Gorilla を使用して Go で特定のクライアントに Websocket メッセージを送信する方法

<code class="go">// hub.go

// ... Existing code ...

type Hub struct {
    // Registered clients.
    clients map[*Client]bool

    // Inbound messages from the clients.
    broadcast chan []byte

    // Register requests from the clients.
    register chan *Client

    // Unregister requests from clients.
    unregister chan *Client

    connections map[string]*connection
}

// ... Existing code ...</code>

<code class="go">// client.go

// ... Existing code ...

type Client struct {
    // unique ID for each client
    ID string

    // Hub object
    hub *Hub

    // The websocket connection.
    conn *websocket.Conn

    // Buffered channel of outbound messages.
    send chan []byte
}

// ... Existing code ...</code>

<code class="go">// hub.go

// ... Existing code ...

type Hub struct {
    // ... Existing fields ...

    // Send channel for specific clients.
    send chan message
}

// ... Existing code ...</code>

<code class="go">// ...
// Send a message to a client with ID "targetID".
hub.send <- message{ID: "targetID", data: messageData}
// ...</code>