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This is helpful to quickly print the configuration log messages without having to specify Voters and Learners separately. It will also come in handy for joint quorums because it allows holding on to voters and learners as a unit, which is useful for unit testing.
76 lines
2.3 KiB
Go
76 lines
2.3 KiB
Go
// Copyright 2019 The etcd Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package quorum
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// JointConfig is a configuration of two groups of (possibly overlapping)
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// majority configurations. Decisions require the support of both majorities.
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type JointConfig [2]MajorityConfig
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func (c JointConfig) String() string {
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if len(c[1]) > 0 {
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return c[0].String() + "&&" + c[1].String()
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}
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return c[0].String()
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}
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// IDs returns a newly initialized map representing the set of voters present
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// in the joint configuration.
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func (c JointConfig) IDs() map[uint64]struct{} {
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m := map[uint64]struct{}{}
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for _, cc := range c {
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for id := range cc {
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m[id] = struct{}{}
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}
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}
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return m
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}
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// Describe returns a (multi-line) representation of the commit indexes for the
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// given lookuper.
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func (c JointConfig) Describe(l AckedIndexer) string {
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return MajorityConfig(c.IDs()).Describe(l)
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}
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// CommittedIndex returns the largest committed index for the given joint
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// quorum. An index is jointly committed if it is committed in both constituent
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// majorities.
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func (c JointConfig) CommittedIndex(l AckedIndexer) Index {
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idx0 := c[0].CommittedIndex(l)
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idx1 := c[1].CommittedIndex(l)
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if idx0 < idx1 {
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return idx0
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}
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return idx1
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}
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// VoteResult takes a mapping of voters to yes/no (true/false) votes and returns
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// a result indicating whether the vote is pending, lost, or won. A joint quorum
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// requires both majority quorums to vote in favor.
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func (c JointConfig) VoteResult(votes map[uint64]bool) VoteResult {
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r1 := c[0].VoteResult(votes)
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r2 := c[1].VoteResult(votes)
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if r1 == r2 {
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// If they agree, return the agreed state.
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return r1
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}
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if r1 == VoteLost || r2 == VoteLost {
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// If either config has lost, loss is the only possible outcome.
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return VoteLost
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}
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// One side won, the other one is pending, so the whole outcome is.
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return VotePending
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}
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