TweinStein/RTOS_Labs_common/eFile.h

/**
 * @file      eFile.h
 * @brief     high-level file system
 * @details   This file system sits on top of eDisk.
 * @version   V1.0
 * @author    Valvano
 * @copyright Copyright 2026 by Jonathan W. Valvano, valvano@mail.utexas.edu,
 * @warning   AS-IS
 * @note      For more information see  http://users.ece.utexas.edu/~valvano/
 * @date      Dec 30, 2025
 ******************************************************************************/


/**
 * @details This function must be called first, before calling any of the other eFile functions
 * @param  none
 * @return 0 if successful and 1 on failure (already initialized)
 * @brief  Activate the file system, without formating
 */
int eFile_Init(void); // initialize file system

/**
 * @details Erase all files, create blank directory, initialize free space manager
 * @param  none
 * @return 0 if successful and 1 on failure (e.g., trouble writing to flash)
 * @brief  Format the disk
 */
int eFile_Format(void); // erase disk, add format

/**
 * @details Mount disk and load file system metadata information
 * @param  none
 * @return 0 if successful and 1 on failure (e.g., already mounted)
 * @brief  Mount the disk
 */
int eFile_Mount(void); // mount disk and file system

/**
 * @details Select working directory for file management
 * @param  dirID ID is 0 or 1, since there are two directories
 * @return 0 if successful and 1 on failure (e.g., already mounted)
 * @brief  Select working directory by ID
 */
int eFile_SelectDirectory(unsigned char dirID); // select directory

/**
 * @details Create a new, empty file with one allocated block
 * @param  name file name is an ASCII string up to seven characters
 * @return 0 if successful and 1 on failure (e.g., already exists)
 * @brief  Create a new file
 */
int eFile_Create(const char name[]);  // create new file, make it empty 

/**
 * @details Open the file for writing, read into RAM last block
 * @param  name file name is an ASCII string up to seven characters
 * @return 0 if successful and 1 on failure (e.g., trouble reading from flash)
 * @brief  Open an existing file for writing
 */
int eFile_WOpen(const char name[]);      // open a file for writing 

/**
 * @details Save one byte at end of the open file
 * @param  data byte to be saved on the disk
 * @return 0 if successful and 1 on failure (e.g., trouble writing to flash)
 * @brief  Write one byte 
 */
int eFile_Write(const char data);  

/**
 * @details Save string at end of the open file
 * @param pt pointer to string to be saved
 * @return 0 if successful and 1 on failure (e.g., trouble writing to flash)
 * @brief  Write string 
 */
 int eFile_WriteString(const char *pt);

//-----------------------eFile_WriteUDec-----------------------
// Write a 32-bit number in unsigned decimal format
// Input: 32-bit number to be transferred
// Output: none
// Variable format 1-10 digits with no space before or after
int eFile_WriteUDec(uint32_t n);

//-----------------------eFile_WriteSDec-----------------------
// Write a 32-bit number in signed decimal format
// Input: 32-bit number to be transferred
// Output: 0 if successful and 1 on failure (e.g., trouble writing to flash)
// Variable format 1-10 digits with space before and no space after
int eFile_WriteSDec(int32_t num);

//-----------------------eFile_WriteSFix2-----------------------
// Write a 32-bit number in signed decimal format
// format signed 16-bit with resolution 0.01
// range -327.67 to +327.67
// Input: signed 16-bit integer part of fixed point number
//         -32768 means invalid fixed-point number
// Output: 0 if successful and 1 on failure (e.g., trouble writing to flash)
// Examples
//  12345 to " 123.45"  
// -22100 to "-221.00"
//   -102 to "  -1.02" 
//     31 to "   0.31" 
// -32768 to " ***.**"  
int eFile_WriteSFix2(int32_t n);

//-----------------------eFile_WriteUFix2-----------------------
// Write a 32-bit number in signed fixed point format
// unsigned 32-bit with resolution 0.01
// range  0.00 to 999.99
// Input: unsigned 32-bit integer part of fixed point number
// Output: 0 if successful and 1 on failure (e.g., trouble writing to flash)
// Examples
//   72345 to " 723.45"  
//   22100 to " 221.00"
//     102 to "   1.02" 
//      31 to "   0.31" 
//  100000 to " ***.**"  
int eFile_WriteUFix2(uint32_t num);

/**
 * @details Close the file, leave disk in a state power can be removed.
 * This function will flush all RAM buffers to the disk.
 * @param  none
 * @return 0 if successful and 1 on failure (e.g., trouble writing to flash)
 * @brief  Close the file that was being written
 */
int eFile_WClose(void); // close the file for writing

/**
 * @details Open the file for reading, read first block into RAM
 * @param  name file name is an ASCII string up to seven characters
 * @return 0 if successful and 1 on failure (e.g., trouble reading from flash)
 * @brief  Open an existing file for reading
 */
int eFile_ROpen(const char name[]);      // open a file for reading 
   
/**
 * @details Read one byte from disk into RAM
 * @param  pt call by reference pointer to place to save data
 * @return 0 if successful and 1 on failure (e.g., trouble reading from flash)
 * @brief  Retreive data from open file
 */
int eFile_ReadNext(char *pt);       // get next byte 

/**
 * @details Read one 32-bit word from disk into RAM, little endian
 * @param  pt call by reference pointer to place to save data
 * @return 0 if successful and 1 on failure (e.g., trouble reading from flash)
 * @brief  Retreive data from open file
 */
uint32_t eFileReadNextWord(uint32_t *pt);       // get next word
                              
/**
 * @details Close the file, leave disk in a state power can be removed.
 * @param  none
 * @return 0 if successful and 1 on failure (e.g., wasn't open)
 * @brief  Close the file that was being read
 */
int eFile_RClose(void); // close the file for writing

/**
 * @details Delete the file with this name, recover blocks so they can be used by another file
 * @param  name file name is an ASCII string up to seven characters
 * @return 0 if successful and 1 on failure (e.g., file doesn't exist)
 * @brief  delete this file
 */
int eFile_Delete(const char name[]);  // remove this file 

/**
 * @details Open a (sub)directory, read into RAM
 * @param directory name is an ASCII string up to seven characters
 * if subdirectories are supported (optional, empty sring for root directory)
 * @return 0 if successful and 1 on failure (e.g., trouble reading from flash)
 */
int eFile_DOpen(const char name[]);
	
/**
 * @details Retreive directory entry from open directory
 * @param pointers to return file name and size by reference
 * @return 0 if successful and 1 on failure (e.g., end of directory)
 */
int eFile_DirNext(char *name[], unsigned long *size);

/**
 * @details Close the directory
 * @param none
 * @return 0 if successful and 1 on failure (e.g., wasn't open)
 */
int eFile_DClose(void);

/**
 * @details Unmount and deactivate the file system.
 * @param  none
 * @return 0 if successful and 1 on failure (e.g., trouble writing to flash)
 * @brief  Unmount the disk
 */
int eFile_Unmount(void);