Lighten memory load when pruning orphan images

Author: RobbWatershed

app/src/main/java/me/devsaki/hentoid/database/DatabaseMaintenance.kt

@@ -351,18 +351,18 @@ object DatabaseMaintenance {
                 }
                 db.insertSearchRecords(searchRecords)
 
-                val imageFiles = db.selectImageFilesWithNullPageUrl()
+                val imageFileIds = db.selectImageFileIdsWithNullPageUrl()
                 Timber.i(
                     "Set default value for ImageFile.dbPageUrl field : %s items detected",
-                    imageFiles.size
+                    imageFileIds.size
                 )
-                max = imageFiles.size
+                max = imageFileIds.size
                 pos = 1f
-                for (c in imageFiles) {
-                    c.dbPageUrl = ""
-                    withContext(Dispatchers.Main) { emitter(pos++ / max) }
+                imageFileIds.chunked(50).forEach {
+                    db.resetPageUrlForImageId(it)
+                    withContext(Dispatchers.Main) { emitter(pos / max) }
+                    pos += it.size
                 }
-                db.insertImageFiles(imageFiles)
 
                 Timber.i("Set default ObjectBox properties : done")
             } finally {

app/src/main/java/me/devsaki/hentoid/database/MaintenanceDAO.kt

@@ -104,11 +104,19 @@ class MaintenanceDAO {
             .isNull(SearchRecord_.entityType).safeFind()
     }
 
-    fun selectImageFilesWithNullPageUrl(): List<ImageFile> {
+    fun selectImageFileIdsWithNullPageUrl(): Set<Long> {
         return ObjectBoxDB.store.boxFor(ImageFile::class.java).query()
             .isNull(ImageFile_.dbPageUrl)
             .or()
-            .equal(ImageFile_.dbPageUrl, "", QueryBuilder.StringOrder.CASE_INSENSITIVE).safeFind()
+            .equal(ImageFile_.dbPageUrl, "", QueryBuilder.StringOrder.CASE_INSENSITIVE)
+            .safeFindIds().toSet()
+    }
+
+    fun resetPageUrlForImageId(ids: Collection<Long>) {
+        val store = ObjectBoxDB.store.boxFor(ImageFile::class.java)
+        val imgFiles = store.get(ids)
+        imgFiles.forEach { it.pageUrl = "" }
+        store.put(imgFiles)
     }
 
     fun selectOrphanQueueRecordIds(): LongArray {
@@ -133,10 +141,6 @@ class MaintenanceDAO {
         ObjectBoxDB.insertGroup(g)
     }
 
-    fun updateImageFileUrl(img: ImageFile) {
-        ObjectBoxDB.updateImageFileUrl(img)
-    }
-
     fun insertImageFiles(imgs: List<ImageFile>) {
         ObjectBoxDB.insertImageFiles(imgs)
     }

app/src/main/java/me/devsaki/hentoid/database/ObjectBoxDB.kt

@@ -1651,15 +1651,6 @@ object ObjectBoxDB {
         store.boxFor(ImageFile::class.java).put(imgs)
     }
 
-    fun updateImageFileUrl(image: ImageFile) {
-        val imgBox = store.boxFor(ImageFile::class.java)
-        val img = imgBox[image.id]
-        if (img != null) {
-            img.url = image.url
-            imgBox.put(img)
-        }
-    }
-
     fun updateImageFileUri(locations: Map<Long, String>) {
         val imgBox = store.boxFor(ImageFile::class.java)
         store.runInTx {