Check available ram before pages prefetch

app/src/main/java/org/koitharu/kotatsu/local/data/PagesCache.kt

@@ -54,9 +54,10 @@ class PagesCache @Inject constructor(@ApplicationContext context: Context) {
 	suspend fun put(url: String, source: Source): File = withContext(Dispatchers.IO) {
 		val file = File(cacheDir.get().parentFile, url.longHashCode().toString())
 		try {
-			file.sink(append = false).buffer().use {
+			val bytes = file.sink(append = false).buffer().use {
 				it.writeAllCancellable(source)
 			}
+			check(bytes != 0L) { "No data has been written" }
 			lruCache.get().put(url, file)
 		} finally {
 			file.delete()

app/src/main/java/org/koitharu/kotatsu/reader/domain/PageLoader.kt

@@ -1,5 +1,6 @@
 package org.koitharu.kotatsu.reader.domain
 
+import android.content.Context
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.net.Uri
@@ -8,6 +9,7 @@ import androidx.collection.LongSparseArray
 import androidx.collection.set
 import dagger.hilt.android.ActivityRetainedLifecycle
 import dagger.hilt.android.lifecycle.RetainedLifecycle
+import dagger.hilt.android.qualifiers.ApplicationContext
 import dagger.hilt.android.scopes.ActivityRetainedScoped
 import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.Dispatchers
@@ -30,8 +32,10 @@ import org.koitharu.kotatsu.parsers.model.MangaPage
 import org.koitharu.kotatsu.parsers.model.MangaSource
 import org.koitharu.kotatsu.parsers.util.await
 import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
+import org.koitharu.kotatsu.utils.FileSize
 import org.koitharu.kotatsu.utils.RetainedLifecycleCoroutineScope
 import org.koitharu.kotatsu.utils.ext.printStackTraceDebug
+import org.koitharu.kotatsu.utils.ext.ramAvailable
 import org.koitharu.kotatsu.utils.ext.withProgress
 import org.koitharu.kotatsu.utils.progress.ProgressDeferred
 import java.io.File
@@ -44,9 +48,11 @@ import kotlin.coroutines.CoroutineContext
 
 private const val PROGRESS_UNDEFINED = -1f
 private const val PREFETCH_LIMIT_DEFAULT = 10
+private const val PREFETCH_MIN_RAM_MB = 80L
 
 @ActivityRetainedScoped
 class PageLoader @Inject constructor(
+	@ApplicationContext private val context: Context,
 	lifecycle: ActivityRetainedLifecycle,
 	private val okHttp: OkHttpClient,
 	private val cache: PagesCache,
@@ -75,7 +81,7 @@ class PageLoader @Inject constructor(
 	}
 
 	fun isPrefetchApplicable(): Boolean {
-		return repository is RemoteMangaRepository && settings.isPagesPreloadEnabled()
+		return repository is RemoteMangaRepository && settings.isPagesPreloadEnabled() && !isLowRam()
 	}
 
 	@AnyThread
@@ -116,6 +122,9 @@ class PageLoader @Inject constructor(
 
 	suspend fun convertInPlace(file: File) {
 		convertLock.withLock {
+			if (context.ramAvailable < file.length() * 2) {
+				return@withLock
+			}
 			runInterruptible(Dispatchers.Default) {
 				val image = BitmapFactory.decodeFile(file.absolutePath)
 				try {
@@ -212,6 +221,10 @@ class PageLoader @Inject constructor(
 		}
 	}
 
+	private fun isLowRam(): Boolean {
+		return context.ramAvailable <= FileSize.MEGABYTES.convert(PREFETCH_MIN_RAM_MB, FileSize.BYTES)
+	}
+
 	private class InternalErrorHandler : AbstractCoroutineContextElement(CoroutineExceptionHandler),
 		CoroutineExceptionHandler {
 

app/src/main/java/org/koitharu/kotatsu/utils/ext/AndroidExt.kt

@@ -2,6 +2,7 @@ package org.koitharu.kotatsu.utils.ext
 
 import android.app.Activity
 import android.app.ActivityManager
+import android.app.ActivityManager.MemoryInfo
 import android.app.ActivityOptions
 import android.content.Context
 import android.content.Context.ACTIVITY_SERVICE
@@ -138,6 +139,13 @@ fun isLowRamDevice(context: Context): Boolean {
 	return context.activityManager?.isLowRamDevice ?: false
 }
 
+val Context.ramAvailable: Long
+	get() {
+		val result = MemoryInfo()
+		activityManager?.getMemoryInfo(result)
+		return result.availMem
+	}
+
 fun scaleUpActivityOptionsOf(view: View): ActivityOptions = ActivityOptions.makeScaleUpAnimation(
 	view,
 	0,