Decouples Cache and Download behaviour

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 +1,24 @@
+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
@@ -82,11 +81,13 @@ object Page {
             }
         }
 
-        val chapterDir = getChapterDir(mangaId, chapterId)
-        File(chapterDir).mkdirs()
         val fileName = getPageName(index)
 
-        return getImageResponse(chapterDir, fileName, useCache) {
+        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 +1,14 @@
+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
+}

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 +1,37 @@
+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.ImageResponse
+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/$fileType")
+    }
+
+    override fun putImage(index: Int, image: InputStream): Boolean {
+        val chapterDir = getChapterDir(mangaId, chapterId)
+        val folder = File(chapterDir)
+        folder.mkdirs()
+        val fileName = getPageName(index)
+        val filePath = "$chapterDir/$fileName"
+        ImageResponse.saveImage(filePath, image)
+        return true
+    }
+
+    override fun delete(): Boolean {
+        val chapterDir = getChapterDir(mangaId, chapterId)
+        return File(chapterDir).deleteRecursively()
+    }
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/util/DirName.kt

@@ -7,6 +7,7 @@ package suwayomi.tachidesk.manga.impl.util
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+import org.jetbrains.exposed.sql.ResultRow
 import org.jetbrains.exposed.sql.select
 import org.jetbrains.exposed.sql.transactions.transaction
 import org.kodein.di.DI
@@ -21,17 +22,16 @@ import java.io.File
 
 private val applicationDirs by DI.global.instance<ApplicationDirs>()
 
-fun getMangaDir(mangaId: Int): String {
-    val mangaEntry = transaction { MangaTable.select { MangaTable.id eq mangaId }.first() }
+fun getMangaDir(mangaId: Int, cache: Boolean = false): String {
+    val mangaEntry = getMangaEntry(mangaId)
     val source = GetCatalogueSource.getCatalogueSourceOrStub(mangaEntry[MangaTable.sourceReference])
 
     val sourceDir = source.toString()
     val mangaDir = SafePath.buildValidFilename(mangaEntry[MangaTable.title])
-
-    return "${applicationDirs.mangaDownloadsRoot}/$sourceDir/$mangaDir"
+    return (if (cache) applicationDirs.cacheRoot else applicationDirs.mangaDownloadsRoot) + "/$sourceDir/$mangaDir"
 }
 
-fun getChapterDir(mangaId: Int, chapterId: Int): String {
+fun getChapterDir(mangaId: Int, chapterId: Int, cache: Boolean = false): String {
     val chapterEntry = transaction { ChapterTable.select { ChapterTable.id eq chapterId }.first() }
 
     val chapterDir = SafePath.buildValidFilename(
@@ -41,12 +41,12 @@ fun getChapterDir(mangaId: Int, chapterId: Int): String {
         }
     )
 
-    return getMangaDir(mangaId) + "/$chapterDir"
+    return getMangaDir(mangaId, cache) + "/$chapterDir"
 }
 
 /** return value says if rename/move was successful */
 fun updateMangaDownloadDir(mangaId: Int, newTitle: String): Boolean {
-    val mangaEntry = transaction { MangaTable.select { MangaTable.id eq mangaId }.first() }
+    val mangaEntry = getMangaEntry(mangaId)
     val source = GetCatalogueSource.getCatalogueSourceOrStub(mangaEntry[MangaTable.sourceReference])
 
     val sourceDir = source.toString()
@@ -66,3 +66,7 @@ fun updateMangaDownloadDir(mangaId: Int, newTitle: String): Boolean {
         true
     }
 }
+
+private fun getMangaEntry(mangaId: Int): ResultRow {
+    return transaction { MangaTable.select { MangaTable.id eq mangaId }.first() }
+}

server/src/main/kotlin/suwayomi/tachidesk/manga/impl/util/storage/ImageResponse.kt

@@ -9,6 +9,7 @@ package suwayomi.tachidesk.manga.impl.util.storage
 
 import okhttp3.Response
 import okhttp3.internal.closeQuietly
+import suwayomi.tachidesk.manga.impl.util.getChapterDir
 import java.io.File
 import java.io.FileInputStream
 import java.io.InputStream
@@ -29,7 +30,7 @@ object ImageResponse {
     }
 
     /** fetch a cached image response, calls `fetcher` if cache fails */
-    suspend fun getCachedImageResponse(saveDir: String, fileName: String, fetcher: suspend () -> Response): Pair<InputStream, String> {
+    private suspend fun getCachedImageResponse(saveDir: String, fileName: String, fetcher: suspend () -> Response): Pair<InputStream, String> {
         val cachedFile = findFileNameStartingWith(saveDir, fileName)
         val filePath = "$saveDir/$fileName"
         if (cachedFile != null) {
@@ -43,34 +44,37 @@ object ImageResponse {
         val response = fetcher()
 
         if (response.code == 200) {
-            val tmpSavePath = "$filePath.tmp"
-            val tmpSaveFile = File(tmpSavePath)
-            response.body!!.source().saveTo(tmpSaveFile)
-
-            // find image type
-            val imageType = response.headers["content-type"]
-                ?: ImageUtil.findImageType { tmpSaveFile.inputStream() }?.mime
-                ?: "image/jpeg"
-
-            val actualSavePath = "$filePath.${imageType.substringAfter("/")}"
-
-            tmpSaveFile.renameTo(File(actualSavePath))
-
+            val (actualSavePath, imageType) = saveImage(filePath, response.body!!.byteStream())
             return pathToInputStream(actualSavePath) to imageType
         } else {
             response.closeQuietly()
             throw Exception("request error! ${response.code}")
         }
     }
 
+    fun saveImage(filePath: String, image: InputStream): Pair<String, String> {
+        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 Pair(actualSavePath, imageType)
+    }
+
     fun clearCachedImage(saveDir: String, fileName: String) {
         val cachedFile = findFileNameStartingWith(saveDir, fileName)
         cachedFile?.also {
             File(it).delete()
         }
     }
 
-    suspend fun getNoCacheImageResponse(fetcher: suspend () -> Response): Pair<InputStream, String> {
+    private suspend fun getNoCacheImageResponse(fetcher: suspend () -> Response): Pair<InputStream, String> {
         val response = fetcher()
 
         if (response.code == 200) {
@@ -88,11 +92,20 @@ object ImageResponse {
         }
     }
 
-    suspend fun getImageResponse(saveDir: String, fileName: String, useCache: Boolean = false, fetcher: suspend () -> Response): Pair<InputStream, String> {
+    suspend fun getImageResponse(saveDir: String, fileName: String, useCache: Boolean, fetcher: suspend () -> Response): Pair<InputStream, String> {
         return if (useCache) {
             getCachedImageResponse(saveDir, fileName, fetcher)
         } else {
             getNoCacheImageResponse(fetcher)
         }
     }
+
+    suspend fun getImageResponse(mangaId: Int, chapterId: Int, fileName: String, useCache: Boolean, fetcher: suspend () -> Response): Pair<InputStream, String> {
+        var saveDir = ""
+        if (useCache) {
+            saveDir = getChapterDir(mangaId, chapterId, true)
+            File(saveDir).mkdirs()
+        }
+        return getImageResponse(saveDir, fileName, useCache, fetcher)
+    }
 }

server/src/main/kotlin/suwayomi/tachidesk/server/ServerSetup.kt

@@ -38,6 +38,7 @@ private val logger = KotlinLogging.logger {}
 class ApplicationDirs(
     val dataRoot: String = ApplicationRootDir
 ) {
+    val cacheRoot = System.getProperty("java.io.tmpdir") + "/tachidesk"
     val extensionsRoot = "$dataRoot/extensions"
     val thumbnailsRoot = "$dataRoot/thumbnails"
     val mangaDownloadsRoot = serverConfig.downloadsPath.ifBlank { "$dataRoot/downloads" }