tinyfsTest.c

/* TinyFS demo file
 *  * Foaad Khosmood, Cal Poly / modified Winter 2014
 *   */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libTinyFS.h"
#include "tinyFS.h"
#include "TinyFS_errno.h"

/* simple helper function to fill Buffer with as many inPhrase strings as possible before reaching size */
int
fillBufferWithPhrase (char *inPhrase, char *Buffer, int size)
{
  int index = 0, i;
  if (!inPhrase || !Buffer || size <= 0 || size < strlen (inPhrase))
    return -1;

  while (index < size)
    {
      for (i = 0; inPhrase[i] != '\0' && (i + index < size); i++)
	Buffer[i + index] = inPhrase[i];
      index += i;
    }
  Buffer[size - 1] = '\0';	/* explicit null termination */
  return 0;
}

/* This program will create 2 files (of sizes 200 and 1000) to be read from or stored in the TinyFS file system. */
int
main ()
{
  char readBuffer;
  char *afileContent, *bfileContent;	/* buffers to store file content */
  int afileSize = 200;		/* sizes in bytes */
  int bfileSize = 1000;

  char phrase1[] = "hello world from (a) file ";
  char phrase2[] = "(b) file content ";

  fileDescriptor aFD, bFD;
  int i, returnValue;
/* try to mount the disk */
  if (tfs_mount(DEFAULT_DISK_NAME) < 0)	/* if mount fails */
    {
      tfs_mkfs(DEFAULT_DISK_NAME, DEFAULT_DISK_SIZE);	/* then make a new disk */
      if (tfs_mount(DEFAULT_DISK_NAME) < 0)	/* if we still can't open it... */
	{
	  perror ("failed to open disk");	/* then just exit */
	  return;
	}
    }else
      printf("mounted\n");

  afileContent = (char *) malloc (afileSize * sizeof (char));
  if (fillBufferWithPhrase (phrase1, afileContent, afileSize) < 0)
    {
      perror ("failed");
      return;
    }

  bfileContent = (char *) malloc (bfileSize * sizeof (char));
  if (fillBufferWithPhrase (phrase2, bfileContent, bfileSize) < 0)
    {
      perror ("failed");
      return;
    }

/* print content of files for debugging */
  printf
    ("(a) File content: %s\n(b) File content: %s\nReady to store in TinyFS\n",
     afileContent, bfileContent);

/* read or write files to TinyFS */

  printf("start\n");
  aFD = tfs_openFile ("afile");
  if (aFD < 0)
    {
      perror ("tfs_openFile failed on afile");
    }

/* now, was there already a file named "afile" that had some content? If we can read from it, yes!
 *  * If we can't read from it, it presumably means the file was empty.
 *   * If the size is 0 (all new files are sized 0) then any "readByte()" should fail, so 
 *    * it's a new file and empty */
  if (tfs_readByte (aFD, &readBuffer) < 0)
    {
      /* if readByte() fails, there was no afile, so we write to it */
     
      if (tfs_writeFile (aFD, afileContent, afileSize) < 0)
	{
	  perror ("tfs_writeFile failed");
	}
      else
	printf ("Successfully written to afile\n");

      
    }
  else
    { int temp;
      /* if yes, then just read and print the rest of afile that was already there */
      printf ("\n*** reading afile from TinyFS: \n%c", readBuffer);	/* print the first byte already read */
      /* now print the rest of it, byte by byte */
      while (temp = tfs_readByte (aFD, &readBuffer) >= 0){	/* go until readByte fails */
         printf ("%c", readBuffer);
      }
      //printf("failed on: %d\n",temp);
      /* close file */
      if (tfs_closeFile (aFD) < 0)
	perror ("tfs_closeFile failed");

      /* now try to delete the file. It should fail because aFD is no longer valid */
      if (tfs_deleteFile (aFD) < 0)
	{
	  aFD = tfs_openFile ("afile");	/* so we open it again */
	  if (tfs_deleteFile (aFD) < 0)
	    perror ("tfs_deleteFile failed");

	}
      else
	perror ("tfs_closeFile should have failed");

    }

/* now bfile tests */
  bFD = tfs_openFile ("bfile");
  if (bFD < 0)
    {
      perror ("tfs_openFile failed on bfile");
    }else

  if (tfs_readByte (bFD, &readBuffer) < 0)
    {
      if (tfs_writeFile (bFD, bfileContent, bfileSize) < 0)
	{
	  perror ("tfs_writeFile failed");
	}
      else
	printf ("Successfully written to bfile\n");
    }
  else
    {
      printf ("\n*** reading bfile from TinyFS: \n%c", readBuffer);
      while (tfs_readByte (bFD, &readBuffer) >= 0)
	printf ("%c", readBuffer);
      tfs_deleteFile (bFD);

    }

/* Free both content buffers */
  free (bfileContent);
  free (afileContent);
  if (tfs_unmount () < 0)
    perror ("tfs_unmount failed");

  printf ("\nend of demo\n\n");
  return 0;
}