rabbitmq-server/deps/rabbitmq_stream/docs/PROTOCOL.adoc

= RabbitMQ Stream Protocol Reference

== Types

int8, int16, int32, int64 - Signed integers (big endian order)

uint64 - Unsigned integer (big endian order)

bytes - int32 for the length followed by the bytes of content, length of -1 indicates null.

string - int16 for the length followed by the bytes of content, length of -1 indicates null.

arrays - int32 for the length followed by the repetition of the structure, notation uses [], e.g.
[int32] for an array of int32.

== Frame Structure

```
Frame => Size (Request | Response | Command)
  Size => int32 (size without the 4 bytes of the size element)

Request => Key Version (CorrelationId) Content
  Key => int16
  Version => int16
  CorrelationId => int32
  Command => bytes // see command details below

Response => Key Version CorrelationId ResponseCode
  Key => int16
  Version => int16
  CorrelationId => int32
  ResponseCode => int16

Command => Key Version Content
  Key => int16
  Version => int16
  Content => bytes // see command details below
```

Most commands are request/reply, but some commands (e.g. `Deliver`) are one-direction only and thus
doest not contain a correlation ID.

== Commands

.Stream Protocol Commands
|===
|Command |From |Key | Expects response?

|<<publish>>
|Client
|0
|No

|<<publishconfirm>>
|Server
|1
|No
|===

=== Publish

```
Publish => Key Version Target PublishedMessages
  Key => int16 // 0
  Version => int16
  Target => string // the name of the queue/topic
  PublishedMessages => [PublishedMessage]
  PublishedMessage => PublishingId Message
  Message => bytes
```

=== PublishConfirm

```
PublishConfirm => Key Version PublishingIds
  Key => int16 // 1
  Version => int16
  PublishingIds => [int64] // to correlate with the messages sent
```