VOL-1868 move simulated onu from voltha-go to voltha-simonu-adapter
Sourced from voltha-go commit 251a11c0ffe60512318a644cd6ce0dc4e12f4018
Change-Id: Iab179bc2f3dd772ed7f488d1c03d1a84ba75e874
diff --git a/vendor/go.etcd.io/etcd/raft/log.go b/vendor/go.etcd.io/etcd/raft/log.go
new file mode 100644
index 0000000..03f83e6
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/raft/log.go
@@ -0,0 +1,370 @@
+// 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 raft
+
+import (
+ "fmt"
+ "log"
+
+ pb "go.etcd.io/etcd/raft/raftpb"
+)
+
+type raftLog struct {
+ // storage contains all stable entries since the last snapshot.
+ storage Storage
+
+ // unstable contains all unstable entries and snapshot.
+ // they will be saved into storage.
+ unstable unstable
+
+ // committed is the highest log position that is known to be in
+ // stable storage on a quorum of nodes.
+ committed uint64
+ // applied is the highest log position that the application has
+ // been instructed to apply to its state machine.
+ // Invariant: applied <= committed
+ applied uint64
+
+ logger Logger
+
+ // maxNextEntsSize is the maximum number aggregate byte size of the messages
+ // returned from calls to nextEnts.
+ maxNextEntsSize uint64
+}
+
+// newLog returns log using the given storage and default options. It
+// recovers the log to the state that it just commits and applies the
+// latest snapshot.
+func newLog(storage Storage, logger Logger) *raftLog {
+ return newLogWithSize(storage, logger, noLimit)
+}
+
+// newLogWithSize returns a log using the given storage and max
+// message size.
+func newLogWithSize(storage Storage, logger Logger, maxNextEntsSize uint64) *raftLog {
+ if storage == nil {
+ log.Panic("storage must not be nil")
+ }
+ log := &raftLog{
+ storage: storage,
+ logger: logger,
+ maxNextEntsSize: maxNextEntsSize,
+ }
+ firstIndex, err := storage.FirstIndex()
+ if err != nil {
+ panic(err) // TODO(bdarnell)
+ }
+ lastIndex, err := storage.LastIndex()
+ if err != nil {
+ panic(err) // TODO(bdarnell)
+ }
+ log.unstable.offset = lastIndex + 1
+ log.unstable.logger = logger
+ // Initialize our committed and applied pointers to the time of the last compaction.
+ log.committed = firstIndex - 1
+ log.applied = firstIndex - 1
+
+ return log
+}
+
+func (l *raftLog) String() string {
+ return fmt.Sprintf("committed=%d, applied=%d, unstable.offset=%d, len(unstable.Entries)=%d", l.committed, l.applied, l.unstable.offset, len(l.unstable.entries))
+}
+
+// maybeAppend returns (0, false) if the entries cannot be appended. Otherwise,
+// it returns (last index of new entries, true).
+func (l *raftLog) maybeAppend(index, logTerm, committed uint64, ents ...pb.Entry) (lastnewi uint64, ok bool) {
+ if l.matchTerm(index, logTerm) {
+ lastnewi = index + uint64(len(ents))
+ ci := l.findConflict(ents)
+ switch {
+ case ci == 0:
+ case ci <= l.committed:
+ l.logger.Panicf("entry %d conflict with committed entry [committed(%d)]", ci, l.committed)
+ default:
+ offset := index + 1
+ l.append(ents[ci-offset:]...)
+ }
+ l.commitTo(min(committed, lastnewi))
+ return lastnewi, true
+ }
+ return 0, false
+}
+
+func (l *raftLog) append(ents ...pb.Entry) uint64 {
+ if len(ents) == 0 {
+ return l.lastIndex()
+ }
+ if after := ents[0].Index - 1; after < l.committed {
+ l.logger.Panicf("after(%d) is out of range [committed(%d)]", after, l.committed)
+ }
+ l.unstable.truncateAndAppend(ents)
+ return l.lastIndex()
+}
+
+// findConflict finds the index of the conflict.
+// It returns the first pair of conflicting entries between the existing
+// entries and the given entries, if there are any.
+// If there is no conflicting entries, and the existing entries contains
+// all the given entries, zero will be returned.
+// If there is no conflicting entries, but the given entries contains new
+// entries, the index of the first new entry will be returned.
+// An entry is considered to be conflicting if it has the same index but
+// a different term.
+// The first entry MUST have an index equal to the argument 'from'.
+// The index of the given entries MUST be continuously increasing.
+func (l *raftLog) findConflict(ents []pb.Entry) uint64 {
+ for _, ne := range ents {
+ if !l.matchTerm(ne.Index, ne.Term) {
+ if ne.Index <= l.lastIndex() {
+ l.logger.Infof("found conflict at index %d [existing term: %d, conflicting term: %d]",
+ ne.Index, l.zeroTermOnErrCompacted(l.term(ne.Index)), ne.Term)
+ }
+ return ne.Index
+ }
+ }
+ return 0
+}
+
+func (l *raftLog) unstableEntries() []pb.Entry {
+ if len(l.unstable.entries) == 0 {
+ return nil
+ }
+ return l.unstable.entries
+}
+
+// nextEnts returns all the available entries for execution.
+// If applied is smaller than the index of snapshot, it returns all committed
+// entries after the index of snapshot.
+func (l *raftLog) nextEnts() (ents []pb.Entry) {
+ off := max(l.applied+1, l.firstIndex())
+ if l.committed+1 > off {
+ ents, err := l.slice(off, l.committed+1, l.maxNextEntsSize)
+ if err != nil {
+ l.logger.Panicf("unexpected error when getting unapplied entries (%v)", err)
+ }
+ return ents
+ }
+ return nil
+}
+
+// hasNextEnts returns if there is any available entries for execution. This
+// is a fast check without heavy raftLog.slice() in raftLog.nextEnts().
+func (l *raftLog) hasNextEnts() bool {
+ off := max(l.applied+1, l.firstIndex())
+ return l.committed+1 > off
+}
+
+func (l *raftLog) snapshot() (pb.Snapshot, error) {
+ if l.unstable.snapshot != nil {
+ return *l.unstable.snapshot, nil
+ }
+ return l.storage.Snapshot()
+}
+
+func (l *raftLog) firstIndex() uint64 {
+ if i, ok := l.unstable.maybeFirstIndex(); ok {
+ return i
+ }
+ index, err := l.storage.FirstIndex()
+ if err != nil {
+ panic(err) // TODO(bdarnell)
+ }
+ return index
+}
+
+func (l *raftLog) lastIndex() uint64 {
+ if i, ok := l.unstable.maybeLastIndex(); ok {
+ return i
+ }
+ i, err := l.storage.LastIndex()
+ if err != nil {
+ panic(err) // TODO(bdarnell)
+ }
+ return i
+}
+
+func (l *raftLog) commitTo(tocommit uint64) {
+ // never decrease commit
+ if l.committed < tocommit {
+ if l.lastIndex() < tocommit {
+ l.logger.Panicf("tocommit(%d) is out of range [lastIndex(%d)]. Was the raft log corrupted, truncated, or lost?", tocommit, l.lastIndex())
+ }
+ l.committed = tocommit
+ }
+}
+
+func (l *raftLog) appliedTo(i uint64) {
+ if i == 0 {
+ return
+ }
+ if l.committed < i || i < l.applied {
+ l.logger.Panicf("applied(%d) is out of range [prevApplied(%d), committed(%d)]", i, l.applied, l.committed)
+ }
+ l.applied = i
+}
+
+func (l *raftLog) stableTo(i, t uint64) { l.unstable.stableTo(i, t) }
+
+func (l *raftLog) stableSnapTo(i uint64) { l.unstable.stableSnapTo(i) }
+
+func (l *raftLog) lastTerm() uint64 {
+ t, err := l.term(l.lastIndex())
+ if err != nil {
+ l.logger.Panicf("unexpected error when getting the last term (%v)", err)
+ }
+ return t
+}
+
+func (l *raftLog) term(i uint64) (uint64, error) {
+ // the valid term range is [index of dummy entry, last index]
+ dummyIndex := l.firstIndex() - 1
+ if i < dummyIndex || i > l.lastIndex() {
+ // TODO: return an error instead?
+ return 0, nil
+ }
+
+ if t, ok := l.unstable.maybeTerm(i); ok {
+ return t, nil
+ }
+
+ t, err := l.storage.Term(i)
+ if err == nil {
+ return t, nil
+ }
+ if err == ErrCompacted || err == ErrUnavailable {
+ return 0, err
+ }
+ panic(err) // TODO(bdarnell)
+}
+
+func (l *raftLog) entries(i, maxsize uint64) ([]pb.Entry, error) {
+ if i > l.lastIndex() {
+ return nil, nil
+ }
+ return l.slice(i, l.lastIndex()+1, maxsize)
+}
+
+// allEntries returns all entries in the log.
+func (l *raftLog) allEntries() []pb.Entry {
+ ents, err := l.entries(l.firstIndex(), noLimit)
+ if err == nil {
+ return ents
+ }
+ if err == ErrCompacted { // try again if there was a racing compaction
+ return l.allEntries()
+ }
+ // TODO (xiangli): handle error?
+ panic(err)
+}
+
+// isUpToDate determines if the given (lastIndex,term) log is more up-to-date
+// by comparing the index and term of the last entries in the existing logs.
+// If the logs have last entries with different terms, then the log with the
+// later term is more up-to-date. If the logs end with the same term, then
+// whichever log has the larger lastIndex is more up-to-date. If the logs are
+// the same, the given log is up-to-date.
+func (l *raftLog) isUpToDate(lasti, term uint64) bool {
+ return term > l.lastTerm() || (term == l.lastTerm() && lasti >= l.lastIndex())
+}
+
+func (l *raftLog) matchTerm(i, term uint64) bool {
+ t, err := l.term(i)
+ if err != nil {
+ return false
+ }
+ return t == term
+}
+
+func (l *raftLog) maybeCommit(maxIndex, term uint64) bool {
+ if maxIndex > l.committed && l.zeroTermOnErrCompacted(l.term(maxIndex)) == term {
+ l.commitTo(maxIndex)
+ return true
+ }
+ return false
+}
+
+func (l *raftLog) restore(s pb.Snapshot) {
+ l.logger.Infof("log [%s] starts to restore snapshot [index: %d, term: %d]", l, s.Metadata.Index, s.Metadata.Term)
+ l.committed = s.Metadata.Index
+ l.unstable.restore(s)
+}
+
+// slice returns a slice of log entries from lo through hi-1, inclusive.
+func (l *raftLog) slice(lo, hi, maxSize uint64) ([]pb.Entry, error) {
+ err := l.mustCheckOutOfBounds(lo, hi)
+ if err != nil {
+ return nil, err
+ }
+ if lo == hi {
+ return nil, nil
+ }
+ var ents []pb.Entry
+ if lo < l.unstable.offset {
+ storedEnts, err := l.storage.Entries(lo, min(hi, l.unstable.offset), maxSize)
+ if err == ErrCompacted {
+ return nil, err
+ } else if err == ErrUnavailable {
+ l.logger.Panicf("entries[%d:%d) is unavailable from storage", lo, min(hi, l.unstable.offset))
+ } else if err != nil {
+ panic(err) // TODO(bdarnell)
+ }
+
+ // check if ents has reached the size limitation
+ if uint64(len(storedEnts)) < min(hi, l.unstable.offset)-lo {
+ return storedEnts, nil
+ }
+
+ ents = storedEnts
+ }
+ if hi > l.unstable.offset {
+ unstable := l.unstable.slice(max(lo, l.unstable.offset), hi)
+ if len(ents) > 0 {
+ ents = append([]pb.Entry{}, ents...)
+ ents = append(ents, unstable...)
+ } else {
+ ents = unstable
+ }
+ }
+ return limitSize(ents, maxSize), nil
+}
+
+// l.firstIndex <= lo <= hi <= l.firstIndex + len(l.entries)
+func (l *raftLog) mustCheckOutOfBounds(lo, hi uint64) error {
+ if lo > hi {
+ l.logger.Panicf("invalid slice %d > %d", lo, hi)
+ }
+ fi := l.firstIndex()
+ if lo < fi {
+ return ErrCompacted
+ }
+
+ length := l.lastIndex() + 1 - fi
+ if lo < fi || hi > fi+length {
+ l.logger.Panicf("slice[%d,%d) out of bound [%d,%d]", lo, hi, fi, l.lastIndex())
+ }
+ return nil
+}
+
+func (l *raftLog) zeroTermOnErrCompacted(t uint64, err error) uint64 {
+ if err == nil {
+ return t
+ }
+ if err == ErrCompacted {
+ return 0
+ }
+ l.logger.Panicf("unexpected error (%v)", err)
+ return 0
+}