Hands-On Software Engineering with Golang

Sending and receiving messages

As we mentioned previously, vertices communicate with each other by exchanging messages. Sending the same message to all immediate neighbors of a particular vertex is an often recurring pattern in several graph algorithms. Let's define a convenience method for handling this fairly common use case:

func (g *Graph) BroadcastToNeighbors(v *Vertex, msg message.Message) error {
    for _, e := range v.edges {
        if err := g.SendMessage(e.dstID, msg); err != nil {
            return err
        }
    }

    return nil
}

BroadcastToNeighbors simply iterates the list of edges for a particular vertex and attempts to send the message to each neighbor with the help of the SendMessage method. With the help of SendMessage, compute functions can send a message ...