Check available ram before pages prefetch

app/src/main/kotlin/org/koitharu/kotatsu/core/util/ext/Android.kt

@@ -2,6 +2,7 @@ package org.koitharu.kotatsu.core.util.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
@@ -23,8 +24,6 @@ import android.widget.Toast
 import androidx.activity.result.ActivityResultLauncher
 import androidx.annotation.IntegerRes
 import androidx.core.app.ActivityOptionsCompat
-import androidx.core.content.IntentCompat
-import androidx.core.content.PackageManagerCompat
 import androidx.core.os.LocaleListCompat
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.coroutineScope
@@ -142,6 +141,13 @@ fun Context.isLowRamDevice(): Boolean {
 	return 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,

app/src/main/kotlin/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/kotlin/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
@@ -27,8 +29,10 @@ import org.koitharu.kotatsu.core.network.MangaHttpClient
 import org.koitharu.kotatsu.core.parser.MangaRepository
 import org.koitharu.kotatsu.core.parser.RemoteMangaRepository
 import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.core.util.FileSize
 import org.koitharu.kotatsu.core.util.RetainedLifecycleCoroutineScope
 import org.koitharu.kotatsu.core.util.ext.ensureSuccess
+import org.koitharu.kotatsu.core.util.ext.ramAvailable
 import org.koitharu.kotatsu.core.util.ext.withProgress
 import org.koitharu.kotatsu.core.util.progress.ProgressDeferred
 import org.koitharu.kotatsu.local.data.CbzFilter
@@ -47,6 +51,7 @@ import kotlin.coroutines.CoroutineContext
 
 @ActivityRetainedScoped
 class PageLoader @Inject constructor(
+	@ApplicationContext private val context: Context,
 	lifecycle: ActivityRetainedLifecycle,
 	@MangaHttpClient private val okHttp: OkHttpClient,
 	private val cache: PagesCache,
@@ -76,7 +81,7 @@ class PageLoader @Inject constructor(
 	}
 
 	fun isPrefetchApplicable(): Boolean {
-		return repository is RemoteMangaRepository && settings.isPagesPreloadEnabled
+		return repository is RemoteMangaRepository && settings.isPagesPreloadEnabled && !isLowRam()
 	}
 
 	@AnyThread
@@ -117,6 +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 {
@@ -204,6 +212,10 @@ 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 {
 
@@ -216,6 +228,7 @@ class PageLoader @Inject constructor(
 
 		private const val PROGRESS_UNDEFINED = -1f
 		private const val PREFETCH_LIMIT_DEFAULT = 10
+		private const val PREFETCH_MIN_RAM_MB = 80L
 
 		fun createPageRequest(page: MangaPage, pageUrl: String) = Request.Builder()
 			.url(pageUrl)