Initial revision

src/libbio/bread.c

@@ -0,0 +1,45 @@
+#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;
+}