# azservicebus

An unofficial and experimental AMQP 1.0 client for Azure Service Bus.

This crate follows a similar structure to the dotnet sdk
([Azure.Messaging.ServiceBus](https://github.com/Azure/azure-sdk-for-net/tree/main/sdk/servicebus/Azure.Messaging.ServiceBus))
and provides more features than
[azure_messaging_servicebus](https://crates.io/crates/azure_messaging_servicebus). The list of
supported Service Bus features can be found below ([Supported Service Bus
Features](#supported-service-bus-features)). A complete comparison of supported features in REST
client and AMQP 1.0 client can be found
[here](https://learn.microsoft.com/en-us/rest/api/servicebus/rest-dotnet-client-support#features-exposed-using-both-the-rest-client-and-the-net-managed-api).

Because this crate currently lives in a fork of `azure-sdk-for-rust` and GitHub doesn't seem to
allow raising issue in forks. Please use the upstream AMQP 1.0 crate
[fe2o3-amqp](https://github.com/minghuaw/fe2o3-amqp) GitHub repo should you have any
issue/feature request.

## Content

- [Homepage](https://github.com/minghuaw/azservicebus)
- [Examples](#examples)
  - [Send messages to queue](#send-messages-to-queue)
  - [Receive messages from queue](#receive-messages-from-queue)
- [Supported Service Bus Features](#supported-service-bus-features)
- [TLS Support](#tls-support)
- [Feature flags](#feature-flags)
- [Change
  log](https://github.com/minghuaw/azservicebus/blob/main/CHANGELOG.md)

## Examples

Below are two examples of sending and receiving messages from a queue. More examples can be
found in the
[examples](https://github.com/minghuaw/azservicebus/tree/main/examples)

### Send messages to queue

```rust
use azservicebus::prelude::*;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Replace "<NAMESPACE-CONNECTION-STRING>" with your connection string,
    // which can be found in the Azure portal and should look like
    // "Endpoint=sb://<NAMESPACE>.servicebus.windows.net/;SharedAccessKeyName=<KEY_NAME>;SharedAccessKey=<KEY_VALUE>"
    let mut client = ServiceBusClient::new_from_connection_string(
        "<NAMESPACE-CONNECTION-STRING>",
        ServiceBusClientOptions::default()
    )
    .await?;

    // Replace "<QUEUE-NAME>" with the name of your queue
    let mut sender = client.create_sender(
        "<QUEUE-NAME>",
        ServiceBusSenderOptions::default()
    )
    .await?;

    // Create a batch
    let mut message_batch = sender.create_message_batch(Default::default())?;

    for i in 0..3 {
        // Create a message
        let message = ServiceBusMessage::new(format!("Message {}", i));
        // Try to add the message to the batch
        if let Err(e) = message_batch.try_add_message(message) {
            // If the batch is full, an error will be returned
            println!("Failed to add message {} to batch: {:?}", i, e);
            break;
        }
    }

    // Send the batch of messages to the queue
    match sender.send_message_batch(message_batch).await {
        Ok(()) => println!("Batch sent successfully"),
        Err(e) => println!("Failed to send batch: {:?}", e),
    }

    sender.dispose().await?;
    client.dispose().await?;

    Ok(())
}
```

### Receive messages from queue

```rust
use azservicebus::prelude::*;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Replace "<NAMESPACE-CONNECTION-STRING>" with your connection string,
    // which can be found in the Azure portal and should look like
    // "Endpoint=sb://<NAMESPACE>.servicebus.windows.net/;SharedAccessKeyName=<KEY_NAME>;SharedAccessKey=<KEY_VALUE>"
    let mut client = ServiceBusClient::new_from_connection_string(
        "<NAMESPACE-CONNECTION-STRING>",
        ServiceBusClientOptions::default()
    )
    .await?;

    // Replace "<QUEUE-NAME>" with the name of your queue
    let mut receiver = client.create_receiver_for_queue(
        "<QUEUE-NAME>",
        ServiceBusReceiverOptions::default()
    )
    .await?;

    // Receive messages from the queue
    // This will wait indefinitely until at least one message is received
    let messages = receiver.receive_messages(3).await?;

    for message in &messages {
        let body = message.body()?;
        println!("Received message: {:?}", std::str::from_utf8(body)?);

        // Complete the message so that it is removed from the queue
        receiver.complete_message(message).await?;
    }

    receiver.dispose().await?;
    client.dispose().await?;

    Ok(())
}
```

## Supported Service Bus Features

Below shows supported Service Bus features

| Feature | Supported |
| ------- | --------- |
| Send messages to queue/topic | Yes |
| Receive messages from queue/subscription | Yes |
| Session receivers for queue/subscription | Yes |
| Prefetch | Yes |
| Schedule messages | Yes |
| Cancel scheduled messages | Yes |
| Peek messages | Yes |
| Complete messages | Yes |
| Abandon messages | Yes |
| Defer messages | Yes |
| Receive deferred messages | Yes |
| Dead-letter messages | Yes |
| Receive dead-lettered messages | Yes |
| Batching | Yes |
| Manage rule filters for subscriptions | Yes |
| Lock renewal | Yes |
| Transaction | Not yet |
| Processor | Not yet |
| Session processor | Not yet |

## TLS Support

Communication between a client application and an Azure Service Bus namespace is encrypted using
Transport Layer Security (TLS). The TLS implementation is exposed to the user through the
corresponding feature flags (please see the feature flag section below). The user should ensure
either the `rustls` or `native-tls` feature is enabled, and one and only one TLS implementation
is enabled. Enabling both features is **not** supported and will result in a compile-time error.

The `native-tls` feature is enabled by default, and it will use the `native-tls` crate to
provide TLS support. The `rustls` feature will use the `rustls` crate and `webpki-roots` crate
to provide TLS support.

## Feature flags

This crate supports the following feature flags:

| Feature | Description |
| ------- | ----------- |
| `default` | Enables "native-tls" feature |
| `rustls` | Enables the use of the `rustls` crate for TLS support |
| `native-tls` | Enables the use of the `native-tls` crate for TLS support |
| `transaction` | This is reserved for future support of transaction and is not implemented yet |

## WebAssembly Support

WebAssembly is supported. Please see the [`wasm32_in_browser`
example](https://github.com/minghuaw/azure-sdk-for-rust/tree/separate_servicebus_crate/sdk/messaging_servicebus/examples/wasm32_in_browser)
for more details.

## MSRV (Minimum Supported Rust Version)

1.75.0

License: MIT