ugfx/src/gfile/inc_strings.c

70 lines
1.5 KiB
C

/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
/**
* This file is included by src/gfile/gfile.c
*/
/********************************************************
* The virtual string file VMT
********************************************************/
#include <string.h>
// Special String VMT
static int StringRead(GFILE *f, void *buf, int size) {
int res;
char *p;
p = ((char *)f->obj) + f->pos;
for(res = 0; res < size && *p; res++, p++, buf = ((char *)buf)+1)
((char *)buf)[0] = *p;
return res;
}
static int StringWrite(GFILE *f, const void *buf, int size) {
if ((f->flags & GFILEFLG_APPEND)) {
while(((char *)f->obj)[f->pos])
f->pos++;
}
memcpy(((char *)f->obj)+f->pos, buf, size);
((char *)f->obj)[f->pos+size] = 0;
return size;
}
static const GFILEVMT StringVMT = {
0, // next
0, // flags
'_', // prefix
0, 0, 0, 0,
0, 0, StringRead, StringWrite,
0, 0, 0,
0, 0, 0,
#if GFILE_NEED_FILELISTS
0, 0, 0,
#endif
};
static void gfileOpenStringFromStaticGFILE(GFILE *f, char *str) {
if ((f->flags & GFILEFLG_TRUNC))
str[0] = 0;
f->vmt = &StringVMT;
f->obj = str;
f->pos = 0;
f->flags |= GFILEFLG_OPEN|GFILEFLG_CANSEEK;
}
GFILE *gfileOpenString(char *str, const char *mode) {
GFILE *f;
// Get an empty file and set the flags
if (!(f = findemptyfile(mode)))
return 0;
// File is open - fill in all the details
gfileOpenStringFromStaticGFILE(f, str);
return f;
}