Fix crash on get 509 and mDownloadReference > 1

app/src/main/kotlin/com/hippo/ehviewer/download/DownloadManager.kt

@@ -54,6 +54,8 @@ import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.transform
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import splitties.preferences.edit
 
 object DownloadManager : OnSpiderListener {
@@ -83,6 +85,8 @@ object DownloadManager : OnSpiderListener {
     private val mutableNotifyFlow = MutableSharedFlow<DownloadInfo>(extraBufferCapacity = 1)
     val notifyFlow = mutableNotifyFlow.asSharedFlow()
 
+    private val mutex = Mutex()
+
     init {
         assertNotMainThread()
         map = runAssertingNotMainThread {
@@ -134,35 +138,37 @@ object DownloadManager : OnSpiderListener {
     }
 
     private suspend fun ensureDownload() {
-        if (mCurrentTask != null) {
-            // Only one download
-            return
-        }
+        mutex.withLock {
+            if (mCurrentTask != null) {
+                // Only one download
+                return
+            }
 
-        // Get download from wait list
-        if (!mWaitList.isEmpty()) {
-            val info = mWaitList.removeFirst()
-            val spider = SpiderQueen.obtainSpiderQueen(info, SpiderQueen.MODE_DOWNLOAD)
-            mCurrentTask = info
-            mCurrentSpider = spider
-            spider.addOnSpiderListener(this)
-            info.state = DownloadInfo.STATE_DOWNLOAD
-            info.speed = -1
-            info.remaining = -1
-            info.total = -1
-            info.finished = 0
-            info.downloaded = 0
-            info.legacy = -1
-            // Update in DB
-            EhDB.putDownloadInfo(info)
-            // Start speed count
-            mSpeedReminder.start()
-            // Notify start downloading
-            if (mDownloadListener != null) {
-                mDownloadListener!!.onStart(info)
+            // Get download from wait list
+            if (!mWaitList.isEmpty()) {
+                val info = mWaitList.removeFirst()
+                val spider = SpiderQueen.obtainSpiderQueen(info, SpiderQueen.MODE_DOWNLOAD)
+                mCurrentTask = info
+                mCurrentSpider = spider
+                spider.addOnSpiderListener(this)
+                info.state = DownloadInfo.STATE_DOWNLOAD
+                info.speed = -1
+                info.remaining = -1
+                info.total = -1
+                info.finished = 0
+                info.downloaded = 0
+                info.legacy = -1
+                // Update in DB
+                EhDB.putDownloadInfo(info)
+                // Start speed count
+                mSpeedReminder.start()
+                // Notify start downloading
+                if (mDownloadListener != null) {
+                    mDownloadListener!!.onStart(info)
+                }
+                // Notify state update
+                mutableNotifyFlow.emit(info)
             }
-            // Notify state update
-            mutableNotifyFlow.emit(info)
         }
     }
 
@@ -365,20 +371,22 @@ object DownloadManager : OnSpiderListener {
     }
 
     suspend fun stopAllDownload() {
-        // Stop all in wait list
-        for (info in mWaitList) {
-            info.state = DownloadInfo.STATE_NONE
-            // Update in DB
-            EhDB.putDownloadInfo(info)
+        mutex.withLock {
+            // Stop all in wait list
+            for (info in mWaitList) {
+                info.state = DownloadInfo.STATE_NONE
+                // Update in DB
+                EhDB.putDownloadInfo(info)
 
-            // Notify
-            mutableNotifyFlow.emit(info)
+                // Notify
+                mutableNotifyFlow.emit(info)
+            }
+            mWaitList.clear()
+
+            // Stop current
+            val info = stopCurrentDownloadInternal()
+            info?.let { mutableNotifyFlow.emit(it) }
         }
-        mWaitList.clear()
-
-        // Stop current
-        val info = stopCurrentDownloadInternal()
-        info?.let { mutableNotifyFlow.emit(it) }
     }
 
     suspend fun deleteDownload(gid: Long, deleteFiles: Boolean = false) {

app/src/main/kotlin/com/hippo/ehviewer/spider/SpiderQueen.kt

@@ -212,7 +212,7 @@ class SpiderQueen private constructor(val galleryInfo: GalleryInfo) : CoroutineS
             MODE_READ -> mReadReference++
             MODE_DOWNLOAD -> mDownloadReference++
         }
-        check(mDownloadReference <= 1) { "mDownloadReference can't more than 0" }
+        check(mDownloadReference <= 1) { "mDownloadReference can't more than 1" }
     }
 
     private fun clearMode(@Mode mode: Int) {
@@ -562,9 +562,11 @@ class SpiderQueen private constructor(val galleryInfo: GalleryInfo) : CoroutineS
                         }
                     }.onFailure {
                         if (it is CancellationException) {
-                            Log.d(WORKER_DEBUG_TAG, "Download image $index cancelled")
-                            if (it.message != FORCE_RETRY) {
-                                updatePageState(index, STATE_FAILED, "Cancelled")
+                            if (mReadReference > 0) {
+                                Log.d(WORKER_DEBUG_TAG, "Download image $index cancelled")
+                                if (it.message != FORCE_RETRY) {
+                                    updatePageState(index, STATE_FAILED, "Cancelled")
+                                }
                             }
                             throw it
                         }