Dynamically allocate miniz internal memory only when zip maintained opened

lib/Epub/Epub.cpp

@@ -60,9 +60,6 @@ bool Epub::parseContentOpf(BookMetadataCache::BookMetadata& bookMetadata) {
   }
 
   ContentOpfParser opfParser(getCachePath(), getBasePath(), contentOpfSize, bookMetadataCache.get());
-  Serial.printf("[%lu] [MEM] Free: %d bytes, Total: %d bytes, Min Free: %d bytes\n", millis(), ESP.getFreeHeap(),
-                ESP.getHeapSize(), ESP.getMinFreeHeap());
-
   if (!opfParser.setup()) {
     Serial.printf("[%lu] [EBP] Could not setup content.opf parser\n", millis());
     return false;
@@ -321,10 +318,9 @@ bool Epub::generateCoverBmp() const {
 }
 
 uint8_t* Epub::readItemContentsToBytes(const std::string& itemHref, size_t* size, const bool trailingNullByte) const {
-  const ZipFile zip("/sd" + filepath);
   const std::string path = FsHelpers::normalisePath(itemHref);
 
-  const auto content = zip.readFileToMemory(path.c_str(), size, trailingNullByte);
+  const auto content = ZipFile("/sd" + filepath).readFileToMemory(path.c_str(), size, trailingNullByte);
   if (!content) {
     Serial.printf("[%lu] [EBP] Failed to read item %s\n", millis(), path.c_str());
     return nullptr;
@@ -334,20 +330,13 @@ uint8_t* Epub::readItemContentsToBytes(const std::string& itemHref, size_t* size
 }
 
 bool Epub::readItemContentsToStream(const std::string& itemHref, Print& out, const size_t chunkSize) const {
-  const ZipFile zip("/sd" + filepath);
   const std::string path = FsHelpers::normalisePath(itemHref);
-
-  return zip.readFileToStream(path.c_str(), out, chunkSize);
+  return ZipFile("/sd" + filepath).readFileToStream(path.c_str(), out, chunkSize);
 }
 
 bool Epub::getItemSize(const std::string& itemHref, size_t* size) const {
-  const ZipFile zip("/sd" + filepath);
-  return getItemSize(zip, itemHref, size);
-}
-
-bool Epub::getItemSize(const ZipFile& zip, const std::string& itemHref, size_t* size) {
   const std::string path = FsHelpers::normalisePath(itemHref);
-  return zip.getInflatedFileSize(path.c_str(), size);
+  return ZipFile("/sd" + filepath).getInflatedFileSize(path.c_str(), size);
 }
 
 int Epub::getSpineItemsCount() const {

lib/Epub/Epub.h

@@ -24,7 +24,6 @@ class Epub {
   bool findContentOpfFile(std::string* contentOpfFile) const;
   bool parseContentOpf(BookMetadataCache::BookMetadata& bookMetadata);
   bool parseTocNcxFile() const;
-  static bool getItemSize(const ZipFile& zip, const std::string& itemHref, size_t* size);
 
  public:
   explicit Epub(std::string filepath, const std::string& cacheDir) : filepath(std::move(filepath)) {
@@ -54,5 +53,5 @@ class Epub {
   size_t getCumulativeSpineItemSize(int spineIndex) const;
 
   size_t getBookSize() const;
-  uint8_t calculateProgress(const int currentSpineIndex, const float currentSpineRead) const;
+  uint8_t calculateProgress(int currentSpineIndex, float currentSpineRead) const;
 };

lib/Epub/Epub/BookMetadataCache.cpp

@@ -122,7 +122,15 @@ 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
 
-  const ZipFile zip("/sd" + epubPath);
+  ZipFile zip("/sd" + epubPath);
+  // Pre-open zip file to speed up size calculations
+  if (!zip.open()) {
+    Serial.printf("[%lu] [BMC] Could not open EPUB zip for size calculations\n", millis());
+    bookFile.close();
+    spineFile.close();
+    tocFile.close();
+    return false;
+  }
   size_t cumSize = 0;
   spineFile.seek(0);
   for (int i = 0; i < spineCount; i++) {
@@ -157,6 +165,8 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
     // Write out spine data to book.bin
     writeSpineEntry(bookFile, spineEntry);
   }
+  // Close opened zip file
+  zip.close();
 
   // Loop through toc entries from toc file writing to book.bin
   tocFile.seek(0);

lib/Epub/Epub/parsers/ContentOpfParser.cpp

@@ -3,7 +3,6 @@
 #include <FsHelpers.h>
 #include <HardwareSerial.h>
 #include <Serialization.h>
-#include <ZipFile.h>
 
 #include "../BookMetadataCache.h"
 

lib/ZipFile/ZipFile.cpp

@@ -27,28 +27,36 @@ bool inflateOneShot(const uint8_t* inputBuf, const size_t deflatedSize, uint8_t*
   return true;
 }
 
-ZipFile::ZipFile(std::string filePath) : filePath(std::move(filePath)) {
-  const bool status = mz_zip_reader_init_file(&zipArchive, this->filePath.c_str(), 0);
-
-  if (!status) {
-    Serial.printf("[%lu] [ZIP] mz_zip_reader_init_file() failed for %s! Error: %s\n", millis(), this->filePath.c_str(),
-                  mz_zip_get_error_string(zipArchive.m_last_error));
+bool ZipFile::loadFileStat(const char* filename, mz_zip_archive_file_stat* fileStat) {
+  const bool wasOpen = isOpen();
+  if (!wasOpen) {
+    if (!open()) {
+      return false;
+    }
   }
-}
 
-bool ZipFile::loadFileStat(const char* filename, mz_zip_archive_file_stat* fileStat) const {
   // find the file
   mz_uint32 fileIndex = 0;
-  if (!mz_zip_reader_locate_file_v2(&zipArchive, filename, nullptr, 0, &fileIndex)) {
+  if (!mz_zip_reader_locate_file_v2(zipArchivePtr.get(), filename, nullptr, 0, &fileIndex)) {
     Serial.printf("[%lu] [ZIP] Could not find file %s\n", millis(), filename);
+    if (!wasOpen) {
+      close();
+    }
     return false;
   }
 
-  if (!mz_zip_reader_file_stat(&zipArchive, fileIndex, fileStat)) {
+  if (!mz_zip_reader_file_stat(zipArchivePtr.get(), fileIndex, fileStat)) {
     Serial.printf("[%lu] [ZIP] mz_zip_reader_file_stat() failed! Error: %s\n", millis(),
-                  mz_zip_get_error_string(zipArchive.m_last_error));
+                  mz_zip_get_error_string(zipArchivePtr->m_last_error));
+    if (!wasOpen) {
+      close();
+    }
     return false;
   }
+
+  if (!wasOpen) {
+    close();
+  }
   return true;
 }
 
@@ -83,8 +91,31 @@ long ZipFile::getDataOffset(const mz_zip_archive_file_stat& fileStat) const {
   return fileOffset + localHeaderSize + filenameLength + extraOffset;
 }
 
-bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) const {
-  mz_zip_archive_file_stat fileStat;
+bool ZipFile::open() {
+  zipArchivePtr.reset(new mz_zip_archive);
+  mz_zip_zero_struct(zipArchivePtr.get());
+  const bool status =
+      mz_zip_reader_init_file(zipArchivePtr.get(), filePath.c_str(), MZ_ZIP_FLAG_DO_NOT_SORT_CENTRAL_DIRECTORY);
+
+  if (!status) {
+    Serial.printf("[%lu] [ZIP] mz_zip_reader_init_file() failed for %s! Error: %s\n", millis(), filePath.c_str(),
+                  mz_zip_get_error_string(zipArchivePtr->m_last_error));
+    zipArchivePtr.reset();
+    return false;
+  }
+  return true;
+}
+
+bool ZipFile::close() {
+  if (zipArchivePtr) {
+    mz_zip_reader_end(zipArchivePtr.get());
+    zipArchivePtr.reset();
+  }
+  return true;
+}
+
+bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) {
+  mz_zip_archive_file_stat fileStat = {};
   if (!loadFileStat(filename, &fileStat)) {
     return false;
   }
@@ -93,7 +124,7 @@ bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) const {
   return true;
 }
 
-uint8_t* ZipFile::readFileToMemory(const char* filename, size_t* size, const bool trailingNullByte) const {
+uint8_t* ZipFile::readFileToMemory(const char* filename, size_t* size, const bool trailingNullByte) {
   mz_zip_archive_file_stat fileStat;
   if (!loadFileStat(filename, &fileStat)) {
     return nullptr;
@@ -173,7 +204,7 @@ uint8_t* ZipFile::readFileToMemory(const char* filename, size_t* size, const boo
   return data;
 }
 
-bool ZipFile::readFileToStream(const char* filename, Print& out, const size_t chunkSize) const {
+bool ZipFile::readFileToStream(const char* filename, Print& out, const size_t chunkSize) {
   mz_zip_archive_file_stat fileStat;
   if (!loadFileStat(filename, &fileStat)) {
     return false;

lib/ZipFile/ZipFile.h

@@ -1,20 +1,28 @@
 #pragma once
 #include <Print.h>
 
+#include <memory>
 #include <string>
 
 #include "miniz.h"
 
 class ZipFile {
   std::string filePath;
-  mutable mz_zip_archive zipArchive = {};
-  bool loadFileStat(const char* filename, mz_zip_archive_file_stat* fileStat) const;
+  std::unique_ptr<mz_zip_archive> zipArchivePtr;
+  bool loadFileStat(const char* filename, mz_zip_archive_file_stat* fileStat);
   long getDataOffset(const mz_zip_archive_file_stat& fileStat) const;
 
  public:
-  explicit ZipFile(std::string filePath);
-  ~ZipFile() { mz_zip_reader_end(&zipArchive); }
-  bool getInflatedFileSize(const char* filename, size_t* size) const;
-  uint8_t* readFileToMemory(const char* filename, size_t* size = nullptr, bool trailingNullByte = false) const;
-  bool readFileToStream(const char* filename, Print& out, size_t chunkSize) const;
+  explicit ZipFile(std::string filePath) : filePath(std::move(filePath)) {}
+  ~ZipFile() = default;
+  // Zip file can be opened and closed by hand in order to allow for quick calculation of inflated file size
+  // It is NOT recommended to pre-open it for any kind of inflation due to memory constraints
+  bool isOpen() const { return zipArchivePtr != nullptr; }
+  bool open();
+  bool close();
+  bool getInflatedFileSize(const char* filename, size_t* size);
+  // Due to the memory required to run each of these, it is recommended to not preopen the zip file for multiple
+  // These functions will open and close the zip as needed
+  uint8_t* readFileToMemory(const char* filename, size_t* size = nullptr, bool trailingNullByte = false);
+  bool readFileToStream(const char* filename, Print& out, size_t chunkSize);
 };