fix: increase loadable epub size (#1638)

## Summary

* **What is the goal of this PR?** Slightly increase the OOM limit when
loading epubs
* **What changes are included?** Switched vectors for parsing epubs to
deques, allowing use of more memory

## Additional Context

* Increases loadable epub size from 2000+ chapter/ToC entries loadable
to 5000+ chapter/ToC entries
* #1574, but without the complicated stuff

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _**NO**_

### Testing
| Commit | Book | Time |
|----------|------|-------|
| 83cd96bc2f | 1000.epub | ~30 sec |
| 83cd96bc2f | 5000.epub | crash |
| PR | 1000.epub | ~29 sec |
| PR | 5000.epub | ~2 min 20 sec |

=> No actual loading time regressions

[tested_epubs.zip](https://github.com/user-attachments/files/26645243/tested_epubs.zip)

lib/Epub/Epub/BookMetadataCache.cpp

@@ -4,7 +4,7 @@
 #include <Serialization.h>
 #include <ZipFile.h>
 
-#include <vector>
+#include <deque>
 
 #include "FsHelpers.h"
 
@@ -50,7 +50,7 @@ bool BookMetadataCache::beginTocPass() {
 
   if (spineCount >= LARGE_SPINE_THRESHOLD) {
     spineHrefIndex.clear();
-    spineHrefIndex.reserve(spineCount);
+    spineHrefIndex.resize(spineCount);
     spineFile.seek(0);
     for (int i = 0; i < spineCount; i++) {
       auto entry = readSpineEntry(spineFile);
@@ -58,7 +58,7 @@ bool BookMetadataCache::beginTocPass() {
       idx.hrefHash = fnvHash64(entry.href);
       idx.hrefLen = static_cast<uint16_t>(entry.href.size());
       idx.spineIndex = static_cast<int16_t>(i);
-      spineHrefIndex.push_back(idx);
+      spineHrefIndex[i] = idx;
     }
     std::sort(spineHrefIndex.begin(), spineHrefIndex.end(),
               [](const SpineHrefIndexEntry& a, const SpineHrefIndexEntry& b) {
@@ -153,7 +153,7 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
   // 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))
-  std::vector<int16_t> spineToTocIndex(spineCount, -1);
+  std::deque<int16_t> spineToTocIndex(spineCount, -1);
   tocFile.seek(0);
   for (int j = 0; j < tocCount; j++) {
     auto tocEntry = readTocEntry(tocFile);
@@ -181,14 +181,14 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
   // This is O(n*log(m)) instead of O(n*m) while avoiding memory exhaustion.
   // See: https://github.com/crosspoint-reader/crosspoint-reader/issues/134
 
-  std::vector<uint32_t> spineSizes;
+  std::deque<uint32_t> spineSizes;
   bool useBatchSizes = false;
 
   if (spineCount >= LARGE_SPINE_THRESHOLD) {
     LOG_DBG("BMC", "Using batch size lookup for %d spine items", spineCount);
 
-    std::vector<ZipFile::SizeTarget> targets;
+    std::deque<ZipFile::SizeTarget> targets;
-    targets.reserve(spineCount);
+    targets.resize(spineCount);
 
     spineFile.seek(0);
     for (int i = 0; i < spineCount; i++) {
@@ -199,7 +199,7 @@ bool BookMetadataCache::buildBookBin(const std::string& epubPath, const BookMeta
       t.hash = ZipFile::fnvHash64(path.c_str(), path.size());
       t.len = static_cast<uint16_t>(path.size());
       t.index = static_cast<uint16_t>(i);
-      targets.push_back(t);
+      targets[i] = t;
     }
 
     std::sort(targets.begin(), targets.end(), [](const ZipFile::SizeTarget& a, const ZipFile::SizeTarget& b) {

lib/Epub/Epub/BookMetadataCache.h

@@ -3,8 +3,8 @@
 #include <HalStorage.h>
 
 #include <algorithm>
+#include <deque>
 #include <string>
-#include <vector>
 
 class BookMetadataCache {
  public:
@@ -61,7 +61,7 @@ class BookMetadataCache {
     uint16_t hrefLen;   // length for collision reduction
     int16_t spineIndex;
   };
-  std::vector<SpineHrefIndexEntry> spineHrefIndex;
+  std::deque<SpineHrefIndexEntry> spineHrefIndex;
   bool useSpineHrefIndex = false;
 
   static constexpr uint16_t LARGE_SPINE_THRESHOLD = 400;

lib/Epub/Epub/parsers/ContentOpfParser.h

@@ -2,6 +2,7 @@
 #include <Print.h>
 
 #include <algorithm>
+#include <deque>
 #include <vector>
 
 #include "Epub.h"
@@ -37,7 +38,7 @@ class ContentOpfParser final : public Print {
     uint16_t idLen;       // length for collision reduction
     uint32_t fileOffset;  // offset in .items.bin
   };
-  std::vector<ItemIndexEntry> itemIndex;
+  std::deque<ItemIndexEntry> itemIndex;
   bool useItemIndex = false;
 
   static constexpr uint16_t LARGE_SPINE_THRESHOLD = 400;

lib/ZipFile/ZipFile.cpp

@@ -295,7 +295,7 @@ bool ZipFile::getInflatedFileSize(const char* filename, size_t* size) {
   return true;
 }
 
-int ZipFile::fillUncompressedSizes(std::vector<SizeTarget>& targets, std::vector<uint32_t>& sizes) {
+int ZipFile::fillUncompressedSizes(std::deque<SizeTarget>& targets, std::deque<uint32_t>& sizes) {
   if (targets.empty()) {
     return 0;
   }

lib/ZipFile/ZipFile.h

@@ -1,9 +1,9 @@
 #pragma once
 #include <HalStorage.h>
 
+#include <deque>
 #include <string>
 #include <unordered_map>
-#include <vector>
 
 class ZipFile {
  public:
@@ -64,7 +64,7 @@ class ZipFile {
   // Batch lookup: scan ZIP central dir once and fill sizes for matching targets.
   // targets must be sorted by (hash, len). sizes[target.index] receives uncompressedSize.
   // Returns number of targets matched.
-  int fillUncompressedSizes(std::vector<SizeTarget>& targets, std::vector<uint32_t>& sizes);
+  int fillUncompressedSizes(std::deque<SizeTarget>& targets, std::deque<uint32_t>& sizes);
   // 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);