Fix RAR loading

Closes #10302

app/src/main/java/eu/kanade/tachiyomi/ui/reader/loader/RarPageLoader.kt

@@ -10,6 +10,7 @@ import java.io.File
 import java.io.InputStream
 import java.io.PipedInputStream
 import java.io.PipedOutputStream
+import java.util.concurrent.Executors
 
 /**
  * Loader used to load a chapter from a .rar or .cbr file.
@@ -20,13 +21,18 @@ internal class RarPageLoader(file: File) : PageLoader() {
 
     override var isLocal: Boolean = true
 
+    /**
+     * Pool for copying compressed files to an input stream.
+     */
+    private val pool = Executors.newFixedThreadPool(1)
+
     override suspend fun getPages(): List<ReaderPage> {
         return rar.fileHeaders.asSequence()
             .filter { !it.isDirectory && ImageUtil.isImage(it.fileName) { rar.getInputStream(it) } }
             .sortedWith { f1, f2 -> f1.fileName.compareToCaseInsensitiveNaturalOrder(f2.fileName) }
             .mapIndexed { i, header ->
                 ReaderPage(i).apply {
-                    stream = { getStream(rar, header) }
+                    stream = { getStream(header) }
                     status = Page.State.READY
                 }
             }
@@ -40,15 +46,16 @@ internal class RarPageLoader(file: File) : PageLoader() {
     override fun recycle() {
         super.recycle()
         rar.close()
+        pool.shutdown()
     }
 
     /**
      * Returns an input stream for the given [header].
      */
-    private fun getStream(rar: Archive, header: FileHeader): InputStream {
+    private fun getStream(header: FileHeader): InputStream {
         val pipeIn = PipedInputStream()
         val pipeOut = PipedOutputStream(pipeIn)
-        synchronized(this) {
+        pool.execute {
             try {
                 pipeOut.use {
                     rar.extractFile(header, it)