urlpick.go

Documentation: go.etcd.io/etcd/server/v3/etcdserver/api/rafthttp

     1  // Copyright 2015 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package rafthttp
    16  
    17  import (
    18  	"net/url"
    19  	"sync"
    20  
    21  	"go.etcd.io/etcd/client/pkg/v3/types"
    22  )
    23  
    24  type urlPicker struct {
    25  	mu     sync.Mutex // guards urls and picked
    26  	urls   types.URLs
    27  	picked int
    28  }
    29  
    30  func newURLPicker(urls types.URLs) *urlPicker {
    31  	return &urlPicker{
    32  		urls: urls,
    33  	}
    34  }
    35  
    36  func (p *urlPicker) update(urls types.URLs) {
    37  	p.mu.Lock()
    38  	defer p.mu.Unlock()
    39  	p.urls = urls
    40  	p.picked = 0
    41  }
    42  
    43  func (p *urlPicker) pick() url.URL {
    44  	p.mu.Lock()
    45  	defer p.mu.Unlock()
    46  	return p.urls[p.picked]
    47  }
    48  
    49  // unreachable notices the picker that the given url is unreachable,
    50  // and it should use other possible urls.
    51  func (p *urlPicker) unreachable(u url.URL) {
    52  	p.mu.Lock()
    53  	defer p.mu.Unlock()
    54  	if u == p.urls[p.picked] {
    55  		p.picked = (p.picked + 1) % len(p.urls)
    56  	}
    57  }
    58
View as plain text