Limit thumb fetcher concurrency

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

@@ -28,7 +28,7 @@ import coil3.SingletonImageLoader
 import coil3.asImage
 import coil3.gif.AnimatedImageDecoder
 import coil3.gif.GifDecoder
-import coil3.network.ktor3.KtorNetworkFetcherFactory
+import coil3.network.NetworkFetcher
 import coil3.request.ErrorResult
 import coil3.request.ImageRequest
 import coil3.request.crossfade
@@ -43,6 +43,7 @@ import com.hippo.ehviewer.coil.HardwareBitmapInterceptor
 import com.hippo.ehviewer.coil.MapExtraInfoInterceptor
 import com.hippo.ehviewer.coil.MergeInterceptor
 import com.hippo.ehviewer.coil.QrCodeInterceptor
+import com.hippo.ehviewer.coil.limitConcurrency
 import com.hippo.ehviewer.dailycheck.checkDawn
 import com.hippo.ehviewer.dao.SearchDatabase
 import com.hippo.ehviewer.download.DownloadManager
@@ -161,7 +162,7 @@ class EhApplication :
         interceptorCoroutineContext(Dispatchers.Default)
         components {
             serviceLoaderEnabled(false)
-            add(KtorNetworkFetcherFactory(httpClient = { ktorClient }))
+            add(NetworkFetcher.Factory({ ktorClient.limitConcurrency() }))
             add(MergeInterceptor)
             add(DownloadThumbInterceptor)
             if (isAtLeastO) {

app/src/main/kotlin/com/hippo/ehviewer/client/EhCacheKeyFactory.kt

@@ -23,8 +23,8 @@ import com.hippo.ehviewer.client.data.NormalGalleryPreview
 // ExHentai Large Preview: https://s.exhentai.org/t/***
 // E-Hentai Large Preview: https://ehgt.org/***
 
-private const val URL_PREFIX_THUMB_E = "https://ehgt.org/"
-private const val URL_PREFIX_THUMB_EX = "https://s.exhentai.org/t/"
+const val URL_PREFIX_THUMB_E = "https://ehgt.org/"
+const val URL_PREFIX_THUMB_EX = "https://s.exhentai.org/t/"
 private const val NORMAL_PREVIEW_PREFIX = "$"
 private val NormalPreviewKeyRegex = Regex("/(\\d+-\\d+)\\.jpg$")
 

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

@@ -0,0 +1,26 @@
+package com.hippo.ehviewer.coil
+
+import coil3.network.NetworkClient
+import coil3.network.NetworkRequest
+import coil3.network.NetworkResponse
+import coil3.network.ktor3.asNetworkClient
+import com.hippo.ehviewer.client.URL_PREFIX_THUMB_E
+import com.hippo.ehviewer.client.URL_PREFIX_THUMB_EX
+import io.ktor.client.HttpClient
+import kotlinx.coroutines.sync.Semaphore
+import kotlinx.coroutines.sync.withPermit
+
+class LimitConcurrencyNetworkClient(val impl: NetworkClient) : NetworkClient {
+    val eSemaphore = Semaphore(4)
+    val exSemaphore = Semaphore(4)
+    override suspend fun <T> executeRequest(req: NetworkRequest, f: suspend (NetworkResponse) -> T): T {
+        val url = req.url
+        return when {
+            URL_PREFIX_THUMB_E in url -> eSemaphore.withPermit { impl.executeRequest(req, f) }
+            URL_PREFIX_THUMB_EX in url -> exSemaphore.withPermit { impl.executeRequest(req, f) }
+            else -> impl.executeRequest(req, f)
+        }
+    }
+}
+
+fun HttpClient.limitConcurrency() = LimitConcurrencyNetworkClient(asNetworkClient())