Move downloader logic outside of caching/image download logic

Author: akabhirav

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/Chapter.kt

@@ -15,7 +15,6 @@ import org.jetbrains.exposed.dao.id.EntityID
 import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.SortOrder.ASC
 import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
-import org.jetbrains.exposed.sql.SqlExpressionBuilder.inList
 import org.jetbrains.exposed.sql.transactions.transaction
 import suwayomi.tachidesk.manga.impl.Manga.getManga
 import suwayomi.tachidesk.manga.impl.util.getChapterDir
@@ -312,9 +311,7 @@ object Chapter {
                 ChapterTable.select { (ChapterTable.manga eq mangaId) and (ChapterTable.sourceOrder eq chapterIndex) }
                     .first()[ChapterTable.id].value
 
-            val chapterDir = getChapterDir(mangaId, chapterId)
-
-            File(chapterDir).deleteRecursively()
+            ChapterDownloadHelper.delete(mangaId, chapterId)
 
             ChapterTable.update({ (ChapterTable.manga eq mangaId) and (ChapterTable.sourceOrder eq chapterIndex) }) {
                 it[isDownloaded] = false

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/ChapterDownloadHelper.kt

@@ -0,0 +1,25 @@
+package suwayomi.tachidesk.manga.impl
+
+import suwayomi.tachidesk.manga.impl.download.DownloadedFilesProvider
+import suwayomi.tachidesk.manga.impl.download.FolderProvider
+import java.io.InputStream
+
+object ChapterDownloadHelper {
+    fun getImage(mangaId: Int, chapterId: Int, index: Int): Pair<InputStream, String> {
+        return provider(mangaId, chapterId).getImage(index)
+    }
+
+    fun delete(mangaId: Int, chapterId: Int): Boolean {
+        return provider(mangaId, chapterId).delete()
+    }
+
+    fun putImage(mangaId: Int, chapterId: Int, index: Int, image: InputStream): Boolean {
+        return provider(mangaId, chapterId).putImage(index, image)
+    }
+
+    // return the appropriate provider based on how the download was saved. For the logic is simple but will evolve when new types of downloads are available
+    private fun provider(mangaId: Int, chapterId: Int): DownloadedFilesProvider {
+        return FolderProvider(mangaId, chapterId)
+    }
+
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/Page.kt

@@ -15,7 +15,6 @@ import org.jetbrains.exposed.sql.and
 import org.jetbrains.exposed.sql.select
 import org.jetbrains.exposed.sql.transactions.transaction
 import org.jetbrains.exposed.sql.update
-import suwayomi.tachidesk.manga.impl.util.getChapterDir
 import suwayomi.tachidesk.manga.impl.util.lang.awaitSingle
 import suwayomi.tachidesk.manga.impl.util.source.GetCatalogueSource.getCatalogueSourceOrStub
 import suwayomi.tachidesk.manga.impl.util.storage.ImageResponse.getImageResponse
@@ -82,10 +81,12 @@ object Page {
             }
         }
 
-        val chapterDir = getChapterDir(mangaId, chapterId)
-        File(chapterDir).mkdirs()
         val fileName = getPageName(index)
 
+        if (chapterEntry[ChapterTable.isDownloaded]) {
+            return ChapterDownloadHelper.getImage(mangaId, chapterId, index)
+        }
+
         return getImageResponse(mangaId, chapterId, fileName, useCache) {
             source.fetchImage(tachiyomiPage).awaitSingle()
         }

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/DownloadedFilesProvider.kt

@@ -0,0 +1,18 @@
+package suwayomi.tachidesk.manga.impl.download
+
+import java.io.InputStream
+
+/*
+* Base class for downloaded chapter files provider, example: Folder, Archive
+* */
+abstract class DownloadedFilesProvider(val mangaId: Int, val chapterId: Int) {
+    abstract fun getImage(index: Int): Pair<InputStream, String>
+
+    abstract fun putImage(index: Int, image: InputStream): Boolean
+
+    abstract fun delete(): Boolean
+
+    private fun getPageName(index: Int): String {
+        return String.format("%03d", index + 1)
+    }
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/Downloader.kt

@@ -23,6 +23,7 @@ import mu.KotlinLogging
 import org.jetbrains.exposed.sql.and
 import org.jetbrains.exposed.sql.transactions.transaction
 import org.jetbrains.exposed.sql.update
+import suwayomi.tachidesk.manga.impl.ChapterDownloadHelper
 import suwayomi.tachidesk.manga.impl.Page.getPageImage
 import suwayomi.tachidesk.manga.impl.chapter.getChapterDownloadReady
 import suwayomi.tachidesk.manga.impl.download.model.DownloadChapter
@@ -99,7 +100,7 @@ class Downloader(
                 for (pageNum in 0 until pageCount) {
                     var pageProgressJob: Job? = null
                     try {
-                        getPageImage(
+                        val image = getPageImage(
                             mangaId = download.mangaId,
                             chapterIndex = download.chapterIndex,
                             index = pageNum,
@@ -113,7 +114,9 @@ class Downloader(
                                     }
                                     .launchIn(scope)
                             }
-                        ).first.close()
+                        ).first
+                        ChapterDownloadHelper.putImage(download.mangaId, download.chapter.id, pageNum, image)
+                        image.close()
                     } finally {
                         // always cancel the page progress job even if it throws an exception to avoid memory leaks
                         pageProgressJob?.cancel()

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/download/FolderProvider.kt

@@ -0,0 +1,45 @@
+package suwayomi.tachidesk.manga.impl.download
+
+import suwayomi.tachidesk.manga.impl.Page.getPageName
+import suwayomi.tachidesk.manga.impl.util.getChapterDir
+import suwayomi.tachidesk.manga.impl.util.storage.ImageUtil
+import java.io.File
+import java.io.FileInputStream
+import java.io.InputStream
+
+/*
+* Provides downloaded files when pages were downloaded into folders
+* */
+class FolderProvider(mangaId: Int, chapterId: Int) : DownloadedFilesProvider(mangaId, chapterId) {
+    override fun getImage(index: Int): Pair<InputStream, String> {
+        val chapterDir = getChapterDir(mangaId, chapterId)
+        val folder = File(chapterDir)
+        folder.mkdirs()
+        val file = folder.listFiles()?.get(index)
+        val fileType = file!!.name.substringAfterLast(".")
+        return Pair(FileInputStream(file).buffered(), "image/$fileType")
+    }
+
+    override fun putImage(index: Int, image: InputStream): Boolean {
+        val chapterDir = getChapterDir(mangaId, chapterId)
+        val fileName = getPageName(index)
+        val filePath = "$chapterDir/$fileName"
+        val tmpSavePath = "$filePath.tmp"
+        val tmpSaveFile = File(tmpSavePath)
+        image.use { input -> tmpSaveFile.outputStream().use { output -> input.copyTo(output) } }
+
+        // find image type
+        val imageType = ImageUtil.findImageType { tmpSaveFile.inputStream() }?.mime
+            ?: "image/jpeg"
+
+        val actualSavePath = "$filePath.${imageType.substringAfter("/")}"
+
+        tmpSaveFile.renameTo(File(actualSavePath))
+        return true
+    }
+
+    override fun delete(): Boolean {
+        val chapterDir = getChapterDir(mangaId, chapterId)
+        return File(chapterDir).deleteRecursively()
+    }
+}