https://github.com/yaa110/pubsub
PubSub Library for Golang
https://github.com/yaa110/pubsub
Last synced: 6 months ago
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PubSub Library for Golang
- Host: GitHub
- URL: https://github.com/yaa110/pubsub
- Owner: yaa110
- License: mit
- Created: 2024-11-02T22:05:29.000Z (8 months ago)
- Default Branch: main
- Last Pushed: 2024-11-03T13:29:48.000Z (8 months ago)
- Last Synced: 2024-11-12T11:06:47.162Z (8 months ago)
- Language: Go
- Homepage:
- Size: 11.7 KB
- Stars: 5
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# PubSub for Golang
[](https://github.com/yaa110/pubsub/actions/workflows/test.yaml) [](http://goreportcard.com/report/yaa110/pubsub) [](https://github.com/yaa110/pubsub/blob/master/LICENSE) [](https://codecov.io/github/yaa110/pubsub) [](https://pkg.go.dev/github.com/yaa110/pubsub)
This package provides an internal PubSub system for Golang, allowing messages to be published and subscribed to.
## Getting Started
- Import package:
```go
import "github.com/yaa110/pubsub"
```
- The pubsub package supports two types of subscribers: channels and types that implement the `pubsub.Receiver` interface. For instance, you can define a receiver as follows:
```go
type CustomMessage struct {
Content string
}
type CustomReceiver struct {
}
func (d *CustomReceiver) Receive(msg *CustomMessage) {
slog.Info("received message", "content", msg.Content)
}
```
- Subscribe/Unsubscribe for a type of message:
```go
// Using a channel as subscriber.
chn := make(chan *CustomMessage)
sd1 := pubsub.Subscribe[CustomMessage](chn) // returns a descriptor
// Using a custom receiver as subscriber.
receiver := &CustomReceiver{}
sd2 := pubsub.Subscribe[CustomMessage](receiver)
// Unsubscribe using the descriptor.
pubsub.Unsubscribe(sd1)
```
**Note** that a topic is automatically created for each message type, allowing all subscribers of that message type to receive the published messages.
- Publish a message:
```go
pubsub.Publish(&CustomMessage{
Content: "data",
})
```
**Note** that all subscribers will receive a pointer to the published message, with each receiver running in a new goroutine, so the user should handle concurrent calls to the `Receive` method.
The pubsub package can also be used with built-in types like `string` or `int`; you simply need to pass a pointer to these types:
```go
chn := make(chan *int, 1) // also a custom receiver can be used to receive *int values
pubsub.Subscribe[int](chn)
assert(*<-chn, 2)
pubsub.Publish(pointer(2)) // publishes to "int" topic
func pointer[T any](t T) *T {
return &t
}
```
**Note** that published messages will only be received by subscribers that were subscribed prior to the message being published.
A single instance of pubsub can handle publishing and subscribing for multiple message types:
```go
pubsub.Publish(pointer(2)) // publishes to "int" topic
pubsub.Publish(pointer("test")) // publishes to "string" topic
```
## Test Isolation
Since a global pubsub instance is created for the entire program, it can lead to issues when tests are run concurrently. To resolve this, call `pubsub.Isolate` at the beginning of each test:
```go
func TestIsolatedPubSub(t *testing.T) {
pubsub.Isolate(t)
// ...
}
func BenchmarkIsolatedPubSub(b *testing.B) {
pubsub.Isolate(b)
// ...
}
```