github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/eventbus/event_bus.go (about)

     1  /*
     2   * Copyright (C) 2019 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package eventbus
    19  
    20  import (
    21  	"fmt"
    22  	"sync"
    23  
    24  	asaskevichEventBus "github.com/mysteriumnetwork/EventBus"
    25  	"github.com/rs/zerolog"
    26  	"github.com/rs/zerolog/log"
    27  )
    28  
    29  // EventBus allows subscribing and publishing data by topic
    30  type EventBus interface {
    31  	Publisher
    32  	Subscriber
    33  }
    34  
    35  // Publisher publishes events
    36  type Publisher interface {
    37  	Publish(topic string, data interface{})
    38  }
    39  
    40  // Subscriber subscribes to events.
    41  type Subscriber interface {
    42  	Subscribe(topic string, fn interface{}) error
    43  	SubscribeAsync(topic string, fn interface{}) error
    44  	Unsubscribe(topic string, fn interface{}) error
    45  	UnsubscribeWithUID(topic, uid string, fn interface{}) error
    46  	SubscribeWithUID(topic, uid string, fn interface{}) error
    47  }
    48  
    49  type simplifiedEventBus struct {
    50  	bus asaskevichEventBus.Bus
    51  
    52  	mu  sync.RWMutex
    53  	sub map[string][]string
    54  }
    55  
    56  func (b *simplifiedEventBus) Unsubscribe(topic string, fn interface{}) error {
    57  	return b.bus.Unsubscribe(topic, fn)
    58  }
    59  
    60  func (b *simplifiedEventBus) UnsubscribeWithUID(topic, uid string, fn interface{}) error {
    61  	b.mu.Lock()
    62  	defer b.mu.Unlock()
    63  
    64  	if len(b.sub[topic]) == 0 {
    65  		return fmt.Errorf("topic %s doesn't exist", topic)
    66  	}
    67  
    68  	for i, id := range b.sub[topic] {
    69  		if id == uid {
    70  			b.sub[topic] = append(b.sub[topic][:i], b.sub[topic][i+1:]...)
    71  
    72  			break
    73  		}
    74  	}
    75  
    76  	if len(b.sub[topic]) == 0 {
    77  		delete(b.sub, topic)
    78  	}
    79  
    80  	return b.bus.Unsubscribe(topic+uid, fn)
    81  }
    82  
    83  func (b *simplifiedEventBus) Subscribe(topic string, fn interface{}) error {
    84  	return b.bus.Subscribe(topic, fn)
    85  }
    86  
    87  func (b *simplifiedEventBus) SubscribeWithUID(topic, uid string, fn interface{}) error {
    88  	b.mu.Lock()
    89  	defer b.mu.Unlock()
    90  
    91  	b.sub[topic] = append(b.sub[topic], uid)
    92  
    93  	return b.bus.Subscribe(topic+uid, fn)
    94  }
    95  
    96  func (b *simplifiedEventBus) SubscribeAsync(topic string, fn interface{}) error {
    97  	return b.bus.SubscribeAsync(topic, fn, false)
    98  }
    99  
   100  func (b *simplifiedEventBus) Publish(topic string, data interface{}) {
   101  	log.WithLevel(levelFor(topic)).Msgf("Published topic=%q event=%+v", topic, data)
   102  	b.bus.Publish(topic, data)
   103  
   104  	b.mu.RLock()
   105  	ids := b.sub[topic]
   106  	idsCopy := make([]string, len(ids))
   107  	copy(idsCopy, ids)
   108  	b.mu.RUnlock()
   109  
   110  	for _, id := range idsCopy {
   111  		b.bus.Publish(topic+id, data)
   112  	}
   113  }
   114  
   115  // New returns implementation of EventBus.
   116  func New() *simplifiedEventBus {
   117  	return &simplifiedEventBus{
   118  		bus: asaskevichEventBus.New(),
   119  		sub: make(map[string][]string),
   120  	}
   121  }
   122  
   123  var logLevelsByTopic = map[string]zerolog.Level{
   124  	"ProposalAdded":            zerolog.Disabled,
   125  	"ProposalUpdated":          zerolog.Disabled,
   126  	"ProposalRemoved":          zerolog.Disabled,
   127  	"proposalEvent":            zerolog.Disabled,
   128  	"Statistics":               zerolog.Disabled,
   129  	"Throughput":               zerolog.Disabled,
   130  	"State change":             zerolog.TraceLevel,
   131  	"Session data transferred": zerolog.TraceLevel,
   132  	"Session change":           zerolog.TraceLevel,
   133  	"hermes_promise_received":  zerolog.TraceLevel,
   134  }
   135  
   136  func levelFor(topic string) zerolog.Level {
   137  	if level, exist := logLevelsByTopic[topic]; exist {
   138  		return level
   139  	}
   140  
   141  	return zerolog.DebugLevel
   142  }