fix(Extractor): drop dead pooled connections instead of timing out

app/src/main/java/com/github/libretube/util/NewPipeDownloaderImpl.kt

@@ -1,15 +1,22 @@
 package com.github.libretube.util
 
+import okhttp3.ConnectionPool
 import okhttp3.OkHttpClient
 import okhttp3.RequestBody.Companion.toRequestBody
 import org.schabi.newpipe.extractor.downloader.Downloader
 import org.schabi.newpipe.extractor.downloader.Request
 import org.schabi.newpipe.extractor.downloader.Response
 import org.schabi.newpipe.extractor.exceptions.ReCaptchaException
 import java.io.IOException
+import java.util.concurrent.TimeUnit
 
 class NewPipeDownloaderImpl : Downloader() {
     private val client = OkHttpClient.Builder()
+        // Routers silently drop idle connections. The client would keep using such a dead connection
+        // and every request on it would run into a timeout, so idle connections are closed early
+        // and HTTP/2 connections are pinged to notice when they died.
+        .connectionPool(ConnectionPool(MAX_IDLE_CONNECTIONS, IDLE_CONNECTION_KEEP_ALIVE_SECONDS, TimeUnit.SECONDS))
+        .pingInterval(PING_INTERVAL_SECONDS, TimeUnit.SECONDS)
         .build()
 
     @Throws(IOException::class, ReCaptchaException::class)
@@ -30,7 +37,7 @@ class NewPipeDownloaderImpl : Downloader() {
                 requestBuilder.addHeader(headerKey, headerValue)
             }
         }
-        val response = client.newCall(requestBuilder.build()).execute()
+        val response = executeOnFreshConnectionIfNeeded(requestBuilder.build())
 
         return when (response.code) {
             429 -> {
@@ -51,7 +58,24 @@ class NewPipeDownloaderImpl : Downloader() {
         }
     }
 
+    /**
+     * If a request fails because of a timeout, the pooled connection it used might be dead.
+     * Drop all pooled connections and try once more on a new one.
+     */
+    private fun executeOnFreshConnectionIfNeeded(request: okhttp3.Request): okhttp3.Response {
+        return try {
+            client.newCall(request).execute()
+        } catch (e: IOException) {
+            client.connectionPool.evictAll()
+            client.newCall(request).execute()
+        }
+    }
+
     companion object {
+        private const val MAX_IDLE_CONNECTIONS = 5
+        private const val IDLE_CONNECTION_KEEP_ALIVE_SECONDS = 20L
+        private const val PING_INTERVAL_SECONDS = 15L
+
         private const val USER_AGENT =
             "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0"
     }