Initial revision

src/libbio/brdstr.c

@@ -0,0 +1,112 @@
+#include	"lib9.h"
+#include	<bio.h>
+
+static char*
+badd(char *p, int *np, char *data, int ndata, int delim, int nulldelim)
+{
+	int n;
+
+	n = *np;
+	p = realloc(p, n+ndata+1);
+	if(p){
+		memmove(p+n, data, ndata);
+		n += ndata;
+		if(n>0 && nulldelim && p[n-1]==delim)
+			p[--n] = '\0';
+		else
+			p[n] = '\0';
+		*np = n;
+	}
+	return p;
+}
+
+char*
+Brdstr(Biobuf *bp, int delim, int nulldelim)
+{
+	char *ip, *ep, *p;
+	int i, j;
+
+	i = -bp->icount;
+	bp->rdline = 0;
+	if(i == 0) {
+		/*
+		 * eof or other error
+		 */
+		if(bp->state != Bractive) {
+			if(bp->state == Bracteof)
+				bp->state = Bractive;
+			bp->gbuf = bp->ebuf;
+			return nil;
+		}
+	}
+
+	/*
+	 * first try in remainder of buffer (gbuf doesn't change)
+	 */
+	ip = (char*)bp->ebuf - i;
+	ep = memchr(ip, delim, i);
+	if(ep) {
+		j = (ep - ip) + 1;
+		bp->icount += j;
+		return badd(nil, &bp->rdline, ip, j, delim, nulldelim);
+	}
+
+	/*
+	 * copy data to beginning of buffer
+	 */
+	if(i < bp->bsize)
+		memmove(bp->bbuf, ip, i);
+	bp->gbuf = bp->bbuf;
+
+	/*
+	 * append to buffer looking for the delim
+	 */
+	p = nil;
+	for(;;){
+		ip = (char*)bp->bbuf + i;
+		while(i < bp->bsize) {
+			j = read(bp->fid, ip, bp->bsize-i);
+			if(j <= 0 && i == 0)
+				return p;
+			if(j <= 0 && i > 0){
+				/*
+				 * end of file but no delim. pretend we got a delim
+				 * by making the delim \0 and smashing it with nulldelim.
+				 */
+				j = 1;
+				ep = ip;
+				delim = '\0';
+				nulldelim = 1;
+				*ep = delim;	/* there will be room for this */
+			}else{
+				bp->offset += j;
+				ep = memchr(ip, delim, j);
+			}
+			i += j;
+			if(ep) {
+				/*
+				 * found in new piece
+				 * copy back up and reset everything
+				 */
+				ip = (char*)bp->ebuf - i;
+				if(i < bp->bsize){
+					memmove(ip, bp->bbuf, i);
+					bp->gbuf = (unsigned char*)ip;
+				}
+				j = (ep - (char*)bp->bbuf) + 1;
+				bp->icount = j - i;
+				return badd(p, &bp->rdline, ip, j, delim, nulldelim);
+			}
+			ip += j;
+		}
+	
+		/*
+		 * full buffer without finding; add to user string and continue
+		 */
+		p = badd(p, &bp->rdline, (char*)bp->bbuf, bp->bsize, 0, 0);
+		i = 0;
+		bp->icount = 0;
+		bp->gbuf = bp->ebuf;
+	}
+	return 0;	/* never happens */
+}