Migrate to kotlinx.serialization for download store and deleter

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

@@ -2,11 +2,12 @@ package eu.kanade.tachiyomi.data.download
 
 import android.content.Context
 import androidx.core.content.edit
-import com.github.salomonbrys.kotson.fromJson
-import com.google.gson.Gson
 import eu.kanade.tachiyomi.data.database.models.Chapter
 import eu.kanade.tachiyomi.data.database.models.Manga
-import uy.kohesive.injekt.injectLazy
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 
 /**
  * Class used to keep a list of chapters for future deletion.
@@ -15,11 +16,6 @@ import uy.kohesive.injekt.injectLazy
  */
 class DownloadPendingDeleter(context: Context) {
 
-    /**
-     * Gson instance to encode and decode chapters.
-     */
-    private val gson by injectLazy<Gson>()
-
     /**
      * Preferences used to store the list of chapters to delete.
      */
@@ -53,7 +49,7 @@ class DownloadPendingDeleter(context: Context) {
             val existingEntry = preferences.getString(manga.id!!.toString(), null)
             if (existingEntry != null) {
                 // Existing entry found on preferences, decode json and add the new chapter
-                val savedEntry = gson.fromJson<Entry>(existingEntry)
+                val savedEntry = Json.decodeFromString<Entry>(existingEntry)
 
                 // Append new chapters
                 val newChapters = savedEntry.chapters.addUniqueById(chapters)
@@ -69,7 +65,7 @@ class DownloadPendingDeleter(context: Context) {
         }
 
         // Save current state
-        val json = gson.toJson(newEntry)
+        val json = Json.encodeToString(newEntry)
         preferences.edit {
             putString(newEntry.manga.id.toString(), json)
         }
@@ -101,7 +97,7 @@ class DownloadPendingDeleter(context: Context) {
     private fun decodeAll(): List<Entry> {
         return preferences.all.values.mapNotNull { rawEntry ->
             try {
-                (rawEntry as? String)?.let { gson.fromJson<Entry>(it) }
+                (rawEntry as? String)?.let { Json.decodeFromString<Entry>(it) }
             } catch (e: Exception) {
                 null
             }
@@ -124,6 +120,7 @@ class DownloadPendingDeleter(context: Context) {
     /**
      * Class used to save an entry of chapters with their manga into preferences.
      */
+    @Serializable
     private data class Entry(
         val chapters: List<ChapterEntry>,
         val manga: MangaEntry
@@ -132,6 +129,7 @@ class DownloadPendingDeleter(context: Context) {
     /**
      * Class used to save an entry for a chapter into preferences.
      */
+    @Serializable
     private data class ChapterEntry(
         val id: Long,
         val url: String,
@@ -142,6 +140,7 @@ class DownloadPendingDeleter(context: Context) {
     /**
      * Class used to save an entry for a manga into preferences.
      */
+    @Serializable
     private data class MangaEntry(
         val id: Long,
         val url: String,

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

@@ -2,12 +2,15 @@ package eu.kanade.tachiyomi.data.download
 
 import android.content.Context
 import androidx.core.content.edit
-import com.google.gson.Gson
 import eu.kanade.tachiyomi.data.database.DatabaseHelper
 import eu.kanade.tachiyomi.data.database.models.Manga
 import eu.kanade.tachiyomi.data.download.model.Download
 import eu.kanade.tachiyomi.source.SourceManager
 import eu.kanade.tachiyomi.source.online.HttpSource
+import kotlinx.serialization.Serializable
+import kotlinx.serialization.decodeFromString
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.Json
 import uy.kohesive.injekt.injectLazy
 
 /**
@@ -25,11 +28,6 @@ class DownloadStore(
      */
     private val preferences = context.getSharedPreferences("active_downloads", Context.MODE_PRIVATE)
 
-    /**
-     * Gson instance to serialize/deserialize downloads.
-     */
-    private val gson: Gson by injectLazy()
-
     private val db: DatabaseHelper by injectLazy()
 
     /**
@@ -111,7 +109,7 @@ class DownloadStore(
      */
     private fun serialize(download: Download): String {
         val obj = DownloadObject(download.manga.id!!, download.chapter.id!!, counter++)
-        return gson.toJson(obj)
+        return Json.encodeToString(obj)
     }
 
     /**
@@ -121,7 +119,7 @@ class DownloadStore(
      */
     private fun deserialize(string: String): DownloadObject? {
         return try {
-            gson.fromJson(string, DownloadObject::class.java)
+            Json.decodeFromString<DownloadObject>(string)
         } catch (e: Exception) {
             null
         }
@@ -134,5 +132,6 @@ class DownloadStore(
      * @param chapterId the id of the chapter.
      * @param order the order of the download in the queue.
      */
+    @Serializable
     data class DownloadObject(val mangaId: Long, val chapterId: Long, val order: Int)
 }