ESPFlash: Open a file with a filename of “/floatArrayExample” and get the last 5 float elements stored in the file with error checking.

ESPFlash_example4.cpp

/*
Open a file with a filename of “/floatArrayExample” and get the last 5
float elements stored in the file with error checking.
*/
float testGet[5];
ESPFlash<float> floatExample("/floatArrayExample");
bool success = floatExample.getBackElements(testGet, sizeof(testGet));

/* The above code replaces the following SPIFFS implementation */
float testGet[5];
File file;
uint32_t fileSizeInBytes = 0;
uint32_t fileSizeInElements = 0;
uint32_t firstElementIndex = 0;
uint32_t bytesRead = 0;
uint32_t getArraySizeInElements = sizeof(testGet);
uint32_t getArraySizeInBytes = sizeof(float)*sizeof(testGet);
bool success = false;
SPIFFS.begin();  
file = SPIFFS.open("/floatArrayExample", "r");
if(file)
{
  fileSizeInBytes = file.size();
  fileSizeInElements = fileSizeInBytes/sizeof(float);
  if(getArraySizeInElements <= fileSizeInElements)
  {
    firstElementIndex = fileSizeInBytes  - getArraySizeInBytes;
    file.seek(firstElementIndex, SeekSet);
    bytesRead = file.read((uint8_t*)testGet, getArraySizeInBytes);
    file.close();
    if(bytesRead == getArraySizeInBytes)
    {
      success = true;
    }
  }
}
file.close();