util: add a Lamport clock implementation as well as a persistable one

1 files changed, 66 insertions, 0 deletions

diff --git a/util/lamport_test.go b/util/lamport_test.go
new file mode 100644
index 00000000..0bac7d51
--- /dev/null
+++ b/util/lamport_test.go
@@ -0,0 +1,66 @@
+/*
+
+	This Source Code Form is subject to the terms of the Mozilla Public
+	License, v. 2.0. If a copy of the MPL was not distributed with this file,
+	You can obtain one at http://mozilla.org/MPL/2.0/.
+
+	Copyright (c) 2013, Armon Dadgar armon.dadgar@gmail.com
+	Copyright (c) 2013, Mitchell Hashimoto mitchell.hashimoto@gmail.com
+
+	Alternatively, the contents of this file may be used under the terms
+	of the GNU General Public License Version 3 or later, as described below:
+
+	This file is free software: you may copy, redistribute and/or modify
+	it under the terms of the GNU General Public License as published by the
+	Free Software Foundation, either version 3 of the License, or (at your
+	option) any later version.
+
+	This file is distributed in the hope that it will be useful, but
+	WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+	Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program. If not, see http://www.gnu.org/licenses/.
+
+*/
+
+package util
+
+import (
+	"testing"
+)
+
+func TestLamportClock(t *testing.T) {
+	l := &LamportClock{}
+
+	if l.Time() != 0 {
+		t.Fatalf("bad time value")
+	}
+
+	if l.Increment() != 1 {
+		t.Fatalf("bad time value")
+	}
+
+	if l.Time() != 1 {
+		t.Fatalf("bad time value")
+	}
+
+	l.Witness(41)
+
+	if l.Time() != 42 {
+		t.Fatalf("bad time value")
+	}
+
+	l.Witness(41)
+
+	if l.Time() != 42 {
+		t.Fatalf("bad time value")
+	}
+
+	l.Witness(30)
+
+	if l.Time() != 42 {
+		t.Fatalf("bad time value")
+	}
+}