Allow configure thumb concurrency temporarily

app/src/main/kotlin/com/hippo/ehviewer/Settings.kt

@@ -212,6 +212,7 @@ object Settings : DataStorePreferences(null) {
     val showNavigationOverlayNewUser = boolPref("reader_navigation_overlay_new_user", true)
     val showNavigationOverlayOnStart = boolPref("reader_navigation_overlay_on_start", false)
     val stripExtraneousAds = boolPref("strip_extraneous_ads", false)
+    var thumbConcurrency by intPref("thumb_concurrency", 4)
 
     val userAgent
         get() = if (desktopSite) CHROME_USER_AGENT else CHROME_MOBILE_USER_AGENT

app/src/main/kotlin/com/hippo/ehviewer/coil/LimitConcurrencyNetworkClient.kt

@@ -4,6 +4,7 @@ import coil3.network.NetworkClient
 import coil3.network.NetworkRequest
 import coil3.network.NetworkResponse
 import coil3.network.ktor3.asNetworkClient
+import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.client.URL_PREFIX_THUMB_E
 import com.hippo.ehviewer.client.URL_PREFIX_THUMB_EX
 import io.ktor.client.HttpClient
@@ -11,8 +12,8 @@ import kotlinx.coroutines.sync.Semaphore
 import kotlinx.coroutines.sync.withPermit
 
 class LimitConcurrencyNetworkClient(val impl: NetworkClient) : NetworkClient {
-    val eSemaphore = Semaphore(4)
-    val exSemaphore = Semaphore(4)
+    val eSemaphore = Semaphore(Settings.thumbConcurrency)
+    val exSemaphore = Semaphore(Settings.thumbConcurrency)
     override suspend fun <T> executeRequest(req: NetworkRequest, f: suspend (NetworkResponse) -> T): T {
         val url = req.url
         return when {

app/src/main/kotlin/com/hippo/ehviewer/ui/settings/AdvancedScreen.kt

@@ -182,6 +182,13 @@ fun AdvancedScreen(navigator: DestinationsNavigator) {
                     value = Settings::enableCronet,
                 )
             }
+            IntSliderPreference(
+                maxValue = 16,
+                minValue = 2,
+                step = 1,
+                title = "Thumb Concurrency (Restart required)",
+                value = Settings::thumbConcurrency,
+            )
             if (isAtLeastO) {
                 IntSliderPreference(
                     maxValue = 16384,