mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
96 lines
2.9 KiB
Go
96 lines
2.9 KiB
Go
// Copyright 2021 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 schema
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import (
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"encoding/binary"
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"fmt"
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"go.etcd.io/etcd/client/pkg/v3/verify"
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"go.etcd.io/etcd/server/v3/storage/backend"
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)
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// UnsafeCreateMetaBucket creates the `meta` bucket (if it does not exist yet).
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func UnsafeCreateMetaBucket(tx backend.UnsafeWriter) {
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tx.UnsafeCreateBucket(Meta)
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}
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// CreateMetaBucket creates the `meta` bucket (if it does not exist yet).
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func CreateMetaBucket(tx backend.BatchTx) {
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tx.LockOutsideApply()
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defer tx.Unlock()
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tx.UnsafeCreateBucket(Meta)
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}
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// UnsafeReadConsistentIndex loads consistent index & term from given transaction.
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// returns 0,0 if the data are not found.
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// Term is persisted since v3.5.
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func UnsafeReadConsistentIndex(tx backend.UnsafeReader) (uint64, uint64) {
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_, vs := tx.UnsafeRange(Meta, MetaConsistentIndexKeyName, nil, 0)
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if len(vs) == 0 {
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return 0, 0
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}
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v := binary.BigEndian.Uint64(vs[0])
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_, ts := tx.UnsafeRange(Meta, MetaTermKeyName, nil, 0)
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if len(ts) == 0 {
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return v, 0
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}
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t := binary.BigEndian.Uint64(ts[0])
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return v, t
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}
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// ReadConsistentIndex loads consistent index and term from given transaction.
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// returns 0 if the data are not found.
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func ReadConsistentIndex(tx backend.ReadTx) (uint64, uint64) {
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tx.RLock()
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defer tx.RUnlock()
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return UnsafeReadConsistentIndex(tx)
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}
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func UnsafeUpdateConsistentIndexForce(tx backend.UnsafeReadWriter, index uint64, term uint64) {
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unsafeUpdateConsistentIndex(tx, index, term, true)
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}
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func UnsafeUpdateConsistentIndex(tx backend.UnsafeReadWriter, index uint64, term uint64) {
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unsafeUpdateConsistentIndex(tx, index, term, false)
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}
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func unsafeUpdateConsistentIndex(tx backend.UnsafeReadWriter, index uint64, term uint64, allowDecreasing bool) {
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if index == 0 {
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// Never save 0 as it means that we didn't load the real index yet.
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return
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}
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bs1 := make([]byte, 8)
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binary.BigEndian.PutUint64(bs1, index)
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if !allowDecreasing {
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verify.Verify(func() {
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previousIndex, _ := UnsafeReadConsistentIndex(tx)
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if index < previousIndex {
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panic(fmt.Errorf("update of consistent index not advancing: previous: %v new: %v", previousIndex, index))
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}
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})
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}
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// put the index into the underlying backend
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// tx has been locked in TxnBegin, so there is no need to lock it again
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tx.UnsafePut(Meta, MetaConsistentIndexKeyName, bs1)
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if term > 0 {
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bs2 := make([]byte, 8)
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binary.BigEndian.PutUint64(bs2, term)
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tx.UnsafePut(Meta, MetaTermKeyName, bs2)
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}
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}
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