trampoline/lib/bio/bread.c

46 lines
681 B
C

#include "lib9.h"
#include <bio.h>
long
Bread(Biobuf *bp, void *ap, long count)
{
long c;
unsigned char *p;
int i, n, ic;
p = ap;
c = count;
ic = bp->icount;
while(c > 0) {
n = -ic;
if(n > c)
n = c;
if(n == 0) {
if(bp->state != Bractive)
break;
i = read(bp->fid, bp->bbuf, bp->bsize);
if(i <= 0) {
bp->state = Bracteof;
if(i < 0)
bp->state = Binactive;
break;
}
bp->gbuf = bp->bbuf;
bp->offset += i;
if(i < bp->bsize) {
memmove(bp->ebuf-i, bp->bbuf, i);
bp->gbuf = bp->ebuf-i;
}
ic = -i;
continue;
}
memmove(p, bp->ebuf+ic, n);
c -= n;
ic += n;
p += n;
}
bp->icount = ic;
return count-c;
}