?? kfs.c
字號(hào):
/*
filename : kfs.c
version : 1.0.1 release
author : eagle
web : www.embseek.com
*/
#include "kfs.h"
#include "kfsdev.h"
#include "str.h"
/*Data=========================================*/
/*file systen start address*/
u8 * fs_start_add;
/*file system length*/
u16 fs_len;
/*current head in the file system*/
u8 * fs_head_add;
/*table of the file head informations*/
struct fhead fheadtable[MAX_FILE_NUM];
/*totle file number in the file system*/
u16 f_num;
/*Operations===================================*/
/****************************************
function : r_fsinit
_fs_start_add : file systen start address
_fs_end_add : file system end address
description : init the file system
****************************************/
void r_fsinit(u8 *_fs_start_add,u8 *_fs_end_add){
u8 * pf;
u16 i;
u8 state;//是否被格式化的標(biāo)記，文件系統(tǒng)第一個(gè)字節(jié)
fs_start_add=_fs_start_add+sizeof(u8)+sizeof(u8 *);
fs_len=_fs_end_add-fs_start_add+1;
f_num=0;
kfsdev_read(_fs_start_add,&state,sizeof(u8));
if(state==0x55){//file system has formated
kfsdev_read(_fs_start_add+sizeof(u8),(u8 *)&(fs_head_add),sizeof(u8 *));
pf=fs_head_add;
for(i=0;i<MAX_FILE_NUM;i++){
kfsdev_read(pf,(u8 *)&(fheadtable[i]._status),sizeof(u16));
if(!fheadtable[i]._status&FHS_FSEND){
kfsdev_read(pf+sizeof(u16),(u8 *)&(fheadtable[i]._size),sizeof(u16));
kfsdev_read(pf+sizeof(u16)*2,fheadtable[i].filename,MAX_FLIE_NAME_LEN);
fheadtable[i]._f_sadd=pf+sizeof(struct fshead);
pf+=sizeof(struct fshead)+fheadtable[i]._size;
f_num++;
}
}
}
else{
fs_head_add=fs_start_add;
kfsdev_write(_fs_start_add+sizeof(u8),(u8 *)&(fs_head_add),sizeof(u8 *));
state=0x55;
kfsdev_write(_fs_start_add,&state,sizeof(u8));
}
}
/****************************************
function : r_fopen
filename : file name less than 12byte
mode : Type of access permitted.
return : point to the opened file
description : open a file
****************************************/
r_FILE * r_fopen(u8 * filename, const u8 mode){
u8 i;
if(es_strlen(filename)>MAX_FLIE_NAME_LEN){
return NULL;
}
for(i=0;i<f_num;i++){
if(es_strcmp(filename,fheadtable[i].filename))/*if file exist*/
{
if(!(fheadtable[i]._status&FHS_DELETED)&&!(fheadtable[i]._status&FHS_OPENED))
{
fheadtable[i]._p=fheadtable[i]._f_sadd;
return &fheadtable[i];
}
}
}
/*file not exist , create a file*/
if(mode&O_CREAT){
if(f_num<MAX_FILE_NUM){
fheadtable[f_num]._status=FHS_FSEND;
es_strcpy(filename,fheadtable[f_num].filename,MAX_FLIE_NAME_LEN);
fheadtable[f_num]._status|=FHS_NAMEMODIFIED;
fheadtable[f_num]._status|=FHS_STATUEMODIFIED;
if(f_num>=1){
fheadtable[f_num]._f_sadd=fheadtable[f_num-1]._f_sadd+fheadtable[f_num-1]._size+sizeof(struct fshead);
}else{
fheadtable[f_num]._f_sadd=fs_head_add+sizeof(struct fshead);
}
fheadtable[f_num]._p=fheadtable[f_num]._f_sadd;
fheadtable[f_num]._status|=FHS_OPENED;
fheadtable[f_num]._size=0;
fheadtable[f_num]._status|=FHS_SIZEMODIFIED;
f_num++;
return &fheadtable[f_num-1];
}
}
return NULL;
}
/****************************************
function : r_fdelete
fp : point to the FILE structure
return : if file was deleted return 1,else return 0;
description : delete a file ,please make sure that there are not any other file opened
****************************************/
void r_fdelete(r_FILE * *_fp){
u8 i,j;
r_FILE * fp,* fpt;
fp=*_fp;
if(fp==&fheadtable[0]){//file is the first file in the file system
fp->_status=FHS_DELETED|FHS_STATUEMODIFIED;
r_fsavehead(fp);
r_frmhead(fp);
fs_head_add=fheadtable[0]._f_sadd-sizeof(struct fshead);
kfsdev_write(fs_start_add-sizeof(u8*),(u8 *)&(fs_head_add),sizeof(u8 *));
}else if(fp->_status&FHS_FSEND){ //file is in the end of the file system
fp->_status=FHS_DELETED|FHS_STATUEMODIFIED|FHS_FSEND;
r_fsavehead(fp);
}else{ //file is not in the end of the file system
j=0;
fp->_status=FHS_DELETED|FHS_STATUEMODIFIED;
for(i=0;i<f_num;i++){
if(!(fheadtable[i]._status&FHS_DELETED)){
j++;
}
if(fp==&fheadtable[i]){
if(j>0){//file is in the middle of the file system
//徹底刪除文件，移動(dòng)后面的文件
//請(qǐng)確保當(dāng)前文件之后的文件未被打開
f_num--;
for(j=i;j<f_num;j++){
fpt=&fheadtable[j+1];
fp->_size=fpt->_size;
es_strcpy(fpt->filename,fp->filename,MAX_FLIE_NAME_LEN);
fp->_status=fpt->_status;
fp->_status|=FHS_SIZEMODIFIED|FHS_STATUEMODIFIED|FHS_NAMEMODIFIED;
r_rewind(fp);
r_rewind(fpt);
for(i=0;i<fp->_size;i++){
r_fputc(fp,r_fgetc(fpt));
}
r_fsavehead(fp);
fpt->_f_sadd=fp->_f_sadd+fp->_size+sizeof(struct fshead);
fp=fpt;
}
*_fp=NULL;
}
else{
r_fsavehead(fp);
return;
}
}
}
}
}
/****************************************
function : r_rewind
fp : point to the FILE structure
description : rewind a file to head
****************************************/
void r_rewind(r_FILE *fp){
fp->_p=fp->_f_sadd;
}
//從fp指向的用戶操作文件中取出當(dāng)前文件指針指向的數(shù)據(jù)（u8類型），并將文件指針的當(dāng)前文件指針地址加1；
/****************************************
function : r_fgetc
fp : point to the FILE structure
return : the character read from the file
description : get a character from the file
****************************************/
u8 r_fgetc(r_FILE * fp){
u8 ret=0;
if(r_feof(fp)){
return ret;
}else{
if(fp->_p>fs_start_add+fs_len-1){
kfsdev_read(fp->_p-fs_len,&ret,1);
}else{
kfsdev_read(fp->_p,&ret,1);
}
fp->_p++;
}
return ret;
}
//向fp指向的用戶操作文件中文件指針指向的數(shù)據(jù)（u8類型）地址寫入一個(gè)字符，并將文件指針的當(dāng)前文件指針地址加1；
/****************************************
function : r_fputc
fp : point to the FILE structure
ch : character to put to file
return : if success return 1,else return 0
description : put a character to file
****************************************/
u8 r_fputc(r_FILE * fp ,u8 ch){
u8 ret=0;
if(fp->_p-(fs_len)>=fs_head_add){
/*超出文件系統(tǒng)長度*/
return 0;
}
if(r_feof(fp)){
if(fp->_status&FHS_FSEND){
fp->_size+=0x01;
if(fp->_p>fs_start_add+fs_len-1){
kfsdev_write(fp->_p-fs_len,&ch,1);
}else{
kfsdev_write(fp->_p,&ch,1);
}
fp->_p+=1;
ret=1;
fp->_status|=FHS_SIZEMODIFIED;
}
}else{
if(fp->_p>fs_start_add+fs_len-1){
kfsdev_write(fp->_p-fs_len,&ch,1);
}else{
kfsdev_write(fp->_p,&ch,1);
}
fp->_p+=1;
ret=1;
}
return ret;
}
//判斷是否到達(dá)文件末尾；是則返回1
/****************************************
function : r_feof
fp : point to the FILE structure
return : if end return 1,else return 0
description : check if got the end of file
****************************************/
u8 r_feof(r_FILE * fp){
u8 ret=0;
if(fp->_p==fp->_f_sadd+fp->_size)
ret=1;
return ret;
}
//關(guān)閉fp指向的文件
/****************************************
function : r_fclose
fp : point to the FILE structure
description : close the file
****************************************/
void r_fclose(r_FILE * * fp){
if(*fp==NULL)
return;
(*fp)->_status&=~FHS_OPENED;
r_rewind(*fp);
if((*fp)->_size==0){
r_frmhead(*fp);
}else{
r_fsavehead(*fp);
}
*fp=NULL;
}
/****************************************
function : r_frmhead
fp : point to the FILE structure
description : remove the file head from
the head table
****************************************/
void r_frmhead(r_FILE * fp){
u8 i,j;
for(i=0;i<f_num;i++){
if(fp==&fheadtable[i]){
for(j=i;j<f_num-1;j++){
fheadtable[j]._status=fheadtable[j+1]._status;
fheadtable[j]._size=fheadtable[j+1]._size;
fheadtable[j]._f_sadd=fheadtable[j+1]._f_sadd;
fheadtable[j]._p=fheadtable[j+1]._p;
es_strcpy(fheadtable[j+1].filename,fheadtable[j].filename,MAX_FLIE_NAME_LEN);
}
f_num-=1;
return;
}
}
}
/****************************************
function : r_fsavehead
fp : point to the FILE structure
description : save the file head
****************************************/
void r_fsavehead(r_FILE * fp){
if(fp==NULL)
return;
if(fp->_status&FHS_SIZEMODIFIED){
fp->_status&=~FHS_SIZEMODIFIED;
kfsdev_write(fp->_f_sadd-sizeof(struct fshead)+sizeof(u16),(u8 *)&(fp->_size),sizeof(u16));
}
if(fp->_status&FHS_NAMEMODIFIED){
fp->_status&=~FHS_NAMEMODIFIED;
kfsdev_write(fp->_f_sadd-sizeof(struct fshead)+sizeof(u16)*2,fp->filename,MAX_FLIE_NAME_LEN);
}
if(fp->_status&FHS_STATUEMODIFIED){
fp->_status&=~FHS_STATUEMODIFIED;
kfsdev_write(fp->_f_sadd-sizeof(struct fshead),(u8 *)&(fp->_status),sizeof(u16));
}
if(fp->_status&FHS_FSEND&&f_num>=2){
if(fheadtable[f_num-2]._status&FHS_FSEND){
fheadtable[f_num-2]._status&=!FHS_FSEND;
kfsdev_write(fheadtable[f_num-2]._f_sadd-sizeof(struct fshead),(u8 *)&(fheadtable[f_num-2]._status),sizeof(u16));
}
}
}
/****************************************
function : r_format
_fs_start_add : file systen start address
_fs_end_add : file system end address
description : format the file system
****************************************/
void r_format(u8 *_fs_start_add,u8 *_fs_end_add){
u8 state;//是否被格式化的標(biāo)記，文件系統(tǒng)第一個(gè)字節(jié)
fs_start_add=_fs_start_add+sizeof(u8)+sizeof(u8 *);
fs_len=_fs_end_add-fs_start_add+1;
f_num=0;
fs_head_add=fs_start_add;
kfsdev_write(_fs_start_add+sizeof(u8),(u8 *)&(fs_head_add),sizeof(u8 *));
state=0x55;
kfsdev_write(_fs_start_add,&state,sizeof(u8));
}
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