perf: reduce bridge and UI churn

android/app/src/main/kotlin/com/zarz/spotiflac/MainActivity.kt

@@ -43,6 +43,8 @@ class MainActivity: FlutterFragmentActivity() {
         "com.zarz.spotiflac/library_scan_progress_stream"
     private val DOWNLOAD_PROGRESS_STREAM_POLLING_INTERVAL_MS = 1200L
     private val LIBRARY_SCAN_PROGRESS_STREAM_POLLING_INTERVAL_MS = 200L
+    private val LARGE_JSON_RESULT_FILE_KEY = "__json_file"
+    private val LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES = 256 * 1024
     private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main)
     private var pendingSafTreeResult: MethodChannel.Result? = null
     private val safScanLock = Any()
@@ -51,6 +53,7 @@ class MainActivity: FlutterFragmentActivity() {
     private var downloadProgressStreamJob: Job? = null
     private var downloadProgressEventSink: EventChannel.EventSink? = null
     private var lastDownloadProgressPayload: String? = null
+    private var lastDownloadProgressSeq = 0L
     private var libraryScanProgressStreamJob: Job? = null
     private var libraryScanProgressEventSink: EventChannel.EventSink? = null
     private var lastLibraryScanProgressPayload: String? = null
@@ -504,17 +507,46 @@ class MainActivity: FlutterFragmentActivity() {
         }
     }
 
+    private fun bridgeJsonResult(payload: String): Any {
+        if (payload.toByteArray(Charsets.UTF_8).size < LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES) {
+            return payload
+        }
+
+        return try {
+            val file = File(cacheDir, "bridge_json_${System.nanoTime()}.json")
+            file.writeText(payload, Charsets.UTF_8)
+            mapOf(LARGE_JSON_RESULT_FILE_KEY to file.absolutePath)
+        } catch (e: Exception) {
+            android.util.Log.w(
+                "SpotiFLAC",
+                "Failed to spill large bridge JSON result to file: ${e.message}",
+            )
+            payload
+        }
+    }
+
+    private fun updateDownloadProgressSeq(payload: String) {
+        try {
+            val seq = JSONObject(payload).optLong("seq", lastDownloadProgressSeq)
+            if (seq > lastDownloadProgressSeq) {
+                lastDownloadProgressSeq = seq
+            }
+        } catch (_: Exception) {}
+    }
+
     private fun startDownloadProgressStream(sink: EventChannel.EventSink) {
         stopDownloadProgressStream()
         downloadProgressEventSink = sink
         lastDownloadProgressPayload = null
+        lastDownloadProgressSeq = 0L
         downloadProgressStreamJob = scope.launch {
             while (isActive && downloadProgressEventSink === sink) {
                 try {
                     val payload = withContext(Dispatchers.IO) {
-                        Gobackend.getAllDownloadProgress()
+                        Gobackend.getAllDownloadProgressDelta(lastDownloadProgressSeq)
                     }
-                    if (payload != lastDownloadProgressPayload) {
+                    if (payload.isNotEmpty() && payload != lastDownloadProgressPayload) {
+                        updateDownloadProgressSeq(payload)
                         lastDownloadProgressPayload = payload
                         sink.success(parseJsonPayload(payload))
                     }
@@ -534,6 +566,7 @@ class MainActivity: FlutterFragmentActivity() {
         downloadProgressStreamJob = null
         downloadProgressEventSink = null
         lastDownloadProgressPayload = null
+        lastDownloadProgressSeq = 0L
     }
 
     private fun startLibraryScanProgressStream(sink: EventChannel.EventSink) {
@@ -580,17 +613,17 @@ class MainActivity: FlutterFragmentActivity() {
         lastLibraryScanProgressPayload = null
     }
 
-    private fun loadExistingFilesJsonFromSnapshot(snapshotPath: String): String {
+    private fun loadExistingFilesFromSnapshot(snapshotPath: String): MutableMap<String, Long> {
+        val result = mutableMapOf<String, Long>()
         if (snapshotPath.isBlank()) {
-            return "{}"
+            return result
         }
 
         val snapshotFile = File(snapshotPath)
         if (!snapshotFile.exists()) {
-            return "{}"
+            return result
         }
 
-        val result = JSONObject()
         snapshotFile.forEachLine { line ->
             if (line.isBlank()) return@forEachLine
             val separatorIndex = line.indexOf('\t')
@@ -600,10 +633,10 @@ class MainActivity: FlutterFragmentActivity() {
             val modTime = line.substring(0, separatorIndex).toLongOrNull() ?: 0L
             val filePath = line.substring(separatorIndex + 1)
             if (filePath.isNotEmpty()) {
-                result.put(filePath, modTime)
+                result[filePath] = modTime
             }
         }
-        return result.toString()
+        return result
     }
 
     private fun resolveSafFile(treeUriStr: String, relativeDir: String, fileName: String): String {
@@ -1452,6 +1485,22 @@ class MainActivity: FlutterFragmentActivity() {
      * @return JSON object with new/changed files and removed URIs
      */
     private fun scanSafTreeIncremental(treeUriStr: String, existingFilesJson: String): String {
+        val existingFiles = mutableMapOf<String, Long>()
+        try {
+            val obj = JSONObject(existingFilesJson)
+            val keys = obj.keys()
+            while (keys.hasNext()) {
+                val key = keys.next()
+                existingFiles[key] = obj.optLong(key, 0)
+            }
+        } catch (_: Exception) {}
+        return scanSafTreeIncremental(treeUriStr, existingFiles)
+    }
+
+    private fun scanSafTreeIncremental(
+        treeUriStr: String,
+        existingFiles: Map<String, Long>,
+    ): String {
         if (treeUriStr.isBlank()) {
             val result = JSONObject()
             result.put("files", JSONArray())
@@ -1471,16 +1520,6 @@ class MainActivity: FlutterFragmentActivity() {
             return result.toString()
         }
 
-        val existingFiles = mutableMapOf<String, Long>()
-        try {
-            val obj = JSONObject(existingFilesJson)
-            val keys = obj.keys()
-            while (keys.hasNext()) {
-                val key = keys.next()
-                existingFiles[key] = obj.optLong(key, 0)
-            }
-        } catch (_: Exception) {}
-
         resetSafScanProgress()
         safScanCancel = false
         safScanActive = true
@@ -3222,11 +3261,19 @@ class MainActivity: FlutterFragmentActivity() {
                             val extensionId = call.argument<String>("extension_id") ?: ""
                             val query = call.argument<String>("query") ?: ""
                             val optionsJson = call.argument<String>("options") ?: ""
+                            val requestId = call.argument<String>("request_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.customSearchWithExtensionJSON(extensionId, query, optionsJson)
+                                Gobackend.customSearchWithExtensionJSONWithRequestID(extensionId, query, optionsJson, requestId)
                             }
                             result.success(response)
                         }
+                        "cancelExtensionRequest" -> {
+                            val requestId = call.argument<String>("request_id") ?: ""
+                            withContext(Dispatchers.IO) {
+                                Gobackend.cancelExtensionRequestJSON(requestId)
+                            }
+                            result.success(null)
+                        }
                         "getSearchProviders" -> {
                             val response = withContext(Dispatchers.IO) {
                                 Gobackend.getSearchProvidersJSON()
@@ -3359,8 +3406,9 @@ class MainActivity: FlutterFragmentActivity() {
                         }
                         "getExtensionHomeFeed" -> {
                             val extensionId = call.argument<String>("extension_id") ?: ""
+                            val requestId = call.argument<String>("request_id") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                Gobackend.getExtensionHomeFeedJSON(extensionId)
+                                Gobackend.getExtensionHomeFeedJSONWithRequestID(extensionId, requestId)
                             }
                             result.success(response)
                         }
@@ -3382,7 +3430,7 @@ class MainActivity: FlutterFragmentActivity() {
                             val folderPath = call.argument<String>("folder_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                Gobackend.scanLibraryFolderJSON(folderPath)
+                                bridgeJsonResult(Gobackend.scanLibraryFolderJSON(folderPath))
                             }
                             result.success(response)
                         }
@@ -3391,7 +3439,9 @@ class MainActivity: FlutterFragmentActivity() {
                             val existingFiles = call.argument<String>("existing_files") ?: "{}"
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                Gobackend.scanLibraryFolderIncrementalJSON(folderPath, existingFiles)
+                                bridgeJsonResult(
+                                    Gobackend.scanLibraryFolderIncrementalJSON(folderPath, existingFiles)
+                                )
                             }
                             result.success(response)
                         }
@@ -3400,9 +3450,11 @@ class MainActivity: FlutterFragmentActivity() {
                             val snapshotPath = call.argument<String>("snapshot_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
                                 safScanActive = false
-                                Gobackend.scanLibraryFolderIncrementalFromSnapshotJSON(
-                                    folderPath,
-                                    snapshotPath,
+                                bridgeJsonResult(
+                                    Gobackend.scanLibraryFolderIncrementalFromSnapshotJSON(
+                                        folderPath,
+                                        snapshotPath,
+                                    )
                                 )
                             }
                             result.success(response)
@@ -3410,7 +3462,7 @@ class MainActivity: FlutterFragmentActivity() {
                         "scanSafTree" -> {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                scanSafTree(treeUri)
+                                bridgeJsonResult(scanSafTree(treeUri))
                             }
                             result.success(response)
                         }
@@ -3418,7 +3470,7 @@ class MainActivity: FlutterFragmentActivity() {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val existingFiles = call.argument<String>("existing_files") ?: "{}"
                             val response = withContext(Dispatchers.IO) {
-                                scanSafTreeIncremental(treeUri, existingFiles)
+                                bridgeJsonResult(scanSafTreeIncremental(treeUri, existingFiles))
                             }
                             result.success(response)
                         }
@@ -3426,9 +3478,9 @@ class MainActivity: FlutterFragmentActivity() {
                             val treeUri = call.argument<String>("tree_uri") ?: ""
                             val snapshotPath = call.argument<String>("snapshot_path") ?: ""
                             val response = withContext(Dispatchers.IO) {
-                                val existingFilesJson =
-                                    loadExistingFilesJsonFromSnapshot(snapshotPath)
-                                scanSafTreeIncremental(treeUri, existingFilesJson)
+                                val existingFiles =
+                                    loadExistingFilesFromSnapshot(snapshotPath)
+                                bridgeJsonResult(scanSafTreeIncremental(treeUri, existingFiles))
                             }
                             result.success(response)
                         }

go_backend/cancel.go

@@ -9,6 +9,10 @@ import (
 // ErrDownloadCancelled is returned when a download is cancelled by the user.
 var ErrDownloadCancelled = errors.New("download cancelled")
 
+// ErrExtensionRequestCancelled is returned when a UI-driven extension request
+// is superseded by a newer home/search request.
+var ErrExtensionRequestCancelled = errors.New("extension request cancelled")
+
 type cancelEntry struct {
 	ctx      context.Context
 	cancel   context.CancelFunc
@@ -19,6 +23,9 @@ type cancelEntry struct {
 var (
 	cancelMu  sync.Mutex
 	cancelMap = make(map[string]*cancelEntry)
+
+	extensionRequestCancelMu  sync.Mutex
+	extensionRequestCancelMap = make(map[string]*cancelEntry)
 )
 
 func initDownloadCancel(itemID string) context.Context {
@@ -98,3 +105,78 @@ func clearDownloadCancel(itemID string) {
 	}
 	cancelMu.Unlock()
 }
+
+func initExtensionRequestCancel(requestID string) context.Context {
+	if requestID == "" {
+		return context.Background()
+	}
+
+	extensionRequestCancelMu.Lock()
+	defer extensionRequestCancelMu.Unlock()
+
+	if entry, ok := extensionRequestCancelMap[requestID]; ok {
+		if entry.ctx == nil {
+			ctx, cancel := context.WithCancel(context.Background())
+			entry.ctx = ctx
+			entry.cancel = cancel
+			if entry.canceled && entry.cancel != nil {
+				entry.cancel()
+			}
+		}
+		entry.refs++
+		return entry.ctx
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	extensionRequestCancelMap[requestID] = &cancelEntry{
+		ctx:      ctx,
+		cancel:   cancel,
+		canceled: false,
+		refs:     1,
+	}
+	return ctx
+}
+
+func cancelExtensionRequest(requestID string) {
+	if requestID == "" {
+		return
+	}
+
+	extensionRequestCancelMu.Lock()
+	if entry, ok := extensionRequestCancelMap[requestID]; ok {
+		entry.canceled = true
+		if entry.cancel != nil {
+			entry.cancel()
+		}
+	} else {
+		extensionRequestCancelMap[requestID] = &cancelEntry{canceled: true}
+	}
+	extensionRequestCancelMu.Unlock()
+}
+
+func isExtensionRequestCancelled(requestID string) bool {
+	if requestID == "" {
+		return false
+	}
+
+	extensionRequestCancelMu.Lock()
+	entry, ok := extensionRequestCancelMap[requestID]
+	canceled := ok && entry.canceled
+	extensionRequestCancelMu.Unlock()
+	return canceled
+}
+
+func clearExtensionRequestCancel(requestID string) {
+	if requestID == "" {
+		return
+	}
+
+	extensionRequestCancelMu.Lock()
+	if entry, ok := extensionRequestCancelMap[requestID]; ok {
+		entry.refs--
+		if entry.refs <= 0 {
+			delete(extensionRequestCancelMap, requestID)
+		}
+	}
+	extensionRequestCancelMu.Unlock()
+}

go_backend/exports.go

@@ -3,6 +3,7 @@ package gobackend
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -1059,6 +1060,10 @@ func GetAllDownloadProgress() string {
 	return GetMultiProgress()
 }
 
+func GetAllDownloadProgressDelta(sinceSeq int64) string {
+	return GetMultiProgressDelta(sinceSeq)
+}
+
 func InitItemProgress(itemID string) {
 	StartItemProgress(itemID)
 }
@@ -3217,6 +3222,10 @@ func EnrichTrackWithExtensionJSON(extensionID, trackJSON string) (string, error)
 }
 
 func CustomSearchWithExtensionJSON(extensionID, query string, optionsJSON string) (string, error) {
+	return CustomSearchWithExtensionJSONWithRequestID(extensionID, query, optionsJSON, "")
+}
+
+func CustomSearchWithExtensionJSONWithRequestID(extensionID, query string, optionsJSON string, requestID string) (string, error) {
 	manager := getExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
 	if err != nil {
@@ -3235,7 +3244,7 @@ func CustomSearchWithExtensionJSON(extensionID, query string, optionsJSON string
 	}
 
 	provider := newExtensionProviderWrapper(ext)
-	tracks, err := provider.CustomSearch(query, options)
+	tracks, err := provider.CustomSearchForRequestID(query, options, requestID)
 	if err != nil {
 		return "", err
 	}
@@ -3714,6 +3723,10 @@ func ClearStoreCacheJSON() error {
 }
 
 func callExtensionFunctionJSON(extensionID, functionName string, timeout time.Duration) (string, error) {
+	return callExtensionFunctionJSONWithRequestID(extensionID, functionName, timeout, "")
+}
+
+func callExtensionFunctionJSONWithRequestID(extensionID, functionName string, timeout time.Duration, requestID string) (string, error) {
 	manager := getExtensionManager()
 	ext, err := manager.GetExtension(extensionID)
 	if err != nil {
@@ -3723,11 +3736,27 @@ func callExtensionFunctionJSON(extensionID, functionName string, timeout time.Du
 	if !ext.Enabled {
 		return "", fmt.Errorf("extension '%s' is disabled", extensionID)
 	}
+	perf := newExtensionCallPerf(extensionID, functionName)
+	defer perf.finish()
+	initStartedAt := time.Now()
 	vm, err := ext.lockReadyVM()
 	if err != nil {
 		return "", err
 	}
+	perf.recordInit(time.Since(initStartedAt))
 	defer ext.VMMu.Unlock()
+	requestCtx := context.Background()
+	if requestID != "" {
+		if ext.runtime != nil {
+			ext.runtime.setActiveRequestID(requestID)
+			defer ext.runtime.clearActiveRequestID()
+		}
+		requestCtx = initExtensionRequestCancel(requestID)
+		defer clearExtensionRequestCancel(requestID)
+		if isExtensionRequestCancelled(requestID) {
+			return "", ErrExtensionRequestCancelled
+		}
+	}
 
 	// Goja runtime is not thread-safe; guard direct extension.*() calls with VMMu
 	// to avoid races with other provider calls (e.g. getAlbum/getPlaylist).
@@ -3740,20 +3769,31 @@ func callExtensionFunctionJSON(extensionID, functionName string, timeout time.Du
 		})()
 	`, functionName, functionName)
 
-	result, err := RunWithTimeoutAndRecover(vm, script, timeout)
+	jsStartedAt := time.Now()
+	result, err := RunWithTimeoutContextAndRecover(requestCtx, vm, script, timeout)
+	perf.recordJS(time.Since(jsStartedAt))
 	if err != nil {
+		if isExtensionRequestCancelled(requestID) || errors.Is(err, ErrExtensionRequestCancelled) {
+			return "", ErrExtensionRequestCancelled
+		}
 		return "", fmt.Errorf("%s failed: %w", functionName, err)
 	}
+	if isExtensionRequestCancelled(requestID) {
+		return "", ErrExtensionRequestCancelled
+	}
 
 	if result == nil || goja.IsUndefined(result) || goja.IsNull(result) {
 		return "", fmt.Errorf("%s returned null", functionName)
 	}
 
-	exported := result.Export()
-	jsonBytes, err := json.Marshal(exported)
+	parseStartedAt := time.Now()
+	jsonBytes, err := json.Marshal(result)
+	perf.recordParse(time.Since(parseStartedAt))
 	if err != nil {
 		return "", fmt.Errorf("failed to marshal result: %w", err)
 	}
+	perf.setPayloadBytes(len(jsonBytes))
+	perf.setItems(countExtensionTopLevelItems(vm, result))
 
 	return string(jsonBytes), nil
 }
@@ -3762,10 +3802,18 @@ func GetExtensionHomeFeedJSON(extensionID string) (string, error) {
 	return callExtensionFunctionJSON(extensionID, "getHomeFeed", 60*time.Second)
 }
 
+func GetExtensionHomeFeedJSONWithRequestID(extensionID, requestID string) (string, error) {
+	return callExtensionFunctionJSONWithRequestID(extensionID, "getHomeFeed", 60*time.Second, requestID)
+}
+
 func GetExtensionBrowseCategoriesJSON(extensionID string) (string, error) {
 	return callExtensionFunctionJSON(extensionID, "getBrowseCategories", 30*time.Second)
 }
 
+func CancelExtensionRequestJSON(requestID string) {
+	cancelExtensionRequest(requestID)
+}
+
 func SetLibraryCoverCacheDirJSON(cacheDir string) {
 	SetLibraryCoverCacheDir(cacheDir)
 }

go_backend/extension_perf.go

@@ -0,0 +1,119 @@
+package gobackend
+
+import (
+	"encoding/json"
+	"time"
+
+	"github.com/dop251/goja"
+)
+
+type extensionCallPerf struct {
+	extensionID  string
+	operation    string
+	startedAt    time.Time
+	initMs       float64
+	jsMs         float64
+	parseMs      float64
+	items        int
+	payloadBytes int
+}
+
+func newExtensionCallPerf(extensionID, operation string) *extensionCallPerf {
+	if !GetLogBuffer().IsLoggingEnabled() {
+		return nil
+	}
+	return &extensionCallPerf{
+		extensionID: extensionID,
+		operation:   operation,
+		startedAt:   time.Now(),
+	}
+}
+
+func extensionDurationMs(duration time.Duration) float64 {
+	return float64(duration.Microseconds()) / 1000.0
+}
+
+func (p *extensionCallPerf) recordInit(duration time.Duration) {
+	if p == nil {
+		return
+	}
+	p.initMs += extensionDurationMs(duration)
+}
+
+func (p *extensionCallPerf) recordJS(duration time.Duration) {
+	if p == nil {
+		return
+	}
+	p.jsMs += extensionDurationMs(duration)
+}
+
+func (p *extensionCallPerf) recordParse(duration time.Duration) {
+	if p == nil {
+		return
+	}
+	p.parseMs += extensionDurationMs(duration)
+}
+
+func (p *extensionCallPerf) recordPayload(value goja.Value) {
+	if p == nil || gojaValueIsEmpty(value) {
+		return
+	}
+	if payload, err := json.Marshal(value); err == nil {
+		p.payloadBytes = len(payload)
+	}
+}
+
+func (p *extensionCallPerf) setPayloadBytes(payloadBytes int) {
+	if p == nil {
+		return
+	}
+	p.payloadBytes = payloadBytes
+}
+
+func (p *extensionCallPerf) setItems(items int) {
+	if p == nil {
+		return
+	}
+	p.items = items
+}
+
+func (p *extensionCallPerf) finish() {
+	if p == nil {
+		return
+	}
+	LogDebug(
+		"ExtensionPerf",
+		"extension=%s op=%s totalMs=%.1f initMs=%.1f jsMs=%.1f parseMs=%.1f items=%d payloadBytes=%d",
+		p.extensionID,
+		p.operation,
+		extensionDurationMs(time.Since(p.startedAt)),
+		p.initMs,
+		p.jsMs,
+		p.parseMs,
+		p.items,
+		p.payloadBytes,
+	)
+}
+
+func countExtensionTopLevelItems(vm *goja.Runtime, value goja.Value) int {
+	if gojaValueIsEmpty(value) {
+		return 0
+	}
+
+	if length, err := gojaArrayLength(value, vm); err == nil && length > 0 {
+		return length
+	}
+
+	obj := value.ToObject(vm)
+	for _, key := range []string{"items", "tracks", "sections", "albums", "artists", "playlists", "results"} {
+		child := obj.Get(key)
+		if gojaValueIsEmpty(child) {
+			continue
+		}
+		if length, err := gojaArrayLength(child, vm); err == nil && length > 0 {
+			return length
+		}
+	}
+
+	return 1
+}

go_backend/extension_providers_test.go

@@ -13,6 +13,8 @@ import (
 	"sync"
 	"testing"
 	"time"
+
+	"github.com/dop251/goja"
 )
 
 func TestSetMetadataProviderPriorityStripsRetiredBuiltIns(t *testing.T) {
@@ -396,3 +398,243 @@ func TestSearchTracksWithMetadataProvidersIgnoresRetiredBuiltIns(t *testing.T) {
 		t.Fatalf("expected retired built-in provider not to be queried, got %v", calls)
 	}
 }
+
+func TestParseExtensionSearchResultAcceptsObjectAndArrayShapes(t *testing.T) {
+	vm := goja.New()
+	value, err := vm.RunString(`({
+		tracks: [{
+			id: "track-1",
+			name: "Song",
+			artists: "Artist",
+			album_name: "Album",
+			duration_ms: 123000,
+			cover_url: "https://img.test/cover.jpg",
+			external_links: { spotify: "spotify:track:1" },
+			audio_quality: "LOSSLESS"
+		}],
+		total: 9
+	})`)
+	if err != nil {
+		t.Fatalf("build object search result: %v", err)
+	}
+
+	result, err := parseExtensionSearchResult(vm, value)
+	if err != nil {
+		t.Fatalf("parse object search result: %v", err)
+	}
+	if result.Total != 9 || len(result.Tracks) != 1 {
+		t.Fatalf("unexpected object result: %+v", result)
+	}
+	track := result.Tracks[0]
+	if track.ID != "track-1" ||
+		track.AlbumName != "Album" ||
+		track.DurationMS != 123000 ||
+		track.CoverURL != "https://img.test/cover.jpg" ||
+		track.ExternalLinks["spotify"] != "spotify:track:1" ||
+		track.AudioQuality != "LOSSLESS" {
+		t.Fatalf("unexpected parsed track: %+v", track)
+	}
+
+	arrayValue, err := vm.RunString(`[
+		{id: "track-2", name: "Other Song", artists: "Other Artist", albumName: "Other Album", durationMs: 456000}
+	]`)
+	if err != nil {
+		t.Fatalf("build array search result: %v", err)
+	}
+
+	arrayResult, err := parseExtensionSearchResult(vm, arrayValue)
+	if err != nil {
+		t.Fatalf("parse array search result: %v", err)
+	}
+	if arrayResult.Total != 1 ||
+		len(arrayResult.Tracks) != 1 ||
+		arrayResult.Tracks[0].AlbumName != "Other Album" ||
+		arrayResult.Tracks[0].DurationMS != 456000 {
+		t.Fatalf("unexpected array result: %+v", arrayResult)
+	}
+}
+
+func TestParseExtensionMetadataAndDownloadResults(t *testing.T) {
+	vm := goja.New()
+	value, err := vm.RunString(`({
+		id: "album-1",
+		name: "Album",
+		artists: "Artist",
+		artistId: "artist-1",
+		coverUrl: "https://img.test/album.jpg",
+		releaseDate: "2024-02-03",
+		totalTracks: 2,
+		albumType: "album",
+		tracks: [
+			{id: "track-1", name: "Song 1", artists: "Artist", durationMs: 180000},
+			{id: "track-2", name: "Song 2", artists: "Artist", duration_ms: 181000}
+		]
+	})`)
+	if err != nil {
+		t.Fatalf("build album value: %v", err)
+	}
+
+	album, err := parseExtensionAlbumValue(vm, value)
+	if err != nil {
+		t.Fatalf("parse album: %v", err)
+	}
+	if album.ID != "album-1" ||
+		album.ArtistID != "artist-1" ||
+		album.CoverURL != "https://img.test/album.jpg" ||
+		album.TotalTracks != 2 ||
+		len(album.Tracks) != 2 ||
+		album.Tracks[0].DurationMS != 180000 ||
+		album.Tracks[1].DurationMS != 181000 {
+		t.Fatalf("unexpected album: %+v", album)
+	}
+
+	artistValue, err := vm.RunString(`({
+		id: "artist-1",
+		name: "Artist",
+		imageUrl: "https://img.test/artist.jpg",
+		headerImage: "https://img.test/header.jpg",
+		listeners: 1234,
+		albums: [{id: "album-1", name: "Album", tracks: [{id: "track-1", name: "Song"}]}],
+		releases: [{id: "single-1", name: "Single"}],
+		topTracks: [{id: "top-1", name: "Top Song"}]
+	})`)
+	if err != nil {
+		t.Fatalf("build artist value: %v", err)
+	}
+
+	artist, err := parseExtensionArtistValue(vm, artistValue)
+	if err != nil {
+		t.Fatalf("parse artist: %v", err)
+	}
+	if artist.ID != "artist-1" ||
+		artist.ImageURL != "https://img.test/artist.jpg" ||
+		artist.HeaderImage != "https://img.test/header.jpg" ||
+		artist.Listeners != 1234 ||
+		len(artist.Albums) != 1 ||
+		len(artist.Albums[0].Tracks) != 1 ||
+		len(artist.Releases) != 1 ||
+		len(artist.TopTracks) != 1 {
+		t.Fatalf("unexpected artist: %+v", artist)
+	}
+
+	downloadValue, err := vm.RunString(`({
+		success: true,
+		filePath: "/tmp/song.flac",
+		alreadyExists: true,
+		bitDepth: 24,
+		sampleRate: 96000,
+		title: "Song",
+		albumArtist: "Album Artist",
+		lyricsLrc: "[00:00.00]Line",
+		decryptionKey: "001122",
+		decryption: {
+			strategy: "mp4_decryption_key",
+			key: "001122",
+			inputFormat: "m4a",
+			options: { map: "0:a" }
+		}
+	})`)
+	if err != nil {
+		t.Fatalf("build download value: %v", err)
+	}
+
+	download := parseExtensionDownloadResultValue(vm, downloadValue)
+	if !download.Success ||
+		download.FilePath != "/tmp/song.flac" ||
+		!download.AlreadyExists ||
+		download.BitDepth != 24 ||
+		download.SampleRate != 96000 ||
+		download.AlbumArtist != "Album Artist" ||
+		download.LyricsLRC != "[00:00.00]Line" ||
+		download.Decryption == nil ||
+		download.Decryption.InputFormat != "m4a" ||
+		download.Decryption.Options["map"] != "0:a" {
+		t.Fatalf("unexpected download result: %+v", download)
+	}
+
+	availabilityValue, err := vm.RunString(`({ available: true, trackId: "track-1", skipFallback: true, reason: "direct" })`)
+	if err != nil {
+		t.Fatalf("build availability value: %v", err)
+	}
+	availability := parseExtensionAvailabilityValue(vm, availabilityValue)
+	if !availability.Available || availability.TrackID != "track-1" || !availability.SkipFallback || availability.Reason != "direct" {
+		t.Fatalf("unexpected availability: %+v", availability)
+	}
+}
+
+func TestParseExtensionURLHandleResult(t *testing.T) {
+	vm := goja.New()
+	value, err := vm.RunString(`({
+		type: "album",
+		name: "Shared Album",
+		coverUrl: "https://img.test/shared.jpg",
+		track: { id: "track-1", name: "Song" },
+		tracks: [{ id: "track-2", name: "Song 2" }],
+		album: { id: "album-1", name: "Album", tracks: [{ id: "track-3", name: "Song 3" }] },
+		artist: { id: "artist-1", name: "Artist", topTracks: [{ id: "track-4", name: "Song 4" }] }
+	})`)
+	if err != nil {
+		t.Fatalf("build URL handle value: %v", err)
+	}
+
+	result, err := parseExtensionURLHandleValue(vm, value)
+	if err != nil {
+		t.Fatalf("parse URL handle: %v", err)
+	}
+	if result.Type != "album" ||
+		result.CoverURL != "https://img.test/shared.jpg" ||
+		result.Track == nil ||
+		result.Track.ID != "track-1" ||
+		len(result.Tracks) != 1 ||
+		result.Album == nil ||
+		len(result.Album.Tracks) != 1 ||
+		result.Artist == nil ||
+		len(result.Artist.TopTracks) != 1 {
+		t.Fatalf("unexpected URL handle result: %+v", result)
+	}
+}
+
+func TestParseExtensionAuxiliaryResults(t *testing.T) {
+	vm := goja.New()
+
+	matchValue, err := vm.RunString(`({ matched: true, trackId: "track-1", confidence: 0.92, reason: "isrc" })`)
+	if err != nil {
+		t.Fatalf("build match value: %v", err)
+	}
+	match := parseExtensionMatchTrackValue(vm, matchValue)
+	if !match.Matched || match.TrackID != "track-1" || match.Confidence != 0.92 || match.Reason != "isrc" {
+		t.Fatalf("unexpected match result: %+v", match)
+	}
+
+	postValue, err := vm.RunString(`({ success: true, newFilePath: "/tmp/new.flac", newFileUri: "content://new", bitDepth: 24, sampleRate: 96000 })`)
+	if err != nil {
+		t.Fatalf("build post-process value: %v", err)
+	}
+	post := parseExtensionPostProcessValue(vm, postValue)
+	if !post.Success || post.NewFilePath != "/tmp/new.flac" || post.NewFileURI != "content://new" || post.BitDepth != 24 || post.SampleRate != 96000 {
+		t.Fatalf("unexpected post-process result: %+v", post)
+	}
+
+	lyricsValue, err := vm.RunString(`({
+		syncType: "LINE_SYNCED",
+		instrumental: false,
+		plainLyrics: "Line",
+		provider: "Lyrics Provider",
+		lines: [{ startTimeMs: 1000, words: "Line", endTimeMs: 2000 }]
+	})`)
+	if err != nil {
+		t.Fatalf("build lyrics value: %v", err)
+	}
+	lyrics, err := parseExtensionLyricsValue(vm, lyricsValue)
+	if err != nil {
+		t.Fatalf("parse lyrics: %v", err)
+	}
+	if lyrics.SyncType != "LINE_SYNCED" ||
+		lyrics.PlainLyrics != "Line" ||
+		lyrics.Provider != "Lyrics Provider" ||
+		len(lyrics.Lines) != 1 ||
+		lyrics.Lines[0].StartTimeMs != 1000 ||
+		lyrics.Lines[0].EndTimeMs != 2000 {
+		t.Fatalf("unexpected lyrics result: %+v", lyrics)
+	}
+}

go_backend/extension_runtime.go

@@ -94,6 +94,9 @@ type extensionRuntime struct {
 	activeDownloadMu     sync.RWMutex
 	activeDownloadItemID string
 
+	activeRequestMu sync.RWMutex
+	activeRequestID string
+
 	storageMu      sync.RWMutex
 	storageCache   map[string]interface{}
 	storageLoaded  bool
@@ -209,6 +212,24 @@ func (r *extensionRuntime) getActiveDownloadItemID() string {
 	return r.activeDownloadItemID
 }
 
+func (r *extensionRuntime) setActiveRequestID(requestID string) {
+	r.activeRequestMu.Lock()
+	defer r.activeRequestMu.Unlock()
+	r.activeRequestID = strings.TrimSpace(requestID)
+}
+
+func (r *extensionRuntime) clearActiveRequestID() {
+	r.activeRequestMu.Lock()
+	defer r.activeRequestMu.Unlock()
+	r.activeRequestID = ""
+}
+
+func (r *extensionRuntime) getActiveRequestID() string {
+	r.activeRequestMu.RLock()
+	defer r.activeRequestMu.RUnlock()
+	return r.activeRequestID
+}
+
 func (r *extensionRuntime) bindDownloadCancelContext(req *http.Request) *http.Request {
 	if req == nil {
 		return nil
@@ -216,7 +237,11 @@ func (r *extensionRuntime) bindDownloadCancelContext(req *http.Request) *http.Re
 
 	itemID := r.getActiveDownloadItemID()
 	if itemID == "" {
-		return req
+		requestID := r.getActiveRequestID()
+		if requestID == "" {
+			return req
+		}
+		return req.WithContext(initExtensionRequestCancel(requestID))
 	}
 
 	return req.WithContext(initDownloadCancel(itemID))
@@ -479,6 +504,7 @@ func (r *extensionRuntime) RegisterAPIs(vm *goja.Runtime) {
 	utilsObj.Set("appUserAgent", r.appUserAgent)
 	utilsObj.Set("sleep", r.sleep)
 	utilsObj.Set("isDownloadCancelled", r.isDownloadCancelled)
+	utilsObj.Set("isRequestCancelled", r.isRequestCancelled)
 	utilsObj.Set("setDownloadStatus", r.setDownloadStatus)
 	vm.Set("utils", utilsObj)
 

go_backend/extension_runtime_utils.go

@@ -312,6 +312,14 @@ func (r *extensionRuntime) isDownloadCancelled(call goja.FunctionCall) goja.Valu
 	return r.vm.ToValue(isDownloadCancelled(itemID))
 }
 
+func (r *extensionRuntime) isRequestCancelled(call goja.FunctionCall) goja.Value {
+	requestID := r.getActiveRequestID()
+	if requestID == "" {
+		return r.vm.ToValue(false)
+	}
+	return r.vm.ToValue(isExtensionRequestCancelled(requestID))
+}
+
 func (r *extensionRuntime) setDownloadStatus(call goja.FunctionCall) goja.Value {
 	itemID := r.getActiveDownloadItemID()
 	if itemID == "" || len(call.Arguments) < 1 {

go_backend/extension_test.go

@@ -1,6 +1,8 @@
 package gobackend
 
 import (
+	"context"
+	"errors"
 	"net/http"
 	"path/filepath"
 	"testing"
@@ -379,6 +381,48 @@ func TestExtensionRuntime_BindDownloadCancelContextPreservesPreCancelledState(t
 	}
 }
 
+func TestRunWithTimeoutContextCancelsExecution(t *testing.T) {
+	vm := goja.New()
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	_, err := RunWithTimeoutContextAndRecover(ctx, vm, `while (true) {}`, 5*time.Second)
+	if !errors.Is(err, ErrExtensionRequestCancelled) {
+		t.Fatalf("expected extension request cancellation, got %v", err)
+	}
+}
+
+func TestExtensionRuntime_BindExtensionRequestCancelContext(t *testing.T) {
+	ext := &loadedExtension{
+		ID: "test-ext",
+		Manifest: &ExtensionManifest{
+			Name: "test-ext",
+		},
+		DataDir: t.TempDir(),
+	}
+	runtime := newExtensionRuntime(ext)
+
+	const requestID = "test-extension-request"
+	clearExtensionRequestCancel(requestID)
+	defer clearExtensionRequestCancel(requestID)
+
+	runtime.setActiveRequestID(requestID)
+	defer runtime.clearActiveRequestID()
+
+	req, err := http.NewRequest(http.MethodGet, "https://example.com", nil)
+	if err != nil {
+		t.Fatalf("new request: %v", err)
+	}
+	req = runtime.bindDownloadCancelContext(req)
+
+	cancelExtensionRequest(requestID)
+	select {
+	case <-req.Context().Done():
+	case <-time.After(time.Second):
+		t.Fatal("expected request context to be cancelled")
+	}
+}
+
 func TestExtensionRuntime_SSRFProtection(t *testing.T) {
 	// Create extension with limited network permissions
 	ext := &loadedExtension{

go_backend/extension_timeout.go

@@ -20,6 +20,10 @@ func (e *JSExecutionError) Error() string {
 }
 
 func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
+	return RunWithTimeoutContext(context.Background(), vm, script, timeout)
+}
+
+func RunWithTimeoutContext(ctx context.Context, vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
 	if vm == nil {
 		return nil, fmt.Errorf("extension runtime unavailable")
 	}
@@ -28,7 +32,10 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 		timeout = DefaultJSTimeout
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	ctx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
 	type result struct {
@@ -67,11 +74,16 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 	case res := <-resultCh:
 		return res.value, res.err
 	case <-ctx.Done():
+		cancelled := ctx.Err() == context.Canceled
 		interruptMu.Lock()
 		interrupted = true
 		interruptMu.Unlock()
 
-		vm.Interrupt("execution timeout")
+		if cancelled {
+			vm.Interrupt("extension request cancelled")
+		} else {
+			vm.Interrupt("execution timeout")
+		}
 
 		// MUST wait for the goroutine to finish before returning.
 		// The Goja VM is NOT thread-safe — if we return while the goroutine
@@ -80,6 +92,9 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 		// pointer dereference.
 		select {
 		case res := <-resultCh:
+			if cancelled {
+				return nil, ErrExtensionRequestCancelled
+			}
 			if res.err != nil {
 				return nil, res.err
 			}
@@ -91,6 +106,9 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 			// Goroutine is truly stuck (e.g. HTTP read with no timeout).
 			// Log a warning — the VM should NOT be reused after this.
 			GoLog("[extensionRuntime] WARNING: JS goroutine did not exit within 60s after interrupt, VM may be unsafe\n")
+			if cancelled {
+				return nil, ErrExtensionRequestCancelled
+			}
 			return nil, &JSExecutionError{
 				Message:   "execution timeout exceeded (force)",
 				IsTimeout: true,
@@ -102,7 +120,11 @@ func RunWithTimeout(vm *goja.Runtime, script string, timeout time.Duration) (goj
 // RunWithTimeoutAndRecover runs JS with timeout and clears interrupt state after
 // This should be used when you want to continue using the VM after a timeout
 func RunWithTimeoutAndRecover(vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
-	result, err := RunWithTimeout(vm, script, timeout)
+	return RunWithTimeoutContextAndRecover(context.Background(), vm, script, timeout)
+}
+
+func RunWithTimeoutContextAndRecover(ctx context.Context, vm *goja.Runtime, script string, timeout time.Duration) (goja.Value, error) {
+	result, err := RunWithTimeoutContext(ctx, vm, script, timeout)
 
 	if vm != nil {
 		vm.ClearInterrupt()

go_backend/progress.go

@@ -2,6 +2,7 @@ package gobackend
 
 import (
 	"encoding/json"
+	"math"
 	"sync"
 	"time"
 )
@@ -24,6 +25,7 @@ type ItemProgress struct {
 	SpeedMBps     float64 `json:"speed_mbps"`
 	IsDownloading bool    `json:"is_downloading"`
 	Status        string  `json:"status"`
+	revision      int64
 }
 
 const (
@@ -37,6 +39,22 @@ type MultiProgress struct {
 	Items map[string]*ItemProgress `json:"items"`
 }
 
+type MultiProgressDelta struct {
+	Seq     int64                    `json:"seq"`
+	Reset   bool                     `json:"reset,omitempty"`
+	Items   map[string]*ItemProgress `json:"items,omitempty"`
+	Removed []string                 `json:"removed,omitempty"`
+}
+
+type progressBridgeState struct {
+	bytesBucket   int64
+	bytesTotal    int64
+	progressPct   int64
+	speedDeciMBps int64
+	downloading   bool
+	status        string
+}
+
 var (
 	downloadDir   string
 	downloadDirMu sync.RWMutex
@@ -45,12 +63,50 @@ var (
 	multiMu             sync.RWMutex
 	multiProgressDirty  = true
 	cachedMultiProgress = "{\"items\":{}}"
+	multiProgressSeq    int64
+	multiProgressReset  int64
+	removedProgressSeq  = make(map[string]int64)
 )
 
 func markMultiProgressDirtyLocked() {
 	multiProgressDirty = true
 }
 
+func nextMultiProgressSeqLocked() int64 {
+	multiProgressSeq++
+	return multiProgressSeq
+}
+
+func itemProgressBridgeState(item *ItemProgress) progressBridgeState {
+	progress := item.Progress
+	if math.IsNaN(progress) || progress <= 0 {
+		progress = 0
+	} else if progress >= 1 {
+		progress = 1
+	}
+
+	speed := item.SpeedMBps
+	if math.IsNaN(speed) || speed <= 0 {
+		speed = 0
+	}
+
+	return progressBridgeState{
+		bytesBucket:   item.BytesReceived / progressUpdateThreshold,
+		bytesTotal:    item.BytesTotal,
+		progressPct:   int64(math.Round(progress * 100)),
+		speedDeciMBps: int64(math.Round(speed * 10)),
+		downloading:   item.IsDownloading,
+		status:        item.Status,
+	}
+}
+
+func markMultiProgressDirtyIfChangedLocked(item *ItemProgress, before progressBridgeState) {
+	if itemProgressBridgeState(item) != before {
+		item.revision = nextMultiProgressSeqLocked()
+		markMultiProgressDirtyLocked()
+	}
+}
+
 func getProgress() DownloadProgress {
 	multiMu.RLock()
 	defer multiMu.RUnlock()
@@ -92,6 +148,54 @@ func GetMultiProgress() string {
 	return cachedMultiProgress
 }
 
+func GetMultiProgressDelta(sinceSeq int64) string {
+	multiMu.RLock()
+	currentSeq := multiProgressSeq
+	if sinceSeq >= currentSeq {
+		multiMu.RUnlock()
+		return ""
+	}
+
+	reset := sinceSeq <= 0 || sinceSeq < multiProgressReset
+	delta := MultiProgressDelta{
+		Seq:   currentSeq,
+		Reset: reset,
+	}
+	if reset {
+		if len(multiProgress.Items) > 0 {
+			delta.Items = make(map[string]*ItemProgress, len(multiProgress.Items))
+			for id, item := range multiProgress.Items {
+				copy := *item
+				copy.revision = 0
+				delta.Items[id] = &copy
+			}
+		}
+	} else {
+		for id, item := range multiProgress.Items {
+			if item.revision > sinceSeq {
+				if delta.Items == nil {
+					delta.Items = make(map[string]*ItemProgress)
+				}
+				copy := *item
+				copy.revision = 0
+				delta.Items[id] = &copy
+			}
+		}
+		for id, revision := range removedProgressSeq {
+			if revision > sinceSeq {
+				delta.Removed = append(delta.Removed, id)
+			}
+		}
+	}
+	multiMu.RUnlock()
+
+	jsonBytes, err := json.Marshal(delta)
+	if err != nil {
+		return ""
+	}
+	return string(jsonBytes)
+}
+
 func GetItemProgress(itemID string) string {
 	multiMu.RLock()
 	defer multiMu.RUnlock()
@@ -114,7 +218,9 @@ func StartItemProgress(itemID string) {
 		Progress:      0,
 		IsDownloading: true,
 		Status:        itemProgressStatusDownloading,
+		revision:      nextMultiProgressSeqLocked(),
 	}
+	delete(removedProgressSeq, itemID)
 	markMultiProgressDirtyLocked()
 }
 
@@ -123,13 +229,14 @@ func SetItemPreparing(itemID string) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.Progress = 0
 		item.BytesReceived = 0
 		item.BytesTotal = 0
 		item.SpeedMBps = 0
 		item.IsDownloading = true
 		item.Status = itemProgressStatusPreparing
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -138,9 +245,10 @@ func SetItemDownloading(itemID string) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.IsDownloading = true
 		item.Status = itemProgressStatusDownloading
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -149,8 +257,9 @@ func SetItemBytesTotal(itemID string, total int64) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.BytesTotal = total
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -159,11 +268,12 @@ func SetItemBytesReceived(itemID string, received int64) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.BytesReceived = received
 		if item.BytesTotal > 0 {
 			item.Progress = float64(received) / float64(item.BytesTotal)
 		}
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -172,12 +282,13 @@ func SetItemBytesReceivedWithSpeed(itemID string, received int64, speedMBps floa
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.BytesReceived = received
 		item.SpeedMBps = speedMBps
 		if item.BytesTotal > 0 {
 			item.Progress = float64(received) / float64(item.BytesTotal)
 		}
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -186,10 +297,11 @@ func CompleteItemProgress(itemID string) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.Progress = 1.0
 		item.IsDownloading = false
 		item.Status = itemProgressStatusCompleted
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -198,6 +310,7 @@ func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.Progress = progress
 		if bytesReceived > 0 {
 			item.BytesReceived = bytesReceived
@@ -205,7 +318,7 @@ func SetItemProgress(itemID string, progress float64, bytesReceived, bytesTotal
 		if bytesTotal > 0 {
 			item.BytesTotal = bytesTotal
 		}
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -214,9 +327,10 @@ func SetItemFinalizing(itemID string) {
 	defer multiMu.Unlock()
 
 	if item, ok := multiProgress.Items[itemID]; ok {
+		before := itemProgressBridgeState(item)
 		item.Progress = 1.0
 		item.Status = itemProgressStatusFinalizing
-		markMultiProgressDirtyLocked()
+		markMultiProgressDirtyIfChangedLocked(item, before)
 	}
 }
 
@@ -224,7 +338,10 @@ func RemoveItemProgress(itemID string) {
 	multiMu.Lock()
 	defer multiMu.Unlock()
 
-	delete(multiProgress.Items, itemID)
+	if _, ok := multiProgress.Items[itemID]; ok {
+		delete(multiProgress.Items, itemID)
+		removedProgressSeq[itemID] = nextMultiProgressSeqLocked()
+	}
 	markMultiProgressDirtyLocked()
 }
 
@@ -233,6 +350,8 @@ func ClearAllItemProgress() {
 	defer multiMu.Unlock()
 
 	multiProgress.Items = make(map[string]*ItemProgress)
+	removedProgressSeq = make(map[string]int64)
+	multiProgressReset = nextMultiProgressSeqLocked()
 	markMultiProgressDirtyLocked()
 }
 
@@ -253,7 +372,7 @@ type ItemProgressWriter struct {
 	lastBytes    int64
 }
 
-const progressUpdateThreshold = 64 * 1024
+const progressUpdateThreshold = 128 * 1024
 
 func NewItemProgressWriter(w interface{ Write([]byte) (int, error) }, itemID string) *ItemProgressWriter {
 	now := time.Now()

go_backend/progress_test.go

@@ -1,6 +1,9 @@
 package gobackend
 
-import "testing"
+import (
+	"encoding/json"
+	"testing"
+)
 
 func TestItemProgressPreparingAndDownloadingStatuses(t *testing.T) {
 	const itemID = "progress-phase-item"
@@ -57,3 +60,50 @@ func TestItemProgressFinalizingAndCompletedStatuses(t *testing.T) {
 		t.Fatalf("status = %q, want %q", item.Status, itemProgressStatusCompleted)
 	}
 }
+
+func TestMultiProgressDeltaResetChangedAndRemoved(t *testing.T) {
+	ClearAllItemProgress()
+	defer ClearAllItemProgress()
+
+	StartItemProgress("item-a")
+	SetItemBytesTotal("item-a", 1000)
+
+	var initial MultiProgressDelta
+	if err := json.Unmarshal([]byte(GetMultiProgressDelta(0)), &initial); err != nil {
+		t.Fatalf("initial delta parse failed: %v", err)
+	}
+	if !initial.Reset {
+		t.Fatal("initial delta should reset")
+	}
+	if initial.Seq <= 0 {
+		t.Fatalf("initial seq = %d, want > 0", initial.Seq)
+	}
+	if _, ok := initial.Items["item-a"]; !ok {
+		t.Fatal("initial delta missing item-a")
+	}
+
+	if delta := GetMultiProgressDelta(initial.Seq); delta != "" {
+		t.Fatalf("delta after same seq = %q, want empty", delta)
+	}
+
+	SetItemBytesReceivedWithSpeed("item-a", 256*1024, 2.5)
+	var changed MultiProgressDelta
+	if err := json.Unmarshal([]byte(GetMultiProgressDelta(initial.Seq)), &changed); err != nil {
+		t.Fatalf("changed delta parse failed: %v", err)
+	}
+	if changed.Reset {
+		t.Fatal("changed delta should not reset")
+	}
+	if _, ok := changed.Items["item-a"]; !ok {
+		t.Fatal("changed delta missing item-a")
+	}
+
+	RemoveItemProgress("item-a")
+	var removed MultiProgressDelta
+	if err := json.Unmarshal([]byte(GetMultiProgressDelta(changed.Seq)), &removed); err != nil {
+		t.Fatalf("removed delta parse failed: %v", err)
+	}
+	if len(removed.Removed) != 1 || removed.Removed[0] != "item-a" {
+		t.Fatalf("removed = %#v, want item-a", removed.Removed)
+	}
+}

ios/Runner/AppDelegate.swift

@@ -7,10 +7,13 @@ import Gobackend  // Import Go framework
     private let CHANNEL = "com.zarz.spotiflac/backend"
     private let DOWNLOAD_PROGRESS_STREAM_CHANNEL = "com.zarz.spotiflac/download_progress_stream"
     private let LIBRARY_SCAN_PROGRESS_STREAM_CHANNEL = "com.zarz.spotiflac/library_scan_progress_stream"
+    private let LARGE_JSON_RESULT_FILE_KEY = "__json_file"
+    private let LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES = 256 * 1024
     private let streamQueue = DispatchQueue(label: "com.zarz.spotiflac.progress_stream", qos: .utility)
     private var downloadProgressTimer: DispatchSourceTimer?
     private var downloadProgressEventSink: FlutterEventSink?
     private var lastDownloadProgressPayload: String?
+    private var lastDownloadProgressSeq: Int64 = 0
     private var libraryScanProgressTimer: DispatchSourceTimer?
     private var libraryScanProgressEventSink: FlutterEventSink?
     private var lastLibraryScanProgressPayload: String?
@@ -131,15 +134,17 @@ import Gobackend  // Import Go framework
         stopDownloadProgressStream()
         downloadProgressEventSink = eventSink
         lastDownloadProgressPayload = nil
+        lastDownloadProgressSeq = 0
 
         let timer = DispatchSource.makeTimerSource(queue: streamQueue)
         timer.schedule(deadline: .now(), repeating: .milliseconds(800))
         timer.setEventHandler { [weak self] in
             guard let self else { return }
-            let payload = GobackendGetAllDownloadProgress() as String? ?? "{}"
-            if payload == self.lastDownloadProgressPayload {
+            let payload = GobackendGetAllDownloadProgressDelta(self.lastDownloadProgressSeq) as String? ?? ""
+            if payload.isEmpty || payload == self.lastDownloadProgressPayload {
                 return
             }
+            self.updateDownloadProgressSeq(payload)
             self.lastDownloadProgressPayload = payload
             DispatchQueue.main.async { [weak self] in
                 self?.downloadProgressEventSink?(self?.parseJsonPayload(payload))
@@ -155,6 +160,7 @@ import Gobackend  // Import Go framework
         downloadProgressTimer = nil
         downloadProgressEventSink = nil
         lastDownloadProgressPayload = nil
+        lastDownloadProgressSeq = 0
     }
 
     private func startLibraryScanProgressStream(_ eventSink: @escaping FlutterEventSink) {
@@ -197,6 +203,34 @@ import Gobackend  // Import Go framework
             return payload
         }
     }
+
+    private func updateDownloadProgressSeq(_ payload: String) {
+        guard let data = payload.data(using: .utf8) else { return }
+        do {
+            if let obj = try JSONSerialization.jsonObject(with: data, options: [.fragmentsAllowed]) as? [String: Any],
+               let seq = obj["seq"] as? NSNumber,
+               seq.int64Value > lastDownloadProgressSeq {
+                lastDownloadProgressSeq = seq.int64Value
+            }
+        } catch {
+        }
+    }
+
+    private func bridgeJsonResult(_ payload: String) -> Any {
+        if payload.utf8.count < LARGE_JSON_RESULT_FILE_THRESHOLD_BYTES {
+            return payload
+        }
+
+        do {
+            let url = FileManager.default.temporaryDirectory
+                .appendingPathComponent("bridge_json_\(UUID().uuidString).json")
+            try payload.write(to: url, atomically: true, encoding: .utf8)
+            return [LARGE_JSON_RESULT_FILE_KEY: url.path]
+        } catch {
+            NSLog("SpotiFLAC: failed to spill large bridge JSON result to file: \(error.localizedDescription)")
+            return payload
+        }
+    }
     
     private func handleMethodCall(call: FlutterMethodCall, result: @escaping FlutterResult) {
         DispatchQueue.global(qos: .userInitiated).async {
@@ -784,10 +818,17 @@ import Gobackend  // Import Go framework
             let extensionId = args["extension_id"] as! String
             let query = args["query"] as! String
             let optionsJson = args["options"] as? String ?? ""
-            let response = GobackendCustomSearchWithExtensionJSON(extensionId, query, optionsJson, &error)
+            let requestId = args["request_id"] as? String ?? ""
+            let response = GobackendCustomSearchWithExtensionJSONWithRequestID(extensionId, query, optionsJson, requestId, &error)
             if let error = error { throw error }
             return response
-            
+
+        case "cancelExtensionRequest":
+            let args = call.arguments as! [String: Any]
+            let requestId = args["request_id"] as? String ?? ""
+            GobackendCancelExtensionRequestJSON(requestId)
+            return nil
+
         case "getSearchProviders":
             let response = GobackendGetSearchProvidersJSON(&error)
             if let error = error { throw error }
@@ -896,7 +937,8 @@ import Gobackend  // Import Go framework
         case "getExtensionHomeFeed":
             let args = call.arguments as! [String: Any]
             let extensionId = args["extension_id"] as! String
-            let response = GobackendGetExtensionHomeFeedJSON(extensionId, &error)
+            let requestId = args["request_id"] as? String ?? ""
+            let response = GobackendGetExtensionHomeFeedJSONWithRequestID(extensionId, requestId, &error)
             if let error = error { throw error }
             return response
             
@@ -919,7 +961,7 @@ import Gobackend  // Import Go framework
             let folderPath = args["folder_path"] as! String
             let response = GobackendScanLibraryFolderJSON(folderPath, &error)
             if let error = error { throw error }
-            return response
+            return bridgeJsonResult(response as String? ?? "[]")
             
         case "scanLibraryFolderIncremental":
             let args = call.arguments as! [String: Any]
@@ -927,7 +969,7 @@ import Gobackend  // Import Go framework
             let existingFiles = args["existing_files"] as? String ?? "{}"
             let response = GobackendScanLibraryFolderIncrementalJSON(folderPath, existingFiles, &error)
             if let error = error { throw error }
-            return response
+            return bridgeJsonResult(response as String? ?? "{}")
             
         case "getLibraryScanProgress":
             let response = GobackendGetLibraryScanProgressJSON()

lib/providers/explore_provider.dart

@@ -213,6 +213,7 @@ List<ExploreSection> _buildExploreSectionsFromNormalizedPayload(
 class ExploreNotifier extends Notifier<ExploreState> {
   static const _cacheKey = 'explore_home_feed_cache';
   static const _cacheTsKey = 'explore_home_feed_ts';
+  int _homeFeedRequestId = 0;
 
   @override
   ExploreState build() {
@@ -281,6 +282,8 @@ class ExploreNotifier extends Notifier<ExploreState> {
     if (ref.read(settingsProvider).homeFeedProvider ==
         AppSettings.homeFeedProviderOff) {
       _log.d('Home feed disabled by user setting');
+      _homeFeedRequestId++;
+      PlatformBridge.cancelExtensionHomeFeedRequests();
       state = const ExploreState();
       return;
     }
@@ -293,11 +296,12 @@ class ExploreNotifier extends Notifier<ExploreState> {
       return;
     }
 
-    if (state.isLoading) {
+    if (state.isLoading && !forceRefresh) {
       _log.d('Home feed fetch already in progress');
       return;
     }
 
+    final requestId = ++_homeFeedRequestId;
     final showLoading = !state.hasContent;
     state = state.copyWith(isLoading: showLoading, error: null);
 
@@ -330,6 +334,7 @@ class ExploreNotifier extends Notifier<ExploreState> {
 
       if (targetExt == null) {
         _log.w('No extension with homeFeed capability found');
+        if (requestId != _homeFeedRequestId) return;
         state = state.copyWith(
           isLoading: false,
           error: 'No extension with home feed support enabled',
@@ -338,7 +343,11 @@ class ExploreNotifier extends Notifier<ExploreState> {
       }
 
       _log.i('Fetching home feed from ${targetExt.id}...');
-      final result = await PlatformBridge.getExtensionHomeFeed(targetExt.id);
+      final result = await PlatformBridge.getExtensionHomeFeed(
+        targetExt.id,
+        cancelPrevious: forceRefresh,
+      );
+      if (requestId != _homeFeedRequestId) return;
 
       if (result == null) {
         state = state.copyWith(
@@ -362,6 +371,7 @@ class ExploreNotifier extends Notifier<ExploreState> {
         _normalizeExploreSectionsPayload,
         sectionsData,
       );
+      if (requestId != _homeFeedRequestId) return;
       final sections = _buildExploreSectionsFromNormalizedPayload(
         normalizedSections,
       );
@@ -388,11 +398,14 @@ class ExploreNotifier extends Notifier<ExploreState> {
       _saveToCache(normalizedSections);
     } catch (e, stack) {
       _log.e('Error fetching home feed: $e', e, stack);
+      if (requestId != _homeFeedRequestId) return;
       state = state.copyWith(isLoading: false, error: e.toString());
     }
   }
 
   void clear() {
+    _homeFeedRequestId++;
+    PlatformBridge.cancelExtensionHomeFeedRequests();
     state = const ExploreState();
   }
 

lib/providers/extension_provider.dart

@@ -15,6 +15,15 @@ const _metadataProviderPriorityKey = 'metadata_provider_priority';
 const _providerPriorityKey = 'provider_priority';
 const _spotifyWebExtensionId = 'spotify-web';
 
+bool _stringListEquals(List<String> a, List<String> b) {
+  if (identical(a, b)) return true;
+  if (a.length != b.length) return false;
+  for (var i = 0; i < a.length; i++) {
+    if (a[i] != b[i]) return false;
+  }
+  return true;
+}
+
 class BuiltInProviderSpec {
   final String id;
   final String displayName;
@@ -1033,7 +1042,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
     }
 
     final sanitized = _sanitizeDownloadProviderPriority(state.providerPriority);
-    if (jsonEncode(sanitized) == jsonEncode(state.providerPriority)) {
+    if (_stringListEquals(sanitized, state.providerPriority)) {
       return;
     }
 
@@ -1053,7 +1062,7 @@ class ExtensionNotifier extends Notifier<ExtensionState> {
       state.metadataProviderPriority,
     );
     final sanitized = _sanitizeMetadataProviderPriority(replaced);
-    if (jsonEncode(sanitized) == jsonEncode(state.metadataProviderPriority)) {
+    if (_stringListEquals(sanitized, state.metadataProviderPriority)) {
       return;
     }
 

lib/providers/track_provider.dart

@@ -778,6 +778,7 @@ class TrackNotifier extends Notifier<TrackState> {
         extensionId,
         query,
         options: options,
+        cancelPrevious: true,
       );
 
       if (!_isRequestValid(requestId)) {

lib/screens/artist_screen.dart

@@ -1,9 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:intl/intl.dart';
-import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/models/track.dart';
 import 'package:spotiflac_android/providers/extension_provider.dart';
@@ -24,6 +22,7 @@ import 'package:spotiflac_android/widgets/download_service_picker.dart';
 import 'package:spotiflac_android/widgets/track_collection_quick_actions.dart';
 import 'package:spotiflac_android/widgets/animation_utils.dart';
 import 'package:spotiflac_android/utils/clickable_metadata.dart';
+import 'package:spotiflac_android/widgets/cached_cover_image.dart';
 
 class _ArtistCache {
   static final Map<String, _CacheEntry> _cache = {};
@@ -1164,12 +1163,11 @@ class _ArtistScreenState extends ConsumerState<ArtistScreen> {
           fit: StackFit.expand,
           children: [
             if (hasValidImage)
-              CachedNetworkImage(
+              CachedCoverImage(
                 imageUrl: imageUrl,
                 fit: BoxFit.cover,
                 alignment: Alignment.topCenter,
                 memCacheWidth: 800,
-                cacheManager: CoverCacheManager.instance,
                 placeholder: (context, url) =>
                     Container(color: colorScheme.surfaceContainerHighest),
                 errorWidget: (context, url, error) => Container(
@@ -1477,33 +1475,18 @@ class _ArtistScreenState extends ConsumerState<ArtistScreen> {
                   ),
                 ),
                 const SizedBox(width: 12),
-                ClipRRect(
-                  borderRadius: BorderRadius.circular(4),
-                  child: track.coverUrl != null
-                      ? CachedNetworkImage(
-                          imageUrl: track.coverUrl!,
+                track.coverUrl != null
+                    ? CachedCoverImage(
+                        imageUrl: track.coverUrl!,
+                        width: 48,
+                        height: 48,
+                        borderRadius: BorderRadius.circular(4),
+                        placeholder: (context, url) => Container(
                           width: 48,
                           height: 48,
-                          fit: BoxFit.cover,
-                          memCacheWidth: 96,
-                          cacheManager: CoverCacheManager.instance,
-                          placeholder: (context, url) => Container(
-                            width: 48,
-                            height: 48,
-                            color: colorScheme.surfaceContainerHighest,
-                          ),
-                          errorWidget: (context, url, error) => Container(
-                            width: 48,
-                            height: 48,
-                            color: colorScheme.surfaceContainerHighest,
-                            child: Icon(
-                              Icons.music_note,
-                              color: colorScheme.onSurfaceVariant,
-                              size: 24,
-                            ),
-                          ),
-                        )
-                      : Container(
+                          color: colorScheme.surfaceContainerHighest,
+                        ),
+                        errorWidget: (context, url, error) => Container(
                           width: 48,
                           height: 48,
                           color: colorScheme.surfaceContainerHighest,
@@ -1513,7 +1496,17 @@ class _ArtistScreenState extends ConsumerState<ArtistScreen> {
                             size: 24,
                           ),
                         ),
-                ),
+                      )
+                    : Container(
+                        width: 48,
+                        height: 48,
+                        color: colorScheme.surfaceContainerHighest,
+                        child: Icon(
+                          Icons.music_note,
+                          color: colorScheme.onSurfaceVariant,
+                          size: 24,
+                        ),
+                      ),
                 const SizedBox(width: 12),
                 Expanded(
                   child: Column(
@@ -1801,13 +1794,12 @@ class _ArtistScreenState extends ConsumerState<ArtistScreen> {
                   ClipRRect(
                     borderRadius: BorderRadius.circular(8),
                     child: album.coverUrl != null
-                        ? CachedNetworkImage(
+                        ? CachedCoverImage(
                             imageUrl: album.coverUrl!,
                             width: tileSize,
                             height: tileSize,
                             fit: BoxFit.cover,
                             memCacheWidth: (tileSize * 2).round(),
-                            cacheManager: CoverCacheManager.instance,
                             placeholder: (context, url) => Container(
                               width: tileSize,
                               height: tileSize,

lib/screens/home_tab.dart

@@ -4,8 +4,6 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:cached_network_image/cached_network_image.dart';
-import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/models/settings.dart';
 import 'package:spotiflac_android/models/track.dart';
@@ -33,6 +31,7 @@ import 'package:spotiflac_android/widgets/animation_utils.dart';
 import 'package:spotiflac_android/utils/clickable_metadata.dart';
 import 'package:spotiflac_android/utils/provider_ui_utils.dart';
 import 'package:spotiflac_android/widgets/audio_quality_badges.dart';
+import 'package:spotiflac_android/widgets/cached_cover_image.dart';
 
 part 'home_tab_helpers.dart';
 part 'home_tab_widgets.dart';
@@ -1182,7 +1181,9 @@ class _HomeTabState extends ConsumerState<HomeTab>
     final mediaQuery = MediaQuery.of(context);
     final screenHeight = mediaQuery.size.height;
     final topPadding = normalizedHeaderTopPadding(context);
-    final historyItems = ref.watch(_homeHistoryPreviewProvider);
+    final hasHistoryItems = ref.watch(
+      _homeHistoryPreviewProvider.select((items) => items.isNotEmpty),
+    );
 
     final recentModeRequested = isShowingRecentAccess || isSearchFocused;
     final showRecentAccess =
@@ -1212,7 +1213,7 @@ class _HomeTabState extends ConsumerState<HomeTab>
         !hasHomeFeedExtension &&
         !hasExploreContent &&
         !hasResults &&
-        historyItems.isEmpty;
+        !hasHistoryItems;
 
     ref.listen<String>(settingsProvider.select((s) => s.defaultSearchTab), (
       previous,
@@ -1393,18 +1394,25 @@ class _HomeTabState extends ConsumerState<HomeTab>
                                       ),
                                 ),
                               ),
-                            if (historyItems.isNotEmpty)
-                              Padding(
-                                padding: const EdgeInsets.fromLTRB(
-                                  24,
-                                  32,
-                                  24,
-                                  24,
-                                ),
-                                child: _buildRecentDownloads(
-                                  historyItems,
-                                  colorScheme,
-                                ),
+                            if (hasHistoryItems)
+                              Consumer(
+                                builder: (context, ref, _) {
+                                  final historyItems = ref.watch(
+                                    _homeHistoryPreviewProvider,
+                                  );
+                                  return Padding(
+                                    padding: const EdgeInsets.fromLTRB(
+                                      24,
+                                      32,
+                                      24,
+                                      24,
+                                    ),
+                                    child: _buildRecentDownloads(
+                                      historyItems,
+                                      colorScheme,
+                                    ),
+                                  );
+                                },
                               ),
                           ],
                         ),
@@ -1717,7 +1725,11 @@ class _HomeTabState extends ConsumerState<HomeTab>
 
           final sectionIndex = index - sectionOffset;
           if (sectionIndex < sections.length) {
-            return _buildExploreSection(sections[sectionIndex], colorScheme);
+            final section = sections[sectionIndex];
+            return KeyedSubtree(
+              key: ValueKey('explore-section-${section.uri}-${section.title}'),
+              child: _buildExploreSection(section, colorScheme),
+            );
           }
 
           return const SizedBox(height: 24);
@@ -1753,6 +1765,9 @@ class _HomeTabState extends ConsumerState<HomeTab>
             itemBuilder: (context, index) {
               final item = section.items[index];
               return StaggeredListItem(
+                key: ValueKey(
+                  'explore-item-${item.type}-${item.id}-${item.uri}',
+                ),
                 index: index,
                 staggerDelay: const Duration(milliseconds: 50),
                 child: _buildExploreItem(item, colorScheme),
@@ -1806,14 +1821,11 @@ class _HomeTabState extends ConsumerState<HomeTab>
                     isArtist ? cardSize / 2 : 10,
                   ),
                   child: item.coverUrl != null && item.coverUrl!.isNotEmpty
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: item.coverUrl!,
                           width: cardSize,
                           height: cardSize,
                           fit: BoxFit.cover,
-                          memCacheWidth: (cardSize * 2).round(),
-                          memCacheHeight: (cardSize * 2).round(),
-                          cacheManager: CoverCacheManager.instance,
                           errorWidget: (context, url, error) => Container(
                             width: cardSize,
                             height: cardSize,
@@ -1968,13 +1980,11 @@ class _HomeTabState extends ConsumerState<HomeTab>
                   ClipRRect(
                     borderRadius: BorderRadius.circular(8),
                     child: item.coverUrl != null && item.coverUrl!.isNotEmpty
-                        ? CachedNetworkImage(
+                        ? CachedCoverImage(
                             imageUrl: item.coverUrl!,
                             width: 64,
                             height: 64,
                             fit: BoxFit.cover,
-                            memCacheWidth: 128,
-                            cacheManager: CoverCacheManager.instance,
                           )
                         : Container(
                             width: 64,
@@ -2474,10 +2484,7 @@ class _HomeTabState extends ConsumerState<HomeTab>
     final targetSize = (360 * dpr).round().clamp(512, 1024).toInt();
     precacheImage(
       ResizeImage(
-        CachedNetworkImageProvider(
-          url,
-          cacheManager: CoverCacheManager.instance,
-        ),
+        cachedCoverImageProvider(url),
         width: targetSize,
         height: targetSize,
       ),

lib/screens/home_tab_widgets.dart

@@ -25,8 +25,12 @@ class _SearchProviderDropdown extends ConsumerWidget {
     final rawCurrentProvider = ref.watch(
       settingsProvider.select((s) => s.searchProvider),
     );
-    final extensionState = ref.watch(extensionProvider);
-    final extensions = extensionState.extensions;
+    final extensions = ref.watch(extensionProvider.select((s) => s.extensions));
+    final providerReadiness = ref.watch(
+      extensionProvider.select(
+        (s) => (isInitialized: s.isInitialized, error: s.error),
+      ),
+    );
     final colorScheme = Theme.of(context).colorScheme;
 
     final searchProviders = extensions
@@ -36,7 +40,7 @@ class _SearchProviderDropdown extends ConsumerWidget {
     final hasAnyProvider =
         searchProviders.isNotEmpty || builtInProviders.isNotEmpty;
     final isProviderLoading =
-        !extensionState.isInitialized && extensionState.error == null;
+        !providerReadiness.isInitialized && providerReadiness.error == null;
 
     if (!hasAnyProvider) {
       return Padding(
@@ -324,14 +328,11 @@ class _TrackItemWithStatus extends ConsumerWidget {
                 ClipRRect(
                   borderRadius: BorderRadius.circular(10),
                   child: track.coverUrl != null
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: track.coverUrl!,
                           width: thumbWidth,
                           height: thumbHeight,
                           fit: BoxFit.cover,
-                          memCacheWidth: (thumbWidth * 2).toInt(),
-                          memCacheHeight: (thumbHeight * 2).toInt(),
-                          cacheManager: CoverCacheManager.instance,
                         )
                       : Container(
                           width: thumbWidth,
@@ -518,14 +519,11 @@ class _CollectionItemWidget extends StatelessWidget {
                 ClipRRect(
                   borderRadius: BorderRadius.circular(isArtist ? 28 : 10),
                   child: item.coverUrl != null && item.coverUrl!.isNotEmpty
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: item.coverUrl!,
                           width: 56,
                           height: 56,
                           fit: BoxFit.cover,
-                          memCacheWidth: 112,
-                          memCacheHeight: 112,
-                          cacheManager: CoverCacheManager.instance,
                         )
                       : Container(
                           width: 56,
@@ -623,14 +621,11 @@ class _SearchArtistItemWidget extends StatelessWidget {
                 ClipRRect(
                   borderRadius: BorderRadius.circular(28),
                   child: hasValidImage
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: artist.imageUrl!,
                           width: 56,
                           height: 56,
                           fit: BoxFit.cover,
-                          memCacheWidth: 112,
-                          memCacheHeight: 112,
-                          cacheManager: CoverCacheManager.instance,
                         )
                       : Container(
                           width: 56,
@@ -724,14 +719,11 @@ class _SearchAlbumItemWidget extends StatelessWidget {
                 ClipRRect(
                   borderRadius: BorderRadius.circular(10),
                   child: hasValidImage
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: album.imageUrl!,
                           width: 56,
                           height: 56,
                           fit: BoxFit.cover,
-                          memCacheWidth: 112,
-                          memCacheHeight: 112,
-                          cacheManager: CoverCacheManager.instance,
                         )
                       : Container(
                           width: 56,
@@ -828,14 +820,11 @@ class _SearchPlaylistItemWidget extends StatelessWidget {
                 ClipRRect(
                   borderRadius: BorderRadius.circular(10),
                   child: hasValidImage
-                      ? CachedNetworkImage(
+                      ? CachedCoverImage(
                           imageUrl: playlist.imageUrl!,
                           width: 56,
                           height: 56,
                           fit: BoxFit.cover,
-                          memCacheWidth: 112,
-                          memCacheHeight: 112,
-                          cacheManager: CoverCacheManager.instance,
                         )
                       : Container(
                           width: 56,
@@ -996,14 +985,13 @@ class _DownloadedOrRemoteCoverState extends State<_DownloadedOrRemoteCover> {
         errorBuilder: (_, _, _) => _fallback(),
       );
     } else if (widget.imageUrl != null && widget.imageUrl!.isNotEmpty) {
-      child = CachedNetworkImage(
+      child = CachedCoverImage(
         imageUrl: widget.imageUrl!,
         width: widget.width,
         height: widget.height,
         fit: BoxFit.cover,
         memCacheWidth: cacheWidth,
         memCacheHeight: cacheHeight,
-        cacheManager: CoverCacheManager.instance,
         errorWidget: (_, _, _) => _fallback(),
       );
     } else {
@@ -1617,7 +1605,12 @@ class _QuickPicksPageViewState extends State<_QuickPicksPageView> {
               return Column(
                 children: List.generate(pageItemCount, (index) {
                   final item = widget.section.items[startIndex + index];
-                  return _buildQuickPickItem(item);
+                  return KeyedSubtree(
+                    key: ValueKey(
+                      'quick-pick-${item.type}-${item.id}-${item.uri}',
+                    ),
+                    child: _buildQuickPickItem(item),
+                  );
                 }),
               );
             },
@@ -1661,14 +1654,11 @@ class _QuickPicksPageViewState extends State<_QuickPicksPageView> {
             ClipRRect(
               borderRadius: BorderRadius.circular(4),
               child: item.coverUrl != null && item.coverUrl!.isNotEmpty
-                  ? CachedNetworkImage(
+                  ? CachedCoverImage(
                       imageUrl: item.coverUrl!,
                       width: 48,
                       height: 48,
                       fit: BoxFit.cover,
-                      memCacheWidth: 96,
-                      memCacheHeight: 96,
-                      cacheManager: CoverCacheManager.instance,
                       errorWidget: (context, url, error) => Container(
                         width: 48,
                         height: 48,

lib/screens/playlist_screen.dart

@@ -1,7 +1,5 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:cached_network_image/cached_network_image.dart';
-import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/models/track.dart';
@@ -19,6 +17,7 @@ import 'package:spotiflac_android/widgets/playlist_picker_sheet.dart';
 import 'package:spotiflac_android/widgets/track_collection_quick_actions.dart';
 import 'package:spotiflac_android/widgets/animation_utils.dart';
 import 'package:spotiflac_android/widgets/audio_quality_badges.dart';
+import 'package:spotiflac_android/widgets/cached_cover_image.dart';
 
 class PlaylistScreen extends ConsumerStatefulWidget {
   final String playlistName;
@@ -297,11 +296,10 @@ class _PlaylistScreenState extends ConsumerState<PlaylistScreen> {
               fit: StackFit.expand,
               children: [
                 if (_coverUrl != null)
-                  CachedNetworkImage(
+                  CachedCoverImage(
                     imageUrl: _highResCoverUrl(_coverUrl) ?? _coverUrl!,
                     fit: BoxFit.cover,
                     memCacheWidth: cacheWidth,
-                    cacheManager: CoverCacheManager.instance,
                     placeholder: (_, _) =>
                         Container(color: colorScheme.surface),
                     errorWidget: (_, _, _) =>
@@ -838,16 +836,11 @@ class _PlaylistTrackItem extends ConsumerWidget {
             borderRadius: BorderRadius.circular(12),
           ),
           leading: track.coverUrl != null
-              ? ClipRRect(
+              ? CachedCoverImage(
+                  imageUrl: track.coverUrl!,
+                  width: 48,
+                  height: 48,
                   borderRadius: BorderRadius.circular(8),
-                  child: CachedNetworkImage(
-                    imageUrl: track.coverUrl!,
-                    width: 48,
-                    height: 48,
-                    fit: BoxFit.cover,
-                    memCacheWidth: 96,
-                    cacheManager: CoverCacheManager.instance,
-                  ),
                 )
               : Container(
                   width: 48,

lib/screens/queue_tab.dart

@@ -4,10 +4,8 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:share_plus/share_plus.dart';
 import 'package:path_provider/path_provider.dart';
-import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/services/ffmpeg_service.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
@@ -31,6 +29,7 @@ import 'package:spotiflac_android/screens/favorite_artists_screen.dart';
 import 'package:spotiflac_android/screens/downloaded_album_screen.dart';
 import 'package:spotiflac_android/widgets/re_enrich_field_dialog.dart';
 import 'package:spotiflac_android/widgets/batch_progress_dialog.dart';
+import 'package:spotiflac_android/widgets/cached_cover_image.dart';
 import 'package:spotiflac_android/screens/library_tracks_folder_screen.dart';
 import 'package:spotiflac_android/screens/local_album_screen.dart';
 import 'package:spotiflac_android/utils/clickable_metadata.dart';
@@ -1841,10 +1840,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     final targetSize = (360 * dpr).round().clamp(512, 1024).toInt();
     precacheImage(
       ResizeImage(
-        CachedNetworkImageProvider(
-          url,
-          cacheManager: CoverCacheManager.instance,
-        ),
+        cachedCoverImageProvider(url),
         width: targetSize,
         height: targetSize,
       ),
@@ -2166,18 +2162,14 @@ class _QueueTabState extends ConsumerState<QueueTab> {
           ),
         );
       }
-      return ClipRRect(
+      return CachedCoverImage(
+        imageUrl: firstCoverUrl,
+        width: size,
+        height: size,
+        memCacheWidth: cacheExtent,
         borderRadius: borderRadius,
-        child: CachedNetworkImage(
-          imageUrl: firstCoverUrl,
-          width: size,
-          height: size,
-          fit: BoxFit.cover,
-          memCacheWidth: cacheExtent,
-          cacheManager: CoverCacheManager.instance,
-          placeholder: (_, _) => placeholder,
-          errorWidget: (_, _, _) => placeholder,
-        ),
+        placeholder: (_, _) => placeholder,
+        errorWidget: (_, _, _) => placeholder,
       );
     }
 
@@ -3799,14 +3791,13 @@ class _QueueTabState extends ConsumerState<QueueTab> {
                       _albumPlaceholder(colorScheme),
                 )
               : album.coverUrl != null
-              ? CachedNetworkImage(
+              ? CachedCoverImage(
                   imageUrl: album.coverUrl!,
                   fit: BoxFit.cover,
                   width: double.infinity,
                   height: double.infinity,
                   memCacheWidth: 300,
                   memCacheHeight: 300,
-                  cacheManager: CoverCacheManager.instance,
                 )
               : null,
           badgeColor: colorScheme.primaryContainer,
@@ -5383,20 +5374,13 @@ class _QueueTabState extends ConsumerState<QueueTab> {
 
   Widget _buildCoverArt(DownloadItem item, ColorScheme colorScheme) {
     final coverSize = _queueCoverSize();
-    final memCacheSize = (coverSize * 2).round();
 
     return item.track.coverUrl != null
-        ? ClipRRect(
+        ? CachedCoverImage(
+            imageUrl: item.track.coverUrl!,
+            width: coverSize,
+            height: coverSize,
             borderRadius: BorderRadius.circular(8),
-            child: CachedNetworkImage(
-              imageUrl: item.track.coverUrl!,
-              width: coverSize,
-              height: coverSize,
-              fit: BoxFit.cover,
-              memCacheWidth: memCacheSize,
-              memCacheHeight: memCacheSize,
-              cacheManager: CoverCacheManager.instance,
-            ),
           )
         : Container(
             width: coverSize,
@@ -5651,19 +5635,15 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     }
 
     if (item.coverUrl != null) {
-      return ClipRRect(
+      return CachedCoverImage(
+        imageUrl: item.coverUrl!,
+        width: size,
+        height: size,
+        memCacheWidth: cacheSize,
+        memCacheHeight: cacheSize,
         borderRadius: BorderRadius.circular(8),
-        child: CachedNetworkImage(
-          imageUrl: item.coverUrl!,
-          width: size,
-          height: size,
-          fit: BoxFit.cover,
-          memCacheWidth: cacheSize,
-          memCacheHeight: cacheSize,
-          cacheManager: CoverCacheManager.instance,
-          placeholder: (context, url) => buildPlaceholder(),
-          errorWidget: (context, url, error) => buildPlaceholder(),
-        ),
+        placeholder: (context, url) => buildPlaceholder(),
+        errorWidget: (context, url, error) => buildPlaceholder(),
       );
     }
 

lib/screens/search_screen.dart

@@ -1,8 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:cached_network_image/cached_network_image.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
-import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/models/track.dart';
 import 'package:spotiflac_android/providers/extension_provider.dart';
 import 'package:spotiflac_android/providers/track_provider.dart';
@@ -12,6 +10,7 @@ import 'package:spotiflac_android/widgets/track_collection_quick_actions.dart';
 import 'package:spotiflac_android/widgets/animation_utils.dart';
 import 'package:spotiflac_android/utils/clickable_metadata.dart';
 import 'package:spotiflac_android/widgets/audio_quality_badges.dart';
+import 'package:spotiflac_android/widgets/cached_cover_image.dart';
 
 class SearchScreen extends ConsumerStatefulWidget {
   final String query;
@@ -49,30 +48,8 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
     }
   }
 
-  void _downloadTrack(Track track) {
-    final settings = ref.read(settingsProvider);
-    final extensionState = ref.read(extensionProvider);
-    final service = resolveEffectiveDownloadService(
-      settings.defaultService,
-      extensionState,
-    );
-    if (service.isEmpty) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text(context.l10n.extensionsNoDownloadProvider)),
-      );
-      return;
-    }
-    ref.read(downloadQueueProvider.notifier).addToQueue(track, service);
-    ScaffoldMessenger.of(context).showSnackBar(
-      SnackBar(content: Text(context.l10n.snackbarAddedToQueue(track.name))),
-    );
-  }
-
   @override
   Widget build(BuildContext context) {
-    final tracks = ref.watch(trackProvider.select((s) => s.tracks));
-    final isLoading = ref.watch(trackProvider.select((s) => s.isLoading));
-    final error = ref.watch(trackProvider.select((s) => s.error));
     final colorScheme = Theme.of(context).colorScheme;
 
     return Scaffold(
@@ -98,36 +75,61 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
           ),
         ],
       ),
-      body: Column(
-        children: [
-          if (isLoading) LinearProgressIndicator(color: colorScheme.primary),
-          if (error != null)
-            Padding(
-              padding: const EdgeInsets.all(16.0),
-              child: Text(error, style: TextStyle(color: colorScheme.error)),
-            ),
-          Expanded(
-            child: AnimatedStateSwitcher(
-              child: isLoading && tracks.isEmpty
-                  ? const TrackListSkeleton(key: ValueKey('loading'))
-                  : tracks.isEmpty
-                  ? _buildEmptyState(colorScheme)
-                  : ListView.builder(
-                      key: const ValueKey('results'),
-                      itemCount: tracks.length,
-                      itemBuilder: (context, index) => StaggeredListItem(
-                        index: index,
-                        child: _buildTrackTile(tracks[index], colorScheme),
-                      ),
-                    ),
-            ),
-          ),
-        ],
-      ),
+      body: const _SearchResultsBody(),
     );
   }
+}
 
-  Widget _buildEmptyState(ColorScheme colorScheme) {
+class _SearchResultsBody extends ConsumerWidget {
+  const _SearchResultsBody();
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final tracks = ref.watch(trackProvider.select((s) => s.tracks));
+    final isLoading = ref.watch(trackProvider.select((s) => s.isLoading));
+    final error = ref.watch(trackProvider.select((s) => s.error));
+    final colorScheme = Theme.of(context).colorScheme;
+
+    return Column(
+      children: [
+        if (isLoading) LinearProgressIndicator(color: colorScheme.primary),
+        if (error != null)
+          Padding(
+            padding: const EdgeInsets.all(16.0),
+            child: Text(error, style: TextStyle(color: colorScheme.error)),
+          ),
+        Expanded(
+          child: AnimatedStateSwitcher(
+            child: isLoading && tracks.isEmpty
+                ? const TrackListSkeleton(key: ValueKey('loading'))
+                : tracks.isEmpty
+                ? _SearchEmptyState(
+                    key: const ValueKey('empty'),
+                    colorScheme: colorScheme,
+                  )
+                : ListView.builder(
+                    key: const ValueKey('results'),
+                    itemCount: tracks.length,
+                    itemBuilder: (context, index) => StaggeredListItem(
+                      key: ValueKey('search-track-${tracks[index].id}-$index'),
+                      index: index,
+                      child: _SearchTrackTile(track: tracks[index]),
+                    ),
+                  ),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _SearchEmptyState extends StatelessWidget {
+  final ColorScheme colorScheme;
+
+  const _SearchEmptyState({super.key, required this.colorScheme});
+
+  @override
+  Widget build(BuildContext context) {
     return Center(
       child: Column(
         mainAxisAlignment: MainAxisAlignment.center,
@@ -144,20 +146,41 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
       ),
     );
   }
+}
 
-  Widget _buildTrackTile(Track track, ColorScheme colorScheme) {
+class _SearchTrackTile extends ConsumerWidget {
+  final Track track;
+
+  const _SearchTrackTile({required this.track});
+
+  void _downloadTrack(BuildContext context, WidgetRef ref) {
+    final settings = ref.read(settingsProvider);
+    final extensionState = ref.read(extensionProvider);
+    final service = resolveEffectiveDownloadService(
+      settings.defaultService,
+      extensionState,
+    );
+    if (service.isEmpty) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text(context.l10n.extensionsNoDownloadProvider)),
+      );
+      return;
+    }
+    ref.read(downloadQueueProvider.notifier).addToQueue(track, service);
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(content: Text(context.l10n.snackbarAddedToQueue(track.name))),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final colorScheme = Theme.of(context).colorScheme;
     final coverWidget = track.coverUrl != null
-        ? ClipRRect(
+        ? CachedCoverImage(
+            imageUrl: track.coverUrl!,
+            width: 48,
+            height: 48,
             borderRadius: BorderRadius.circular(8),
-            child: CachedNetworkImage(
-              imageUrl: track.coverUrl!,
-              width: 48,
-              height: 48,
-              fit: BoxFit.cover,
-              memCacheWidth: 144,
-              memCacheHeight: 144,
-              cacheManager: CoverCacheManager.instance,
-            ),
           )
         : Container(
             width: 48,
@@ -218,11 +241,11 @@ class _SearchScreenState extends ConsumerState<SearchScreen> {
           IconButton(
             icon: const Icon(Icons.download_rounded),
             tooltip: context.l10n.dialogDownload,
-            onPressed: () => _downloadTrack(track),
+            onPressed: () => _downloadTrack(context, ref),
           ),
         ],
       ),
-      onTap: () => _downloadTrack(track),
+      onTap: () => _downloadTrack(context, ref),
     );
   }
 }

lib/services/platform_bridge.dart

@@ -1,19 +1,61 @@
+import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:flutter/services.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'package:spotiflac_android/services/download_request_payload.dart';
 import 'package:spotiflac_android/utils/logger.dart';
 
 final _log = AppLogger('PlatformBridge');
 
+class _BridgeCacheEntry {
+  final Map<String, dynamic> value;
+  final DateTime expiresAt;
+
+  const _BridgeCacheEntry({required this.value, required this.expiresAt});
+
+  bool get isExpired => DateTime.now().isAfter(expiresAt);
+}
+
+class _BridgeInFlight<T> {
+  final String requestId;
+  final String scopeKey;
+  final Future<T> future;
+
+  const _BridgeInFlight({
+    required this.requestId,
+    required this.scopeKey,
+    required this.future,
+  });
+}
+
 class PlatformBridge {
   static const _channel = MethodChannel('com.zarz.spotiflac/backend');
+  static const _jsonResultFileKey = '__json_file';
+  static const _metadataCacheTtl = Duration(minutes: 20);
+  static const _availabilityCacheTtl = Duration(minutes: 15);
+  static const _bridgeCacheMaxEntries = 256;
+  static const _metadataPersistentCacheKey = 'bridge_metadata_lookup_cache_v1';
+  static const _availabilityPersistentCacheKey =
+      'bridge_availability_lookup_cache_v1';
   static const _downloadProgressEvents = EventChannel(
     'com.zarz.spotiflac/download_progress_stream',
   );
   static const _libraryScanProgressEvents = EventChannel(
     'com.zarz.spotiflac/library_scan_progress_stream',
   );
+  static final Map<String, _BridgeCacheEntry> _metadataCache = {};
+  static final Map<String, _BridgeCacheEntry> _availabilityCache = {};
+  static final Map<String, Future<Map<String, dynamic>>> _metadataInFlight = {};
+  static final Map<String, Future<Map<String, dynamic>>> _availabilityInFlight =
+      {};
+  static final Map<String, _BridgeInFlight<List<Map<String, dynamic>>>>
+  _customSearchInFlight = {};
+  static final Map<String, _BridgeInFlight<Map<String, dynamic>?>>
+  _homeFeedInFlight = {};
+  static Future<void>? _persistentLookupCacheLoadFuture;
+  static int _lookupCacheGeneration = 0;
+  static int _extensionRequestSequence = 0;
 
   static bool get supportsCoreBackend => Platform.isAndroid || Platform.isIOS;
 
@@ -24,12 +66,324 @@ class PlatformBridge {
     String spotifyId,
     String isrc,
   ) async {
-    _log.d('checkAvailability: $spotifyId (ISRC: $isrc)');
-    final result = await _channel.invokeMethod('checkAvailability', {
-      'spotify_id': spotifyId,
-      'isrc': isrc,
+    final cacheKey = _availabilityCacheKey(spotifyId, isrc);
+    if (cacheKey.isEmpty) {
+      _log.d('checkAvailability: $spotifyId (ISRC: $isrc)');
+      final result = await _channel.invokeMethod('checkAvailability', {
+        'spotify_id': spotifyId,
+        'isrc': isrc,
+      });
+      return _decodeRequiredMapResult(result, 'checkAvailability');
+    }
+    await _ensurePersistentLookupCachesLoaded();
+    final cached = _getCachedMap(_availabilityCache, cacheKey);
+    if (cached != null) return cached;
+
+    final inFlight = _availabilityInFlight[cacheKey];
+    if (inFlight != null) return _copyStringMap(await inFlight);
+
+    final generation = _lookupCacheGeneration;
+    final future = _invokeCachedMap(
+      cacheKey,
+      _availabilityCache,
+      () async {
+        _log.d('checkAvailability: $spotifyId (ISRC: $isrc)');
+        final result = await _channel.invokeMethod('checkAvailability', {
+          'spotify_id': spotifyId,
+          'isrc': isrc,
+        });
+        return _decodeRequiredMapResult(result, 'checkAvailability');
+      },
+      _availabilityCacheTtl,
+      generation,
+      _availabilityPersistentCacheKey,
+    );
+    _availabilityInFlight[cacheKey] = future;
+    try {
+      return _copyStringMap(await future);
+    } finally {
+      _availabilityInFlight.remove(cacheKey);
+    }
+  }
+
+  static Future<Map<String, dynamic>> _invokeCachedMap(
+    String key,
+    Map<String, _BridgeCacheEntry> cache,
+    Future<Map<String, dynamic>> Function() loader,
+    Duration ttl,
+    int generation,
+    String persistentCacheKey,
+  ) async {
+    final value = await loader();
+    if (generation == _lookupCacheGeneration) {
+      _putCachedMap(cache, key, value, ttl, persistentCacheKey);
+    }
+    return _copyStringMap(value);
+  }
+
+  static String _availabilityCacheKey(String spotifyId, String isrc) {
+    final normalizedIsrc = isrc.trim().toUpperCase();
+    if (normalizedIsrc.isNotEmpty) {
+      return 'isrc:$normalizedIsrc';
+    }
+    final normalizedSpotifyId = spotifyId.trim();
+    if (normalizedSpotifyId.isEmpty) return '';
+    return 'spotify:$normalizedSpotifyId';
+  }
+
+  static String _providerMetadataCacheKey(
+    String providerId,
+    String resourceType,
+    String resourceId,
+  ) {
+    return [
+      providerId.trim().toLowerCase(),
+      resourceType.trim().toLowerCase(),
+      resourceId.trim(),
+    ].join(':');
+  }
+
+  static Map<String, dynamic>? _getCachedMap(
+    Map<String, _BridgeCacheEntry> cache,
+    String key,
+  ) {
+    _pruneExpiredBridgeCache(cache);
+    final entry = cache[key];
+    if (entry == null) return null;
+    if (entry.isExpired) {
+      cache.remove(key);
+      return null;
+    }
+    return _copyStringMap(entry.value);
+  }
+
+  static void _putCachedMap(
+    Map<String, _BridgeCacheEntry> cache,
+    String key,
+    Map<String, dynamic> value,
+    Duration ttl,
+    String persistentCacheKey,
+  ) {
+    _pruneExpiredBridgeCache(cache);
+    while (cache.length >= _bridgeCacheMaxEntries && cache.isNotEmpty) {
+      cache.remove(cache.keys.first);
+    }
+    cache[key] = _BridgeCacheEntry(
+      value: _copyStringMap(value),
+      expiresAt: DateTime.now().add(ttl),
+    );
+    unawaited(
+      _persistLookupCache(cache, persistentCacheKey, _lookupCacheGeneration),
+    );
+  }
+
+  static void _pruneExpiredBridgeCache(Map<String, _BridgeCacheEntry> cache) {
+    if (cache.isEmpty) return;
+    final now = DateTime.now();
+    cache.removeWhere((_, entry) => now.isAfter(entry.expiresAt));
+  }
+
+  static dynamic _copyJsonLike(dynamic value) {
+    if (value is Map) {
+      return <String, dynamic>{
+        for (final entry in value.entries)
+          entry.key.toString(): _copyJsonLike(entry.value),
+      };
+    }
+    if (value is List) {
+      return value.map(_copyJsonLike).toList(growable: false);
+    }
+    return value;
+  }
+
+  static Map<String, dynamic> _copyStringMap(Map<String, dynamic> value) {
+    return <String, dynamic>{
+      for (final entry in value.entries) entry.key: _copyJsonLike(entry.value),
+    };
+  }
+
+  static Map<String, dynamic>? _copyNullableStringMap(
+    Map<String, dynamic>? value,
+  ) {
+    if (value == null) return null;
+    return _copyStringMap(value);
+  }
+
+  static List<Map<String, dynamic>> _copyMapList(
+    List<Map<String, dynamic>> value,
+  ) {
+    return value.map(_copyStringMap).toList(growable: false);
+  }
+
+  static dynamic _canonicalizeJsonLike(dynamic value) {
+    if (value is Map) {
+      final entries = value.entries.toList()
+        ..sort((a, b) => a.key.toString().compareTo(b.key.toString()));
+      return <String, dynamic>{
+        for (final entry in entries)
+          entry.key.toString(): _canonicalizeJsonLike(entry.value),
+      };
+    }
+    if (value is List) {
+      return value.map(_canonicalizeJsonLike).toList(growable: false);
+    }
+    return value;
+  }
+
+  static Future<void> _ensurePersistentLookupCachesLoaded() {
+    return _persistentLookupCacheLoadFuture ??= _loadPersistentLookupCaches(
+      _lookupCacheGeneration,
+    );
+  }
+
+  static Future<void> _loadPersistentLookupCaches(int generation) async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      if (generation != _lookupCacheGeneration) return;
+      _restorePersistentCache(
+        prefs,
+        _metadataPersistentCacheKey,
+        _metadataCache,
+      );
+      _restorePersistentCache(
+        prefs,
+        _availabilityPersistentCacheKey,
+        _availabilityCache,
+      );
+    } catch (e) {
+      _log.w('Failed to load bridge lookup cache: $e');
+    }
+  }
+
+  static void _restorePersistentCache(
+    SharedPreferences prefs,
+    String prefsKey,
+    Map<String, _BridgeCacheEntry> target,
+  ) {
+    final raw = prefs.getString(prefsKey);
+    if (raw == null || raw.isEmpty) return;
+
+    final decoded = jsonDecode(raw);
+    if (decoded is! Map) return;
+
+    final now = DateTime.now();
+    for (final entry in decoded.entries) {
+      if (target.length >= _bridgeCacheMaxEntries) break;
+      final key = entry.key.toString();
+      final rawEntry = entry.value;
+      if (key.isEmpty || rawEntry is! Map) continue;
+
+      final expiresAtMs = rawEntry['expires_at'];
+      final value = rawEntry['value'];
+      if (expiresAtMs is! int || value is! Map) continue;
+
+      final expiresAt = DateTime.fromMillisecondsSinceEpoch(expiresAtMs);
+      if (!expiresAt.isAfter(now)) continue;
+
+      target[key] = _BridgeCacheEntry(
+        value: _copyStringMap(Map<String, dynamic>.from(value)),
+        expiresAt: expiresAt,
+      );
+    }
+  }
+
+  static Future<void> _persistLookupCache(
+    Map<String, _BridgeCacheEntry> cache,
+    String prefsKey,
+    int generation,
+  ) async {
+    try {
+      _pruneExpiredBridgeCache(cache);
+      final data = <String, dynamic>{
+        for (final entry in cache.entries)
+          entry.key: {
+            'expires_at': entry.value.expiresAt.millisecondsSinceEpoch,
+            'value': entry.value.value,
+          },
+      };
+      final prefs = await SharedPreferences.getInstance();
+      if (generation != _lookupCacheGeneration) return;
+      await prefs.setString(prefsKey, jsonEncode(data));
+    } catch (e) {
+      _log.w('Failed to persist bridge lookup cache: $e');
+    }
+  }
+
+  static Future<void> _clearPersistentLookupCaches() async {
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.remove(_metadataPersistentCacheKey);
+      await prefs.remove(_availabilityPersistentCacheKey);
+    } catch (e) {
+      _log.w('Failed to clear bridge lookup cache: $e');
+    }
+  }
+
+  static Future<void> _clearLookupCaches() async {
+    _lookupCacheGeneration++;
+    _persistentLookupCacheLoadFuture = null;
+    _metadataCache.clear();
+    _availabilityCache.clear();
+    _metadataInFlight.clear();
+    _availabilityInFlight.clear();
+    for (final inFlight in _customSearchInFlight.values) {
+      _cancelExtensionRequestUnawaited(inFlight.requestId);
+    }
+    for (final inFlight in _homeFeedInFlight.values) {
+      _cancelExtensionRequestUnawaited(inFlight.requestId);
+    }
+    _customSearchInFlight.clear();
+    _homeFeedInFlight.clear();
+    await _clearPersistentLookupCaches();
+  }
+
+  static String _nextExtensionRequestId(String kind, String extensionId) {
+    _extensionRequestSequence++;
+    return [
+      kind,
+      DateTime.now().microsecondsSinceEpoch,
+      _extensionRequestSequence,
+      extensionId.trim(),
+    ].join(':');
+  }
+
+  static void _cancelExtensionRequestUnawaited(String requestId) {
+    if (requestId.isEmpty) return;
+    unawaited(
+      cancelExtensionRequest(requestId).catchError((Object e) {
+        _log.w('Failed to cancel extension request $requestId: $e');
+      }),
+    );
+  }
+
+  static Future<void> cancelExtensionRequest(String requestId) async {
+    if (requestId.isEmpty) return;
+    await _channel.invokeMethod('cancelExtensionRequest', {
+      'request_id': requestId,
     });
-    return _decodeRequiredMapResult(result, 'checkAvailability');
+  }
+
+  static void _cancelCustomSearchInFlightForScope(
+    String scopeKey, {
+    String? exceptKey,
+  }) {
+    for (final entry in _customSearchInFlight.entries.toList()) {
+      if (entry.key == exceptKey || entry.value.scopeKey != scopeKey) continue;
+      _cancelExtensionRequestUnawaited(entry.value.requestId);
+    }
+  }
+
+  static void cancelExtensionHomeFeedRequests() {
+    for (final inFlight in _homeFeedInFlight.values) {
+      _cancelExtensionRequestUnawaited(inFlight.requestId);
+    }
+    _homeFeedInFlight.clear();
+  }
+
+  static int _lookupCacheSize() {
+    _pruneExpiredBridgeCache(_metadataCache);
+    _pruneExpiredBridgeCache(_availabilityCache);
+    return _metadataCache.length + _availabilityCache.length;
   }
 
   static Future<Map<String, dynamic>> _invokeDownloadMethod(
@@ -485,11 +839,13 @@ class PlatformBridge {
   }
 
   static Future<int> getTrackCacheSize() async {
+    await _ensurePersistentLookupCachesLoaded();
     final result = await _channel.invokeMethod('getTrackCacheSize');
-    return result as int;
+    return (result as int) + _lookupCacheSize();
   }
 
   static Future<void> clearTrackCache() async {
+    await _clearLookupCaches();
     await _channel.invokeMethod('clearTrackCache');
   }
 
@@ -533,17 +889,45 @@ class PlatformBridge {
     String resourceType,
     String resourceId,
   ) async {
-    final result = await _channel.invokeMethod('getProviderMetadata', {
-      'provider_id': providerId,
-      'resource_type': resourceType,
-      'resource_id': resourceId,
-    });
-    if (result == null) {
-      throw Exception(
-        'getProviderMetadata returned null for $providerId:$resourceType:$resourceId',
-      );
+    final cacheKey = _providerMetadataCacheKey(
+      providerId,
+      resourceType,
+      resourceId,
+    );
+    await _ensurePersistentLookupCachesLoaded();
+    final cached = _getCachedMap(_metadataCache, cacheKey);
+    if (cached != null) return cached;
+
+    final inFlight = _metadataInFlight[cacheKey];
+    if (inFlight != null) return _copyStringMap(await inFlight);
+
+    final generation = _lookupCacheGeneration;
+    final future = _invokeCachedMap(
+      cacheKey,
+      _metadataCache,
+      () async {
+        final result = await _channel.invokeMethod('getProviderMetadata', {
+          'provider_id': providerId,
+          'resource_type': resourceType,
+          'resource_id': resourceId,
+        });
+        if (result == null) {
+          throw Exception(
+            'getProviderMetadata returned null for $providerId:$resourceType:$resourceId',
+          );
+        }
+        return _decodeRequiredMapResult(result, 'getProviderMetadata');
+      },
+      _metadataCacheTtl,
+      generation,
+      _metadataPersistentCacheKey,
+    );
+    _metadataInFlight[cacheKey] = future;
+    try {
+      return _copyStringMap(await future);
+    } finally {
+      _metadataInFlight.remove(cacheKey);
     }
-    return _decodeRequiredMapResult(result, 'getProviderMetadata');
   }
 
   static Future<Map<String, dynamic>> searchDeezerByISRC(
@@ -584,11 +968,39 @@ class PlatformBridge {
     String resourceType,
     String spotifyId,
   ) async {
-    final result = await _channel.invokeMethod('convertSpotifyToDeezer', {
-      'resource_type': resourceType,
-      'spotify_id': spotifyId,
-    });
-    return _decodeRequiredMapResult(result, 'convertSpotifyToDeezer');
+    final cacheKey = _providerMetadataCacheKey(
+      'spotify-to-deezer',
+      resourceType,
+      spotifyId,
+    );
+    await _ensurePersistentLookupCachesLoaded();
+    final cached = _getCachedMap(_metadataCache, cacheKey);
+    if (cached != null) return cached;
+
+    final inFlight = _metadataInFlight[cacheKey];
+    if (inFlight != null) return _copyStringMap(await inFlight);
+
+    final generation = _lookupCacheGeneration;
+    final future = _invokeCachedMap(
+      cacheKey,
+      _metadataCache,
+      () async {
+        final result = await _channel.invokeMethod('convertSpotifyToDeezer', {
+          'resource_type': resourceType,
+          'spotify_id': spotifyId,
+        });
+        return _decodeRequiredMapResult(result, 'convertSpotifyToDeezer');
+      },
+      _metadataCacheTtl,
+      generation,
+      _metadataPersistentCacheKey,
+    );
+    _metadataInFlight[cacheKey] = future;
+    try {
+      return _copyStringMap(await future);
+    } finally {
+      _metadataInFlight.remove(cacheKey);
+    }
   }
 
   static Future<List<Map<String, dynamic>>> getGoLogs() async {
@@ -641,6 +1053,7 @@ class PlatformBridge {
     String filePath,
   ) async {
     _log.d('loadExtensionFromPath: $filePath');
+    await _clearLookupCaches();
     final result = await _channel.invokeMethod('loadExtensionFromPath', {
       'file_path': filePath,
     });
@@ -649,6 +1062,7 @@ class PlatformBridge {
 
   static Future<void> unloadExtension(String extensionId) async {
     _log.d('unloadExtension: $extensionId');
+    await _clearLookupCaches();
     await _channel.invokeMethod('unloadExtension', {
       'extension_id': extensionId,
     });
@@ -656,6 +1070,7 @@ class PlatformBridge {
 
   static Future<void> removeExtension(String extensionId) async {
     _log.d('removeExtension: $extensionId');
+    await _clearLookupCaches();
     await _channel.invokeMethod('removeExtension', {
       'extension_id': extensionId,
     });
@@ -663,6 +1078,7 @@ class PlatformBridge {
 
   static Future<Map<String, dynamic>> upgradeExtension(String filePath) async {
     _log.d('upgradeExtension: $filePath');
+    await _clearLookupCaches();
     final result = await _channel.invokeMethod('upgradeExtension', {
       'file_path': filePath,
     });
@@ -689,6 +1105,7 @@ class PlatformBridge {
     bool enabled,
   ) async {
     _log.d('setExtensionEnabled: $extensionId = $enabled');
+    await _clearLookupCaches();
     await _channel.invokeMethod('setExtensionEnabled', {
       'extension_id': extensionId,
       'enabled': enabled,
@@ -697,6 +1114,7 @@ class PlatformBridge {
 
   static Future<void> setProviderPriority(List<String> providerIds) async {
     _log.d('setProviderPriority: $providerIds');
+    await _clearLookupCaches();
     await _channel.invokeMethod('setProviderPriority', {
       'priority': jsonEncode(providerIds),
     });
@@ -711,6 +1129,7 @@ class PlatformBridge {
     List<String>? extensionIds,
   ) async {
     _log.d('setDownloadFallbackExtensionIds: $extensionIds');
+    await _clearLookupCaches();
     await _channel.invokeMethod('setDownloadFallbackExtensionIds', {
       'extension_ids': extensionIds == null ? '' : jsonEncode(extensionIds),
     });
@@ -720,6 +1139,7 @@ class PlatformBridge {
     List<String> providerIds,
   ) async {
     _log.d('setMetadataProviderPriority: $providerIds');
+    await _clearLookupCaches();
     await _channel.invokeMethod('setMetadataProviderPriority', {
       'priority': jsonEncode(providerIds),
     });
@@ -744,6 +1164,7 @@ class PlatformBridge {
     Map<String, dynamic> settings,
   ) async {
     _log.d('setExtensionSettings: $extensionId');
+    await _clearLookupCaches();
     await _channel.invokeMethod('setExtensionSettings', {
       'extension_id': extensionId,
       'settings': jsonEncode(settings),
@@ -883,13 +1304,45 @@ class PlatformBridge {
     String extensionId,
     String query, {
     Map<String, dynamic>? options,
+    bool cancelPrevious = false,
   }) async {
-    final result = await _channel.invokeMethod('customSearchWithExtension', {
-      'extension_id': extensionId,
-      'query': query,
-      'options': options != null ? jsonEncode(options) : '',
-    });
-    return _decodeMapListResult(result, 'customSearchWithExtension');
+    final optionsJson = options != null ? jsonEncode(options) : '';
+    final scopeKey = 'customSearch:${extensionId.trim()}';
+    final cacheKey = [
+      scopeKey,
+      query,
+      jsonEncode(_canonicalizeJsonLike(options ?? const <String, dynamic>{})),
+    ].join('\n');
+    final inFlight = _customSearchInFlight[cacheKey];
+    if (inFlight != null) return _copyMapList(await inFlight.future);
+    if (cancelPrevious) {
+      _cancelCustomSearchInFlightForScope(scopeKey, exceptKey: cacheKey);
+    }
+
+    final requestId = _nextExtensionRequestId('customSearch', extensionId);
+    final future = (() async {
+      final result = await _channel.invokeMethod('customSearchWithExtension', {
+        'extension_id': extensionId,
+        'query': query,
+        'options': optionsJson,
+        'request_id': requestId,
+      });
+      return _decodeMapListResult(result, 'customSearchWithExtension');
+    })();
+
+    final entry = _BridgeInFlight<List<Map<String, dynamic>>>(
+      requestId: requestId,
+      scopeKey: scopeKey,
+      future: future,
+    );
+    _customSearchInFlight[cacheKey] = entry;
+    try {
+      return _copyMapList(await future);
+    } finally {
+      if (identical(_customSearchInFlight[cacheKey], entry)) {
+        _customSearchInFlight.remove(cacheKey);
+      }
+    }
   }
 
   static Future<List<Map<String, dynamic>>> getSearchProviders() async {
@@ -927,16 +1380,44 @@ class PlatformBridge {
   }
 
   static Future<Map<String, dynamic>?> getExtensionHomeFeed(
-    String extensionId,
-  ) async {
+    String extensionId, {
+    bool cancelPrevious = false,
+  }) async {
+    final cacheKey = 'homeFeed:${extensionId.trim()}';
+    final inFlight = _homeFeedInFlight[cacheKey];
+    if (inFlight != null) {
+      if (!cancelPrevious) {
+        return _copyNullableStringMap(await inFlight.future);
+      }
+      _cancelExtensionRequestUnawaited(inFlight.requestId);
+      _homeFeedInFlight.remove(cacheKey);
+    }
+
+    final requestId = _nextExtensionRequestId('homeFeed', extensionId);
+    final future = (() async {
+      try {
+        final result = await _channel.invokeMethod('getExtensionHomeFeed', {
+          'extension_id': extensionId,
+          'request_id': requestId,
+        });
+        return _decodeNullableMapResult(result, 'getExtensionHomeFeed');
+      } catch (e) {
+        _log.e('getExtensionHomeFeed failed: $e');
+        return null;
+      }
+    })();
+    final entry = _BridgeInFlight<Map<String, dynamic>?>(
+      requestId: requestId,
+      scopeKey: cacheKey,
+      future: future,
+    );
+    _homeFeedInFlight[cacheKey] = entry;
     try {
-      final result = await _channel.invokeMethod('getExtensionHomeFeed', {
-        'extension_id': extensionId,
-      });
-      return _decodeNullableMapResult(result, 'getExtensionHomeFeed');
-    } catch (e) {
-      _log.e('getExtensionHomeFeed failed: $e');
-      return null;
+      return _copyNullableStringMap(await future);
+    } finally {
+      if (identical(_homeFeedInFlight[cacheKey], entry)) {
+        _homeFeedInFlight.remove(cacheKey);
+      }
     }
   }
 
@@ -969,7 +1450,7 @@ class PlatformBridge {
     final result = await _channel.invokeMethod('scanLibraryFolder', {
       'folder_path': folderPath,
     });
-    return _decodeMapListResult(result, 'scanLibraryFolder');
+    return _decodeMapListResultAsync(result, 'scanLibraryFolder');
   }
 
   static Future<Map<String, dynamic>> scanLibraryFolderIncremental(
@@ -983,7 +1464,10 @@ class PlatformBridge {
       'folder_path': folderPath,
       'existing_files': jsonEncode(existingFiles),
     });
-    return _decodeRequiredMapResult(result, 'scanLibraryFolderIncremental');
+    return _decodeRequiredMapResultAsync(
+      result,
+      'scanLibraryFolderIncremental',
+    );
   }
 
   static Future<Map<String, dynamic>> scanLibraryFolderIncrementalFromSnapshot(
@@ -994,7 +1478,7 @@ class PlatformBridge {
       'scanLibraryFolderIncrementalFromSnapshot',
       {'folder_path': folderPath, 'snapshot_path': snapshotPath},
     );
-    return _decodeRequiredMapResult(
+    return _decodeRequiredMapResultAsync(
       result,
       'scanLibraryFolderIncrementalFromSnapshot',
     );
@@ -1005,7 +1489,7 @@ class PlatformBridge {
     final result = await _channel.invokeMethod('scanSafTree', {
       'tree_uri': treeUri,
     });
-    return _decodeMapListResult(result, 'scanSafTree');
+    return _decodeMapListResultAsync(result, 'scanSafTree');
   }
 
   static Future<Map<String, dynamic>> scanSafTreeIncremental(
@@ -1019,7 +1503,7 @@ class PlatformBridge {
       'tree_uri': treeUri,
       'existing_files': jsonEncode(existingFiles),
     });
-    return _decodeRequiredMapResult(result, 'scanSafTreeIncremental');
+    return _decodeRequiredMapResultAsync(result, 'scanSafTreeIncremental');
   }
 
   static Future<Map<String, dynamic>> scanSafTreeIncrementalFromSnapshot(
@@ -1030,7 +1514,7 @@ class PlatformBridge {
       'scanSafTreeIncrementalFromSnapshot',
       {'tree_uri': treeUri, 'snapshot_path': snapshotPath},
     );
-    return _decodeRequiredMapResult(
+    return _decodeRequiredMapResultAsync(
       result,
       'scanSafTreeIncrementalFromSnapshot',
     );
@@ -1067,6 +1551,22 @@ class PlatformBridge {
     return result;
   }
 
+  static Future<Object?> _decodeJsonResultAsync(dynamic result) async {
+    if (result is Map && result[_jsonResultFileKey] is String) {
+      final file = File(result[_jsonResultFileKey] as String);
+      try {
+        final contents = await file.readAsString();
+        if (contents.isEmpty) return null;
+        return jsonDecode(contents);
+      } finally {
+        try {
+          await file.delete();
+        } catch (_) {}
+      }
+    }
+    return _decodeJsonResult(result);
+  }
+
   static Map<String, dynamic> _decodeRequiredMapResult(
     dynamic result,
     String method,
@@ -1094,6 +1594,19 @@ class PlatformBridge {
     );
   }
 
+  static Future<Map<String, dynamic>> _decodeRequiredMapResultAsync(
+    dynamic result,
+    String method,
+  ) async {
+    final decoded = await _decodeJsonResultAsync(result);
+    if (decoded is Map) {
+      return decoded.cast<String, dynamic>();
+    }
+    throw FormatException(
+      'Expected map result from $method, got ${decoded.runtimeType}',
+    );
+  }
+
   static List<dynamic> _decodeRequiredListResult(
     dynamic result,
     String method,
@@ -1105,6 +1618,17 @@ class PlatformBridge {
     );
   }
 
+  static Future<List<dynamic>> _decodeRequiredListResultAsync(
+    dynamic result,
+    String method,
+  ) async {
+    final decoded = await _decodeJsonResultAsync(result);
+    if (decoded is List) return decoded;
+    throw FormatException(
+      'Expected list result from $method, got ${decoded.runtimeType}',
+    );
+  }
+
   static List<Map<String, dynamic>> _decodeMapListResult(
     dynamic result,
     String method,
@@ -1117,6 +1641,19 @@ class PlatformBridge {
     }).toList();
   }
 
+  static Future<List<Map<String, dynamic>>> _decodeMapListResultAsync(
+    dynamic result,
+    String method,
+  ) async {
+    final decoded = await _decodeRequiredListResultAsync(result, method);
+    return decoded.map((entry) {
+      if (entry is Map) return entry.cast<String, dynamic>();
+      throw FormatException(
+        'Expected map entry from $method, got ${entry.runtimeType}',
+      );
+    }).toList();
+  }
+
   static List<String> _decodeStringListResult(dynamic result, String method) {
     return _decodeRequiredListResult(result, method).map((entry) {
       if (entry is String) return entry;

lib/widgets/cached_cover_image.dart

@@ -3,10 +3,14 @@ import 'package:cached_network_image/cached_network_image.dart';
 import 'package:spotiflac_android/services/cover_cache_manager.dart';
 
 class CachedCoverImage extends StatelessWidget {
+  static const int _defaultMinCacheExtent = 64;
+  static const int _defaultMaxCacheExtent = 512;
+
   final String imageUrl;
   final double? width;
   final double? height;
   final BoxFit fit;
+  final Alignment alignment;
   final int? memCacheWidth;
   final int? memCacheHeight;
   final Widget Function(BuildContext, String, Object)? errorWidget;
@@ -19,6 +23,7 @@ class CachedCoverImage extends StatelessWidget {
     this.width,
     this.height,
     this.fit = BoxFit.cover,
+    this.alignment = Alignment.center,
     this.memCacheWidth,
     this.memCacheHeight,
     this.errorWidget,
@@ -28,36 +33,65 @@ class CachedCoverImage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final autoMemCacheWidth =
+        memCacheWidth ?? _cacheExtentForLogicalSize(context, width);
+    final autoMemCacheHeight =
+        memCacheHeight ?? _cacheExtentForLogicalSize(context, height);
     final image = CachedNetworkImage(
       imageUrl: imageUrl,
       width: width,
       height: height,
       fit: fit,
-      memCacheWidth: memCacheWidth,
-      memCacheHeight: memCacheHeight,
-      cacheManager: CoverCacheManager.isInitialized 
-          ? CoverCacheManager.instance 
+      alignment: alignment,
+      memCacheWidth: autoMemCacheWidth,
+      memCacheHeight: autoMemCacheHeight,
+      maxWidthDiskCache: autoMemCacheWidth,
+      maxHeightDiskCache: autoMemCacheHeight,
+      cacheManager: CoverCacheManager.isInitialized
+          ? CoverCacheManager.instance
           : null,
+      fadeInDuration: Duration.zero,
+      fadeOutDuration: Duration.zero,
+      useOldImageOnUrlChange: true,
+      filterQuality: FilterQuality.low,
       errorWidget: errorWidget,
       placeholder: placeholder,
     );
 
     if (borderRadius != null) {
-      return ClipRRect(
-        borderRadius: borderRadius!,
-        child: image,
-      );
+      return ClipRRect(borderRadius: borderRadius!, child: image);
     }
 
     return image;
   }
+
+  static int? _cacheExtentForLogicalSize(BuildContext context, double? size) {
+    if (size == null || !size.isFinite || size <= 0) return null;
+    final dpr = MediaQuery.devicePixelRatioOf(
+      context,
+    ).clamp(1.0, 3.0).toDouble();
+    return (size * dpr)
+        .round()
+        .clamp(_defaultMinCacheExtent, _defaultMaxCacheExtent)
+        .toInt();
+  }
 }
 
 CachedNetworkImageProvider cachedCoverImageProvider(String url) {
   return CachedNetworkImageProvider(
     url,
-    cacheManager: CoverCacheManager.isInitialized 
-        ? CoverCacheManager.instance 
+    cacheManager: CoverCacheManager.isInitialized
+        ? CoverCacheManager.instance
         : null,
   );
 }
+
+int coverImageCacheExtent(
+  BuildContext context,
+  double logicalSize, {
+  int min = 64,
+  int max = 512,
+}) {
+  final dpr = MediaQuery.devicePixelRatioOf(context).clamp(1.0, 3.0).toDouble();
+  return (logicalSize * dpr).round().clamp(min, max).toInt();
+}