From f98411f421236abdd309e98e75a8eca671e47936 Mon Sep 17 00:00:00 2001
From: Robin Mueller <muellerr@irs.uni-stuttgart.de>
Date: Mon, 22 Aug 2022 10:35:23 +0200
Subject: [PATCH] speed up crc proc significantly

---
 linux/devices/ploc/PlocSupvHelper.cpp | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/linux/devices/ploc/PlocSupvHelper.cpp b/linux/devices/ploc/PlocSupvHelper.cpp
index 13185d2d..a8858e25 100644
--- a/linux/devices/ploc/PlocSupvHelper.cpp
+++ b/linux/devices/ploc/PlocSupvHelper.cpp
@@ -1,5 +1,7 @@
 #include "PlocSupvHelper.h"
 
+#include <etl/crc16_ccitt.h>
+
 #include <cmath>
 #include <filesystem>
 #include <fstream>
@@ -10,7 +12,6 @@
 #include "bsp_q7s/memory/SdCardManager.h"
 #endif
 
-#include "fsfw/globalfunctions/CRC.h"
 #include "fsfw/tasks/TaskFactory.h"
 #include "fsfw/timemanager/Countdown.h"
 #include "mission/utility/Filenaming.h"
@@ -509,32 +510,39 @@ ReturnValue_t PlocSupvHelper::calcImageCrc() {
 #ifdef XIPHOS_Q7S
   result = FilesystemHelper::checkPath(update.file);
 #endif
+  auto crc16Calcer = etl::crc16_ccitt();
   if (result != RETURN_OK) {
     sif::warning << "PlocSupvHelper::calcImageCrc: File " << update.file << " does not exist"
                  << std::endl;
     return result;
   }
   std::ifstream file(update.file, std::ifstream::binary);
-  uint16_t remainder = CRC16_INIT;
-  uint8_t input;
+  std::array<uint8_t, 1025> crcBuf;
 #if OBSW_DEBUG_PLOC_SUPERVISOR == 1
   ProgressPrinter progress("Supervisor update crc calculation", update.length,
                            ProgressPrinter::ONE_PERCENT);
 #endif /* OBSW_DEBUG_PLOC_SUPERVISOR == 1 */
   uint32_t byteCount = 0;
-  for (byteCount = 0; byteCount < update.length; byteCount++) {
+  while (byteCount < update.length) {
+    size_t bytesToRead = 1024;
+    size_t remLen = update.length - byteCount;
+    if (remLen < 1024) {
+      bytesToRead = remLen;
+    }
     file.seekg(byteCount, file.beg);
-    file.read(reinterpret_cast<char*>(&input), 1);
-    remainder = CRC::crc16ccitt(&input, sizeof(input), remainder);
+    file.read(reinterpret_cast<char*>(crcBuf.data()), bytesToRead);
+    crc16Calcer.add(crcBuf.begin(), crcBuf.begin() + bytesToRead);
+
 #if OBSW_DEBUG_PLOC_SUPERVISOR == 1
     progress.print(byteCount);
 #endif /* OBSW_DEBUG_PLOC_SUPERVISOR == 1 */
+    byteCount += bytesToRead;
   }
 #if OBSW_DEBUG_PLOC_SUPERVISOR == 1
   progress.print(byteCount);
 #endif /* OBSW_DEBUG_PLOC_SUPERVISOR == 1 */
   file.close();
-  update.crc = remainder;
+  update.crc = crc16Calcer.value();
   return result;
 }