1 files changed, 161 insertions, 0 deletions
diff --git a/emu/port/devsnarf.c b/emu/port/devsnarf.c
new file mode 100644
index 00000000..4778c130
--- /dev/null
+++ b/emu/port/devsnarf.c
@@ -0,0 +1,161 @@
+/*
+ * host's snarf buffer
+ */
+
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+enum{
+	Qdir,
+	Qsnarf,
+
+	Maxsnarf=	100*1024
+};
+
+static
+Dirtab snarftab[]={
+	".",		{Qdir, 0, QTDIR},	0,	0555,
+	"snarf",	{Qsnarf},			0,	0666,
+};
+
+static QLock snarflock;	/* easiest to synchronise all access */
+
+static Chan*
+snarfattach(char *spec)
+{
+	return devattach('^', spec);
+}
+
+static Walkqid*
+snarfwalk(Chan *c, Chan *nc, char **name, int nname)
+{
+	return devwalk(c, nc, name, nname, snarftab, nelem(snarftab), devgen);
+}
+
+static int
+snarfstat(Chan* c, uchar *db, int n)
+{
+	return devstat(c, db, n, snarftab, nelem(snarftab), devgen);
+}
+
+static Chan*
+snarfopen(Chan* c, int omode)
+{
+	c = devopen(c, omode, snarftab, nelem(snarftab), devgen);
+	if(c->qid.path == Qsnarf){
+		if(c->mode == ORDWR || c->mode == OWRITE){
+			qlock(&snarflock);
+			free(c->aux);
+			c->aux = nil;
+			qunlock(&snarflock);
+		}
+	}
+	return c;
+}
+
+static void
+snarfclose(Chan* c)
+{
+	if((c->flag & COPEN) == 0)
+		return;
+	if(c->qid.path == Qsnarf){
+		/* this must be the last reference: no need to lock */
+		if(c->mode == ORDWR || c->mode == OWRITE){
+			if(!waserror()){
+				clipwrite(c->aux);
+				poperror();
+			}
+		}
+		free(c->aux);
+	}
+}
+
+static long
+snarfread(Chan* c, void* a, long n, vlong offset)
+{
+	void *p;
+
+	switch((ulong)c->qid.path){
+	case Qdir:
+		return devdirread(c, a, n, snarftab, nelem(snarftab), devgen);
+	case Qsnarf:
+		qlock(&snarflock);
+		if(waserror()){
+			qunlock(&snarflock);
+			nexterror();
+		}
+		if(offset == 0){
+			p = c->aux;
+			c->aux = nil;
+			free(p);
+			c->aux = clipread();
+		}
+		if(c->aux != nil)
+			n = readstr(offset, a, n, c->aux);
+		else
+			n = 0;
+		poperror();
+		qunlock(&snarflock);
+		break;
+	default:
+		n=0;
+		break;
+	}
+	return n;
+}
+
+static long
+snarfwrite(Chan* c, void* va, long n, vlong offset)
+{
+	ulong l;
+	char *p;
+
+	switch((ulong)c->qid.path){
+	case Qsnarf:
+		/* append only */
+		USED(offset);	/* not */
+		qlock(&snarflock);
+		if(waserror()){
+			qunlock(&snarflock);
+			nexterror();
+		}
+		if(c->aux != nil)
+			l = strlen(c->aux);
+		else
+			l = 0;
+		if(l+n > Maxsnarf)
+			error(Etoobig);
+		c->aux = realloc(c->aux, l+n+1);
+		if((p = c->aux) == nil)
+			error(Enovmem);
+		memmove(p+l, va, n);
+		p[l+n] = 0;
+		snarftab[1].qid.vers++;
+		poperror();
+		qunlock(&snarflock);
+		break;
+	default:
+		error(Ebadusefd);
+	}
+	return n;
+}
+
+Dev snarfdevtab = {
+	'^',
+	"snarf",
+
+	devinit,
+	snarfattach,
+	snarfwalk,
+	snarfstat,
+	snarfopen,
+	devcreate,
+	snarfclose,
+	snarfread,
+	devbread,
+	snarfwrite,
+	devbwrite,
+	devremove,
+	devwstat,
+};