Add RemoveAll and Visit functions to kv store

tools/kv/keyvaluestore.go

@@ -71,6 +71,33 @@ func (k *Store) Remove(key string) {
 	k.logChange(removeOperation, key, nil)
 }
 
+// RemoveAll removes all entries from the store
+// These changes are not persisted until you call Save()
+func (k *Store) RemoveAll() {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+
+	// Log all changes
+	for key, _ := range k.db {
+		k.logChange(removeOperation, key, nil)
+	}
+	k.db = make(map[string]interface{})
+}
+
+// Visit walks through the entire store via a function; return false from
+// your visitor function to halt the walk
+func (k *Store) Visit(cb func(string, interface{}) bool) {
+	// Read-only lock
+	k.mu.RLock()
+	defer k.mu.RUnlock()
+
+	for k, v := range k.db {
+		if !cb(k, v) {
+			break
+		}
+	}
+}
+
 // Append a change to the log; mutex must already be locked
 func (k *Store) logChange(op operation, key string, value interface{}) {
 	k.log = append(k.log, change{op, key, value})

tools/kv/keyvaluestore_test.go

@@ -66,6 +66,29 @@ func TestStoreSimple(t *testing.T) {
 	n = kvs2.Get("noValue")
 	assert.Nil(t, n)
 
+	// Test remove all
+	kvs2.RemoveAll()
+	s = kvs2.Get("stringVal")
+	assert.Nil(t, s)
+	i = kvs2.Get("intVal")
+	assert.Nil(t, i)
+	f = kvs2.Get("floatVal")
+	assert.Nil(t, f)
+	c = kvs2.Get("structVal")
+	assert.Nil(t, c)
+
+	err = kvs2.Save()
+	assert.Nil(t, err)
+	kvs2 = nil
+
+	// Now confirm that we can read blank & get nothing
+	kvs, err = NewStore(filename)
+	kvs.Visit(func(k string, v interface{}) bool {
+		// Should not be called
+		assert.Fail(t, "Should be no entries")
+		return true
+	})
+
 }
 
 func TestStoreOptimisticConflict(t *testing.T) {