From b596f21e61bf3b872d3181f58e122d2a2e9f9825 Mon Sep 17 00:00:00 2001
From: hooligan333 <59103913+hooligan333@users.noreply.github.com>
Date: Sat, 11 Jul 2026 19:57:48 -0700
Subject: [PATCH] perf: stream NCX/NAV TOC into parser, drop temp-file
 round-trip (#2440)

Co-authored-by: Erica Jensen <erica@mailershaven.com>
---
 lib/Epub/Epub.cpp | 73 +++++++++--------------------------------------
 1 file changed, 14 insertions(+), 59 deletions(-)

diff --git a/lib/Epub/Epub.cpp b/lib/Epub/Epub.cpp
index 5f5dcc8a..0f38f566 100644
--- a/lib/Epub/Epub.cpp
+++ b/lib/Epub/Epub.cpp
@@ -153,18 +153,11 @@ bool Epub::parseTocNcxFile() const {
 
   LOG_DBG("EBP", "Parsing toc ncx file: %s", tocNcxItem.c_str());
 
-  const auto tmpNcxPath = getCachePath() + "/toc.ncx";
-  HalFile tempNcxFile;
-  if (!Storage.openFileForWrite("EBP", tmpNcxPath, tempNcxFile)) {
+  size_t ncxSize;
+  if (!getItemSize(tocNcxItem, &ncxSize)) {
+    LOG_ERR("EBP", "Could not get size of toc ncx file");
     return false;
   }
-  readItemContentsToStream(tocNcxItem, tempNcxFile, 1024);
-  // Explicitly close() file before reopening for reading
-  tempNcxFile.close();
-  if (!Storage.openFileForRead("EBP", tmpNcxPath, tempNcxFile)) {
-    return false;
-  }
-  const auto ncxSize = tempNcxFile.size();
 
   TocNcxParser ncxParser(contentBasePath, ncxSize, bookMetadataCache.get());
 
@@ -173,29 +166,13 @@ bool Epub::parseTocNcxFile() const {
     return false;
   }
 
-  const auto ncxBuffer = static_cast<uint8_t*>(malloc(1024));
-  if (!ncxBuffer) {
-    LOG_ERR("EBP", "Could not allocate memory for toc ncx parser");
+  // Stream the decompressed NCX straight into the parser instead of round-tripping
+  // through a temp file on the SD card (decompress -> write -> reopen -> reread -> delete).
+  if (!readItemContentsToStream(tocNcxItem, ncxParser, 1024)) {
+    LOG_ERR("EBP", "Could not read toc ncx file");
     return false;
   }
 
-  while (tempNcxFile.available()) {
-    const auto readSize = tempNcxFile.read(ncxBuffer, 1024);
-    if (readSize == 0) break;
-    const auto processedSize = ncxParser.write(ncxBuffer, readSize);
-
-    if (processedSize != readSize) {
-      LOG_ERR("EBP", "Could not process all toc ncx data");
-      free(ncxBuffer);
-      return false;
-    }
-  }
-
-  free(ncxBuffer);
-  // Explicitly close() file before calling Storage.remove()
-  tempNcxFile.close();
-  Storage.remove(tmpNcxPath.c_str());
-
   LOG_DBG("EBP", "Parsed TOC items");
   return true;
 }
@@ -209,18 +186,11 @@ bool Epub::parseTocNavFile() const {
 
   LOG_DBG("EBP", "Parsing toc nav file: %s", tocNavItem.c_str());
 
-  const auto tmpNavPath = getCachePath() + "/toc.nav";
-  HalFile tempNavFile;
-  if (!Storage.openFileForWrite("EBP", tmpNavPath, tempNavFile)) {
+  size_t navSize;
+  if (!getItemSize(tocNavItem, &navSize)) {
+    LOG_ERR("EBP", "Could not get size of toc nav file");
     return false;
   }
-  readItemContentsToStream(tocNavItem, tempNavFile, 1024);
-  // Explicitly close() file before reopening for reading
-  tempNavFile.close();
-  if (!Storage.openFileForRead("EBP", tmpNavPath, tempNavFile)) {
-    return false;
-  }
-  const auto navSize = tempNavFile.size();
 
   // Note: We can't use `contentBasePath` here as the nav file may be in a different folder to the content.opf
   // and the HTMLX nav file will have hrefs relative to itself
@@ -232,28 +202,13 @@ bool Epub::parseTocNavFile() const {
     return false;
   }
 
-  const auto navBuffer = static_cast<uint8_t*>(malloc(1024));
-  if (!navBuffer) {
-    LOG_ERR("EBP", "Could not allocate memory for toc nav parser");
+  // Stream the decompressed nav document straight into the parser instead of round-tripping
+  // through a temp file on the SD card (decompress -> write -> reopen -> reread -> delete).
+  if (!readItemContentsToStream(tocNavItem, navParser, 1024)) {
+    LOG_ERR("EBP", "Could not read toc nav file");
     return false;
   }
 
-  while (tempNavFile.available()) {
-    const auto readSize = tempNavFile.read(navBuffer, 1024);
-    const auto processedSize = navParser.write(navBuffer, readSize);
-
-    if (processedSize != readSize) {
-      LOG_ERR("EBP", "Could not process all toc nav data");
-      free(navBuffer);
-      return false;
-    }
-  }
-
-  free(navBuffer);
-  // Explicitly close() file before calling Storage.remove()
-  tempNavFile.close();
-  Storage.remove(tmpNavPath.c_str());
-
   LOG_DBG("EBP", "Parsed TOC nav items");
   return true;
 }