zfscfileapi.c

zilog的实时操作系统RZK,可以移植到多种处理器上

/*
 * File       : ZFSCFileApi.c
 * Description: This file contains the "C" file API implementation
 * Author     : Mahadev K C
 * Created on : 25-APR-2003
 *
 * Copyright 2004 ZiLOG Inc.  ALL RIGHTS RESERVED.
 *
 * This file contains unpublished confidential and proprietary information
 * of ZiLOG, Inc.
 * NO PART OF THIS WORK MAY BE DUPLICATED, STORED, PUBLISHED OR DISCLOSED 
 * IN ANY FORM WITHOUT THE PRIOR WRITTEN CONSENT OF ZiLOG, INC.
 * This is not a license and no use of any kind of this work is authorized
 * in the absence of a written license granted by ZiLOG, Inc. in ZiLOG's 
 * sole discretion 
 */

#ifdef FS_DEBUG
#include <stdio.h>
#endif

#include "zfsdef.h"
#include "cfileapi.h"
#include "zfsapi.h"
#include "zfstruct.h"

#define SIZE_T_DEFINED
#include <string.h>

// Function Name: fopen
// Description: This function will open a file for reading/writing. Returns the handle on success or NULL on failure
FILE *fopen( const INT8 *filename, const INT8 *mode )
{
	ZFS_HANDLE_t 	handle ;
	ZFS_STATUS_t	status ;
	UINT8 			new_mode ;
	UINT8			new_attr = ZFS_MODE_ASCII ;
	UINT 			len ;

#ifdef FS_DEBUG
	printf(" fopen start") ;
#endif
	len = strlen( mode ) ;

	if( len == 0 || len > 3 )
		{
#ifdef FS_DEBUG
	printf(" fopen end") ;
#endif
		return NULL ;
		}
	
	// validate the input values.
	if( *mode == 'r' )
		{
		new_mode = ZFS_READ ;
		}
	else if( *mode == 'w' )
		{
		new_mode = ZFS_WRITE ;
		}
	else if( *mode == 'a' )
		{
		new_mode = ZFS_APPEND ;
		}
	else
		{
#ifdef FS_DEBUG
	printf(" fopen end") ;
#endif
		return NULL ;
		}
	if( len > 1 )
		{
		mode ++ ;
		if( *mode == 'b' )
			{
			new_attr = ZFS_MODE_BINARY ;
			}
		else if( *mode == '+' && new_mode == ZFS_READ )
			{
			new_mode = ZFS_READ_WRITE ;
			}
		else
			{
#ifdef FS_DEBUG
	printf(" fopen end") ;
#endif
			return NULL ;
			}
		}

	if( len > 2 )
		{
		mode++;
		if( *mode == 'b' && new_mode == ZFS_READ_WRITE )
			new_attr = ZFS_MODE_BINARY ;
		else
			{
#ifdef FS_DEBUG
	printf(" fopen end") ;
#endif
			return NULL ;
			}
		}
			

	handle = ZFSOpen( (INT8 *)filename, new_mode, new_attr ) ;

	if( new_mode == ZFS_APPEND && handle == NULL  )
		{
		// this implements the functionality of "a" of WINDOWS
		//Opens for writing at the end of the file (appending) without removing the EOF marker before writing new data to the file; creates the file first if it doesn抰 exist.
		// check if ZFSOpen returns any error that indicates a file does not exist
		// so create one file.
		handle = ZFSOpen(  (INT8 *)filename, ZFS_WRITE, new_attr ) ;
		if( handle )
			{
			status = ZFSClose( handle ) ;
			if( status == ZFSERR_SUCCESS )
				{
				handle = ZFSOpen(  (INT8 *)filename, ZFS_APPEND, new_attr ) ;
				}
			else
				handle = NULL ;
			}
		}
			
#ifdef FS_DEBUG
	printf(" fopen end") ;
#endif
	return handle;
}

// Function Name: fclose
// Description: This function will close an opened file
INT fclose( FILE *stream )
{
#ifdef FS_DEBUG
	printf(" fclose start") ;
#endif
	if( ZFSClose( stream ) == ZFSERR_SUCCESS )
		{
#ifdef FS_DEBUG
	printf(" fclose end") ;
#endif
		return 0 ;
		}
	else
		{
#ifdef FS_DEBUG
	printf(" fclose end") ;
#endif
		return -1 ;
		}
}

// Function Name: fputc
// Description: This function will write a character to the opened file.
INT fputc( INT c, FILE *stream )
{
	UINT8 cdata = ( UINT8 ) c ;
	INT32 bytes_written ;

#ifdef FS_DEBUG
	printf(" fputc start") ;
#endif
	bytes_written = ZFSWrite( stream, &cdata, 1 ) ;

	if( bytes_written == 0 )
		{
#ifdef FS_DEBUG
	printf(" fputc end") ;
#endif
		return -1 ;
		}
	else
		{
#ifdef FS_DEBUG
	printf(" fputc end") ;
#endif
		return c ;
		}
}

// Function Name: fputs
// Description: This function will store the given string to the opened file
INT fputs( const INT8 *string, FILE *stream )
{
	UINT len = strlen( string ) ;
	INT32 bytes_written ;

#ifdef FS_DEBUG
	printf(" fputs start") ;
#endif
	bytes_written = ZFSWrite( stream, ( UINT8 *) string, len ) ;

#ifdef FS_DEBUG
	printf(" fputs end") ;
#endif
	if( bytes_written > 0 )
		return bytes_written ;
	else
		return -1 ;
//	return (int) bytes_written ;
}

// Function Name: fgetc
// Description: This function will get a character from opened file
INT fgetc( FILE *stream )
{
	UINT8 cdata ;
	INT32 bytes_read ;

#ifdef FS_DEBUG
	printf(" fgetc start") ;
#endif
	bytes_read = ZFSRead( stream, &cdata, 1 ) ;


	if( bytes_read == ZFSERR_INVALID_OPERATION) 
		{
#ifdef FS_DEBUG
	printf(" fgetc end") ;
#endif
		return -1 ;
		}
	else
		{
#ifdef FS_DEBUG
	printf(" fgetc end") ;
#endif
		return cdata ;
		}
}

// Function Name: fgets
// Description: This function will get the string from the opened file
INT8 *fgets( INT8 *string, INT n, FILE *stream )
{
//	UINT8 cdata ;
	INT32 bytes_read ;
	INT8 *ptr = string ;

#ifdef FS_DEBUG
	printf(" fgets start") ;
#endif
	bytes_read = ZFSRead( stream, ( UINT8*) string, n) ;

	if( bytes_read == 0 )
		{
#ifdef FS_DEBUG
	printf(" fgets end") ;
#endif
		return ( INT8 * ) NULL ;
		}
	else
		{
		while( n >= 0 )
			{
			//if( *ptr == '\n' || *ptr == '\r' )
			    if(*ptr == EOF)
				{
				*ptr = 0x00 ;
				break ;
				}
			n-- ;
			ptr++ ;
			}
#ifdef FS_DEBUG
	printf(" fgets end") ;
#endif

		return string ;
		}
}

// Function Name: fread
// Description: This function will get the required number of items from the file
size_t fread( void *buffer, size_t size, size_t count, FILE *stream )
{
	INT32 bytes_read ;
    size_t new_cnt ;
	UINT32 bytes_to_read = size * count ;

#ifdef FS_DEBUG
	printf(" fread start") ;
#endif
	bytes_read = ZFSRead( stream, ( UINT8 * ) buffer, bytes_to_read ) ;

	new_cnt = bytes_read / size ;
#ifdef FS_DEBUG
	printf(" fread end") ;
#endif

	return new_cnt ;
}

// Function Name: fwrite
// Description: This function will write the required number of items into the file
size_t fwrite( const void *buffer, size_t size, size_t count, FILE *stream )
{
	INT32 bytes_written ; 
	UINT32 bytes_to_write = size * count ;
    size_t new_cnt ;

#ifdef FS_DEBUG
	printf(" fwrite start") ;
#endif
	bytes_written = ZFSWrite( stream,  (UINT8 *)buffer, bytes_to_write ) ;

	new_cnt = bytes_written / size ;

#ifdef FS_DEBUG
	printf(" fwrite end") ;
#endif

	return  new_cnt ;
}

// Function Name: fseek
// Description: This function will move the file pointer appropriately
INT fseek( FILE *stream, INT32 offset, INT origin )
{
	ZFS_STATUS_t status ;
#ifdef FS_DEBUG
	printf(" fseek start") ;
#endif
	status = ZFSSeek( stream, offset, origin) ;
#ifdef FS_DEBUG
	printf(" fseek end") ;
#endif
	return (INT) status ;

}

// Function Name: ftell
// Description: This function will return the file pointer position
INT32 ftell( FILE *stream )
{
#ifdef FS_DEBUG
	printf(" ftell start") ;
#endif
	// just validate the stream handle
	if( ( ( PZFS_OPEN_REC_t ) stream)->status != ZFS_OR_MAGIC_NUM )
		{
#ifdef FS_DEBUG
	printf(" ftell end") ;
#endif
		return -1 ;
		}
#ifdef FS_DEBUG
	printf(" ftell end") ;
#endif

	return ( INT32 ) ( ( PZFS_OPEN_REC_t ) stream)->offset ;
}
		
// Function Name: feof
// Description: This function will check whether it is end of file or not
INT feof( FILE *stream )
{
#ifdef FS_DEBUG
	printf(" feof start") ;
#endif
	if( ( ( PZFS_OPEN_REC_t) stream)->offset == ( ( PZFS_OPEN_REC_t) stream)->size )
		{
#ifdef FS_DEBUG
	printf(" feof end") ;
#endif
		return -1 ;
		}
	else
		{
#ifdef FS_DEBUG
	printf(" feof end") ;
#endif
		return 0 ;
		}
}