Initial revision

src/libbio/binit.c

@@ -0,0 +1,142 @@
+#include	"lib9.h"
+#include	<bio.h>
+
+enum
+{
+	MAXBUFS	= 20
+};
+
+static	Biobuf*	wbufs[MAXBUFS];
+static	int		atexitflag;
+
+static
+void
+batexit(void)
+{
+	Biobuf *bp;
+	int i;
+
+	for(i=0; i<MAXBUFS; i++) {
+		bp = wbufs[i];
+		if(bp != 0) {
+			wbufs[i] = 0;
+			Bflush(bp);
+		}
+	}
+}
+
+static
+void
+deinstall(Biobuf *bp)
+{
+	int i;
+
+	for(i=0; i<MAXBUFS; i++)
+		if(wbufs[i] == bp)
+			wbufs[i] = 0;
+}
+
+static
+void
+install(Biobuf *bp)
+{
+	int i;
+
+	deinstall(bp);
+	for(i=0; i<MAXBUFS; i++)
+		if(wbufs[i] == 0) {
+			wbufs[i] = bp;
+			break;
+		}
+	if(atexitflag == 0) {
+		atexitflag = 1;
+		atexit(batexit);
+	}
+}
+
+int
+Binits(Biobuf *bp, int f, int mode, unsigned char *p, int size)
+{
+
+	p += Bungetsize;	/* make room for Bungets */
+	size -= Bungetsize;
+
+	switch(mode) {
+	default:
+		fprint(2, "Bopen: 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) {
+	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 = creat(name, 0666);
+		if(f < 0)
+			return 0;
+	}
+	bp = malloc(sizeof(Biobuf));
+	if(bp == 0)
+		return 0;
+	Binits(bp, f, mode, bp->b, sizeof(bp->b));
+	bp->flag = Bmagic;
+	return bp;
+}
+
+int
+Bterm(Biobuf *bp)
+{
+
+	deinstall(bp);
+	Bflush(bp);
+	if(bp->flag == Bmagic) {
+		bp->flag = 0;
+		close(bp->fid);
+		free(bp);
+	}
+	return 0;
+}