2aa18cafc6
With CoreDNS now supporting etcdv3 as the DNS backend, we can update our federation target to etcdv3. Users will now be able to use etcdv3 server as the federation backbone. Minio will update bucket data to etcdv3 and CoreDNS can pick that data up and serve it as bucket style DNS path.
151 lines
3 KiB
Go
151 lines
3 KiB
Go
// Copyright 2016 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 clientv3
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import (
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"context"
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"sync"
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pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
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"google.golang.org/grpc"
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)
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// Txn is the interface that wraps mini-transactions.
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//
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// Txn(context.TODO()).If(
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// Compare(Value(k1), ">", v1),
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// Compare(Version(k1), "=", 2)
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// ).Then(
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// OpPut(k2,v2), OpPut(k3,v3)
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// ).Else(
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// OpPut(k4,v4), OpPut(k5,v5)
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// ).Commit()
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//
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type Txn interface {
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// If takes a list of comparison. If all comparisons passed in succeed,
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// the operations passed into Then() will be executed. Or the operations
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// passed into Else() will be executed.
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If(cs ...Cmp) Txn
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// Then takes a list of operations. The Ops list will be executed, if the
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// comparisons passed in If() succeed.
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Then(ops ...Op) Txn
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// Else takes a list of operations. The Ops list will be executed, if the
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// comparisons passed in If() fail.
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Else(ops ...Op) Txn
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// Commit tries to commit the transaction.
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Commit() (*TxnResponse, error)
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}
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type txn struct {
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kv *kv
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ctx context.Context
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mu sync.Mutex
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cif bool
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cthen bool
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celse bool
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isWrite bool
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cmps []*pb.Compare
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sus []*pb.RequestOp
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fas []*pb.RequestOp
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callOpts []grpc.CallOption
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}
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func (txn *txn) If(cs ...Cmp) Txn {
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txn.mu.Lock()
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defer txn.mu.Unlock()
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if txn.cif {
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panic("cannot call If twice!")
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}
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if txn.cthen {
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panic("cannot call If after Then!")
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}
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if txn.celse {
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panic("cannot call If after Else!")
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}
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txn.cif = true
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for i := range cs {
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txn.cmps = append(txn.cmps, (*pb.Compare)(&cs[i]))
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}
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return txn
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}
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func (txn *txn) Then(ops ...Op) Txn {
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txn.mu.Lock()
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defer txn.mu.Unlock()
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if txn.cthen {
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panic("cannot call Then twice!")
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}
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if txn.celse {
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panic("cannot call Then after Else!")
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}
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txn.cthen = true
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for _, op := range ops {
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txn.isWrite = txn.isWrite || op.isWrite()
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txn.sus = append(txn.sus, op.toRequestOp())
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}
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return txn
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}
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func (txn *txn) Else(ops ...Op) Txn {
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txn.mu.Lock()
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defer txn.mu.Unlock()
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if txn.celse {
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panic("cannot call Else twice!")
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}
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txn.celse = true
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for _, op := range ops {
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txn.isWrite = txn.isWrite || op.isWrite()
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txn.fas = append(txn.fas, op.toRequestOp())
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}
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return txn
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}
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func (txn *txn) Commit() (*TxnResponse, error) {
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txn.mu.Lock()
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defer txn.mu.Unlock()
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r := &pb.TxnRequest{Compare: txn.cmps, Success: txn.sus, Failure: txn.fas}
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var resp *pb.TxnResponse
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var err error
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resp, err = txn.kv.remote.Txn(txn.ctx, r, txn.callOpts...)
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if err != nil {
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return nil, toErr(txn.ctx, err)
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}
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return (*TxnResponse)(resp), nil
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}
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