Make PatternReg a 32-bit integer + handle overflow

The Server-Server communication protocol assumes that pattern
registration IDs are 32bit. 64bit IDs are a bit overkill, anyway.

1 files changed, 10 insertions, 3 deletions

diff --git a/server.go b/server.go
index 65123e2..64d3715 100644
--- a/server.go
+++ b/server.go
@@ -1,6 +1,6 @@
 package tanja
 
-type PatternReg uint64
+type PatternReg int32
 
 type Server struct {
 	ref   chan<- int
@@ -57,6 +57,13 @@ type serverRegister struct {
 	reply chan<- PatternReg
 }
 
+func (i *PatternReg) inc() {
+	*i++
+	if *i < 0 {
+		*i = 1
+	}
+}
+
 // Manages a Matcher object and routes messages to sessions
 func serverRouter(ref <-chan int, reg <-chan *serverRegister, unreg <-chan PatternReg, snd <-chan *serverSend) {
 	p := make(map[PatternReg]*MatcherItem)
@@ -69,12 +76,12 @@ func serverRouter(ref <-chan int, reg <-chan *serverRegister, unreg <-chan Patte
 			clients += n
 		case n := <-reg:
 			for p[lastId] != nil {
-				lastId++
+				lastId.inc()
 			}
 			n.dat.id = lastId
 			p[lastId] = m.Add(n.pat, n.dat)
 			n.reply <- lastId
-			lastId++
+			lastId.inc()
 		case n := <-unreg:
 			if r, e := p[n]; e {
 				m.Remove(r)