Move top level packages to internal.

internal/lamport/clock.go

@@ -0,0 +1,29 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// Package lamport implements a simple Lamport Clock for versioning
+package lamport
+
+import "sync"
+
+var Default = Clock{}
+
+type Clock struct {
+	val uint64
+	mut sync.Mutex
+}
+
+func (c *Clock) Tick(v uint64) uint64 {
+	c.mut.Lock()
+	if v > c.val {
+		c.val = v + 1
+		c.mut.Unlock()
+		return v + 1
+	} else {
+		c.val++
+		v = c.val
+		c.mut.Unlock()
+		return v
+	}
+}

internal/lamport/clock_test.go

@@ -0,0 +1,22 @@
+// Copyright (C) 2014 Jakob Borg and Contributors (see the CONTRIBUTORS file).
+// All rights reserved. Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+package lamport
+
+import "testing"
+
+var inputs = []uint64{0, 42, 2, 3, 4, 8, 9, 33, 44, 112, 100}
+
+func TestClock(t *testing.T) {
+	c := Clock{}
+
+	var prev uint64
+	for _, input := range inputs {
+		cur := c.Tick(input)
+		if cur <= prev || cur <= input {
+			t.Error("Clock moving backwards")
+		}
+		prev = cur
+	}
+}