Using TcpConnection

Each accepted connection gives a std.net.TcpConnection instance, and you can then spawn a new Navi coroutine to handle the connection.

This guide provides an overview of the std.net.TcpConnection type, focusing on creating a connection, reading from it, writing to it, and shutting it down. By following this guide, you will be able to understand and implement TCP communication in their applications.

What is TcpConnection?

A std.net.TcpConnection represents a TCP connection between a local and a remote socket.

Reading and writing to a std.net.TcpConnection is typically done using the convenience methods found on the Read and Write traits. The write_all() method is defined on the Write trait.

Creating a TcpConnection

A std.net.TcpConnection can be created by accepting a connection from a listener. An example is shown below.

use std.net.TcpListener;

fn main() throws {
    let listener = try TcpListener.bind("127.0.0.1:3000");
    loop {
        let conn = try listener.accept();
        spawn {
            // Handling the connection
        }
    }
}

Read

The read() method pulls some bytes from the std.net.TcpConnection into the specified buffer, returning the number of bytes read. An example is shown below.

let buf = Bytes.new(len: 1024);
let n = try! conn.read(buf);
io.println(`read ${n} bytes`);

In the above example, a buffer of 1024 bytes is created to hold the data read from the connection. The read() method reads data from the connection into the buffer. The number of bytes read is returned. The number of bytes read is printed.

Write

The write() method writes a buffer into the std.net.TcpConnection, returning the number of bytes written. The flush() method ensures that all intermediately buffered contents reach their destination. An example is shown below.

let data = "hello world".bytes();
let n = try! conn.write(data);
try! conn.flush();
io.println(`wrote ${n} bytes`);

In the above example, a buffer containing the string "Hello, world!" is created. The write method writes the data to the connection. The number of bytes written is returned. The flush method ensures that all buffered data is sent. The number of bytes written is printed.

The Remote Address

For each accepted connection, you can obtain the remote address of the client using the connection's remote_addr method.

Close The Connection

To close the connection in the write direction, you can call the close method. This will cause the other peer to receive a read of length 0, indicating that no more data will be sent. This only closes the connection in one direction. An example is shown below.

try conn.close();