优化

app/src/main/java/io/legado/app/model/ReadBook.kt

@@ -47,7 +47,9 @@ import kotlinx.coroutines.ensureActive
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.flow.receiveAsFlow
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.Semaphore
+import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
 import splitties.init.appCtx
 import kotlin.math.max
@@ -68,6 +70,12 @@ object ReadBook : CoroutineScope by MainScope() {
     var prevTextChapter: TextChapter? = null
     var curTextChapter: TextChapter? = null
     var nextTextChapter: TextChapter? = null
+    var prevChapterLoadingJob: Coroutine<*>? = null
+    var curChapterLoadingJob: Coroutine<*>? = null
+    var nextChapterLoadingJob: Coroutine<*>? = null
+    var prevChapterLoadingLock = Mutex()
+    var curChapterLoadingLock = Mutex()
+    var nextChapterLoadingLock = Mutex()
     var bookSource: BookSource? = null
     var msg: String? = null
     private val loadingChapters = arrayListOf<Int>()
@@ -675,6 +683,7 @@ object ReadBook : CoroutineScope by MainScope() {
     /**
      * 内容加载完成
      */
+    @Synchronized
     fun contentLoadFinish(
         book: Book,
         chapter: BookChapter,
@@ -684,11 +693,17 @@ object ReadBook : CoroutineScope by MainScope() {
         canceled: Boolean = false,
         success: (() -> Unit)? = null
     ) {
+        removeLoading(chapter.index)
         if (canceled || chapter.index !in durChapterIndex - 1..durChapterIndex + 1) {
-            removeLoading(chapter.index)
             return
         }
-        Coroutine.async(start = CoroutineStart.LAZY) {
+        val offset = chapter.index - durChapterIndex
+        when (offset) {
+            0 -> curChapterLoadingJob?.cancel()
+            -1 -> prevChapterLoadingJob?.cancel()
+            1 -> nextChapterLoadingJob?.cancel()
+        }
+        val job = Coroutine.async(this, start = CoroutineStart.LAZY) {
             val contentProcessor = ContentProcessor.get(book.name, book.origin)
             val displayTitle = chapter.getDisplayTitle(
                 contentProcessor.getTitleReplaceRules(),
@@ -696,12 +711,12 @@ object ReadBook : CoroutineScope by MainScope() {
             )
             val contents = contentProcessor
                 .getContent(book, chapter, content, includeTitle = false)
+            ensureActive()
             val textChapter = ChapterProvider.getTextChapterAsync(
-                this@ReadBook, book, chapter, displayTitle, contents, simulatedChapterSize
+                this, book, chapter, displayTitle, contents, simulatedChapterSize
             )
-            when (val offset = chapter.index - durChapterIndex) {
-                0 -> {
-                    curTextChapter?.cancelLayout()
+            when (offset) {
+                0 -> curChapterLoadingLock.withLock {
                     withContext(Main) {
                         curTextChapter = textChapter
                     }
@@ -727,8 +742,7 @@ object ReadBook : CoroutineScope by MainScope() {
                     callBack?.contentLoadFinish()
                 }
 
-                -1 -> {
-                    prevTextChapter?.cancelLayout()
+                -1 -> prevChapterLoadingLock.withLock {
                     withContext(Main) {
                         prevTextChapter = textChapter
                     }
@@ -736,8 +750,7 @@ object ReadBook : CoroutineScope by MainScope() {
                     if (upContent) callBack?.upContent(offset, resetPageOffset)
                 }
 
-                1 -> {
-                    nextTextChapter?.cancelLayout()
+                1 -> nextChapterLoadingLock.withLock {
                     withContext(Main) {
                         nextTextChapter = textChapter
                     }
@@ -759,9 +772,13 @@ object ReadBook : CoroutineScope by MainScope() {
             appCtx.toastOnUi("ChapterProvider ERROR:\n${it.stackTraceStr}")
         }.onSuccess {
             success?.invoke()
-        }.onFinally {
-            removeLoading(chapter.index)
-        }.start()
+        }
+        when (offset) {
+            0 -> curChapterLoadingJob = job
+            -1 -> prevChapterLoadingJob = job
+            1 -> nextChapterLoadingJob = job
+        }
+        job.start()
     }
 
     suspend fun contentLoadFinishAwait(
@@ -771,8 +788,8 @@ object ReadBook : CoroutineScope by MainScope() {
         upContent: Boolean = true,
         resetPageOffset: Boolean
     ) {
+        removeLoading(chapter.index)
         if (chapter.index !in durChapterIndex - 1..durChapterIndex + 1) {
-            removeLoading(chapter.index)
             return
         }
         kotlin.runCatching {
@@ -843,7 +860,6 @@ object ReadBook : CoroutineScope by MainScope() {
             AppLog.put("ChapterProvider ERROR", it)
             appCtx.toastOnUi("ChapterProvider ERROR:\n${it.stackTraceStr}")
         }
-        removeLoading(chapter.index)
     }
 
     @Synchronized