Rust

WebSocket Send/Receive Binary Data

See more WebSocket Examples

Demonstrates how to send and receive binary data on a websocket. This example uses Chilkat's websocket test echo server at ws://websockets.chilkat.io/wsChilkatEcho.ashx

Note: The websockets.chilkat.io server imposes the following limitations:
Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.

Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

let ws = chilkat::WebSocket::new();

// For brevity, this example does not check for errors when etablishing the WebSocket connection.
// See Establish WebSocket Connection for more complete sample code for making the connection.

let rest = chilkat::Rest::new();
// Connect to websockets.chilkat.io
// IMPORTANT: websockets.chilkat.io accepts frames of up to 16K in size and echoes them back.
// IMPORTANT: The websockets.chilkat.io server imposes the following limitations: 
// ---------- Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.
let _ = rest.connect("websockets.chilkat.io", 80, false, false).is_ok();
let _ = ws.use_connection(&rest);
let _ = ws.add_client_headers();
let response_body_ignored = rest.full_request_no_body("GET", "/wsChilkatEcho.ashx").unwrap_or_default();
if ws.validate_server_handshake().is_err() {
    println!("{}", ws.last_error_text());
    return;
}

// This example sends a small JPG file (about 7KB) in a websocket frame.
let jpg_data = chilkat::BinData::new();
let _ = jpg_data.load_file("qa_data/jpg/starfish.jpg").is_ok();

println!("Number of bytes to send = {}", jpg_data.num_bytes());

// Send a frame containing the JPG image data.
// This will be the first and final frame, and therefore this constitutes the entire message.
let final_frame = true;
if ws.send_frame_bd(&jpg_data, final_frame).is_err() {
    println!("{}", ws.last_error_text());
    return;
}

// Read the echoed binary frame(s).
// (We sent the JPG file in a single frame, but we may receive the echo in multiple frames, but it will be one message.)
// Read an incoming frames until we receive the final frame.
let mut received_final_frame = false;
while !received_final_frame {

    // The ws object is accumulating the received data internally.  Once we get the final frame, we'll get the 
    // accumulated data which should constitute the entire JPG.
    if ws.read_frame().is_err() {
        println!("Failed to receive a frame");
        println!("ReadFrame fail reason = {}", ws.read_frame_fail_reason());
        println!("{}", ws.last_error_text());
        return;
    }

    received_final_frame = ws.final_frame();

    // Show the opcode and final frame bit for the frame just received:
    println!("Frame opcode: {}", ws.frame_opcode());
    println!("Final frame: {}", received_final_frame);
}

// Get the accumulated received data.
let jpg_received_data = chilkat::BinData::new();
let _ = ws.get_frame_data_bd(&jpg_received_data);
println!("Received {} bytes", jpg_received_data.num_bytes());

// Save the received JPG to a file so we can check it..
let _ = jpg_received_data.write_file("qa_output/starfish_ws.jpg");

// Close the websocket connection.
if ws.send_close(true, 1000, "Closing this websocket.").is_err() {
    println!("{}", ws.last_error_text());
    return;
}

// Read the Close response.
if ws.read_frame().is_err() {
    println!("ReadFrame fail reason = {}", ws.read_frame_fail_reason());
    println!("{}", ws.last_error_text());
    return;
}

// Should receive the "Close" opcode.
println!("Received opcode: {}", ws.frame_opcode());
// Should be the same status code we sent (1000)
println!("Received close status code: {}", ws.close_status_code());
// The server may echo the close reason.  If not, this will be empty.
println!("Echoed close reason: {}", ws.close_reason());

println!("Success.");