Merge branch 'master' of https://github.com/jpirnay/crosspoint-reader into refactor-progress-theme

.skills/SKILL.md

@@ -847,8 +847,8 @@ rm -rf /path/to/sd/.crosspoint/epub_<hash>/sections/
 **Source**: `lib/Epub/Epub/Section.cpp`, `lib/Epub/Epub/BookMetadataCache.cpp`
 
 **Current Versions** (as of docs/file-formats.md):
-- `book.bin`: **Version 5** (metadata structure)
-- `section.bin`: **Version 20** (layout structure, includes paragraph LUT)
+- `book.bin`: **Version 7** (header A includes cached `tocReliable` byte)
+- `section.bin`: **Version 23** (layout structure, includes paragraph LUT)
 
 **Version Increment Rules**:
 1. **ALWAYS increment version** BEFORE changing binary structure

docs/epub-toc-navigation.md

@@ -22,6 +22,14 @@ Spine items before the first TOC entry (cover pages) and after the last (appendi
 - `getTocItem(i)` returns the TOC entry (title, spineIndex, anchor) for TOC index `i` -- also a file seek per call, not cached in memory. Code that queries TOC metadata in a loop should cache the results locally first.
 - `getSpineIndexForTocIndex(i)` does the reverse lookup (TOC index to spine index).
 
+### Cached TOC reliability flag
+
+`hasReliableToc()` answers whether the TOC has enough spine coverage (>=25% of spines referenced) to drive chapter UX, with short-circuits for `tocCount <= 0` and the "large book with one TOC entry" pathology.
+
+The result is computed once during `buildBookBin` (folded into the existing `spineIndex->tocIndex` scan, so no extra disk pass) and persisted as a single byte in book.bin's header A. `Epub::hasReliableToc()` reads `BookMetadataCache::isTocReliable()` and caches the bool in `tocReliabilityState`.
+
+This matters because the check used to recompute the answer on demand by calling `getTocEntry(i)` for every TOC entry, which does two SD-card seeks per call. On a 2858-entry web-novel TOC that was ~5700 seeks (~7 seconds) added to first-page latency. `BOOK_CACHE_VERSION` was bumped to 7 for this layout change; older caches are rebuilt on next open.
+
 ## Section cache file format
 
 The section cache (`.bin`) stores pre-rendered page data for a spine item. The file layout:

docs/file-formats.md

@@ -2,7 +2,7 @@
 
 ## `book.bin`
 
-### Version 3
+### Version 7
 
 ImHex Pattern:
 
@@ -12,7 +12,7 @@ import std.string;
 import std.core;
 
 // === Configuration ===
-#define EXPECTED_VERSION 3
+#define EXPECTED_VERSION 7
 #define MAX_STRING_LENGTH 65535
 
 // === String Structure ===
@@ -34,8 +34,12 @@ fn format_string(String s) {
 struct Metadata {
     String title [[comment("Book title")]];
     String author [[comment("Book author")]];
+    String language [[comment("BCP47 language tag")]];
     String coverItemHref [[comment("Path to cover image")]];
     String textReferenceHref [[comment("Path to guided first text reference")]];
+    String series [[comment("Series name")]];
+    String seriesIndex [[comment("Series index/position")]];
+    String description [[comment("Book description / blurb")]];
 } [[comment("Book metadata information")]];
 
 // === Spine Entry Structure ===
@@ -70,7 +74,8 @@ struct BookBin {
     u32 lutOffset [[comment("Offset to lookup tables"), color("6BCB77")]];
     u16 spineCount [[comment("Number of spine entries"), color("4D96FF")]];
     u16 tocCount [[comment("Number of TOC entries"), color("FF6B9D")]];
-    
+    u8 tocReliable [[comment("1 if TOC has >=25% spine coverage, 0 otherwise"), color("F4A261")]];
+
     // Metadata section
     Metadata metadata [[comment("Book metadata")]];
     

lib/Epub/Epub.cpp

@@ -868,35 +868,10 @@ bool Epub::hasReliableToc() const {
     return false;
   }
 
-  const int spineCount = bookMetadataCache->getSpineCount();
-  const int tocCount = bookMetadataCache->getTocCount();
-
-  if (spineCount <= 0 || tocCount <= 0) {
-    tocReliabilityState = 0;
-    return false;
-  }
-
-  // If a larger book only exposes one TOC entry, treat TOC as unusable for chapter UX.
-  if (spineCount >= 8 && tocCount <= 1) {
-    tocReliabilityState = 0;
-    return false;
-  }
-
-  std::vector<bool> spineReferenced(static_cast<size_t>(spineCount), false);
-  int distinctSpinesReferenced = 0;
-  for (int i = 0; i < tocCount; i++) {
-    const auto toc = bookMetadataCache->getTocEntry(i);
-    if (toc.spineIndex >= 0 && toc.spineIndex < spineCount) {
-      const size_t idx = static_cast<size_t>(toc.spineIndex);
-      if (!spineReferenced[idx]) {
-        spineReferenced[idx] = true;
-        distinctSpinesReferenced++;
-      }
-    }
-  }
-
-  // Require at least 25% spine coverage from TOC references.
-  const bool reliable = (distinctSpinesReferenced * 4 >= spineCount);
+  // Reliability is computed once at indexing time and persisted in book.bin's header.
+  // This avoids the O(tocCount) seek-heavy scan that previously fired on first page load
+  // for every book — a large web-novel TOC (~3000 entries) added several seconds of latency.
+  const bool reliable = bookMetadataCache->isTocReliable();
   tocReliabilityState = reliable ? 1 : 0;
   return reliable;
 }

lib/Epub/Epub/BookMetadataCache.cpp

@@ -9,7 +9,7 @@
 #include "FsHelpers.h"
 
 namespace {
-constexpr uint8_t BOOK_CACHE_VERSION = 6;
+constexpr uint8_t BOOK_CACHE_VERSION = 7;
 constexpr char bookBinFile[] = "/book.bin";
 constexpr char tmpSpineBinFile[] = "/spine.bin.tmp";
 constexpr char tmpTocBinFile[] = "/toc.bin.tmp";
@@ -113,8 +113,8 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
     return false;
   }
 
-  constexpr uint32_t headerASize =
-      sizeof(BOOK_CACHE_VERSION) + /* LUT Offset */ sizeof(uint32_t) + sizeof(spineCount) + sizeof(tocCount);
+  constexpr uint32_t headerASize = sizeof(BOOK_CACHE_VERSION) + /* LUT Offset */ sizeof(uint32_t) + sizeof(spineCount) +
+                                   sizeof(tocCount) + sizeof(uint8_t) /* tocReliable */;
   const uint32_t metadataSize = metadata.title.size() + metadata.author.size() + metadata.language.size() +
                                 metadata.coverItemHref.size() + metadata.textReferenceHref.size() +
                                 metadata.series.size() + metadata.seriesIndex.size() + metadata.description.size() +
@@ -122,11 +122,14 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
   const uint32_t lutSize = sizeof(uint32_t) * spineCount + sizeof(uint32_t) * tocCount;
   const uint32_t lutOffset = headerASize + metadataSize;
 
-  // Header A
+  // Header A. tocReliable is patched at the end once the TOC scan below has computed it.
+  const uint32_t tocReliableHeaderPos =
+      sizeof(BOOK_CACHE_VERSION) + sizeof(uint32_t) /* lutOffset */ + sizeof(spineCount) + sizeof(tocCount);
   serialization::writePod(bookFile, BOOK_CACHE_VERSION);
   serialization::writePod(bookFile, lutOffset);
   serialization::writePod(bookFile, spineCount);
   serialization::writePod(bookFile, tocCount);
+  serialization::writePod(bookFile, static_cast<uint8_t>(0));  // placeholder for tocReliable
   // Metadata
   serialization::writeString(bookFile, metadata.title);
   serialization::writeString(bookFile, metadata.author);
@@ -156,18 +159,31 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
   // LUTs complete
   // Loop through spines from spine file matching up TOC indexes, calculating cumulative size and writing to book.bin
 
-  // Build spineIndex->tocIndex mapping in one pass (O(n) instead of O(n*m))
+  // Build spineIndex->tocIndex mapping in one pass (O(n) instead of O(n*m)).
+  // Also count distinct spines referenced by the TOC so tocReliable can be persisted in the
+  // header below — without this, every first-page load on a large book pays an O(tocCount)
+  // seek-heavy scan in Epub::hasReliableToc().
   std::deque<int16_t> spineToTocIndex(spineCount, -1);
+  int distinctSpinesReferenced = 0;
   tocFile.seek(0);
   for (int j = 0; j < tocCount; j++) {
     auto tocEntry = readTocEntry(tocFile);
     if (tocEntry.spineIndex >= 0 && tocEntry.spineIndex < spineCount) {
       if (spineToTocIndex[tocEntry.spineIndex] == -1) {
         spineToTocIndex[tocEntry.spineIndex] = static_cast<int16_t>(j);
+        distinctSpinesReferenced++;
       }
     }
   }
 
+  // Mirrors the heuristic in Epub::hasReliableToc(): require >=25% distinct spine coverage,
+  // with short-circuits for edge cases (no entries, or large book with a single TOC entry).
+  if (spineCount > 0 && tocCount > 0 && !(spineCount >= 8 && tocCount <= 1)) {
+    tocReliable = (distinctSpinesReferenced * 4 >= spineCount);
+  } else {
+    tocReliable = false;
+  }
+
   ZipFile zip(epubPath);
   // Pre-open zip file to speed up size calculations
   if (!zip.open()) {
@@ -269,6 +285,10 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
     writeTocEntry(bookFile, tocEntry);
   }
 
+  // Patch tocReliable placeholder in header A
+  bookFile.seek(tocReliableHeaderPos);
+  serialization::writePod(bookFile, static_cast<uint8_t>(tocReliable ? 1 : 0));
+
   bookFile.close();
   spineFile.close();
   tocFile.close();
@@ -384,6 +404,9 @@ bool BookMetadataCache::load() {
   serialization::readPod(bookFile, lutOffset);
   serialization::readPod(bookFile, spineCount);
   serialization::readPod(bookFile, tocCount);
+  uint8_t tocReliableByte;
+  serialization::readPod(bookFile, tocReliableByte);
+  tocReliable = (tocReliableByte != 0);
 
   serialization::readString(bookFile, coreMetadata.title);
   serialization::readString(bookFile, coreMetadata.author);

lib/Epub/Epub/BookMetadataCache.h

@@ -50,6 +50,7 @@ class BookMetadataCache {
   size_t lutOffset;
   uint16_t spineCount;
   uint16_t tocCount;
+  bool tocReliable;
   bool loaded;
   bool buildMode;
 
@@ -88,7 +89,13 @@ class BookMetadataCache {
   BookMetadata coreMetadata;
 
   explicit BookMetadataCache(std::string cachePath)
-      : cachePath(std::move(cachePath)), lutOffset(0), spineCount(0), tocCount(0), loaded(false), buildMode(false) {}
+      : cachePath(std::move(cachePath)),
+        lutOffset(0),
+        spineCount(0),
+        tocCount(0),
+        tocReliable(false),
+        loaded(false),
+        buildMode(false) {}
   ~BookMetadataCache() = default;
 
   // Building phase (stream to disk immediately)
@@ -111,5 +118,6 @@ class BookMetadataCache {
   TocEntry getTocEntry(int index);
   int getSpineCount() const { return spineCount; }
   int getTocCount() const { return tocCount; }
+  bool isTocReliable() const { return tocReliable; }
   bool isLoaded() const { return loaded; }
 };

src/activities/reader/XtcReaderActivity.cpp

@@ -14,13 +14,14 @@
 
 #include <algorithm>
 
+#include <algorithm>
+
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"
 #include "ReaderUtils.h"
 #include "RecentBooksStore.h"
 #include "XtcReaderChapterSelectionActivity.h"
-#include "components/UITheme.h"
 #include "fontIds.h"
 
 namespace {
@@ -477,12 +478,12 @@ void XtcReaderActivity::onButtonAction(const CrossPointSettings::BUTTON_ACTION a
     case BA::BTN_PREV_SECTION:
       if (xtc->hasChapters()) {
         const auto& chapters = xtc->getChapters();
-        for (int i = static_cast<int>(chapters.size()) - 1; i >= 0; i--) {
-          if (chapters[i].startPage < currentPage) {
-            currentPage = chapters[i].startPage;
-            requestUpdate();
-            break;
-          }
+        const auto prevChapter = std::find_if(chapters.rbegin(), chapters.rend(),
+                                              [this](const auto& ch) { return ch.startPage < currentPage; });
+
+        if (prevChapter != chapters.rend()) {
+          currentPage = prevChapter->startPage;
+          requestUpdate();
         }
       }
       break;