Add touch gesture support and LilyGo T5 S3 board

Implements bottom-edge swipe-up gesture detection and delayed touch-select with tracking state. Adds isTouchTapCandidate() to distinguish taps from swipes. Includes LilyGo T5 S3 board configuration with USB CDC logging transport for boards where Serial operator bool reports false incorrectly.

lib/Epub/Epub/BookMetadataCache.cpp

@@ -13,8 +13,47 @@ constexpr uint8_t BOOK_CACHE_VERSION = 7;
 constexpr char bookBinFile[] = "/book.bin";
 constexpr char tmpSpineBinFile[] = "/spine.bin.tmp";
 constexpr char tmpTocBinFile[] = "/toc.bin.tmp";
+constexpr uint32_t MAX_CACHE_STRING_LEN = 4096;
+
+bool readStringBounded(HalFile& file, std::string& out, const uint32_t maxLen = MAX_CACHE_STRING_LEN) {
+  uint32_t len = 0;
+  if (file.read(&len, sizeof(len)) != static_cast<int>(sizeof(len))) {
+    return false;
+  }
+  if (len > maxLen || len > static_cast<uint32_t>(file.available())) {
+    LOG_ERR("BMC", "Invalid cache string length: %lu (max=%lu available=%d)", static_cast<unsigned long>(len),
+            static_cast<unsigned long>(maxLen), file.available());
+    return false;
+  }
+  out.clear();
+  if (len == 0) {
+    return true;
+  }
+  out.resize(len);
+  return file.read(out.data(), len) == static_cast<int>(len);
+}
+
+class CacheIoLock {
+ public:
+  explicit CacheIoLock(SemaphoreHandle_t mutex) : mutex(mutex) {
+    if (mutex) xSemaphoreTakeRecursive(mutex, portMAX_DELAY);
+  }
+  ~CacheIoLock() {
+    if (mutex) xSemaphoreGiveRecursive(mutex);
+  }
+
+ private:
+  SemaphoreHandle_t mutex;
+};
 }  // namespace
 
+BookMetadataCache::~BookMetadataCache() {
+  if (ioMutex) {
+    vSemaphoreDelete(ioMutex);
+    ioMutex = nullptr;
+  }
+}
+
 /* ============= WRITING / BUILDING FUNCTIONS ================ */
 
 bool BookMetadataCache::beginWrite() {
@@ -372,6 +411,7 @@ void BookMetadataCache::createTocEntry(const std::string& title, const std::stri
 /* ============= READING / LOADING FUNCTIONS ================ */
 
 bool BookMetadataCache::load() {
+  CacheIoLock ioLock(ioMutex);
   if (!Storage.openFileForRead("BMC", cachePath + bookBinFile, bookFile)) {
     return false;
   }
@@ -389,11 +429,13 @@ bool BookMetadataCache::load() {
   serialization::readPod(bookFile, spineCount);
   serialization::readPod(bookFile, tocCount);
 
-  serialization::readString(bookFile, coreMetadata.title);
-  serialization::readString(bookFile, coreMetadata.author);
-  serialization::readString(bookFile, coreMetadata.language);
-  serialization::readString(bookFile, coreMetadata.coverItemHref);
-  serialization::readString(bookFile, coreMetadata.textReferenceHref);
+  if (!readStringBounded(bookFile, coreMetadata.title) || !readStringBounded(bookFile, coreMetadata.author) ||
+      !readStringBounded(bookFile, coreMetadata.language) || !readStringBounded(bookFile, coreMetadata.coverItemHref) ||
+      !readStringBounded(bookFile, coreMetadata.textReferenceHref)) {
+    LOG_ERR("BMC", "Invalid cache metadata strings");
+    bookFile.close();
+    return false;
+  }
 
   loaded = true;
   LOG_DBG("BMC", "Loaded cache data: %d spine, %d TOC entries", spineCount, tocCount);
@@ -401,6 +443,7 @@ bool BookMetadataCache::load() {
 }
 
 BookMetadataCache::SpineEntry BookMetadataCache::getSpineEntry(const int index) {
+  CacheIoLock ioLock(ioMutex);
   if (!loaded) {
     LOG_ERR("BMC", "getSpineEntry called but cache not loaded");
     return {};
@@ -415,11 +458,16 @@ BookMetadataCache::SpineEntry BookMetadataCache::getSpineEntry(const int index)
   bookFile.seek(lutOffset + sizeof(uint32_t) * index);
   uint32_t spineEntryPos;
   serialization::readPod(bookFile, spineEntryPos);
+  if (spineEntryPos >= bookFile.size()) {
+    LOG_ERR("BMC", "Spine entry offset out of range: %lu", static_cast<unsigned long>(spineEntryPos));
+    return {};
+  }
   bookFile.seek(spineEntryPos);
   return readSpineEntry(bookFile);
 }
 
 BookMetadataCache::TocEntry BookMetadataCache::getTocEntry(const int index) {
+  CacheIoLock ioLock(ioMutex);
   if (!loaded) {
     LOG_ERR("BMC", "getTocEntry called but cache not loaded");
     return {};
@@ -434,24 +482,33 @@ BookMetadataCache::TocEntry BookMetadataCache::getTocEntry(const int index) {
   bookFile.seek(lutOffset + sizeof(uint32_t) * spineCount + sizeof(uint32_t) * index);
   uint32_t tocEntryPos;
   serialization::readPod(bookFile, tocEntryPos);
+  if (tocEntryPos >= bookFile.size()) {
+    LOG_ERR("BMC", "TOC entry offset out of range: %lu", static_cast<unsigned long>(tocEntryPos));
+    return {};
+  }
   bookFile.seek(tocEntryPos);
   return readTocEntry(bookFile);
 }
 
 BookMetadataCache::SpineEntry BookMetadataCache::readSpineEntry(HalFile& file) const {
   SpineEntry entry;
-  serialization::readString(file, entry.href);
-  serialization::readPod(file, entry.cumulativeSize);
-  serialization::readPod(file, entry.tocIndex);
+  if (!readStringBounded(file, entry.href) ||
+      file.read(&entry.cumulativeSize, sizeof(entry.cumulativeSize)) != static_cast<int>(sizeof(entry.cumulativeSize)) ||
+      file.read(&entry.tocIndex, sizeof(entry.tocIndex)) != static_cast<int>(sizeof(entry.tocIndex))) {
+    LOG_ERR("BMC", "Invalid spine cache entry");
+    return {};
+  }
   return entry;
 }
 
 BookMetadataCache::TocEntry BookMetadataCache::readTocEntry(HalFile& file) const {
   TocEntry entry;
-  serialization::readString(file, entry.title);
-  serialization::readString(file, entry.href);
-  serialization::readString(file, entry.anchor);
-  serialization::readPod(file, entry.level);
-  serialization::readPod(file, entry.spineIndex);
+  if (!readStringBounded(file, entry.title) || !readStringBounded(file, entry.href) ||
+      !readStringBounded(file, entry.anchor) ||
+      file.read(&entry.level, sizeof(entry.level)) != static_cast<int>(sizeof(entry.level)) ||
+      file.read(&entry.spineIndex, sizeof(entry.spineIndex)) != static_cast<int>(sizeof(entry.spineIndex))) {
+    LOG_ERR("BMC", "Invalid TOC cache entry");
+    return {};
+  }
   return entry;
 }

lib/Epub/Epub/BookMetadataCache.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <HalStorage.h>
+#include <freertos/semphr.h>
 
 #include <algorithm>
 #include <deque>
@@ -54,6 +55,7 @@ class BookMetadataCache {
   // Temp file handles during build
   HalFile spineFile;
   HalFile tocFile;
+  SemaphoreHandle_t ioMutex;
 
   // Index for fast href→spineIndex lookup (used only for large EPUBs)
   struct SpineHrefIndexEntry {
@@ -85,8 +87,14 @@ class BookMetadataCache {
   BookMetadata coreMetadata;
 
   explicit BookMetadataCache(std::string cachePath)
-      : cachePath(std::move(cachePath)), lutOffset(0), spineCount(0), tocCount(0), loaded(false), buildMode(false) {}
-  ~BookMetadataCache() = default;
+      : cachePath(std::move(cachePath)),
+        lutOffset(0),
+        spineCount(0),
+        tocCount(0),
+        loaded(false),
+        buildMode(false),
+        ioMutex(xSemaphoreCreateRecursiveMutex()) {}
+  ~BookMetadataCache();
 
   // Building phase (stream to disk immediately)
   bool beginWrite();