Re-use ZipFile instances in PageLoader

app/src/main/kotlin/org/koitharu/kotatsu/core/zip/ZipPool.kt

@@ -0,0 +1,32 @@
+package org.koitharu.kotatsu.core.zip
+
+import android.net.Uri
+import androidx.annotation.WorkerThread
+import androidx.collection.LruCache
+import okhttp3.internal.closeQuietly
+import okio.Source
+import okio.source
+import java.io.File
+import java.util.zip.ZipFile
+
+class ZipPool(maxSize: Int) : LruCache<String, ZipFile>(maxSize) {
+
+	override fun entryRemoved(evicted: Boolean, key: String, oldValue: ZipFile, newValue: ZipFile?) {
+		super.entryRemoved(evicted, key, oldValue, newValue)
+		oldValue.closeQuietly()
+	}
+
+	override fun create(key: String): ZipFile {
+		return ZipFile(File(key), ZipFile.OPEN_READ)
+	}
+
+	@Synchronized
+	@WorkerThread
+	operator fun get(uri: Uri): Source {
+		val zip = requireNotNull(get(uri.schemeSpecificPart)) {
+			"Cannot obtain zip by \"$uri\""
+		}
+		val entry = zip.getEntry(uri.fragment)
+		return zip.getInputStream(entry).source()
+	}
+}

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

@@ -23,7 +23,6 @@ import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 import okhttp3.OkHttpClient
 import okhttp3.Request
-import okio.source
 import org.koitharu.kotatsu.core.network.CommonHeaders
 import org.koitharu.kotatsu.core.network.ImageProxyInterceptor
 import org.koitharu.kotatsu.core.network.MangaHttpClient
@@ -39,6 +38,7 @@ import org.koitharu.kotatsu.core.util.ext.printStackTraceDebug
 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.core.zip.ZipPool
 import org.koitharu.kotatsu.local.data.CbzFilter
 import org.koitharu.kotatsu.local.data.PagesCache
 import org.koitharu.kotatsu.parsers.model.MangaPage
@@ -47,7 +47,6 @@ import org.koitharu.kotatsu.reader.ui.pager.ReaderPage
 import java.io.File
 import java.util.LinkedList
 import java.util.concurrent.atomic.AtomicInteger
-import java.util.zip.ZipFile
 import javax.inject.Inject
 import kotlin.coroutines.AbstractCoroutineContextElement
 import kotlin.coroutines.CoroutineContext
@@ -74,6 +73,7 @@ class PageLoader @Inject constructor(
 	private val prefetchLock = Mutex()
 	private var repository: MangaRepository? = null
 	private val prefetchQueue = LinkedList<MangaPage>()
+	private val zipPool = ZipPool(2)
 	private val counter = AtomicInteger(0)
 	private var prefetchQueueLimit = PREFETCH_LIMIT_DEFAULT // TODO adaptive
 
@@ -81,6 +81,7 @@ class PageLoader @Inject constructor(
 		synchronized(tasks) {
 			tasks.clear()
 		}
+		zipPool.evictAll()
 	}
 
 	fun isPrefetchApplicable(): Boolean {
@@ -196,14 +197,9 @@ class PageLoader @Inject constructor(
 		val uri = Uri.parse(pageUrl)
 		return if (CbzFilter.isUriSupported(uri)) {
 			runInterruptible(Dispatchers.IO) {
-				ZipFile(uri.schemeSpecificPart)
-			}.use { zip ->
-				runInterruptible(Dispatchers.IO) {
-					val entry = zip.getEntry(uri.fragment)
-					zip.getInputStream(entry)
-				}.use {
-					cache.put(pageUrl, it.source())
-				}
+				zipPool[uri]
+			}.use {
+				cache.put(pageUrl, it)
 			}
 		} else {
 			val request = createPageRequest(page, pageUrl)