Implement server deletion

server/collection.go

@@ -1,7 +1,18 @@
 package server
 
+import "sync"
+
 type Collection struct {
 	items []*Server
+	mutex *sync.Mutex
+}
+
+// Create a new collection from a slice of servers.
+func NewCollection(servers []*Server) *Collection {
+	return &Collection{
+		items: servers,
+		mutex: &sync.Mutex{},
+	}
 }
 
 // Return all of the items in the collection.
@@ -11,11 +22,17 @@ func (c *Collection) All() []*Server {
 
 // Adds an item to the collection store.
 func (c *Collection) Add(s *Server) {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
 	c.items = append(c.items, s)
 }
 
 // Returns only those items matching the filter criteria.
-func (c *Collection) Filter(filter func (*Server) bool) []*Server {
+func (c *Collection) Filter(filter func(*Server) bool) []*Server {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
 	r := make([]*Server, 0)
 	for _, v := range c.items {
 		if filter(v) {
@@ -28,7 +45,7 @@ func (c *Collection) Filter(filter func (*Server) bool) []*Server {
 
 // Returns a single element from the collection matching the filter. If nothing is
 // found a nil result is returned.
-func (c *Collection) Find(filter func (*Server) bool) *Server {
+func (c *Collection) Find(filter func(*Server) bool) *Server {
 	for _, v := range c.items {
 		if filter(v) {
 			return v
@@ -36,4 +53,19 @@ func (c *Collection) Find(filter func (*Server) bool) *Server {
 	}
 
 	return nil
-}
+}
+
+// Removes all items from the collection that match the filter function.
+func (c *Collection) Remove(filter func(*Server) bool) {
+	c.mutex.Lock()
+	defer c.mutex.Unlock()
+
+	r := make([]*Server, 0)
+	for _, v := range c.items {
+		if !filter(v) {
+			r = append(r, v)
+		}
+	}
+
+	c.items = r
+}