优化 EPUB 翻页与后台分页刷新

Sources/RDReaderView/EPUBTextRendering/BuildPipeline/RDEPUBTextBookCache.swift

@@ -137,7 +137,7 @@ public final class RDEPUBTextBookCache {
             let fileURL = cacheDirectory.appendingPathComponent(key)
             guard FileManager.default.fileExists(atPath: fileURL.path) else {
                 #if DEBUG
-                print("[Cache] load MISS key=\(key)")
+//                print("[Cache] load MISS key=\(key)")
                 #endif
                 return nil
             }
@@ -148,7 +148,7 @@ public final class RDEPUBTextBookCache {
                     from: data
                 ) else {
                     #if DEBUG
-                    print("[Cache] load MISS key=\(key) (unarchive returned nil)")
+//                    print("[Cache] load MISS key=\(key) (unarchive returned nil)")
                     #endif
                     return nil
                 }
@@ -157,12 +157,12 @@ public final class RDEPUBTextBookCache {
                     result[chapter.href] = chapter.toCache()
                 }
                 #if DEBUG
-                print("[Cache] load HIT key=\(key) chapters=\(result.count)")
+//                print("[Cache] load HIT key=\(key) chapters=\(result.count)")
                 #endif
                 return result
             } catch {
                 #if DEBUG
-                print("[Cache] load MISS key=\(key) error=\(error)")
+//                print("[Cache] load MISS key=\(key) error=\(error)")
                 #endif
                 return nil
             }

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBMetadataParseWorker.swift

@@ -56,6 +56,8 @@ final class RDEPUBMetadataParseWorker {
 
     private let catalog: [(key: RDEPUBChapterCacheKey, spineIndex: Int, href: String, title: String)]
 
+    private let progressLogStride = 4
+
     init(
         context: RDEPUBReaderContext,
         cancellationController: RDEPUBMetadataParseCancellationController,
@@ -116,19 +118,38 @@ final class RDEPUBMetadataParseWorker {
     func start(token: UUID, restoreLocation: RDEPUBLocation?) {
         let cancellationController = self.cancellationController
 
-        DispatchQueue.global(qos: .utility).async { [weak self] in
+        DispatchQueue.global(qos: .utility).async { [self] in
-            guard let self else { return }
+            RDEPUBBackgroundTrace.log(
+                "Metadata",
+                "workerDispatched token=\(token.uuidString)"
+            )
             let context = self.context
             guard let context,
                   context.controller != nil,
                   !cancellationController.isCancelled,
-                  context.paginationToken == token else { return }
+                  context.paginationToken == token else {
+                RDEPUBBackgroundTrace.log(
+                    "Metadata",
+                    "workerAbortedBeforeStart reason=contextUnavailableOrTokenMismatch"
+                )
+                return
+            }
             defer { context.runtime?.paginationCoordinator.finishMetadataParseCancellationController(cancellationController) }
             guard context.controller != nil,
                   !cancellationController.isCancelled,
-                  context.paginationToken == token else { return }
+                  context.paginationToken == token else {
+                RDEPUBBackgroundTrace.log(
+                    "Metadata",
+                    "workerAbortedAfterStart reason=contextUnavailableOrTokenMismatch"
+                )
+                return
+            }
 
             if let restoredPageMap = self.restoreBookPageMapIfPossible() {
+                RDEPUBBackgroundTrace.log(
+                    "Metadata",
+                    "restoreBookPageMapIfPossible hit totalChapters=\(restoredPageMap.totalChapters) totalPages=\(restoredPageMap.totalPages)"
+                )
                 DispatchQueue.main.async {
                     guard context.paginationToken == token,
                           context.controller != nil,
@@ -175,13 +196,26 @@ final class RDEPUBMetadataParseWorker {
 
             let uncachedSpineIndices = prioritizedSpineIndices
 
+            RDEPUBBackgroundTrace.log(
+                "Metadata",
+                "waitingForInteractionCooldown elapsedSinceNavigation=\(String(format: "%.2f", context.secondsSinceLastUserNavigation())) uncached=\(uncachedSpineIndices.count)"
+            )
             self.waitForReadingInteractionToSettle(cancellationController: cancellationController)
             guard !cancellationController.isCancelled,
                   context.controller != nil,
                   context.paginationToken == token else {
+                RDEPUBBackgroundTrace.log(
+                    "Metadata",
+                    "workerAbortedDuringCooldown"
+                )
                 return
             }
 
+            RDEPUBBackgroundTrace.log(
+                "Metadata",
+                "start totalBuildable=\(self.allBuildableIndices.count) cached=\(cachedSpineIndices.count) uncached=\(uncachedSpineIndices.count) concurrency=\(self.workerCount) refreshInterval=\(self.pageMapRefreshInterval)"
+            )
+
             let wallClockStart = CFAbsoluteTimeGetCurrent()
             var totalRenderMs: Double = 0
             var totalWriteMs: Double = 0
@@ -283,6 +317,10 @@ final class RDEPUBMetadataParseWorker {
                         resultLock.lock()
                         parseState.summariesBySpineIndex[spineIndex] = renderResult
                         parseState.totalResolvedCount += 1
+                        let resolvedCount = parseState.totalResolvedCount
+                        let shouldLogProgress = resolvedCount == self.allBuildableIndices.count
+                            || resolvedCount == cachedSpineIndices.count + 1
+                            || resolvedCount % self.progressLogStride == 0
                         if parseState.totalResolvedCount - parseState.lastAppliedCount >= refreshInterval
                             || parseState.totalResolvedCount == self.allBuildableIndices.count {
                             parseState.lastAppliedCount = parseState.totalResolvedCount
@@ -290,6 +328,17 @@ final class RDEPUBMetadataParseWorker {
                         }
                         resultLock.unlock()
 
+                        if shouldLogProgress {
+                            let progressPercent = Self.progressPercent(
+                                resolved: resolvedCount,
+                                total: self.allBuildableIndices.count
+                            )
+                            RDEPUBBackgroundTrace.log(
+                                "Metadata",
+                                "chapterReady spine=\(spineIndex) resolved=\(resolvedCount)/\(self.allBuildableIndices.count) progress=\(progressPercent)% pageCount=\(renderResult.pageCount)"
+                            )
+                        }
+
                         if let snapshot {
                             let mergeStart = CFAbsoluteTimeGetCurrent()
                             let partialMap = self.buildPageMap(summaries: snapshot)
@@ -297,6 +346,10 @@ final class RDEPUBMetadataParseWorker {
                             timingLock.lock()
                             totalMergeMs += mergeElapsed
                             timingLock.unlock()
+                            RDEPUBBackgroundTrace.log(
+                                "Metadata",
+                                "partialMap resolvedChapters=\(snapshot.count) totalPages=\(partialMap.totalPages) mergeMs=\(Int(mergeElapsed))"
+                            )
                             DispatchQueue.main.async {
                                 guard context.paginationToken == token,
                                       context.controller != nil,
@@ -314,6 +367,10 @@ final class RDEPUBMetadataParseWorker {
                         timingLock.lock()
                         failedChapters += 1
                         timingLock.unlock()
+                        RDEPUBBackgroundTrace.log(
+                            "Metadata",
+                            "chapterFailed spine=\(spineIndex) retryScheduled=true error=\(String(describing: error))"
+                        )
 
                         self.scheduleRetry(
                             spineIndex: spineIndex,
@@ -354,6 +411,10 @@ final class RDEPUBMetadataParseWorker {
             let finalMergeStart = CFAbsoluteTimeGetCurrent()
             let pageMap = self.buildPageMap(summaries: parseState.summariesBySpineIndex)
             let finalMergeMs = Int((CFAbsoluteTimeGetCurrent() - finalMergeStart) * 1000)
+            RDEPUBBackgroundTrace.log(
+                "Metadata",
+                "finish resolved=\(parseState.summariesBySpineIndex.count)/\(self.allBuildableIndices.count) totalPages=\(pageMap.totalPages) elapsedMs=\(wallClockMs) renderMs=\(renderTotal) writeMs=\(writeTotal) mergeMs=\(mergeTotal + finalMergeMs) failed=\(failed)"
+            )
 
             if let coverageStore = context.runtime?.backgroundCoverageStore {
                 let resolvedSpineIndices = Set(parseState.summariesBySpineIndex.keys)
@@ -407,10 +468,18 @@ final class RDEPUBMetadataParseWorker {
         cancellationController: RDEPUBMetadataParseCancellationController
     ) {
         guard retryCount < Self.maxRetryCount else {
+            RDEPUBBackgroundTrace.log(
+                "Metadata",
+                "retryAborted spine=\(spineIndex) retryCount=\(retryCount)"
+            )
             return
         }
 
         let delay = Self.retryDelays[min(retryCount, Self.retryDelays.count - 1)]
+        RDEPUBBackgroundTrace.log(
+            "Metadata",
+            "retryScheduled spine=\(spineIndex) retryCount=\(retryCount + 1) delayMs=\(Int(delay * 1000))"
+        )
 
         DispatchQueue.global(qos: .utility).asyncAfter(deadline: .now() + delay) { [weak self] in
             guard let self, let context = self.context else { return }
@@ -474,6 +543,10 @@ final class RDEPUBMetadataParseWorker {
 
                 if shouldRefresh {
                     let partialMap = self.buildPageMap(summaries: parseState.summariesBySpineIndex)
+                    RDEPUBBackgroundTrace.log(
+                        "Metadata",
+                        "retryPartialMap resolvedChapters=\(parseState.summariesBySpineIndex.count) totalPages=\(partialMap.totalPages)"
+                    )
                     DispatchQueue.main.async {
                         guard context.paginationToken == self.token,
                               context.controller != nil,
@@ -495,6 +568,11 @@ final class RDEPUBMetadataParseWorker {
         }
     }
 
+    private static func progressPercent(resolved: Int, total: Int) -> Int {
+        guard total > 0 else { return 0 }
+        return Int((Double(resolved) / Double(total) * 100.0).rounded())
+    }
+
     private func restoreBookPageMapIfPossible() -> RDEPUBBookPageMap? {
         guard let summaryDiskCache else { return nil }
         guard summaryDiskCache.isCacheComplete(keys: catalog.map(\.key)) else {

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBPresentationRuntime.swift

@@ -21,6 +21,8 @@ final class RDEPUBPresentationRuntime {
 
     private unowned let reconciliationCoordinator: RDEPUBPageMapReconciliationCoordinator
 
+    private var pendingCommitRetryWorkItem: DispatchWorkItem?
+
     init(
         context: RDEPUBReaderContext,
         locationCoordinator: RDEPUBReaderLocationCoordinator,
@@ -62,11 +64,22 @@ final class RDEPUBPresentationRuntime {
         guard let readerView = context.readerView,
               let controller = context.controller else { return }
 
-        guard !controller.isRepaginating else { return }
+        guard !context.pendingPageMapUpdates.isEmpty else {
-        guard !readerView.isPageCurlTransitioning else {
+            cancelPendingCommitRetry()
             return
         }
 
+        guard !controller.isRepaginating else {
+            schedulePendingCommitRetry()
+            return
+        }
+        guard !readerView.isPageCurlTransitioning else {
+            schedulePendingCommitRetry()
+            return
+        }
+
+        cancelPendingCommitRetry()
+
         let rankedUpdates = rankedPendingPageMapUpdates()
         for (index, update) in rankedUpdates {
             if commitPendingPageMapUpdate(
@@ -75,9 +88,16 @@ final class RDEPUBPresentationRuntime {
                 readerView: readerView,
                 controller: controller
             ) {
+                if !context.pendingPageMapUpdates.isEmpty {
+                    schedulePendingCommitRetry()
+                }
                 return
             }
         }
+
+        if !context.pendingPageMapUpdates.isEmpty {
+            schedulePendingCommitRetry()
+        }
     }
 
     func queueExtendedPartialPageMap(
@@ -139,19 +159,40 @@ final class RDEPUBPresentationRuntime {
         controller: RDEPUBReaderController
     ) {
         let currentLocation = locationCoordinator.currentVisibleLocation()
+        let livePageBeforeApply = readerView.currentPage + 1
 
         context.textBook = nil
         applyPageMapToLiveModel(newPageMap)
+        RDEPUBBackgroundTrace.log(
+            "Reconciliation",
+            "applyFullPageMapReplacement livePageBeforeApply=\(livePageBeforeApply) totalPages=\(newPageMap.totalPages) totalChapters=\(newPageMap.totalChapters)"
+        )
 
         if let currentLocation {
-            if rebindVisibleLocation(currentLocation, readerView: readerView, controller: controller) == false {
+            let resolvedTargetPage = controller.pageNumber(for: currentLocation)
-                let newPageNumber = controller.pageNumber(for: currentLocation) ?? (readerView.currentPage + 1)
+            let shouldTrustResolvedLocation = shouldTrustFullReplaceResolvedPage(
-                let newPage = max(0, newPageNumber - 1)
+                resolvedTargetPage,
-                rebindVisiblePage(
+                livePageBeforeApply: livePageBeforeApply
-                    to: newPage,
+            )
-                    readerView: readerView
+            RDEPUBBackgroundTrace.log(
-                )
+                "Reconciliation",
+                "applyFullPageMapReplacement decision livePage=\(livePageBeforeApply) resolvedTargetPage=\(resolvedTargetPage ?? -1) trustResolved=\(shouldTrustResolvedLocation) href=\(currentLocation.href)"
+            )
+
+            if shouldTrustResolvedLocation,
+               rebindVisibleLocation(currentLocation, readerView: readerView, controller: controller) {
+                return
             }
+
+            let fallbackPage = max(livePageBeforeApply, 1)
+            RDEPUBBackgroundTrace.log(
+                "Reconciliation",
+                "applyFullPageMapReplacement preserveLivePage fallbackPage=\(fallbackPage) currentReaderPage=\(readerView.currentPage + 1)"
+            )
+            rebindVisiblePage(
+                to: fallbackPage - 1,
+                readerView: readerView
+            )
         } else {
             readerView.reloadPageCountOnly()
         }
@@ -223,17 +264,23 @@ final class RDEPUBPresentationRuntime {
                 return false
             }
 
-        case .extendPartial(_, let currentLocation):
+        case .extendPartial(let capturedPageNumber, let currentLocation):
             removePendingPageMapUpdate(at: index)
             applyPageMapToLiveModel(update.pageMap)
-            if let currentLocation,
+            let livePageNumber = max(readerView.currentPage, 0) + 1
+            let shouldTrustCapturedLocation = livePageNumber == max(capturedPageNumber, 1)
+            RDEPUBBackgroundTrace.log(
+                "Reconciliation",
+                "extendPartial commit capturedPage=\(capturedPageNumber) livePage=\(livePageNumber) trustCaptured=\(shouldTrustCapturedLocation) totalPages=\(update.pageMap.totalPages) totalChapters=\(update.pageMap.totalChapters)"
+            )
+            if shouldTrustCapturedLocation,
+               let currentLocation,
                rebindVisibleLocation(currentLocation, readerView: readerView, controller: controller) {
                 return true
             }
-            // Fallback: prefer the live readerView.currentPage over the stale captured
+            // Prefer the live readerView page when the user has moved since the
-            // currentPageNumber, which may be outdated by the time this commit runs
+            // extension request was created; otherwise a stale captured location can
-            // (especially in pageCurl mode where the user may have turned several pages
+            // snap pageCurl back to the previous page after the turn completes.
-            // since the extension was initiated).
             let livePageIndex = max(readerView.currentPage, 0)
             rebindVisiblePage(
                 to: livePageIndex,
@@ -250,6 +297,19 @@ final class RDEPUBPresentationRuntime {
     }
 
     private func rebindVisiblePage(to pageIndex: Int, readerView: RDReaderView) {
+        if pageIndex == readerView.currentPage {
+            RDEPUBBackgroundTrace.log(
+                "Reconciliation",
+                "rebindVisiblePage pageUnchanged currentPage=\(readerView.currentPage + 1) displayType=\(readerView.currentDisplayType)"
+            )
+            readerView.reloadPageCountOnly()
+            return
+        }
+
+        RDEPUBBackgroundTrace.log(
+            "Reconciliation",
+            "rebindVisiblePage targetPage=\(pageIndex + 1) currentPage=\(readerView.currentPage + 1) displayType=\(readerView.currentDisplayType) isPageCurlTransitioning=\(readerView.isPageCurlTransitioning)"
+        )
         if readerView.currentDisplayType == .pageCurl {
             if readerView.isPageCurlTransitioning {
                 // Defer the transition until the current page-curl animation completes,
@@ -257,6 +317,10 @@ final class RDEPUBPresentationRuntime {
                 DispatchQueue.main.async { [weak readerView] in
                     guard let readerView, !readerView.isPageCurlTransitioning else { return }
                     let livePageIndex = max(readerView.currentPage, 0)
+                    RDEPUBBackgroundTrace.log(
+                        "Reconciliation",
+                        "rebindVisiblePage deferredTransition livePage=\(livePageIndex + 1)"
+                    )
                     readerView.transitionToPage(pageNum: livePageIndex, animated: false)
                 }
             } else {
@@ -276,6 +340,10 @@ final class RDEPUBPresentationRuntime {
         controller: RDEPUBReaderController
     ) -> Bool {
         guard let targetPageNumber = controller.pageNumber(for: location) else {
+            RDEPUBBackgroundTrace.log(
+                "Reconciliation",
+                "rebindVisibleLocation failedToResolve locationHref=\(location.href) currentPage=\(readerView.currentPage + 1)"
+            )
             return false
         }
 
@@ -284,9 +352,18 @@ final class RDEPUBPresentationRuntime {
                 forAbsolutePageNumber: targetPageNumber,
                 allowSynchronousLoad: false
            ) == false {
+            RDEPUBBackgroundTrace.log(
+                "Reconciliation",
+                "rebindVisibleLocation prepareOnDemandBlocked targetPage=\(targetPageNumber) currentPage=\(readerView.currentPage + 1)"
+            )
             return false
         }
 
+        RDEPUBBackgroundTrace.log(
+            "Reconciliation",
+            "rebindVisibleLocation targetPage=\(targetPageNumber) currentPage=\(readerView.currentPage + 1) href=\(location.href)"
+        )
+
         rebindVisiblePage(
             to: max(targetPageNumber - 1, 0),
             readerView: readerView
@@ -353,4 +430,29 @@ final class RDEPUBPresentationRuntime {
                     && candidate.pageMap.totalPages >= existing.pageMap.totalPages
             )
     }
-}
+
+    private func shouldTrustFullReplaceResolvedPage(
+        _ resolvedTargetPage: Int?,
+        livePageBeforeApply: Int
+    ) -> Bool {
+        guard let resolvedTargetPage else { return false }
+        return abs(resolvedTargetPage - livePageBeforeApply) <= 1
+    }
+
+    private func schedulePendingCommitRetry() {
+        guard pendingCommitRetryWorkItem == nil else { return }
+
+        let workItem = DispatchWorkItem { [weak self] in
+            guard let self else { return }
+            self.pendingCommitRetryWorkItem = nil
+            self.commitPendingPageMapUpdateIfNeeded()
+        }
+        pendingCommitRetryWorkItem = workItem
+        DispatchQueue.main.asyncAfter(deadline: .now() + 0.05, execute: workItem)
+    }
+
+    private func cancelPendingCommitRetry() {
+        pendingCommitRetryWorkItem?.cancel()
+        pendingCommitRetryWorkItem = nil
+    }
+}

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderEnvironment.swift

@@ -1,5 +1,27 @@
 import UIKit
 
+enum RDEPUBTextPageLayoutMetrics {
+
+    static let pageNumberTrailingPadding: CGFloat = 4
+
+    static let pageNumberFooterPadding: CGFloat = 8
+
+    static let pageNumberReservedHeight: CGFloat = ceil(UIFont.systemFont(ofSize: 13).lineHeight) + pageNumberFooterPadding
+
+    static func contentInsets(
+        configuration: RDEPUBReaderConfiguration,
+        safeAreaInsets: UIEdgeInsets
+    ) -> UIEdgeInsets {
+        let configInsets = configuration.reflowableContentInsets
+        return UIEdgeInsets(
+            top: max(configInsets.top, safeAreaInsets.top),
+            left: max(configInsets.left, safeAreaInsets.left),
+            bottom: max(configInsets.bottom, safeAreaInsets.bottom) + pageNumberReservedHeight,
+            right: max(configInsets.right, safeAreaInsets.right)
+        )
+    }
+}
+
 final class RDEPUBReaderEnvironment {
 
     weak var controller: RDEPUBReaderController?
@@ -46,11 +68,14 @@ final class RDEPUBReaderEnvironment {
         configuration: RDEPUBReaderConfiguration,
         pageSize: CGSize
     ) -> RDEPUBTextLayoutConfig {
-        let layoutContext = currentLayoutContext(configuration: configuration)
+        let safeAreaInsets = controller?.view.safeAreaInsets ?? .zero
         return RDEPUBTextLayoutConfig(
             frameWidth: max(pageSize.width, 1),
             frameHeight: max(pageSize.height, 1),
-            edgeInsets: layoutContext.safeReflowableContentInsets,
+            edgeInsets: RDEPUBTextPageLayoutMetrics.contentInsets(
+                configuration: configuration,
+                safeAreaInsets: safeAreaInsets
+            ),
             numberOfColumns: configuration.numberOfColumns,
             columnGap: configuration.columnGap,
             avoidOrphans: false,

Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderPaginationCoordinator.swift

@@ -191,12 +191,21 @@ final class RDEPUBReaderPaginationCoordinator {
                     runtime: runtime,
                     layoutSnapshot: layoutSnapshot
                 )
+                RDEPUBBackgroundTrace.log(
+                    "Pagination",
+                    "anchorChapterReady spine=\(runtimeChapter.spineIndex) pages=\(runtimeChapter.pages.count)"
+                )
                 let initialChapters = self.loadInitialInteractiveRuntimeChapters(
                     anchorChapter: runtimeChapter,
                     publication: publication,
                     runtime: runtime,
                     layoutSnapshot: layoutSnapshot
                 )
+                let initialPageCount = initialChapters.reduce(0) { $0 + $1.pages.count }
+                RDEPUBBackgroundTrace.log(
+                    "Pagination",
+                    "initialInteractiveChapters ready count=\(initialChapters.count) pages=\(initialPageCount) spines=\(initialChapters.map(\.spineIndex))"
+                )
 
                 DispatchQueue.main.async {
                     guard context.paginationToken == token,
@@ -220,9 +229,17 @@ final class RDEPUBReaderPaginationCoordinator {
                         parser: parser,
                         publication: publication
                     )
+                    RDEPUBBackgroundTrace.log(
+                        "Pagination",
+                        "startingMetadataWorker token=\(token.uuidString) anchorSpine=\(runtimeChapter.spineIndex) partialPages=\(partialMap.totalPages) partialChapters=\(partialMap.totalChapters)"
+                    )
                     worker.start(token: token, restoreLocation: restoreLocation)
                 }
             } catch {
+                RDEPUBBackgroundTrace.log(
+                    "Pagination",
+                    "initialPaginationFailed error=\(String(describing: error)) prioritizedCandidates=\(prioritizedCandidates)"
+                )
                 DispatchQueue.main.async {
                     guard context.paginationToken == token,
                           context.controller != nil else { return }

Sources/RDReaderView/ReaderView/Paging/RDReaderPreloadController.swift

@@ -78,8 +78,12 @@ final class RDReaderPreloadController {
         environment: Environment,
         contentViewProvider: (Int, UIView?) -> UIView?
     ) -> UIView {
-        let reusableView = detachedReusablePageView(for: pageNum)
+        let view: UIView
-        let view = contentViewProvider(pageNum, reusableView) ?? reusableView ?? UIView()
+        if let reusableView = detachedReusablePageView(for: pageNum) {
+            view = reusableView
+        } else {
+            view = contentViewProvider(pageNum, nil) ?? UIView()
+        }
         if shouldCache(view: view, for: pageNum, environment: environment) {
             pageCurlCachedViews[pageNum] = view
         } else {
@@ -111,8 +115,14 @@ final class RDReaderPreloadController {
         preloadHostView.frame = parentView.bounds
 
         for targetPage in targets {
-            let existing = detachedReusablePageView(for: targetPage)
+            let contentView: UIView
-            let contentView = contentViewProvider(targetPage, existing) ?? existing ?? UIView()
+            if let existing = preloadedPageViews[targetPage], existing.superview === preloadHostView {
+                contentView = existing
+            } else if let cached = pageCurlCachedViews.removeValue(forKey: targetPage), cached.superview == nil {
+                contentView = cached
+            } else {
+                contentView = contentViewProvider(targetPage, nil) ?? UIView()
+            }
             let shouldCacheContentView = shouldCache(view: contentView, for: targetPage, environment: environment)
             if shouldCacheContentView {
                 preloadedPageViews[targetPage] = contentView

Sources/RDReaderView/ReaderView/RDReaderView.swift

@@ -763,6 +763,14 @@ public class RDReaderView: UIView {
         guard let safePageNum = clampedPageNumber(pageNum) else { return }
         switch currentDisplayType {
         case .pageCurl:
+            if !animated, safePageNum == currentPage, !detectPageViewControllerFault(pageViewController) {
+                RDReaderTapDebug.log(
+                    "ReaderView.transitionToPage",
+                    "skip same page page=\(safePageNum) animated=\(animated)"
+                )
+                return
+            }
+
             let request = PageTransitionRequest(pageNum: safePageNum, animated: animated)
             if shouldQueuePageTransition(request) {
                 return
@@ -823,6 +831,7 @@ public class RDReaderView: UIView {
     }
 
     public func reloadData() {
+        invalidatePageCaches()
         switchReaderDisplayType(currentDisplayType)
         topToolView = resolvedTopChromeView()
         bottomToolView = resolvedBottomChromeView()
@@ -830,8 +839,9 @@ public class RDReaderView: UIView {
 
     public func reloadPageCountOnly() {
         if currentDisplayType == .pageCurl {
-            if !isPageCurlTransitioning, currentPage >= 0, numberOfPages() > 0 {
+            let totalPages = numberOfPages()
-                transitionToPage(pageNum: currentPage, animated: false)
+            if !isPageCurlTransitioning, currentPage >= totalPages, totalPages > 0 {
+                transitionToPage(pageNum: totalPages - 1, animated: false)
             }
         } else {
             collectionView.reloadData()