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#include "os.h"
static Biobufhdr* wbufs[20];
static int atexitflag;
static
void
batexit(void)
{
Biobufhdr *bp;
int i;
for(i=0; i<nelem(wbufs); i++) {
bp = wbufs[i];
if(bp != 0) {
wbufs[i] = 0;
Bflush(bp);
}
}
}
static
void
deinstall(Biobufhdr *bp)
{
int i;
for(i=0; i<nelem(wbufs); i++)
if(wbufs[i] == bp)
wbufs[i] = 0;
}
static
void
install(Biobufhdr *bp)
{
int i;
deinstall(bp);
for(i=0; i<nelem(wbufs); i++)
if(wbufs[i] == 0) {
wbufs[i] = bp;
break;
}
if(atexitflag == 0) {
atexitflag = 1;
atexit(batexit);
}
}
int
Binits(Biobufhdr *bp, int f, int mode, uchar *p, int size)
{
p += Bungetsize; /* make room for Bungets */
size -= Bungetsize;
switch(mode&3) {
default:
fprint(2, "Binits: unknown mode %d\n", mode);
return Beof;
case OREAD:
bp->state = Bractive;
bp->ocount = 0;
break;
case OWRITE:
install(bp);
bp->state = Bwactive;
bp->ocount = -size;
break;
}
bp->bbuf = p;
bp->ebuf = p+size;
bp->bsize = size;
bp->icount = 0;
bp->gbuf = bp->ebuf;
bp->fid = f;
bp->flag = 0;
bp->rdline = 0;
bp->offset = 0;
bp->runesize = 0;
return 0;
}
int
Binit(Biobuf *bp, int f, int mode)
{
return Binits(bp, f, mode, bp->b, sizeof(bp->b));
}
Biobuf*
Bopen(char *name, int mode)
{
Biobuf *bp;
int f;
switch(mode&3) {
default:
fprint(2, "Bopen: unknown mode %d\n", mode);
return 0;
case OREAD:
f = open(name, OREAD);
if(f < 0)
return 0;
break;
case OWRITE:
f = open(name, O_CREAT|O_TRUNC|OWRITE, 0666);
if(f < 0)
return 0;
}
bp = malloc(sizeof(Biobuf));
Binits(bp, f, mode, bp->b, sizeof(bp->b));
bp->flag = Bmagic;
return bp;
}
int
Bterm(Biobufhdr *bp)
{
deinstall(bp);
Bflush(bp);
if(bp->flag == Bmagic) {
bp->flag = 0;
close(bp->fid);
free(bp);
}
return 0;
}
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