go.uber.org/yarpc@v1.72.1/yarpctest/fake_peer.go (about)

     1  // Copyright (c) 2022 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package yarpctest
    22  
    23  import (
    24  	"sync"
    25  
    26  	"go.uber.org/yarpc/api/peer"
    27  )
    28  
    29  // FakePeer is a fake peer with an identifier.
    30  type FakePeer struct {
    31  	id peer.Identifier
    32  
    33  	// mutable
    34  	lock sync.RWMutex
    35  	// subscribers needs to be modified under lock in FakeTransport
    36  	subscribers []peer.Subscriber
    37  	status      peer.Status
    38  }
    39  
    40  // Identifier returns the fake peer identifier.
    41  func (p *FakePeer) Identifier() string {
    42  	return p.id.Identifier()
    43  }
    44  
    45  // String returns a humane representation of the peer and its status for debugging.
    46  func (p *FakePeer) String() string {
    47  	p.lock.RLock()
    48  	defer p.lock.RUnlock()
    49  
    50  	return p.id.Identifier() + ":" + p.status.String()
    51  }
    52  
    53  // Status returns the fake peer status.
    54  func (p *FakePeer) Status() peer.Status {
    55  	p.lock.RLock()
    56  	defer p.lock.RUnlock()
    57  
    58  	return p.status
    59  }
    60  
    61  // StartRequest increments pending request count.
    62  func (p *FakePeer) StartRequest() {
    63  	p.lock.Lock()
    64  	defer p.lock.Unlock()
    65  
    66  	p.status.PendingRequestCount++
    67  }
    68  
    69  // EndRequest decrements pending request count.
    70  func (p *FakePeer) EndRequest() {
    71  	p.lock.Lock()
    72  	defer p.lock.Unlock()
    73  
    74  	p.status.PendingRequestCount--
    75  }
    76  
    77  func (p *FakePeer) simulateConnect() {
    78  	p.simulateStatusChange(peer.Available)
    79  }
    80  
    81  func (p *FakePeer) simulateDisconnect() {
    82  	p.simulateStatusChange(peer.Unavailable)
    83  }
    84  
    85  func (p *FakePeer) simulateStatusChange(status peer.ConnectionStatus) {
    86  	for _, sub := range p.prepareStatusChange(status) {
    87  		sub.NotifyStatusChanged(p.id)
    88  	}
    89  }
    90  
    91  func (p *FakePeer) prepareStatusChange(status peer.ConnectionStatus) []peer.Subscriber {
    92  	p.lock.Lock()
    93  	defer p.lock.Unlock()
    94  
    95  	p.status.ConnectionStatus = status
    96  	subscribers := make([]peer.Subscriber, len(p.subscribers))
    97  	copy(subscribers, p.subscribers)
    98  	return subscribers
    99  }
   100  
   101  func (p *FakePeer) subscribe(ps peer.Subscriber) {
   102  	p.lock.Lock()
   103  	defer p.lock.Unlock()
   104  
   105  	p.subscribers = append(p.subscribers, ps)
   106  }
   107  
   108  func (p *FakePeer) unsubscribe(ps peer.Subscriber) int {
   109  	p.lock.Lock()
   110  	defer p.lock.Unlock()
   111  
   112  	subscribers, count := filterSubscriber(p.subscribers, ps)
   113  	p.subscribers = subscribers
   114  	return count
   115  }
   116  
   117  func filterSubscriber(subs []peer.Subscriber, ps peer.Subscriber) ([]peer.Subscriber, int) {
   118  	res := make([]peer.Subscriber, 0, len(subs))
   119  	count := 0
   120  	for _, sub := range subs {
   121  		if sub != ps {
   122  			res = append(res, sub)
   123  		} else {
   124  			count++
   125  		}
   126  	}
   127  	return res, count
   128  }