65 lines
1.9 KiB
Go
65 lines
1.9 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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"net/url"
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"strings"
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"sync/atomic"
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"golang.org/x/net/context"
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"google.golang.org/grpc"
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)
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// simpleBalancer does the bare minimum to expose multiple eps
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// to the grpc reconnection code path
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type simpleBalancer struct {
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// eps are the client's endpoints stripped of any URL scheme
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eps []string
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ch chan []grpc.Address
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numGets uint32
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}
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func newSimpleBalancer(eps []string) grpc.Balancer {
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ch := make(chan []grpc.Address, 1)
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addrs := make([]grpc.Address, len(eps))
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for i := range eps {
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addrs[i].Addr = getHost(eps[i])
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}
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ch <- addrs
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return &simpleBalancer{eps: eps, ch: ch}
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}
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func (b *simpleBalancer) Start(target string) error { return nil }
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func (b *simpleBalancer) Up(addr grpc.Address) func(error) { return func(error) {} }
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func (b *simpleBalancer) Get(ctx context.Context, opts grpc.BalancerGetOptions) (grpc.Address, func(), error) {
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v := atomic.AddUint32(&b.numGets, 1)
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ep := b.eps[v%uint32(len(b.eps))]
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return grpc.Address{Addr: getHost(ep)}, func() {}, nil
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}
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func (b *simpleBalancer) Notify() <-chan []grpc.Address { return b.ch }
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func (b *simpleBalancer) Close() error {
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close(b.ch)
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return nil
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}
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func getHost(ep string) string {
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url, uerr := url.Parse(ep)
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if uerr != nil || !strings.Contains(ep, "://") {
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return ep
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}
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return url.Host
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}
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