VOL-2112 move to voltha-lib-go
Change-Id: Ic1af08003c1d2c698c0cce371e64f47b47b8d875
diff --git a/vendor/go.etcd.io/etcd/raft/raftpb/confchange.go b/vendor/go.etcd.io/etcd/raft/raftpb/confchange.go
new file mode 100644
index 0000000..46a7a70
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/raft/raftpb/confchange.go
@@ -0,0 +1,170 @@
+// Copyright 2019 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 raftpb
+
+import (
+ "fmt"
+ "strconv"
+ "strings"
+
+ "github.com/gogo/protobuf/proto"
+)
+
+// ConfChangeI abstracts over ConfChangeV2 and (legacy) ConfChange to allow
+// treating them in a unified manner.
+type ConfChangeI interface {
+ AsV2() ConfChangeV2
+ AsV1() (ConfChange, bool)
+}
+
+// MarshalConfChange calls Marshal on the underlying ConfChange or ConfChangeV2
+// and returns the result along with the corresponding EntryType.
+func MarshalConfChange(c ConfChangeI) (EntryType, []byte, error) {
+ var typ EntryType
+ var ccdata []byte
+ var err error
+ if ccv1, ok := c.AsV1(); ok {
+ typ = EntryConfChange
+ ccdata, err = ccv1.Marshal()
+ } else {
+ ccv2 := c.AsV2()
+ typ = EntryConfChangeV2
+ ccdata, err = ccv2.Marshal()
+ }
+ return typ, ccdata, err
+}
+
+// AsV2 returns a V2 configuration change carrying out the same operation.
+func (c ConfChange) AsV2() ConfChangeV2 {
+ return ConfChangeV2{
+ Changes: []ConfChangeSingle{{
+ Type: c.Type,
+ NodeID: c.NodeID,
+ }},
+ Context: c.Context,
+ }
+}
+
+// AsV1 returns the ConfChange and true.
+func (c ConfChange) AsV1() (ConfChange, bool) {
+ return c, true
+}
+
+// AsV2 is the identity.
+func (c ConfChangeV2) AsV2() ConfChangeV2 { return c }
+
+// AsV1 returns ConfChange{} and false.
+func (c ConfChangeV2) AsV1() (ConfChange, bool) { return ConfChange{}, false }
+
+// EnterJoint returns two bools. The second bool is true if and only if this
+// config change will use Joint Consensus, which is the case if it contains more
+// than one change or if the use of Joint Consensus was requested explicitly.
+// The first bool can only be true if second one is, and indicates whether the
+// Joint State will be left automatically.
+func (c *ConfChangeV2) EnterJoint() (autoLeave bool, ok bool) {
+ // NB: in theory, more config changes could qualify for the "simple"
+ // protocol but it depends on the config on top of which the changes apply.
+ // For example, adding two learners is not OK if both nodes are part of the
+ // base config (i.e. two voters are turned into learners in the process of
+ // applying the conf change). In practice, these distinctions should not
+ // matter, so we keep it simple and use Joint Consensus liberally.
+ if c.Transition != ConfChangeTransitionAuto || len(c.Changes) > 1 {
+ // Use Joint Consensus.
+ var autoLeave bool
+ switch c.Transition {
+ case ConfChangeTransitionAuto:
+ autoLeave = true
+ case ConfChangeTransitionJointImplicit:
+ autoLeave = true
+ case ConfChangeTransitionJointExplicit:
+ default:
+ panic(fmt.Sprintf("unknown transition: %+v", c))
+ }
+ return autoLeave, true
+ }
+ return false, false
+}
+
+// LeaveJoint is true if the configuration change leaves a joint configuration.
+// This is the case if the ConfChangeV2 is zero, with the possible exception of
+// the Context field.
+func (c *ConfChangeV2) LeaveJoint() bool {
+ cpy := *c
+ cpy.Context = nil
+ return proto.Equal(&cpy, &ConfChangeV2{})
+}
+
+// ConfChangesFromString parses a Space-delimited sequence of operations into a
+// slice of ConfChangeSingle. The supported operations are:
+// - vn: make n a voter,
+// - ln: make n a learner,
+// - rn: remove n, and
+// - un: update n.
+func ConfChangesFromString(s string) ([]ConfChangeSingle, error) {
+ var ccs []ConfChangeSingle
+ toks := strings.Split(strings.TrimSpace(s), " ")
+ if toks[0] == "" {
+ toks = nil
+ }
+ for _, tok := range toks {
+ if len(tok) < 2 {
+ return nil, fmt.Errorf("unknown token %s", tok)
+ }
+ var cc ConfChangeSingle
+ switch tok[0] {
+ case 'v':
+ cc.Type = ConfChangeAddNode
+ case 'l':
+ cc.Type = ConfChangeAddLearnerNode
+ case 'r':
+ cc.Type = ConfChangeRemoveNode
+ case 'u':
+ cc.Type = ConfChangeUpdateNode
+ default:
+ return nil, fmt.Errorf("unknown input: %s", tok)
+ }
+ id, err := strconv.ParseUint(tok[1:], 10, 64)
+ if err != nil {
+ return nil, err
+ }
+ cc.NodeID = id
+ ccs = append(ccs, cc)
+ }
+ return ccs, nil
+}
+
+// ConfChangesToString is the inverse to ConfChangesFromString.
+func ConfChangesToString(ccs []ConfChangeSingle) string {
+ var buf strings.Builder
+ for i, cc := range ccs {
+ if i > 0 {
+ buf.WriteByte(' ')
+ }
+ switch cc.Type {
+ case ConfChangeAddNode:
+ buf.WriteByte('v')
+ case ConfChangeAddLearnerNode:
+ buf.WriteByte('l')
+ case ConfChangeRemoveNode:
+ buf.WriteByte('r')
+ case ConfChangeUpdateNode:
+ buf.WriteByte('u')
+ default:
+ buf.WriteString("unknown")
+ }
+ fmt.Fprintf(&buf, "%d", cc.NodeID)
+ }
+ return buf.String()
+}