fermentord/vendor/github.com/nats-io/nats.go/legacy_jetstream.md

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2024-06-15 13:58:47 +00:00
# Legacy JetStream API
This is a documentation for the legacy JetStream API. A README for the current
API can be found [here](jetstream/README.md)
## JetStream Basic Usage
```go
import "github.com/nats-io/nats.go"
// Connect to NATS
nc, _ := nats.Connect(nats.DefaultURL)
// Create JetStream Context
js, _ := nc.JetStream(nats.PublishAsyncMaxPending(256))
// Simple Stream Publisher
js.Publish("ORDERS.scratch", []byte("hello"))
// Simple Async Stream Publisher
for i := 0; i < 500; i++ {
js.PublishAsync("ORDERS.scratch", []byte("hello"))
}
select {
case <-js.PublishAsyncComplete():
case <-time.After(5 * time.Second):
fmt.Println("Did not resolve in time")
}
// Simple Async Ephemeral Consumer
js.Subscribe("ORDERS.*", func(m *nats.Msg) {
fmt.Printf("Received a JetStream message: %s\n", string(m.Data))
})
// Simple Sync Durable Consumer (optional SubOpts at the end)
sub, err := js.SubscribeSync("ORDERS.*", nats.Durable("MONITOR"), nats.MaxDeliver(3))
m, err := sub.NextMsg(timeout)
// Simple Pull Consumer
sub, err := js.PullSubscribe("ORDERS.*", "MONITOR")
msgs, err := sub.Fetch(10)
// Unsubscribe
sub.Unsubscribe()
// Drain
sub.Drain()
```
## JetStream Basic Management
```go
import "github.com/nats-io/nats.go"
// Connect to NATS
nc, _ := nats.Connect(nats.DefaultURL)
// Create JetStream Context
js, _ := nc.JetStream()
// Create a Stream
js.AddStream(&nats.StreamConfig{
Name: "ORDERS",
Subjects: []string{"ORDERS.*"},
})
// Update a Stream
js.UpdateStream(&nats.StreamConfig{
Name: "ORDERS",
MaxBytes: 8,
})
// Create a Consumer
js.AddConsumer("ORDERS", &nats.ConsumerConfig{
Durable: "MONITOR",
})
// Delete Consumer
js.DeleteConsumer("ORDERS", "MONITOR")
// Delete Stream
js.DeleteStream("ORDERS")
```