext
 import org.koin.androidx.viewmodel.dsl.viewModel
 import org.koin.dsl.module
+import org.koitharu.kotatsu.download.domain.DownloadManager
 import org.koitharu.kotatsu.local.data.LocalStorageManager
 import org.koitharu.kotatsu.local.domain.LocalMangaRepository
 import org.koitharu.kotatsu.local.ui.LocalListViewModel
@@ -16,5 +17,7 @@ val localModule
 
 		factory { ExternalStorageHelper(androidContext()) }
 
+		factory { DownloadManager.Factory(androidContext(), get(), get(), get(), get(), get()) }
+
 		viewModel { LocalListViewModel(get(), get(), get(), get()) }
 	}

app/src/main/java/org/koitharu/kotatsu/settings/ContentSettingsFragment.kt

@@ -4,7 +4,6 @@ import android.content.SharedPreferences
 import android.os.Bundle
 import android.view.View
 import androidx.preference.Preference
-import java.io.File
 import kotlinx.coroutines.launch
 import org.koin.android.ext.android.inject
 import org.koitharu.kotatsu.R
@@ -13,8 +12,10 @@ import org.koitharu.kotatsu.base.ui.dialog.StorageSelectDialog
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.local.data.LocalStorageManager
 import org.koitharu.kotatsu.parsers.model.MangaSource
+import org.koitharu.kotatsu.settings.utils.SliderPreference
 import org.koitharu.kotatsu.utils.ext.getStorageName
 import org.koitharu.kotatsu.utils.ext.viewLifecycleScope
+import java.io.File
 
 class ContentSettingsFragment :
 	BasePreferenceFragment(R.string.content),
@@ -29,6 +30,13 @@ class ContentSettingsFragment :
 		findPreference<Preference>(AppSettings.KEY_SUGGESTIONS)?.setSummary(
 			if (settings.isSuggestionsEnabled) R.string.enabled else R.string.disabled
 		)
+		findPreference<SliderPreference>(AppSettings.KEY_DOWNLOADS_PARALLELISM)?.run {
+			summary = value.toString()
+			setOnPreferenceChangeListener { preference, newValue ->
+				preference.summary = newValue.toString()
+				true
+			}
+		}
 		bindRemoteSourcesSummary()
 	}
 

app/src/main/java/org/koitharu/kotatsu/utils/ext/AndroidExt.kt

@@ -17,6 +17,7 @@ suspend fun ConnectivityManager.waitForNetwork(): Network {
 	return suspendCancellableCoroutine { cont ->
 		val callback = object : ConnectivityManager.NetworkCallback() {
 			override fun onAvailable(network: Network) {
+				unregisterNetworkCallback(this)
 				if (cont.isActive) {
 					cont.resume(network)
 				}