initial implementation of IP allocator, only using memory storage
diff --git a/ip-allocator/allocate.go b/ip-allocator/allocate.go
new file mode 100644
index 0000000..11eded4
--- /dev/null
+++ b/ip-allocator/allocate.go
@@ -0,0 +1,42 @@
+package main
+
+func Allocate(store Storage, mac string) (string, error) {
+ // Check to see if an IP address is already allocated and if so just
+ // return that value
+ ip, err := store.Get(mac)
+ if err != nil {
+ return "", err
+ }
+
+ if ip != "" {
+ return ip, nil
+ }
+
+ // This MAC does not already have an IP assigned, so pull then next
+ // one off the available queue and return it
+ ip, err = store.Dequeue()
+ if err != nil {
+ return "", err
+ }
+ err = store.Put(mac, ip)
+ if err != nil {
+ store.Enqueue(ip)
+ return "", err
+ }
+ return ip, nil
+}
+
+func Release(store Storage, mac string) error {
+ ip, err := store.Remove(mac)
+ if err != nil {
+ return err
+ }
+
+ if ip != "" {
+ err = store.Enqueue(ip)
+ if err != nil {
+ return err
+ }
+ }
+ return nil
+}