Minor updates to downloader from upstream

Such as available space check and using io thread instead of ui

Co-Authored-By: arkon <4098258+arkon@users.noreply.github.com>

app/src/main/java/eu/kanade/tachiyomi/data/download/Downloader.kt

@@ -5,6 +5,7 @@ import android.webkit.MimeTypeMap
 import com.hippo.unifile.UniFile
 import com.jakewharton.rxrelay.BehaviorRelay
 import com.jakewharton.rxrelay.PublishRelay
+import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.cache.ChapterCache
 import eu.kanade.tachiyomi.data.database.models.Chapter
 import eu.kanade.tachiyomi.data.database.models.Manga
@@ -20,8 +21,8 @@ import eu.kanade.tachiyomi.util.lang.plusAssign
 import eu.kanade.tachiyomi.util.storage.DiskUtil
 import eu.kanade.tachiyomi.util.storage.saveTo
 import eu.kanade.tachiyomi.util.system.ImageUtil
+import eu.kanade.tachiyomi.util.system.launchIO
 import eu.kanade.tachiyomi.util.system.launchNow
-import eu.kanade.tachiyomi.util.system.launchUI
 import kotlinx.coroutines.async
 import okhttp3.Response
 import rx.Observable
@@ -29,6 +30,7 @@ import rx.android.schedulers.AndroidSchedulers
 import rx.schedulers.Schedulers
 import rx.subscriptions.CompositeSubscription
 import timber.log.Timber
+import uy.kohesive.injekt.injectLazy
 import java.io.File
 
 /**
@@ -52,6 +54,8 @@ class Downloader(
     private val sourceManager: SourceManager
 ) {
 
+    private val chapterCache: ChapterCache by injectLazy()
+
     /**
      * Store for persisting downloads across restarts.
      */
@@ -119,7 +123,9 @@ class Downloader(
      */
     fun stop(reason: String? = null) {
         destroySubscriptions()
-        queue.filter { it.status == Download.DOWNLOADING }.forEach { it.status = Download.ERROR }
+        queue
+            .filter { it.status == Download.DOWNLOADING }
+            .forEach { it.status = Download.ERROR }
 
         if (reason != null) {
             notifier.onWarning(reason)
@@ -142,7 +148,9 @@ class Downloader(
      */
     fun pause() {
         destroySubscriptions()
-        queue.filter { it.status == Download.DOWNLOADING }.forEach { it.status = Download.QUEUE }
+        queue
+            .filter { it.status == Download.DOWNLOADING }
+            .forEach { it.status = Download.QUEUE }
         notifier.paused = true
     }
 
@@ -161,7 +169,8 @@ class Downloader(
 
         // Needed to update the chapter view
         if (isNotification) {
-            queue.filter { it.status == Download.QUEUE }
+            queue
+                .filter { it.status == Download.QUEUE }
                 .forEach { it.status = Download.NOT_DOWNLOADED }
         }
         queue.clear()
@@ -207,7 +216,7 @@ class Downloader(
                 },
                 5
             )
-            .onBackpressureBuffer()
+            .onBackpressureLatest()
             .observeOn(AndroidSchedulers.mainThread())
             .subscribe(
                 {
@@ -239,8 +248,8 @@ class Downloader(
      * @param chapters the list of chapters to download.
      * @param autoStart whether to start the downloader after enqueing the chapters.
      */
-    fun queueChapters(manga: Manga, chapters: List<Chapter>, autoStart: Boolean) = launchUI {
-        val source = sourceManager.get(manga.source) as? HttpSource ?: return@launchUI
+    fun queueChapters(manga: Manga, chapters: List<Chapter>, autoStart: Boolean) = launchIO {
+        val source = sourceManager.get(manga.source) as? HttpSource ?: return@launchIO
         val wasEmpty = queue.isEmpty()
         // Called in background thread, the operation can be slow with SAF.
         val chaptersWithoutDir = async {
@@ -281,15 +290,23 @@ class Downloader(
      * @param download the chapter to be downloaded.
      */
     private fun downloadChapter(download: Download): Observable<Download> = Observable.defer {
-        val chapterDirname = provider.getChapterDirName(download.chapter)
         val mangaDir = provider.getMangaDir(download.manga, download.source)
+
+        val availSpace = DiskUtil.getAvailableStorageSpace(mangaDir)
+        if (availSpace != -1L && availSpace < MIN_DISK_SPACE) {
+            download.status = Download.ERROR
+            notifier.onError(context.getString(R.string.couldnt_download_low_space), download.chapter.name)
+            return@defer Observable.just(download)
+        }
+
+        val chapterDirname = provider.getChapterDirName(download.chapter)
         val tmpDir = mangaDir.createDirectory(chapterDirname + TMP_DIR_SUFFIX)
 
         val pageListObservable = if (download.pages == null) {
             // Pull page list from network and add them to download object
             download.source.fetchPageList(download.chapter).doOnNext { pages ->
                 if (pages.isEmpty()) {
-                    throw Exception("Page list is empty")
+                    throw Exception(context.getString(R.string.no_pages_found))
                 }
                 download.pages = pages
             }
@@ -298,20 +315,25 @@ class Downloader(
             Observable.just(download.pages!!)
         }
 
-        pageListObservable.doOnNext { _ ->
-            // Delete all temporary (unfinished) files
-            tmpDir.listFiles()?.filter { it.name!!.endsWith(".tmp") }?.forEach { it.delete() }
+        pageListObservable
+            .doOnNext { _ ->
+                // Delete all temporary (unfinished) files
+                tmpDir.listFiles()
+                    ?.filter { it.name!!.endsWith(".tmp") }
+                    ?.forEach { it.delete() }
 
-            download.downloadedImages = 0
-            download.status = Download.DOWNLOADING
-        }
+                download.downloadedImages = 0
+                download.status = Download.DOWNLOADING
+            }
             // Get all the URLs to the source images, fetch pages if necessary
             .flatMap { download.source.fetchAllImageUrlsFromPageList(it) }
             // Start downloading images, consider we can have downloaded images already
             // Concurrently do 5 pages at a time
             .flatMap({ page -> getOrDownloadImage(page, download, tmpDir) }, 5)
             // Do when page is downloaded.
-            .doOnNext { notifier.onProgressChange(download) }.toList().map { _ -> download }
+            .doOnNext { notifier.onProgressChange(download) }
+            .toList()
+            .map { download }
             // Do after download completes
             .doOnNext { ensureSuccessfulDownload(download, mangaDir, tmpDir, chapterDirname) }
             // If the page list threw, it will resume here
@@ -336,7 +358,9 @@ class Downloader(
         tmpDir: UniFile
     ): Observable<Page> {
         // If the image URL is empty, do nothing
-        if (page.imageUrl == null) return Observable.just(page)
+        if (page.imageUrl == null) {
+            return Observable.just(page)
+        }
 
         val filename = String.format("%03d", page.number)
         val tmpFile = tmpDir.findFile("$filename.tmp")
@@ -346,16 +370,11 @@ class Downloader(
 
         // Try to find the image file.
         val imageFile = tmpDir.listFiles()!!.find { it.name!!.startsWith("$filename.") }
-        val cache = ChapterCache(context)
+
         // If the image is already downloaded, do nothing. Otherwise download from network
         val pageObservable = when {
             imageFile != null -> Observable.just(imageFile)
-            cache.isImageInCache(page.imageUrl!!) -> moveFromCache(
-                page,
-                cache.getImageFile(page.imageUrl!!),
-                tmpDir,
-                filename
-            )
+            chapterCache.isImageInCache(page.imageUrl!!) -> moveImageFromCache(chapterCache.getImageFile(page.imageUrl!!), tmpDir, filename)
             else -> downloadImage(page, download.source, tmpDir, filename)
         }
 
@@ -366,7 +385,8 @@ class Downloader(
                 page.progress = 100
                 download.downloadedImages++
                 page.status = Page.READY
-            }.map { page }
+            }
+            .map { page }
             // Mark this page as error and allow to download the remaining
             .onErrorReturn {
                 page.progress = 0
@@ -376,30 +396,27 @@ class Downloader(
     }
 
     /**
-     * Returns the observable which takes from the downloaded image from cache
+     * Return the observable which copies the image from cache.
      *
-     * @param page the page to download.
-     * @param file the file from cache
+     * @param cacheFile the file from cache.
      * @param tmpDir the temporary directory of the download.
      * @param filename the filename of the image.
      */
-    private fun moveFromCache(
-        page: Page,
-        file: File,
+    private fun moveImageFromCache(
+        cacheFile: File,
         tmpDir: UniFile,
         filename: String
     ): Observable<UniFile> {
-        return Observable.just(file).map {
+        return Observable.just(cacheFile).map {
             val tmpFile = tmpDir.createFile("$filename.tmp")
-            val inputStream = file.inputStream()
-            inputStream.use { input ->
+            cacheFile.inputStream().use { input ->
                 tmpFile.openOutputStream().use { output ->
                     input.copyTo(output)
                 }
             }
-            val extension = ImageUtil.findImageType(file.inputStream()) ?: return@map tmpFile
+            val extension = ImageUtil.findImageType(cacheFile.inputStream()) ?: return@map tmpFile
             tmpFile.renameTo("$filename.${extension.extension}")
-            file.delete()
+            cacheFile.delete()
             tmpFile
         }
     }
@@ -420,19 +437,20 @@ class Downloader(
     ): Observable<UniFile> {
         page.status = Page.DOWNLOAD_IMAGE
         page.progress = 0
-        return source.fetchImage(page).map { response ->
-            val file = tmpDir.createFile("$filename.tmp")
-            try {
-                response.body!!.source().saveTo(file.openOutputStream())
-                val extension = getImageExtension(response, file)
-                file.renameTo("$filename.$extension")
-            } catch (e: Exception) {
-                response.close()
-                file.delete()
-                throw e
+        return source.fetchImage(page)
+            .map { response ->
+                val file = tmpDir.createFile("$filename.tmp")
+                try {
+                    response.body!!.source().saveTo(file.openOutputStream())
+                    val extension = getImageExtension(response, file)
+                    file.renameTo("$filename.$extension")
+                } catch (e: Exception) {
+                    response.close()
+                    file.delete()
+                    throw e
+                }
+                file
             }
-            file
-        }
             // Retry 3 times, waiting 2, 4 and 8 seconds between attempts.
             .retryWhen(RetryWithDelay(3, { (2 shl it - 1) * 1000 }, Schedulers.trampoline()))
     }
@@ -514,5 +532,8 @@ class Downloader(
 
     companion object {
         const val TMP_DIR_SUFFIX = "_tmp"
+
+        // Arbitrary minimum required space to start a download: 50 MB
+        const val MIN_DISK_SPACE = 50 * 1024 * 1024
     }
 }

app/src/main/java/eu/kanade/tachiyomi/util/storage/DiskUtil.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.content.Intent
 import android.net.Uri
 import android.os.Environment
+import android.os.StatFs
 import androidx.core.content.ContextCompat
 import androidx.core.os.EnvironmentCompat
 import com.hippo.unifile.UniFile
@@ -28,6 +29,18 @@ object DiskUtil {
         return size
     }
 
+    /**
+     * Gets the available space for the disk that a file path points to, in bytes.
+     */
+    fun getAvailableStorageSpace(f: UniFile): Long {
+        return try {
+            val stat = StatFs(f.uri.path)
+            stat.availableBlocksLong * stat.blockSizeLong
+        } catch (_: Exception) {
+            -1L
+        }
+    }
+
     /**
      * Returns the root folders of all the available external storages.
      */

app/src/main/java/eu/kanade/tachiyomi/util/system/CoroutinesExtensions.kt

@@ -11,6 +11,9 @@ import kotlinx.coroutines.withContext
 fun launchUI(block: suspend CoroutineScope.() -> Unit): Job =
     GlobalScope.launch(Dispatchers.Main, CoroutineStart.DEFAULT, block)
 
+fun launchIO(block: suspend CoroutineScope.() -> Unit): Job =
+    GlobalScope.launch(Dispatchers.IO, CoroutineStart.DEFAULT, block)
+
 fun launchNow(block: suspend CoroutineScope.() -> Unit): Job =
     GlobalScope.launch(Dispatchers.Main, CoroutineStart.UNDISPATCHED, block)
 

app/src/main/res/values/strings.xml

@@ -760,6 +760,7 @@
     <string name="manage_whats_downloading">Manage what\'s downloading</string>
     <string name="visit_recents_for_download_queue">Visit the recents tab to access the download
         queue. You can also double tap or press and hold for quicker access</string>
+    <string name="couldnt_download_low_space">Couldn\'t download chapters due to low disk space</string>
 
     <!-- Download Notification -->
     <string name="could_not_download_unexpected_error">Could not download chapter due to unexpected error</string>