[VOL-2235] Mocks and interfaces for rw-core
This update consists of mocks that are used by the rw-core
during unit testing. It also includes interfaces used for unit
tests.
Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/pkg/idutil/id.go b/vendor/go.etcd.io/etcd/pkg/idutil/id.go
new file mode 100644
index 0000000..63a02cd
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/pkg/idutil/id.go
@@ -0,0 +1,75 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package idutil implements utility functions for generating unique,
+// randomized ids.
+package idutil
+
+import (
+ "math"
+ "sync/atomic"
+ "time"
+)
+
+const (
+ tsLen = 5 * 8
+ cntLen = 8
+ suffixLen = tsLen + cntLen
+)
+
+// Generator generates unique identifiers based on counters, timestamps, and
+// a node member ID.
+//
+// The initial id is in this format:
+// High order 2 bytes are from memberID, next 5 bytes are from timestamp,
+// and low order one byte is a counter.
+// | prefix | suffix |
+// | 2 bytes | 5 bytes | 1 byte |
+// | memberID | timestamp | cnt |
+//
+// The timestamp 5 bytes is different when the machine is restart
+// after 1 ms and before 35 years.
+//
+// It increases suffix to generate the next id.
+// The count field may overflow to timestamp field, which is intentional.
+// It helps to extend the event window to 2^56. This doesn't break that
+// id generated after restart is unique because etcd throughput is <<
+// 256req/ms(250k reqs/second).
+type Generator struct {
+ // high order 2 bytes
+ prefix uint64
+ // low order 6 bytes
+ suffix uint64
+}
+
+func NewGenerator(memberID uint16, now time.Time) *Generator {
+ prefix := uint64(memberID) << suffixLen
+ unixMilli := uint64(now.UnixNano()) / uint64(time.Millisecond/time.Nanosecond)
+ suffix := lowbit(unixMilli, tsLen) << cntLen
+ return &Generator{
+ prefix: prefix,
+ suffix: suffix,
+ }
+}
+
+// Next generates a id that is unique.
+func (g *Generator) Next() uint64 {
+ suffix := atomic.AddUint64(&g.suffix, 1)
+ id := g.prefix | lowbit(suffix, suffixLen)
+ return id
+}
+
+func lowbit(x uint64, n uint) uint64 {
+ return x & (math.MaxUint64 >> (64 - n))
+}