teensy-sdfat/examples/debug/TestMkdir/TestMkdir.ino

/*
 * This sketch is a test of subdirectory and file creation.
 * It also tests allocation of clusters to directories.
 *
 * It will create two subdirectories and create enough files 
 * to force the allocation of a cluster to each directory.
 *
 * More than 3000 files may be created on a FAT32 volume.
 *
 * Note: Some cards may 'stutter' others just get slow due 
 * to the number of flash erases this program causes.
 */
#include <SdFat.h>

const uint8_t SD_CHIP_SELECT = SS;

SdFat sd;
typedef File file_t;

// store error strings in flash to save RAM
#define error(s) sd.errorHalt(&Serial, F(s))

/*
 * create enough files to force a cluster to be allocated to dir.
 */
void dirAllocTest(file_t* dir) {
  char buf[32], name[32];
  file_t file;
  uint16_t n; 
  uint32_t size = dir->dirSize();
 
  // create files and write name to file
  for (n = 0; ; n++){
    // make file name
    sprintf(name, "%u.TXT", n);
   
    // open start time
    uint32_t t0 = millis();
    if (!file.open(dir, name, O_WRONLY | O_CREAT | O_EXCL)) {
      error("open for write failed");
    }
   
    // open end time and write start time
    uint32_t t1 = millis();
    // write file name to file
    file.print(name);
    if (!file.close()) error("close write");
   
    // write end time
    uint32_t t2 = millis();
    Serial.print(F("WR "));
    Serial.print(n);
    Serial.write(' ');
   
    // print time to create file
    Serial.print(t1 - t0);
    Serial.write(' ');
   
    // print time to write file
    Serial.println(t2 - t1);
   
    // directory size will change when a cluster is added
    if (dir->curPosition() > size) break;
  }

  // read files and check content
  for (uint16_t i = 0; i <= n; i++) {
    sprintf(name, "%u.TXT", i);
   
    // open start time
    uint32_t t0 = millis();
    if (!file.open(dir, name, O_RDONLY)) {
      error("open for read failed");
    }
    
    // open end time and read start time
    uint32_t t1 = millis();
    int16_t nr = file.read(buf, sizeof(buf));
    if (nr < 5) error("file.read failed");
    
    // read end time
    uint32_t t2 = millis();
    
    // check file content
    if (strlen(name) != (size_t)nr || strncmp(name, buf, nr)) {
      error("content compare failed");
    }
    if (!file.close()) error("close read failed");
    
    Serial.print(F("RD "));
    Serial.print(i);
    Serial.write(' ');
    
    // print open time
    Serial.print(t1 - t0);
    Serial.write(' ');
    
    // print read time
    Serial.println(t2 - t1);
  }
}

void setup() {
  file_t root;
  Serial.begin(9600);
  while (!Serial) {}  // wait for Leonardo
  Serial.println(F("Type any character to start"));
  while (Serial.read() <= 0) {}
  delay(200);  // Catch Due reset problem
  
  // initialize the SD card at SPI_FULL_SPEED for best performance.
  // try SPI_HALF_SPEED if bus errors occur.
  if (!sd.begin(SD_CHIP_SELECT, SPI_FULL_SPEED)) {
    sd.initErrorHalt(&Serial);
  }
  root.openRoot(&sd);    
  uint32_t m = millis();   
  // write files to root if not FAT16
  if (sd.fatType() != 16) {
    Serial.println(F("Writing files to root"));
    dirAllocTest(&root);
  }
  
  // create sub1 and write files
  file_t sub1;
  if (!sub1.mkdir(&root, "SUB1")) error("makdeDir SUB1 failed");
  Serial.println(F("Writing files to SUB1"));
  dirAllocTest(&sub1);

  // create sub2 and write files
  file_t sub2;
  if (!sub2.mkdir(&sub1, "SUB2")) error("mkdir SUB2 failed");
  Serial.println(F("Writing files to SUB2")); 
  dirAllocTest(&sub2);
  m = millis() - m;
  Serial.print(F("Done millis: "));
  Serial.println(m);
}

void loop() { }