'性能优化'

package.json

@@ -80,5 +80,6 @@
     "typescript": "^4.1.0",
     "webpack": "^5.78.0",
     "webpack-obfuscator": "^3.5.1"
-  }
+  },
+  "packageManager": "pnpm@10.25.0+sha1.2cfb3ab644446565c127f58165cc76368c9c920b"
 }

src/pages/book/index.scss

@@ -187,6 +187,11 @@
     word-wrap: break-word;
     overflow-wrap: break-word;
 
+    /* 目录 scrollIntoView 时预留固定顶栏高度（与 .book_header_div 一致） */
+    [data-chunk-index] {
+      scroll-margin-top: 88px;
+    }
+
     h1 {
       font-size: 48px !important;
       font-weight: 800;
@@ -574,6 +579,10 @@
       max-width: 800PX;
       margin: 0 auto;
 
+      [data-chunk-index] {
+        scroll-margin-top: 56PX;
+      }
+
       h1 {
         font-size: 28PX !important;
         margin: 36PX 0 14PX;

src/pages/book/index.tsx

@@ -3,7 +3,7 @@ import { View, Image } from "@tarojs/components";
 import Taro, { useRouter } from "@tarojs/taro";
 import "./index.scss";
 import { AtButton, AtDrawer, AtIcon } from "taro-ui";
-import React, { useEffect, useState, useRef, useCallback } from "react";
+import React, { useEffect, useState, useRef, useCallback, useLayoutEffect } from "react";
 import { chunks as infoChunks, headers as infoHeaders } from "./info.md";
 import hackrobot from "../../images/hackrobot.jpg";
 
@@ -13,11 +13,15 @@ function getPb() {
   return PB ? new PB(PB_URL) : null;
 }
 
-const LazyChunk = React.memo(({ html, estimatedHeight, forceVisible }) => {
+const LazyChunk = React.memo(({ html, estimatedHeight, forceVisible, chunkIndex }) => {
   const [visible, setVisible] = useState(forceVisible);
   const ref = useRef(null);
   const show = forceVisible || visible;
 
+  useEffect(() => {
+    if (forceVisible) setVisible(true);
+  }, [forceVisible]);
+
   useEffect(() => {
     if (forceVisible) return;
     if (visible) return;
@@ -37,9 +41,23 @@ const LazyChunk = React.memo(({ html, estimatedHeight, forceVisible }) => {
   }, [forceVisible, visible]);
 
   if (show) {
-    return <div className="chunk-enter" dangerouslySetInnerHTML={{ __html: html }} />;
+    const animate = !forceVisible;
+    return (
+      <div
+        data-chunk-index={chunkIndex}
+        className={animate ? "chunk-enter" : undefined}
+        dangerouslySetInnerHTML={{ __html: html }}
+      />
+    );
   }
-  return <div ref={ref} className="chunk-placeholder" style={{ minHeight: estimatedHeight }} />;
+  return (
+    <div
+      ref={ref}
+      data-chunk-index={chunkIndex}
+      className="chunk-placeholder"
+      style={{ minHeight: estimatedHeight }}
+    />
+  );
 });
 
 const Book = () => {
@@ -49,7 +67,11 @@ const Book = () => {
   const [paidType, setPaidType] = useState(null);
   const [userId, setUserId] = useState(Taro.getStorageSync("userId") || null);
   const [loading, setLoading] = useState(true);
-  const [forceShowAll, setForceShowAll] = useState(false);
+  /** 目录跳转时至少渲染到该索引的 chunk；null 表示仅首块 + 懒加载 */
+  const [visibleUntilIndex, setVisibleUntilIndex] = useState(null);
+  /** 每次点击目录递增，驱动 useLayoutEffect 在 DOM 提交后滚动（不依赖 visibleUntilIndex 是否变化） */
+  const [jumpSeq, setJumpSeq] = useState(0);
+  const pendingJumpIndexRef = useRef(null);
   const [readProgress, setReadProgress] = useState(0);
   const [showBackTop, setShowBackTop] = useState(false);
   const [bookData, setBookData] = useState(null);
@@ -182,45 +204,94 @@ const Book = () => {
       if (e.target.tagName === "IMG") e.target.classList.add("loaded");
     };
     el.addEventListener("load", onImgLoad, true);
+    let raf = 0;
+    let pending = false;
     const checkCached = () => {
+      pending = false;
       el.querySelectorAll("img").forEach(img => {
         if (img.complete) img.classList.add("loaded");
       });
     };
-    const mo = new MutationObserver(checkCached);
+    const scheduleCheck = () => {
+      if (pending) return;
+      pending = true;
+      raf = requestAnimationFrame(checkCached);
+    };
+    const mo = new MutationObserver(() => scheduleCheck());
     mo.observe(el, { childList: true, subtree: true });
-    checkCached();
+    scheduleCheck();
     return () => {
+      cancelAnimationFrame(raf);
       el.removeEventListener("load", onImgLoad, true);
       mo.disconnect();
     };
   }, [contentLoading]);
 
-  const handleJump = useCallback((index) => {
-    setForceShowAll(true);
-    setshow(false);
-
-    const run = () => {
-      const root = contentRef.current;
-      if (!root) return;
-      const h1s = root.querySelectorAll("h1");
-      const el = h1s[index];
-      if (el) {
-        try {
-          el.scrollIntoView({ behavior: "smooth", block: "start" });
-        } catch (_) {
-          const top = el.getBoundingClientRect().top + (window.pageYOffset || document.documentElement.scrollTop) - 60;
-          window.scrollTo({ top: Math.max(0, top), behavior: "smooth" });
-        }
-      }
-    };
-
-    run();
-    setTimeout(run, 100);
-    setTimeout(run, 300);
-    setTimeout(run, 600);
+  const getMarkdownRoot = useCallback(() => {
+    const el = contentRef.current;
+    if (el && typeof el.querySelector === "function") return el;
+    if (typeof document !== "undefined") {
+      return document.querySelector(".Book .markdown-body");
+    }
+    return null;
   }, []);
 
+  const scrollToChapterIndex = useCallback((index, attempt = 0) => {
+    const root = getMarkdownRoot();
+    if (!root) return;
+    const el = root.querySelector(`[data-chunk-index="${index}"]`);
+    if (el?.classList.contains("chunk-placeholder") && attempt < 48) {
+      requestAnimationFrame(() => scrollToChapterIndex(index, attempt + 1));
+      return;
+    }
+    const h1list = root.querySelectorAll("h1");
+    const target = el || h1list[index];
+    if (!target) return;
+    try {
+      target.scrollIntoView({ block: "start", behavior: "auto" });
+    } catch (_) {
+      const rect = target.getBoundingClientRect();
+      const st = window.pageYOffset || document.documentElement.scrollTop || 0;
+      const dest = Math.max(0, rect.top + st - 60);
+      try {
+        window.scrollTo({ top: dest, behavior: "auto" });
+      } catch (__) {
+        window.scrollTo(0, dest);
+      }
+    }
+  }, [getMarkdownRoot]);
+
+  const handleJump = useCallback((rawIndex) => {
+    const index =
+      typeof rawIndex === "number" && Number.isFinite(rawIndex)
+        ? rawIndex
+        : parseInt(String(rawIndex), 10);
+    if (!Number.isFinite(index) || index < 0) return;
+    pendingJumpIndexRef.current = index;
+    setVisibleUntilIndex(prev => Math.max(prev ?? -1, index));
+    setshow(false);
+    setJumpSeq(s => s + 1);
+  }, []);
+
+  useLayoutEffect(() => {
+    if (jumpSeq === 0) return;
+    const index = pendingJumpIndexRef.current;
+    if (index === null || index === undefined) return;
+    const run = () => scrollToChapterIndex(index);
+    run();
+    const t1 = setTimeout(run, 50);
+    const t2 = setTimeout(run, 200);
+    const t3 = setTimeout(run, 450);
+    requestAnimationFrame(() => {
+      requestAnimationFrame(run);
+    });
+    return () => {
+      clearTimeout(t1);
+      clearTimeout(t2);
+      clearTimeout(t3);
+    };
+  }, [jumpSeq, scrollToChapterIndex]);
+
   const submitPayForm = (xorpayUrl, xorpayParams) => {
     const form = document.createElement("form");
     form.method = "POST";
@@ -301,16 +372,17 @@ const Book = () => {
             <View className="loading-text">正在加载...</View>
           </View>
         ) : (
-          <View ref={contentRef} className="markdown-body">
+          <div ref={contentRef} className="markdown-body">
             {activeChunks.map((chunk, i) => (
               <LazyChunk
                 key={`${isPaid}-${i}`}
+                chunkIndex={i}
                 html={chunk.html}
                 estimatedHeight={chunk.estimatedHeight}
-                forceVisible={forceShowAll || i === 0}
+                forceVisible={(visibleUntilIndex !== null && i <= visibleUntilIndex) || i === 0}
               />
             ))}
-          </View>
+          </div>
         )}
 
         <AtDrawer