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vertx-tcp-eventbus-bridge

This is a TCP eventbus bridge implementation.

The protocol

The protocol is quite simple:

• 4bytes int32 message length (big endian encoding)
• json string (encoded in UTF-8)

Messages from the bridge -> client

Every JSON message will include a type key, with a string value. Each type is shown below, along with the companion keys for that type:

type: "pong"

pong requires no additional keys.

It is the response to the ping request from client to bridge.

type: "err"

• message: (string, required) The type of error, one of: "access_denied", "unknown_address", "unknown_type"

type: "message"

For a regular message, the object will also contain:

• address: (string, required) Destination address.
• body: (any, required) Message content as a JSON valid type.
• headers: (object, optional) Headers as a JSON object with String values.
• replyAddress: (string, optional) Address for replying to.
• send: (boolean, required) Will be true if the message is a send, false if a publish.

When a message from the client requests a reply, and that reply fails, the object will instead contain:

• failureCode: (number, required) The failure code
• failureType: (string, required) The failure name
• message: (string, required) The message from the exception that signaled the failure

Messages from the client -> bridge

The JSON object must contain a type key with a string value. Each type is shown below, along with the companion keys for that type:

type: "send", type: "publish"

• address: (string, required) Destination address
• body: (any, required) Message content as a JSON valid type.
• headers: (object, optional) Headers as a JSON object with String values.
• replyAddress: (string, optional) Address for replying to.

When type is "send" if the message contains the key failureCode the original message will be failed, content is then:

• address: (string, required) Destination address to fail
• failureCode: (integer, required) Failure code
• message: (string, required) Message that explains the failure

type: "register", type: "unregister"

• address: (string, required) Destination address
• headers: (object, optional) Headers as a JSON object with String values.

type: "ping"

ping requires no additional keys.

Example

An example nodejs client is provided as an example using the same API as SockJS bridge e.g.:

var EventBus = require('tcp-vertx-eventbus');

var eb = new EventBus('localhost', 7000);

eb.onopen = function () {
  // send a echo message
  eb.send('echo', {value: 'vert.x'}, function (err, res) {
    ...
  });
};