added code

id.go

@@ -0,0 +1,43 @@
+package idg
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"time"
+)
+
+// This thing contains a channel that when initialized (see NewIdGenerator)
+// will return a bunch of (as best as I can tell) unique md5 hashes.
+//
+// we use this for naming players, games, etc.
+//
+// It will consume a single goroutine
+type IdGenerator struct {
+	id chan int64
+}
+
+func NewIdGenerator() *IdGenerator {
+	return &IdGenerator{
+		id: make(chan int64),
+	}
+}
+
+// Run is called (typically in a gorotine) to allow for queries to be made
+// against IdGenerator.id throgh the Hash method.
+func (idg *IdGenerator) Run() {
+	var i int64
+	for i = 0; ; i++ {
+		idg.id <- i
+	}
+}
+
+// Hash is the method used by a properly instantiated IdGenerator that gives
+// fairly unique strings. They are currently truncated md5 hashes of the time
+// plus a unique counter
+func (id *IdGenerator) Hash() string {
+	h := md5.New()
+	ns := time.Now().UnixNano() + <-id.id
+	io.WriteString(h, fmt.Sprintf("%d", ns))
+	return fmt.Sprintf("%x", h.Sum(nil))[:8]
+}

id_test.go

@@ -0,0 +1,19 @@
+package idg
+
+import (
+	"testing"
+)
+
+func TestIDGenerator(t *testing.T) {
+	cache := make(map[string]bool)
+	var cur string
+	gg := NewIdGenerator()
+	go gg.Run()
+	for i := 0; i < 10000; i++ {
+		cur = gg.Hash()
+		if _, ok := cache[cur]; ok {
+			t.Errorf("unexpected duplicate key")
+		}
+		cache[cur] = true
+	}
+}