ReadViewSDK/Sources/RDReaderView/EPUBTextRendering/BuildPipeline/RDEPUBPaginationCacheCoordinator.swift

46 lines
1.5 KiB
Swift

import UIKit
/// Keeps pagination cache key generation and cache IO in one BuildPipeline role.
struct RDEPUBPaginationCacheCoordinator {
private let cache: RDEPUBTextBookCache?
private let layoutConfig: RDEPUBTextLayoutConfig
init(cache: RDEPUBTextBookCache?, layoutConfig: RDEPUBTextLayoutConfig) {
self.cache = cache
self.layoutConfig = layoutConfig
}
func cacheKey(
bookID: String,
pageSize: CGSize,
style: RDEPUBTextRenderStyle
) -> String? {
guard let cache else { return nil }
return cache.cacheKey(
bookID: bookID,
fontSize: style.font.pointSize,
lineHeightMultiple: style.lineSpacing,
contentInsets: layoutConfig.edgeInsets,
pageSize: pageSize,
layoutConfigSignature: layoutConfig.cacheSignature
)
}
func load(key: String?) -> [String: RDEPUBTextChapterPaginationCache]? {
key.flatMap { cache?.load(key: $0) }
}
func save(chapters: [RDEPUBTextChapter], key: String?) {
guard let key else { return }
let paginationCache = chapters.map { chapter in
RDEPUBTextChapterPaginationCache(
href: chapter.href,
pageRanges: chapter.pages.map(\.contentRange),
breakReasons: chapter.pages.map(\.metadata.breakReason),
semanticHints: Array(Set(chapter.pages.flatMap(\.metadata.semanticHints)))
)
}
cache?.save(paginationCache, key: key)
}
}