pubsubchannel

Documentation

Overview

Copyright 2019 The Swarm Authors This file is part of the Swarm library.

The Swarm library is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

The Swarm library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the Swarm library. If not, see <http://www.gnu.org/licenses/>.

Index

• type PubSubChannel
  • func New(inboxSize int) *PubSubChannel
  • func (psc *PubSubChannel) Close()
  • func (psc *PubSubChannel) NumSubscriptions() int
  • func (psc *PubSubChannel) Publish(msg interface{})
  • func (psc *PubSubChannel) Subscribe() *Subscription
• type Subscription
  • func (sub *Subscription) ID() string
  • func (sub *Subscription) IsClosed() bool
  • func (sub *Subscription) MessageCount() int
  • func (sub *Subscription) Pending() int64
  • func (sub *Subscription) ReceiveChannel() <-chan interface{}
  • func (sub *Subscription) Unsubscribe()

Types

type PubSubChannel

type PubSubChannel struct {
	// contains filtered or unexported fields
}

PubSubChannel represents a pubsub system where subscriber can .Subscribe() and publishers can .Publish() or .Close(). When it publishes a message, it notifies all subscribers semi-asynchronously, meaning that each subscription will have an inbox of size inboxSize, but then a different goroutine will send those messages to the subscribers.

func New

func New(inboxSize int) *PubSubChannel

New creates a new PubSubChannel.

func (*PubSubChannel) Close

func (psc *PubSubChannel) Close()

Close cancels all subscriptions closing the channels associated with them. Usually the publisher is in charge of calling Close().

func (*PubSubChannel) NumSubscriptions

func (psc *PubSubChannel) NumSubscriptions() int

NumSubscriptions returns how many subscriptions are currently active.

func (*PubSubChannel) Publish

func (psc *PubSubChannel) Publish(msg interface{})

Publish broadcasts a message synchronously to each subscriber inbox.

func (*PubSubChannel) Subscribe

func (psc *PubSubChannel) Subscribe() *Subscription

Subscribe creates a subscription to a channel, each subscriber should keep its own Subscription instance.

type Subscription

type Subscription struct {
	// contains filtered or unexported fields
}

Subscription is created in PubSubChannel using pubSub.Subscribe(). Subscribers can receive using .ReceiveChannel(). or .Unsubscribe()

func (*Subscription) ID

func (sub *Subscription) ID() string

ID returns a unique id in the PubSubChannel of this subscription. Useful for debugging.

func (*Subscription) IsClosed

func (sub *Subscription) IsClosed() bool

IsClosed returns if the subscription is closed via Unsubscribe() or Close() in the pubSub that creates it.

func (*Subscription) MessageCount

func (sub *Subscription) MessageCount() int

func (*Subscription) Pending

func (sub *Subscription) Pending() int64

func (*Subscription) ReceiveChannel

func (sub *Subscription) ReceiveChannel() <-chan interface{}

ReceiveChannel returns the channel where the subscriber will receive messages.

func (*Subscription) Unsubscribe

func (sub *Subscription) Unsubscribe()

Unsubscribe cancels subscription from the subscriber side. Channel is marked as closed but only writer should close it.