1 b2cfc4e2 2003-09-30 devnull #include	"lib9.h"
 2 b2cfc4e2 2003-09-30 devnull #include	<bio.h>
 3 b2cfc4e2 2003-09-30 devnull 
 4 b2cfc4e2 2003-09-30 devnull int
 5 b2cfc4e2 2003-09-30 devnull Bgetc(Biobuf *bp)
 6 b2cfc4e2 2003-09-30 devnull {
 7 b2cfc4e2 2003-09-30 devnull 	int i;
 8 b2cfc4e2 2003-09-30 devnull 
 9 b2cfc4e2 2003-09-30 devnull loop:
10 b2cfc4e2 2003-09-30 devnull 	i = bp->icount;
11 b2cfc4e2 2003-09-30 devnull 	if(i != 0) {
12 b2cfc4e2 2003-09-30 devnull 		bp->icount = i+1;
13 b2cfc4e2 2003-09-30 devnull 		return bp->ebuf[i];
14 b2cfc4e2 2003-09-30 devnull 	}
15 b2cfc4e2 2003-09-30 devnull 	if(bp->state != Bractive) {
16 b2cfc4e2 2003-09-30 devnull 		if(bp->state == Bracteof)
17 b2cfc4e2 2003-09-30 devnull 			bp->state = Bractive;
18 b2cfc4e2 2003-09-30 devnull 		return Beof;
19 b2cfc4e2 2003-09-30 devnull 	}
20 b2cfc4e2 2003-09-30 devnull 	/*
21 b2cfc4e2 2003-09-30 devnull 	 * get next buffer, try to keep Bungetsize
22 b2cfc4e2 2003-09-30 devnull 	 * characters pre-catenated from the previous
23 b2cfc4e2 2003-09-30 devnull 	 * buffer to allow that many ungets.
24 b2cfc4e2 2003-09-30 devnull 	 */
25 b2cfc4e2 2003-09-30 devnull 	memmove(bp->bbuf-Bungetsize, bp->ebuf-Bungetsize, Bungetsize);
26 b2cfc4e2 2003-09-30 devnull 	i = read(bp->fid, bp->bbuf, bp->bsize);
27 b2cfc4e2 2003-09-30 devnull 	bp->gbuf = bp->bbuf;
28 b2cfc4e2 2003-09-30 devnull 	if(i <= 0) {
29 b2cfc4e2 2003-09-30 devnull 		if(i < 0)
30 b2cfc4e2 2003-09-30 devnull 			bp->state = Binactive;
31 b2cfc4e2 2003-09-30 devnull 		return Beof;
32 b2cfc4e2 2003-09-30 devnull 	}
33 b2cfc4e2 2003-09-30 devnull 	if(i < bp->bsize) {
34 b2cfc4e2 2003-09-30 devnull 		memmove(bp->ebuf-i-Bungetsize, bp->bbuf-Bungetsize, i+Bungetsize);
35 b2cfc4e2 2003-09-30 devnull 		bp->gbuf = bp->ebuf-i;
36 b2cfc4e2 2003-09-30 devnull 	}
37 b2cfc4e2 2003-09-30 devnull 	bp->icount = -i;
38 b2cfc4e2 2003-09-30 devnull 	bp->offset += i;
39 b2cfc4e2 2003-09-30 devnull 	goto loop;
40 b2cfc4e2 2003-09-30 devnull }
41 b2cfc4e2 2003-09-30 devnull 
42 b2cfc4e2 2003-09-30 devnull int
43 b2cfc4e2 2003-09-30 devnull Bungetc(Biobuf *bp)
44 b2cfc4e2 2003-09-30 devnull {
45 b2cfc4e2 2003-09-30 devnull 
46 b2cfc4e2 2003-09-30 devnull 	if(bp->state == Bracteof)
47 b2cfc4e2 2003-09-30 devnull 		bp->state = Bractive;
48 b2cfc4e2 2003-09-30 devnull 	if(bp->state != Bractive)
49 b2cfc4e2 2003-09-30 devnull 		return Beof;
50 b2cfc4e2 2003-09-30 devnull 	bp->icount--;
51 b2cfc4e2 2003-09-30 devnull 	return 1;
52 b2cfc4e2 2003-09-30 devnull }