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1. run ./scripts/fix.sh; 2. cd tools/mod; gofmt -w . & go mod tidy; Signed-off-by: Benjamin Wang <wachao@vmware.com>
46 lines
1.7 KiB
Go
46 lines
1.7 KiB
Go
// Copyright 2017 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 leasing serves linearizable reads from a local cache by acquiring
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// exclusive write access to keys through a client-side leasing protocol. This
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// leasing layer can either directly wrap the etcd client or it can be exposed
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// through the etcd grpc proxy server, granting multiple clients write access.
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//
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// First, create a leasing KV from a clientv3.Client 'cli':
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//
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// lkv, err := leasing.NewKV(cli, "leasing-prefix")
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// if err != nil {
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// // handle error
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// }
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//
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// A range request for a key "abc" tries to acquire a leasing key so it can cache the range's
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// key locally. On the server, the leasing key is stored to "leasing-prefix/abc":
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//
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// resp, err := lkv.Get(context.TODO(), "abc")
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//
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// Future linearized read requests using 'lkv' will be served locally for the lease's lifetime:
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//
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// resp, err = lkv.Get(context.TODO(), "abc")
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//
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// If another leasing client writes to a leased key, then the owner relinquishes its exclusive
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// access, permitting the writer to modify the key:
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//
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// lkv2, err := leasing.NewKV(cli, "leasing-prefix")
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// if err != nil {
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// // handle error
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// }
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// lkv2.Put(context.TODO(), "abc", "456")
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// resp, err = lkv.Get("abc")
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package leasing
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