smugfs(4): new program

1 files changed, 120 insertions, 0 deletions

diff --git a/src/cmd/smugfs/log.c b/src/cmd/smugfs/log.c
new file mode 100644
index 00000000..5603211e
--- /dev/null
+++ b/src/cmd/smugfs/log.c
@@ -0,0 +1,120 @@
+#include "a.h"
+
+void
+lbkick(Logbuf *lb)
+{
+	char *s;
+	int n;
+	Req *r;
+
+	while(lb->wait && lb->rp != lb->wp){
+		r = lb->wait;
+		lb->wait = r->aux;
+		if(lb->wait == nil)
+			lb->waitlast = &lb->wait;
+		r->aux = nil;
+		if(r->ifcall.count < 5){
+			respond(r, "log read request count too short");
+			continue;
+		}
+		s = lb->msg[lb->rp];
+		lb->msg[lb->rp] = nil;
+		if(++lb->rp == nelem(lb->msg))
+			lb->rp = 0;
+		n = r->ifcall.count;
+		if(n < strlen(s)+1+1){
+			memmove(r->ofcall.data, s, n-5);
+			n -= 5;
+			r->ofcall.data[n] = '\0';
+			/* look for first byte of UTF-8 sequence by skipping continuation bytes */
+			while(n>0 && (r->ofcall.data[--n]&0xC0)==0x80)
+				;
+			strcpy(r->ofcall.data+n, "...\n");
+		}else{
+			strcpy(r->ofcall.data, s);
+			strcat(r->ofcall.data, "\n");
+		}
+		r->ofcall.count = strlen(r->ofcall.data);
+		free(s);
+		respond(r, nil);
+	}
+}
+
+void
+lbread(Logbuf *lb, Req *r)
+{
+	if(lb->waitlast == nil)
+		lb->waitlast = &lb->wait;
+	*lb->waitlast = r;
+	lb->waitlast = (Req**)(void*)&r->aux;
+	r->aux = nil;
+	lbkick(lb);
+}
+
+void
+lbflush(Logbuf *lb, Req *r)
+{
+	Req **l;
+
+	for(l=&lb->wait; *l; l=(Req**)(void*)&(*l)->aux){
+		if(*l == r){
+			*l = r->aux;
+			r->aux = nil;
+			if(*l == nil)
+				lb->waitlast = l;
+			respond(r, "interrupted");
+			break;
+		}
+	}
+}
+
+void
+lbappend(Logbuf *lb, char *fmt, ...)
+{
+	va_list arg;
+
+	va_start(arg, fmt);
+	lbvappend(lb, fmt, arg);
+	va_end(arg);
+}
+
+void
+lbvappend(Logbuf *lb, char *fmt, va_list arg)
+{
+	char *s;
+
+	s = vsmprint(fmt, arg);
+	if(s == nil)
+		sysfatal("out of memory");
+	if(lb->msg[lb->wp])
+		free(lb->msg[lb->wp]);
+	lb->msg[lb->wp] = s;
+	if(++lb->wp == nelem(lb->msg))
+		lb->wp = 0;
+	lbkick(lb);
+}
+
+Logbuf rpclogbuf;
+
+void
+rpclogread(Req *r)
+{
+	lbread(&rpclogbuf, r);
+}
+
+void
+rpclogflush(Req *r)
+{
+	lbflush(&rpclogbuf, r);
+}
+
+void
+rpclog(char *fmt, ...)
+{
+	va_list arg;
+
+	va_start(arg, fmt);
+	lbvappend(&rpclogbuf, fmt, arg);
+	va_end(arg);
+}
+