ReadViewSDK/Sources/RDReaderView/EPUBUI/ReaderController/RDEPUBReaderPaginationCoordinator.swift
shen 7de661eb54 feat: 架构整改 — Context拆分、Runtime拆分、异步章节加载、UI测试覆盖
Phase 1: Context 拆分
- 新增 RDEPUBReaderState/RDEPUBReaderEnvironment/RDEPUBReaderServices
- RDEPUBReaderContext 改为过渡门面,代理到 State/Environment/Services

Phase 2: Runtime 拆分
- 新增 RDEPUBPresentationRuntime 处理分页状态管理
- 新增 RDEPUBChapterWarmupOrchestrator 处理章节预热与加载编排
- RDEPUBReaderRuntime 从 1277 行收缩,公共 API 转发到新 facade

Phase 0.5: 性能优化
- prepareOnDemandChapter 支持异步模式(allowSynchronousLoad: false)
- extendPartialBookPageMapIfNeeded 改为 DispatchGroup 并发加载
- RDEPUBChapterOffsetMap.cfiMap 加 NSLock 保护数据竞争
- CFI Map 构建延迟到后台队列(scheduleDeferredCFIMapBuildIfNeeded)
- RDEPUBTextPageRenderView 引入静态位图缓存
- RDEPUBTextContentView 新增 loadingSpinner 占位页

Phase 3: 状态机
- 新增 RDEPUBNavigationStateMachine(含 DEBUG 合法转换校验)
- 新增 RDEPUBPaginationState 记录分页来源

Review 修复
- makeSummary 重复方法合并
- ensureNavigationTargetAvailable 同步路径加注释标记

UI 测试
- 新增 AsyncChapterLoadingTests(20 个测试,覆盖全部架构整改场景)
- 跨章节翻页、延迟 CFI、状态机、内存警告、预加载、位置恢复等
2026-06-23 08:17:08 +08:00

948 lines
42 KiB
Swift

import Foundation
final class RDEPUBReaderPaginationCoordinator {
private final class MetadataParseState {
var summariesBySpineIndex: [Int: RDEPUBChapterSummary]
var totalResolvedCount: Int
var lastAppliedCount: Int
init(
summariesBySpineIndex: [Int: RDEPUBChapterSummary],
totalResolvedCount: Int,
lastAppliedCount: Int
) {
self.summariesBySpineIndex = summariesBySpineIndex
self.totalResolvedCount = totalResolvedCount
self.lastAppliedCount = lastAppliedCount
}
}
private final class MetadataParseCancellationController {
let token: UUID
private let lock = NSLock()
private weak var queue: OperationQueue?
private var cancelled = false
init(token: UUID) {
self.token = token
}
func attach(queue: OperationQueue) {
let shouldCancelImmediately: Bool
lock.lock()
self.queue = queue
shouldCancelImmediately = cancelled
lock.unlock()
if shouldCancelImmediately {
queue.cancelAllOperations()
}
}
func cancel() {
let queueToCancel: OperationQueue?
lock.lock()
cancelled = true
queueToCancel = queue
lock.unlock()
queueToCancel?.cancelAllOperations()
}
var isCancelled: Bool {
lock.lock()
let value = cancelled
lock.unlock()
return value
}
}
private let backgroundInteractionCooldown: CFAbsoluteTime = 0.8
static var pageMapRefreshInterval: Int = 32
private unowned let context: RDEPUBReaderContext
private let metadataParseControlLock = NSLock()
private var activeMetadataParseCancellationController: MetadataParseCancellationController?
init(context: RDEPUBReaderContext) {
self.context = context
}
func paginatePublication(restoreLocation: RDEPUBLocation?) {
guard let controller = context.controller,
let parser = context.parser,
let publication = context.publication,
let readingSession = context.readingSession else {
return
}
controller.isRepaginating = true
context.runtime?.presentationRuntime.navigationStateMachine.transition(to: .repaginating)
controller.errorLabel.isHidden = true
controller.showLoading()
let token = UUID()
context.paginationToken = token
#if DEBUG
print("[EPUB][Pagination] profile=\(publication.readingProfile.rawValue) layout=\(publication.layout.rawValue) spine=\(publication.spine.count)")
#endif
if publication.readingProfile == .textReflowable {
#if DEBUG
print("[EPUB][Pagination] path=text-reflowable-on-demand")
#endif
paginateTextPublication(
parser: parser,
publication: publication,
readingSession: readingSession,
restoreLocation: restoreLocation,
token: token
)
return
}
if publication.layout == .fixed {
#if DEBUG
print("[EPUB][Pagination] path=fixed-layout")
#endif
let snapshot = readingSession.makePaginationSnapshot(
pageCounts: Array(repeating: 1, count: publication.spine.count),
preferences: controller.currentPreferences(),
layoutContext: controller.currentLayoutContext()
)
context.runtime?.applyPaginationSnapshot(snapshot, restoreLocation: restoreLocation)
return
}
let paginator = context.makePaginator()
#if DEBUG
print("[EPUB][Pagination] path=web-paginator")
#endif
context.paginator = paginator
paginator.calculate(
parser: parser,
hostingView: controller.ensurePaginationHostView(),
presentation: controller.currentPreferences().presentationStyle(viewportSize: controller.currentLayoutContext().viewportSize)
) { [weak controller] pageCounts in
guard let controller, self.context.paginationToken == token else { return }
let snapshot = readingSession.makePaginationSnapshot(
pageCounts: pageCounts,
preferences: controller.currentPreferences(),
layoutContext: controller.currentLayoutContext()
)
self.context.paginator = nil
self.context.runtime?.applyPaginationSnapshot(snapshot, restoreLocation: restoreLocation)
}
}
func applyTextBook(_ textBook: RDEPUBTextBook, restoreLocation: RDEPUBLocation?) {
guard let controller = context.controller else { return }
context.textBook = textBook
context.bookPageMap = nil
context.pendingFullPageMap = nil
let snapshot = controller.nativeTextSnapshot(from: textBook)
context.replaceActiveSnapshot(snapshot)
guard !textBook.pages.isEmpty else {
context.handle(error: RDEPUBParserError.emptySpine)
return
}
finishPagination(restoreLocation: restoreLocation)
}
func applyPaginationSnapshot(
_ snapshot: (pages: [EPUBPage], chapters: [EPUBChapterInfo]),
restoreLocation: RDEPUBLocation?
) {
guard context.controller != nil else { return }
context.textBook = nil
context.bookPageMap = nil
context.pendingFullPageMap = nil
context.replaceActiveSnapshot(snapshot)
guard !snapshot.pages.isEmpty else {
context.handle(error: RDEPUBParserError.emptySpine)
return
}
finishPagination(restoreLocation: restoreLocation)
}
func finishPagination(restoreLocation: RDEPUBLocation?) {
guard let controller = context.controller,
let readerView = context.readerView else { return }
controller.isRepaginating = false
context.runtime?.presentationRuntime.navigationStateMachine.transition(to: .presentingWindow)
controller.hideLoading()
readerView.reloadData()
if let targetLocation = restoreLocation {
controller.restoreReadingLocation(targetLocation)
context.readingSession?.transition(to: .idle)
} else {
readerView.transitionToPage(pageNum: 0)
context.readingSession?.transition(to: .idle)
}
context.runtime?.viewportMonitor.processPendingChangeAfterPagination()
}
func repaginatePreservingCurrentLocation() {
guard context.publication != nil else { return }
let restoreLocation = context.runtime?.viewportMonitor.consumePendingPresentationRestoreLocation()
?? context.currentVisibleLocation()
?? context.persistenceLocation()
paginatePublication(restoreLocation: restoreLocation)
}
func refreshVisibleContentPreservingLocation() {
guard let readerView = context.readerView else { return }
let restoreLocation = context.currentVisibleLocation() ?? context.persistenceLocation()
readerView.reloadData()
if let restoreLocation {
_ = context.restoreReadingLocation(restoreLocation)
}
}
func rebuildExternalTextBook() {
guard let controller = context.controller,
let textFileURL = controller.textFileURL else { return }
let restoreLocation = context.currentVisibleLocation() ?? context.persistenceLocation()
let pageSize = controller.currentTextPageSize()
let style = controller.currentTextRenderStyle()
let builder = context.makePlainTextBookBuilder(layoutConfig: controller.currentTextLayoutConfig(pageSize: pageSize))
if let newBook = try? builder.build(textFileURL: textFileURL, pageSize: pageSize, style: style) {
context.runtime?.applyTextBook(newBook, restoreLocation: restoreLocation)
}
}
private func paginateTextPublication(
parser: RDEPUBParser,
publication: RDEPUBPublication,
readingSession: RDEPUBReadingSession,
restoreLocation: RDEPUBLocation?,
token: UUID
) {
guard let controller = context.controller else { return }
let context = self.context
let pageSize = controller.currentTextPageSize()
context.lastTextPaginationPageSize = pageSize
DispatchQueue.global(qos: .utility).async { [weak controller] in
guard controller != nil else { return }
guard context.controller != nil else { return }
let prioritizedCandidates = self.prioritizedBuildableSpineIndices(
publication: publication,
readingSession: readingSession,
restoreLocation: restoreLocation
)
guard prioritizedCandidates.first != nil else {
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil else { return }
context.handle(error: RDEPUBParserError.emptySpine)
}
return
}
do {
guard context.controller != nil,
let runtime = context.runtime else { return }
RDEPUBBackgroundTrace.log(
"QuickOpen",
"begin token=\(token.uuidString) candidates=\(prioritizedCandidates.count) restoreSpine=\(readingSession.initialSpineIndex(for: restoreLocation))"
)
let runtimeChapter = try RDEPUBBackgroundTrace.measure(
"QuickOpen",
"loadFirstRenderableRuntimeChapter"
) {
try self.loadFirstRenderableRuntimeChapter(
prioritizedSpineIndices: prioritizedCandidates,
runtime: runtime
)
}
RDEPUBBackgroundTrace.log(
"QuickOpen",
"ready anchorSpine=\(runtimeChapter.spineIndex) pages=\(runtimeChapter.pages.count)"
)
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil else { return }
runtime.chapterRuntimeStore.setCurrentChapter(
spineIndex: runtimeChapter.spineIndex,
totalSpineCount: publication.spine.count,
windowRadius: context.configuration.chapterWindowRadius
)
let partialMap = self.makePartialPageMap(from: [runtimeChapter])
runtime.applyBookPageMap(partialMap, restoreLocation: restoreLocation)
runtime.prefetchForwardChaptersAfterInitialOpen(
anchorSpineIndex: runtimeChapter.spineIndex,
totalSpineCount: publication.spine.count
)
self.paginateMetadataOnly(token: token, restoreLocation: restoreLocation)
}
} catch {
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil else { return }
context.handle(error: error)
}
}
}
}
private func loadFirstRenderableRuntimeChapter(
prioritizedSpineIndices: [Int],
runtime: RDEPUBReaderRuntime
) throws -> RDEPUBRuntimeChapter {
var lastError: Error?
for spineIndex in prioritizedSpineIndices {
do {
return try runtime.chapterLoader.loadChapterSynchronouslyForMigration(
spineIndex: spineIndex,
store: runtime.chapterRuntimeStore
)
} catch {
lastError = error
RDEPUBBackgroundTrace.log("QuickOpen", "skip spine=\(spineIndex) reason=\(error)")
}
}
throw lastError ?? RDEPUBParserError.emptySpine
}
private func makePartialPageMap(from chapters: [RDEPUBRuntimeChapter]) -> RDEPUBBookPageMap {
var builder = RDEPUBBookPageMap.Builder()
for chapter in chapters {
builder.add(
spineIndex: chapter.spineIndex,
href: chapter.href,
title: chapter.title,
pageCount: chapter.pages.count,
fragmentOffsets: chapter.chapterOffsetMap.fragmentOffsets
)
}
return builder.build()
}
private func prioritizedBuildableSpineIndices(
publication: RDEPUBPublication,
readingSession: RDEPUBReadingSession,
restoreLocation: RDEPUBLocation?
) -> [Int] {
let preferred = readingSession.initialSpineIndex(for: restoreLocation)
return publication.spine.indices
.filter { isBuildableTextSpine(at: $0, in: publication) }
.sorted { lhs, rhs in
abs(lhs - preferred) < abs(rhs - preferred)
}
}
private func allBuildableSpineIndices(in publication: RDEPUBPublication) -> [Int] {
publication.spine.indices.filter { isBuildableTextSpine(at: $0, in: publication) }
}
private func waitForReadingInteractionToSettle(
using context: RDEPUBReaderContext,
cancellationController: MetadataParseCancellationController? = nil
) {
while context.controller != nil,
cancellationController?.isCancelled != true,
context.secondsSinceLastUserNavigation() < backgroundInteractionCooldown {
Thread.sleep(forTimeInterval: 0.08)
}
}
private func isBuildableTextSpine(at index: Int, in publication: RDEPUBPublication) -> Bool {
guard publication.spine.indices.contains(index) else { return false }
let item = publication.spine[index]
return item.linear && (item.mediaType.contains("html") || item.mediaType.contains("xhtml"))
}
private static let maxRetryCount = 3
private static let retryDelays: [TimeInterval] = [0.5, 2.0, 8.0]
func paginateMetadataOnly(token: UUID, restoreLocation: RDEPUBLocation?) {
let context = self.context
guard let parser = context.parser,
let publication = context.publication else { return }
let cancellationController = beginMetadataParseCancellationController(for: token)
let pageSize = context.currentTextPageSize()
let layoutConfig = context.currentTextLayoutConfig(pageSize: pageSize)
let style = context.currentTextRenderStyle()
let renderSignature = context.currentRenderSignature()
let allBuildableIndices = allBuildableSpineIndices(in: publication)
let summaryDiskCache = context.runtime?.summaryDiskCache
let workerCount = max(1, context.configuration.metadataParsingConcurrency)
let cpuCount = ProcessInfo.processInfo.activeProcessorCount
RDEPUBBackgroundTrace.log("MetadataParse", "config concurrency=\(workerCount) cpuCores=\(cpuCount)")
DispatchQueue.global(qos: .utility).async { [weak self] in
guard let self else { return }
defer { self.finishMetadataParseCancellationController(cancellationController) }
guard context.controller != nil,
!cancellationController.isCancelled,
context.paginationToken == token else { return }
if let restoredPageMap = self.restoreBookPageMapIfPossible(publication: publication) {
RDEPUBBackgroundTrace.log(
"MetadataParse",
"full cache restore hit chapters=\(restoredPageMap.totalChapters) pages=\(restoredPageMap.totalPages)"
)
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil,
!cancellationController.isCancelled else { return }
context.runtime?.refreshBookPageMapInPlace(restoredPageMap)
}
return
}
let prewarmStart = CFAbsoluteTimeGetCurrent()
var contentHashBySpineIndex: [Int: String] = [:]
for spineIndex in allBuildableIndices {
guard !cancellationController.isCancelled,
context.paginationToken == token,
context.controller != nil else {
RDEPUBBackgroundTrace.log("MetadataParse", "abort during content hash prewarm")
return
}
guard let href = publication.spine.indices.contains(spineIndex)
? publication.spine[spineIndex].href : nil,
let html = parser.htmlString(forRelativePath: href) else {
contentHashBySpineIndex[spineIndex] = ""
continue
}
contentHashBySpineIndex[spineIndex] = html.sha256Hex
}
let prewarmMs = Int((CFAbsoluteTimeGetCurrent() - prewarmStart) * 1000)
RDEPUBBackgroundTrace.log("MetadataParse", "prewarmHashMs=\(prewarmMs) chapters=\(allBuildableIndices.count)")
let catalog = allBuildableIndices.map { spineIndex in
let item = publication.spine[spineIndex]
return (
key: context.chapterCacheKey(
forSpineIndex: spineIndex,
precomputedContentHash: contentHashBySpineIndex[spineIndex] ?? "",
renderSignature: renderSignature
),
spineIndex: spineIndex,
href: item.href,
title: item.title
)
}
let restored = summaryDiskCache?.readAll(keys: catalog)
RDEPUBBackgroundTrace.log(
"MetadataParse",
"begin token=\(token.uuidString) buildableChapters=\(allBuildableIndices.count) concurrency=\(workerCount)"
)
let cachedSummaries = restored?.summaries ?? [:]
let cachedSpineIndices = Set(cachedSummaries.keys)
let resultLock = NSLock()
let parseState = MetadataParseState(
summariesBySpineIndex: cachedSummaries,
totalResolvedCount: cachedSpineIndices.count,
lastAppliedCount: cachedSpineIndices.count
)
if !cachedSpineIndices.isEmpty {
RDEPUBBackgroundTrace.log(
"MetadataParse",
"resumeFromCache cachedChapters=\(cachedSpineIndices.count) total=\(allBuildableIndices.count)"
)
let cachedMap = self.buildPageMap(from: catalog, summaries: parseState.summariesBySpineIndex)
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil else { return }
context.runtime?.refreshBookPageMapInPlace(cachedMap)
}
}
let prioritizedSpineIndices: [Int]
if let priorityManager = context.runtime?.backgroundPriorityManager {
let currentSpineIndex = context.runtime?.locationCoordinator.currentVisibleLocation()
.flatMap { context.normalizedSpineIndex(for: $0) }
prioritizedSpineIndices = priorityManager.makeMetadataPriorityOrder(
allBuildableIndices: allBuildableIndices,
currentSpineIndex: currentSpineIndex,
cachedSpineIndices: cachedSpineIndices
)
RDEPUBBackgroundTrace.log(
"MetadataParse",
"prioritized hot=\(prioritizedSpineIndices.prefix(10).count) total=\(prioritizedSpineIndices.count)"
)
} else {
prioritizedSpineIndices = allBuildableIndices.filter { !cachedSpineIndices.contains($0) }
}
let uncachedSpineIndices = prioritizedSpineIndices
self.waitForReadingInteractionToSettle(
using: context,
cancellationController: cancellationController
)
guard !cancellationController.isCancelled,
context.controller != nil,
context.paginationToken == token else {
RDEPUBBackgroundTrace.log("MetadataParse", "abort before queue start")
return
}
let wallClockStart = CFAbsoluteTimeGetCurrent()
var totalRenderMs: Double = 0
var totalWriteMs: Double = 0
var totalMergeMs: Double = 0
var completedChapters = 0
var failedChapters = 0
let timingLock = NSLock()
let queue = OperationQueue()
queue.name = "com.rdreader.metadata.parse"
queue.qualityOfService = .utility
queue.maxConcurrentOperationCount = workerCount
cancellationController.attach(queue: queue)
let refreshInterval = RDEPUBReaderPaginationCoordinator.pageMapRefreshInterval
for (offset, spineIndex) in uncachedSpineIndices.enumerated() {
let operation = BlockOperation()
operation.addExecutionBlock { [weak operation] in
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled,
operation?.isCancelled != true else {
return
}
do {
RDEPUBBackgroundTrace.log("MetadataParse", "正在解析 spine=\(spineIndex) \(offset + 1)/\(uncachedSpineIndices.count)")
let renderResult: RDEPUBChapterSummary? = try autoreleasepool { () -> RDEPUBChapterSummary? in
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled,
operation?.isCancelled != true else {
return nil
}
let chapterBuilder = context.makeTextBookBuilder(layoutConfig: layoutConfig)
let renderStart = CFAbsoluteTimeGetCurrent()
guard let result = try chapterBuilder.buildChapter(
parser: parser,
publication: publication,
spineIndex: spineIndex,
pageSize: pageSize,
style: style
) else {
return nil
}
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled,
operation?.isCancelled != true else {
RDEPUBBackgroundTrace.log("MetadataParse", "drop rendered chapter due to cancellation spine=\(spineIndex)")
return nil
}
let renderElapsed = (CFAbsoluteTimeGetCurrent() - renderStart) * 1000
let chapter = result.chapter
let precomputedHash = contentHashBySpineIndex[spineIndex] ?? ""
let cacheKey = context.chapterCacheKey(
forSpineIndex: spineIndex,
precomputedContentHash: precomputedHash,
renderSignature: renderSignature
)
let summary = RDEPUBChapterSummary(
pageRanges: chapter.pages.map { .init(location: $0.contentRange.location, length: $0.contentRange.length) },
pageCount: chapter.pages.count,
fragmentOffsets: chapter.fragmentOffsets,
cfiMap: chapter.cfiMap,
renderSignature: cacheKey.renderSignature,
schemaVersion: RDEPUBChapterSummary.currentSchemaVersion,
chapterContentHash: cacheKey.chapterContentHash,
pageMetadataList: chapter.pages.map { .from($0.metadata) }
)
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled,
operation?.isCancelled != true else {
RDEPUBBackgroundTrace.log("MetadataParse", "skip disk write due to cancellation spine=\(spineIndex)")
return nil
}
let writeStart = CFAbsoluteTimeGetCurrent()
summaryDiskCache?.write(summary: summary, for: cacheKey)
let writeElapsed = (CFAbsoluteTimeGetCurrent() - writeStart) * 1000
timingLock.lock()
totalRenderMs += renderElapsed
totalWriteMs += writeElapsed
completedChapters += 1
timingLock.unlock()
RDEPUBBackgroundTrace.log(
"MetadataParse",
"spine=\(spineIndex) renderMs=\(Int(renderElapsed)) writeMs=\(Int(writeElapsed))"
)
return summary
}
guard let renderResult else { return }
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled,
operation?.isCancelled != true else {
return
}
var snapshot: [Int: RDEPUBChapterSummary]?
resultLock.lock()
parseState.summariesBySpineIndex[spineIndex] = renderResult
parseState.totalResolvedCount += 1
if parseState.totalResolvedCount - parseState.lastAppliedCount >= refreshInterval
|| parseState.totalResolvedCount == allBuildableIndices.count {
parseState.lastAppliedCount = parseState.totalResolvedCount
snapshot = parseState.summariesBySpineIndex
}
resultLock.unlock()
if let snapshot {
let mergeStart = CFAbsoluteTimeGetCurrent()
let partialMap = self.buildPageMap(from: catalog, summaries: snapshot)
let mergeElapsed = (CFAbsoluteTimeGetCurrent() - mergeStart) * 1000
timingLock.lock()
totalMergeMs += mergeElapsed
timingLock.unlock()
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil,
!cancellationController.isCancelled else { return }
context.runtime?.refreshBookPageMapInPlace(partialMap)
}
}
} catch {
guard !cancellationController.isCancelled,
context.paginationToken == token,
context.controller != nil,
operation?.isCancelled != true else {
return
}
timingLock.lock()
failedChapters += 1
timingLock.unlock()
RDEPUBBackgroundTrace.log("MetadataParse", "buildChapter FAILED: spine=\(spineIndex) error=\(error)")
self.scheduleRetry(
spineIndex: spineIndex,
retryCount: 0,
token: token,
context: context,
parser: parser,
publication: publication,
pageSize: pageSize,
layoutConfig: layoutConfig,
style: style,
renderSignature: renderSignature,
summaryDiskCache: summaryDiskCache,
contentHashBySpineIndex: contentHashBySpineIndex,
resultLock: resultLock,
parseState: parseState,
allBuildableIndices: allBuildableIndices,
catalog: catalog,
refreshInterval: refreshInterval,
cancellationController: cancellationController
)
}
}
queue.addOperation(operation)
}
queue.waitUntilAllOperationsAreFinished()
if !cancellationController.isCancelled,
context.paginationToken == token,
context.controller != nil {
summaryDiskCache?.flushPendingWrites()
}
let wallClockMs = Int((CFAbsoluteTimeGetCurrent() - wallClockStart) * 1000)
timingLock.lock()
let renderTotal = Int(totalRenderMs)
let writeTotal = Int(totalWriteMs)
let mergeTotal = Int(totalMergeMs)
let rendered = completedChapters
let failed = failedChapters
timingLock.unlock()
let avgRenderMs = rendered > 0 ? renderTotal / rendered : 0
RDEPUBBackgroundTrace.log(
"MetadataParse",
"timing wallClockMs=\(wallClockMs) chapters=\(rendered) failed=\(failed) " +
"prewarmHashMs=\(prewarmMs) renderTotalMs=\(renderTotal) writeTotalMs=\(writeTotal) " +
"mergeTotalMs=\(mergeTotal) avgRenderMs=\(avgRenderMs) concurrency=\(workerCount)"
)
context.lastMetadataParseWallClockMs = wallClockMs
context.lastMetadataParseConcurrency = workerCount
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled else {
RDEPUBBackgroundTrace.log("MetadataParse", "abort: reader dismissed or token changed")
return
}
let finalMergeStart = CFAbsoluteTimeGetCurrent()
let pageMap = self.buildPageMap(from: catalog, summaries: parseState.summariesBySpineIndex)
let finalMergeMs = Int((CFAbsoluteTimeGetCurrent() - finalMergeStart) * 1000)
RDEPUBBackgroundTrace.log(
"MetadataParse",
"complete chapters=\(pageMap.totalChapters) pages=\(pageMap.totalPages) finalMergeMs=\(finalMergeMs)"
)
if let coverageStore = context.runtime?.backgroundCoverageStore {
let resolvedSpineIndices = Set(parseState.summariesBySpineIndex.keys)
let lowerSpine = resolvedSpineIndices.min() ?? 0
let upperSpine = resolvedSpineIndices.max() ?? 0
let estimatedBytes = 256 + pageMap.entries.count * 96 + resolvedSpineIndices.count * 16
let segment = RDEPUBBackgroundCoverageSegment(
lowerSpineIndex: lowerSpine,
upperSpineIndex: upperSpine,
pageMap: pageMap,
resolvedSpineIndices: resolvedSpineIndices,
generatedAt: CFAbsoluteTimeGetCurrent(),
renderSignature: renderSignature,
estimatedMemoryBytes: estimatedBytes
)
coverageStore.addSegment(segment)
}
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil else { return }
context.runtime?.refreshBookPageMapInPlace(pageMap)
}
}
}
private func scheduleRetry(
spineIndex: Int,
retryCount: Int,
token: UUID,
context: RDEPUBReaderContext,
parser: RDEPUBParser,
publication: RDEPUBPublication,
pageSize: CGSize,
layoutConfig: RDEPUBTextLayoutConfig,
style: RDEPUBTextRenderStyle,
renderSignature: String,
summaryDiskCache: RDEPUBChapterSummaryDiskCache?,
contentHashBySpineIndex: [Int: String],
resultLock: NSLock,
parseState: MetadataParseState,
allBuildableIndices: [Int],
catalog: [(key: RDEPUBChapterCacheKey, spineIndex: Int, href: String, title: String)],
refreshInterval: Int,
cancellationController: MetadataParseCancellationController
) {
guard retryCount < Self.maxRetryCount else {
RDEPUBBackgroundTrace.log(
"MetadataParse",
"spine=\(spineIndex) max retries reached, marking as deferredFailure"
)
return
}
let delay = Self.retryDelays[min(retryCount, Self.retryDelays.count - 1)]
RDEPUBBackgroundTrace.log(
"MetadataParse",
"scheduling retry for spine=\(spineIndex) attempt=\(retryCount + 1) delay=\(delay)s"
)
DispatchQueue.global(qos: .utility).asyncAfter(deadline: .now() + delay) { [weak self] in
guard let self else { return }
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled else {
return
}
do {
let chapterBuilder = context.makeTextBookBuilder(layoutConfig: layoutConfig)
guard let result = try chapterBuilder.buildChapter(
parser: parser,
publication: publication,
spineIndex: spineIndex,
pageSize: pageSize,
style: style
) else {
return
}
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled else {
RDEPUBBackgroundTrace.log("MetadataParse", "drop retry result due to cancellation spine=\(spineIndex)")
return
}
let chapter = result.chapter
let precomputedHash = contentHashBySpineIndex[spineIndex] ?? ""
let cacheKey = context.chapterCacheKey(
forSpineIndex: spineIndex,
precomputedContentHash: precomputedHash,
renderSignature: renderSignature
)
let summary = RDEPUBChapterSummary(
pageRanges: chapter.pages.map { .init(location: $0.contentRange.location, length: $0.contentRange.length) },
pageCount: chapter.pages.count,
fragmentOffsets: chapter.fragmentOffsets,
cfiMap: chapter.cfiMap,
renderSignature: cacheKey.renderSignature,
schemaVersion: RDEPUBChapterSummary.currentSchemaVersion,
chapterContentHash: cacheKey.chapterContentHash,
pageMetadataList: chapter.pages.map { .from($0.metadata) }
)
guard context.controller != nil,
context.paginationToken == token,
!cancellationController.isCancelled else {
RDEPUBBackgroundTrace.log("MetadataParse", "skip retry disk write due to cancellation spine=\(spineIndex)")
return
}
summaryDiskCache?.write(summary: summary, for: cacheKey)
resultLock.lock()
parseState.summariesBySpineIndex[spineIndex] = summary
parseState.totalResolvedCount += 1
let shouldRefresh =
parseState.totalResolvedCount - parseState.lastAppliedCount >= refreshInterval
|| parseState.totalResolvedCount == allBuildableIndices.count
if shouldRefresh {
parseState.lastAppliedCount = parseState.totalResolvedCount
}
resultLock.unlock()
if shouldRefresh {
let partialMap = self.buildPageMap(from: catalog, summaries: parseState.summariesBySpineIndex)
DispatchQueue.main.async {
guard context.paginationToken == token,
context.controller != nil,
!cancellationController.isCancelled else { return }
context.runtime?.refreshBookPageMapInPlace(partialMap)
}
}
RDEPUBBackgroundTrace.log(
"MetadataParse",
"retry succeeded for spine=\(spineIndex) attempt=\(retryCount + 1)"
)
} catch {
RDEPUBBackgroundTrace.log(
"MetadataParse",
"retry failed for spine=\(spineIndex) attempt=\(retryCount + 1) error=\(error)"
)
self.scheduleRetry(
spineIndex: spineIndex,
retryCount: retryCount + 1,
token: token,
context: context,
parser: parser,
publication: publication,
pageSize: pageSize,
layoutConfig: layoutConfig,
style: style,
renderSignature: renderSignature,
summaryDiskCache: summaryDiskCache,
contentHashBySpineIndex: contentHashBySpineIndex,
resultLock: resultLock,
parseState: parseState,
allBuildableIndices: allBuildableIndices,
catalog: catalog,
refreshInterval: refreshInterval,
cancellationController: cancellationController
)
}
}
}
func cancelActiveMetadataParseWork() {
metadataParseControlLock.lock()
let controller = activeMetadataParseCancellationController
activeMetadataParseCancellationController = nil
metadataParseControlLock.unlock()
controller?.cancel()
}
private func beginMetadataParseCancellationController(for token: UUID) -> MetadataParseCancellationController {
let controller = MetadataParseCancellationController(token: token)
metadataParseControlLock.lock()
let previous = activeMetadataParseCancellationController
activeMetadataParseCancellationController = controller
metadataParseControlLock.unlock()
previous?.cancel()
return controller
}
private func finishMetadataParseCancellationController(_ controller: MetadataParseCancellationController) {
metadataParseControlLock.lock()
if activeMetadataParseCancellationController === controller {
activeMetadataParseCancellationController = nil
}
metadataParseControlLock.unlock()
}
private func restoreBookPageMapIfPossible(publication: RDEPUBPublication) -> RDEPUBBookPageMap? {
guard let summaryDiskCache = context.runtime?.summaryDiskCache,
let parser = context.parser else {
return nil
}
let renderSignature = context.currentRenderSignature()
let catalog = allBuildableSpineIndices(in: publication).map { spineIndex in
let item = publication.spine[spineIndex]
let href = item.href
let contentHash = parser.htmlString(forRelativePath: href)?.sha256Hex ?? ""
return (
key: context.chapterCacheKey(
forSpineIndex: spineIndex,
precomputedContentHash: contentHash,
renderSignature: renderSignature
),
spineIndex: spineIndex,
href: href,
title: item.title
)
}
guard summaryDiskCache.isCacheComplete(keys: catalog.map(\.key)) else {
return nil
}
let restored = summaryDiskCache.readAll(keys: catalog)
guard restored.summaries.count == catalog.count else {
return nil
}
return restored.mapBuilder.build()
}
private func buildPageMap(
from catalog: [(key: RDEPUBChapterCacheKey, spineIndex: Int, href: String, title: String)],
summaries: [Int: RDEPUBChapterSummary]
) -> RDEPUBBookPageMap {
var builder = RDEPUBBookPageMap.Builder()
for item in catalog {
guard let summary = summaries[item.spineIndex] else { continue }
builder.add(
spineIndex: item.spineIndex,
href: item.href,
title: item.title,
pageCount: summary.pageCount,
fragmentOffsets: summary.fragmentOffsets
)
}
return builder.build()
}
}