fix(reader): remove the dead converted-PDF fallback for chapter books

validFallback only accepted PDF objects in the deleted vomebook/Reader-Assets
dataset, while every current sidecar fallback is a CHM-native EPUB in the
reader-assets-v2 bucket, so the redirect to ext=pdf never ran. Remove
ReaderFallback from assetFields and from the backend record and reader-resolve
fields, the fallback reader parameter, validFallback and the chapter-load
redirect; a load failure keeps showing the classified error.

backend/record_metadata.py

@@ -120,17 +120,14 @@ def reader_asset_fields(asset: dict, original_extension: str) -> dict:
             if asset.get("b") == "vomebook/pdf-pages-v2" or asset.get("ob") == "vomebook/pdf-pages-v2" else f"{READER_ASSETS_BASE}{ocr_path}"
         )
         fields["ocr_mode"] = str(asset.get("om") or "")
-    for key, field in (("c", "chapter_manifest"), ("f", "fallback")):
-        if asset.get(key):
-            if key == "c" and asset.get("cb") in {"vomebook/pdf-pages-v2", "vomebook/reader-assets-v2"}:
-                if asset.get("cb") == "vomebook/reader-assets-v2":
-                    fields[field] = ("https://voiceofml-search.hf.space/api/reader-bucket-resource?path="
-                                     + quote(asset[key], safe="/"))
-                else:
-                    fields[field] = ("/api/reader-bucket-resource?path="
-                                     + quote(asset[key], safe="/"))
-            else:
-                fields[field] = f"{READER_ASSETS_BASE}{asset[key]}"
+    if asset.get("c"):
+        if asset.get("cb") == "vomebook/reader-assets-v2":
+            fields["chapter_manifest"] = ("https://voiceofml-search.hf.space/api/reader-bucket-resource?path="
+                                          + quote(asset["c"], safe="/"))
+        elif asset.get("cb") == "vomebook/pdf-pages-v2":
+            fields["chapter_manifest"] = "/api/reader-bucket-resource?path=" + quote(asset["c"], safe="/")
+        else:
+            fields["chapter_manifest"] = f"{READER_ASSETS_BASE}{asset['c']}"
     return fields
 
 
@@ -149,7 +146,7 @@ def enrich_reader_record(record: dict, asset: dict) -> dict:
                   "extension": direct_modes[direct_extension][0]}
     if fields:
         for source, target in (("url", "ReaderLink"), ("extension", "ReaderExtension"),
-                               ("chapter_manifest", "ReaderChapterManifest"), ("fallback", "ReaderFallback"),
+                               ("chapter_manifest", "ReaderChapterManifest"),
                                 ("ocr_manifest", "ReaderOcrManifest"), ("ocr_mode", "ReaderOcrMode"),
                                 ("pdf_document", "ReaderPdfDocument")):
             if source in fields:

static/app.js

@@ -2417,7 +2417,7 @@ function getReaderLink(rec, returnUrl = location.href, cacheMetadata = true) {
     readerRecord.OcrUrl = `/txt/${encodeRecordPath(VoiceOfMLReader.txtRelativePath(relPath))}`;
   }
   const readerUrl = VoiceOfMLReader.readerUrl(readerRecord, "/static/reader.html");
-  if (cacheMetadata) try { const readerId = new URL(readerUrl, location.origin).searchParams.get("id"); if (readerId) { const sourceData = { url: readerRecord.ReaderLink || readerRecord.Link, download: readerRecord.Link, title: readerRecord.File, extension: readerRecord.ReaderExtension || readerRecord.Extension, original_extension: readerRecord.Extension, repo: String(readerRecord.Repo || "").split("/").pop(), folder: readerRecord.Folder, chapter_manifest: readerRecord.ReaderChapterManifest || "", fallback: readerRecord.ReaderFallback || "", pdf_document: readerRecord.ReaderPdfDocument || "" }; cacheReaderMetadata(readerId, sourceData, true); } } catch (_) {}
+  if (cacheMetadata) try { const readerId = new URL(readerUrl, location.origin).searchParams.get("id"); if (readerId) { const sourceData = { url: readerRecord.ReaderLink || readerRecord.Link, download: readerRecord.Link, title: readerRecord.File, extension: readerRecord.ReaderExtension || readerRecord.Extension, original_extension: readerRecord.Extension, repo: String(readerRecord.Repo || "").split("/").pop(), folder: readerRecord.Folder, chapter_manifest: readerRecord.ReaderChapterManifest || "", pdf_document: readerRecord.ReaderPdfDocument || "" }; cacheReaderMetadata(readerId, sourceData, true); } } catch (_) {}
   return readerUrl;
 }
 

static/reader.js

@@ -154,7 +154,6 @@ const readerContext = {
   get epubSeekTarget() { return epubSeekTarget; }, set epubSeekTarget(value) { epubSeekTarget = value; },
   get extension() { return extension; }, set extension(value) { extension = value; },
   get fail() { return fail; }, set fail(value) { fail = value; },
-  get fallbackUrl() { return fallbackUrl; }, set fallbackUrl(value) { fallbackUrl = value; },
   get fetchReaderResponse() { return fetchReaderResponse; }, set fetchReaderResponse(value) { fetchReaderResponse = value; },
   get fetchReaderUrl() { return fetchReaderUrl; }, set fetchReaderUrl(value) { fetchReaderUrl = value; },
   get filterPanel() { return filterPanel; }, set filterPanel(value) { filterPanel = value; },
@@ -428,7 +427,6 @@ const readerContext = {
   get updateSearchState() { return updateSearchState; }, set updateSearchState(value) { updateSearchState = value; },
   get updateTocCurrentMark() { return updateTocCurrentMark; }, set updateTocCurrentMark(value) { updateTocCurrentMark = value; },
   get v3ResourceUrl() { return v3ResourceUrl; }, set v3ResourceUrl(value) { v3ResourceUrl = value; },
-  get validFallback() { return validFallback; }, set validFallback(value) { validFallback = value; },
   get validOcr() { return validOcr; }, set validOcr(value) { validOcr = value; },
   get validSource() { return validSource; }, set validSource(value) { validSource = value; },
   get validatePageMap() { return validatePageMap; },
@@ -572,7 +570,7 @@ let {
 let {
   readerContentUrl, readerDownloadApiUrl, readerDownloadUrl, startReaderDownload,
   normalizeSourceUrl, resolveReaderId, applyReaderMetadata, applyReaderPathMetadata,
-  validSource, validOcr, validFallback, readerAssetObjectFamily,
+  validSource, validOcr, readerAssetObjectFamily,
   trustedReaderAssetManifestUrl, trustedChapterUrl, trustedChapterReferenceUrl, trustedChapterResourceUrl
 } = createReaderSource(readerContext);
 
@@ -795,7 +793,6 @@ const documentState = readerRuntime.state.document,
 
 readerBindings.initializeDocumentTitle();
 
-let fallbackUrl = params.get("fallback") || "";
 const ocrUrl = params.get("ocr") || "";
 let ocrManifestUrl = params.get("ocr_manifest") || "";
 let returnUrl = params.get("return") || "";

static/reader/core/reader-contract.js

@@ -432,7 +432,6 @@
            ? `${bucketBase}?path=${encodeURIComponent(asset.c)}`
           : assetBase + asset.c
         : "",
-      ReaderFallback: asset.f ? assetBase + asset.f : "",
       ReaderOcrManifest: ocrUrl || (ocrPath.endsWith("/ocr-manifest.json") ? assetBase + ocrPath : ""),
       ReaderOcrMode: String(asset.om || ""),
       ReaderPdfDocument: asset.pd && ["vomebook/reader-assets-v2", "vomebook/pdf-pages-v2"].includes(asset.pdb) &&
@@ -466,8 +465,6 @@
       params.set("ocr", record.OcrUrl || record.ocrUrl);
     if (!shortId && (record.ReaderOcrManifest || record.readerOcrManifest))
       params.set("ocr_manifest", record.ReaderOcrManifest || record.readerOcrManifest);
-    if (!shortId && (record.ReaderFallback || record.readerFallback))
-      params.set("fallback", record.ReaderFallback || record.readerFallback);
     if (!shortId && record.ReaderPdfDocument) params.set("pdf_document", record.ReaderPdfDocument);
     if (
       !shortId &&

static/reader/core/reader-source.mjs

@@ -180,21 +180,6 @@ export function createReaderSource(readerContext) {
     }
   }
 
-  function validFallback(raw) {
-    try {
-      const url = new URL(raw);
-      return (
-        url.protocol === "https:" &&
-        ["huggingface.co", "hf-mirror.com"].includes(url.hostname) &&
-        /\/datasets\/vomebook\/Reader-Assets\/resolve\/[^/]+\/objects\/[0-9a-f]{2}\/[0-9a-f]{64}\/(?:linearized\.pdf|(?:[a-z0-9-]+\/)?document\.pdf)$/.test(
-          url.pathname
-        )
-      );
-    } catch (_) {
-      return false;
-    }
-  }
-
   function readerAssetObjectFamily(raw, base = location.href) {
     try {
       const url = new URL(raw, base);
@@ -330,7 +315,6 @@ export function createReaderSource(readerContext) {
     applyReaderPathMetadata,
     validSource,
     validOcr,
-    validFallback,
     readerAssetObjectFamily,
     trustedReaderAssetManifestUrl,
     trustedChapterUrl,

static/reader/formats/reader-format-controller.mjs

@@ -116,7 +116,6 @@ export function createReaderFormatController(readerContext) {
     readerContext.contentUrl = readerContext.readerContentUrl(readerContext.sourceUrl);
     readerContext.downloadUrl = resolved.download || readerContext.sourceUrl;
     readerContext.chapterManifestUrl = resolved.chapter_manifest || "";
-    readerContext.fallbackUrl = resolved.fallback || "";
     if (resolved.extension) readerContext.extension = String(resolved.extension).toLowerCase();
     if (
       readerContext.extension === "pdf" &&
@@ -231,21 +230,6 @@ export function createReaderFormatController(readerContext) {
     } catch (error) {
       if (readerContext.readerAbortController.signal.aborted || error?.name === "AbortError") return;
       console.error(error);
-      if (
-        error?.code !== "READER_RESTORE" &&
-        readerContext.capability.mode === "epub-chapters" &&
-        readerContext.validFallback(readerContext.fallbackUrl)
-      ) {
-        const target = new URL(location.href);
-        target.searchParams.set("url", readerContext.fallbackUrl);
-        target.searchParams.set("ext", "pdf");
-        target.searchParams.delete("chapter_manifest");
-        target.searchParams.delete("fallback");
-        if (readerContext.isReaderOverlayFrame())
-          window.parent.postMessage({ type: "voice-reader-open", url: target.href }, location.origin);
-        else location.replace(target.href);
-        return;
-      }
       readerContext.fail(
         error && error.message ? error.message : "原文件加载失败",
         readerContext.classifyReaderError(error, readerContext.capability.mode === "foliate" ? "READER_CORRUPT" : "READER_PARSE")

tests/test_fastapi_endpoints.py

@@ -601,7 +601,7 @@ class FastApiEndpointTests(unittest.TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertEqual(result["ReaderExtension"], "epub-chapters")
         self.assertTrue(result["ReaderChapterManifest"].endswith(chapter_manifest))
-        self.assertTrue(result["ReaderFallback"].endswith(fallback))
+        self.assertNotIn("ReaderFallback", result)
         self.assertEqual(result["DownloadLink"], original_link)
 
     def test_reader_resolve_exposes_chapter_metadata_for_id_reader(self):
@@ -620,7 +620,7 @@ class FastApiEndpointTests(unittest.TestCase):
         result = response.json()
         self.assertEqual(result["extension"], "epub-chapters")
         self.assertTrue(result["chapter_manifest"].endswith(chapter_manifest))
-        self.assertTrue(result["fallback"].endswith(fallback))
+        self.assertNotIn("fallback", result)
 
     def test_reader_static_assets_are_served(self):
         for path in ("/static/reader.html", "/static/reader.js", "/static/reader.css", "/static/reader/core/reader-contract.js"):

tests/test_reader_backend.py

@@ -832,7 +832,8 @@ class ReaderBackendTests(unittest.IsolatedAsyncioTestCase):
         self.assertEqual(resolved["extension"], "pdf-pages")
         self.assertEqual(resolved["extension"], enriched["ReaderExtension"])
         self.assertEqual(resolved["chapter_manifest"], enriched["ReaderChapterManifest"])
-        self.assertEqual(resolved["fallback"], enriched["ReaderFallback"])
+        self.assertNotIn("fallback", resolved)
+        self.assertNotIn("ReaderFallback", enriched)
 
 
 if __name__ == "__main__":

tests/test_reader_regression.js

@@ -138,7 +138,7 @@ const convertedParams = new URL(`https://example.test${convertedUrl}`).searchPar
 assert.strictEqual(convertedParams.get('ext'), 'epub')
 assert.strictEqual(convertedParams.get('title'), '原始书名.mobi')
 assert.strictEqual(convertedParams.get('download'), 'https://download.example.test/books/book.mobi')
-assert.strictEqual(convertedParams.get('fallback'), 'https://huggingface.co/datasets/vomebook/Reader-Assets/resolve/main/fallback.pdf')
+assert.strictEqual(convertedParams.get('fallback'), null)
 assert.strictEqual(convertedParams.get('chapter_manifest'), 'https://huggingface.co/datasets/vomebook/Reader-Assets/resolve/main/chapters.json')
 const pageAssetUrl = sandbox.self.VoiceOfMLReader.readerUrl({
   ReaderLink: 'https://huggingface.co/datasets/vomebook/Reader-Assets/resolve/main/objects/aa/' + 'a'.repeat(64) + '/1234567890abcdef/page-manifest.json',