88 lines
2.6 KiB
Go
88 lines
2.6 KiB
Go
// Copyright 2016 CoreOS, Inc.
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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 recipe
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import (
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"errors"
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"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
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"github.com/coreos/etcd/Godeps/_workspace/src/google.golang.org/grpc"
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pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
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spb "github.com/coreos/etcd/storage/storagepb"
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)
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var (
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ErrKeyExists = errors.New("key already exists")
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ErrWaitMismatch = errors.New("unexpected wait result")
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)
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type EtcdClient struct {
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conn *grpc.ClientConn
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KV pb.KVClient
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Lease pb.LeaseClient
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Watch pb.WatchClient
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}
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func NewEtcdClient(conn *grpc.ClientConn) *EtcdClient {
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kv := pb.NewKVClient(conn)
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lease := pb.NewLeaseClient(conn)
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watch := pb.NewWatchClient(conn)
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return &EtcdClient{conn, kv, lease, watch}
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}
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// deleteRevKey deletes a key by revision, returning false if key is missing
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func (ec *EtcdClient) deleteRevKey(key string, rev int64) (bool, error) {
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cmp := &pb.Compare{
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Result: pb.Compare_EQUAL,
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Target: pb.Compare_MOD,
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Key: []byte(key),
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ModRevision: rev}
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req := &pb.RequestUnion{RequestDeleteRange: &pb.DeleteRangeRequest{Key: []byte(key)}}
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txnresp, err := ec.KV.Txn(
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context.TODO(),
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&pb.TxnRequest{[]*pb.Compare{cmp}, []*pb.RequestUnion{req}, nil})
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if err != nil {
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return false, err
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} else if txnresp.Succeeded == false {
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return false, nil
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}
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return true, nil
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}
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func (ec *EtcdClient) claimFirstKey(kvs []*spb.KeyValue) (*spb.KeyValue, error) {
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for _, kv := range kvs {
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ok, err := ec.deleteRevKey(string(kv.Key), kv.ModRevision)
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if err != nil {
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return nil, err
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} else if ok {
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return kv, nil
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}
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}
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return nil, nil
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}
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func putEmptyKey(kv pb.KVClient, key string) (*pb.PutResponse, error) {
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return kv.Put(context.TODO(), &pb.PutRequest{Key: []byte(key), Value: []byte{}})
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}
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// deletePrefix performs a RangeRequest to get keys on a given prefix
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func deletePrefix(kv pb.KVClient, prefix string) (*pb.DeleteRangeResponse, error) {
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return kv.DeleteRange(
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context.TODO(),
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&pb.DeleteRangeRequest{
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Key: []byte(prefix),
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RangeEnd: []byte(prefixEnd(prefix))})
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}
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