91 lines
1.5 KiB
Go
91 lines
1.5 KiB
Go
package raft
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const (
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normal int = iota
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configAdd
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configRemove
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)
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type Entry struct {
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Type int
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Term int
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Data []byte
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}
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type log struct {
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ents []Entry
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committed int
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applied int
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}
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func newLog() *log {
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return &log{
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ents: make([]Entry, 1),
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committed: 0,
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applied: 0,
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}
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}
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func (l *log) maybeAppend(index, logTerm, committed int, ents ...Entry) bool {
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if l.matchTerm(index, logTerm) {
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l.append(index, ents...)
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l.committed = committed
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return true
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}
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return false
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}
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func (l *log) append(after int, ents ...Entry) int {
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l.ents = append(l.ents[:after+1], ents...)
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return l.lastIndex()
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}
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func (l *log) lastIndex() int {
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return len(l.ents) - 1
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}
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func (l *log) term(i int) int {
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if i > l.lastIndex() {
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return -1
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}
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return l.ents[i].Term
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}
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func (l *log) entries(i int) []Entry {
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if i > l.lastIndex() {
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return nil
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}
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return l.ents[i:]
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}
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func (l *log) isUpToDate(i, term int) bool {
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e := l.ents[l.lastIndex()]
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return term > e.Term || (term == e.Term && i >= l.lastIndex())
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}
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func (l *log) matchTerm(i, term int) bool {
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if i > l.lastIndex() {
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return false
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}
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return l.ents[i].Term == term
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}
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func (l *log) maybeCommit(maxIndex, term int) bool {
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if maxIndex > l.committed && l.term(maxIndex) == term {
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l.committed = maxIndex
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return true
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}
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return false
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}
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// nextEnts returns all the avaliable entries for execution.
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// all the returned entries will be marked as applied.
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func (l *log) nextEnts() (ents []Entry) {
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if l.committed > l.applied {
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ents = l.ents[l.applied+1 : l.committed+1]
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l.applied = l.committed
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}
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return ents
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}
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