Zig

Subscribe to Multiple Bitfinex Tickers on One Connection

See more WebSocket Examples

Subscribes to multiple ticker symbols on the public Bitfinex websocket ticker channel and receives ticker updates. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    const ws = try chilkat.WebSocket.init();
    defer ws.deinit();

    // 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.

    const rest = try chilkat.Rest.init();
    defer rest.deinit();

    // Connect to api.bitfinex.com
    try rest.connect("api.bitfinex.com", 443, true, false);
    ws.useConnection(rest) catch {};
    ws.addClientHeaders() catch {};

    const response_body = try rest.fullRequestNoBody(alloc, "GET", "/ws");
    ws.validateServerHandshake() catch {
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        std.debug.print("{s}\n", .{response_body});
        std.debug.print("{s}\n", .{try rest.getResponseHeader(alloc)});
        return;
    };

    // After connecting, the bitfinex websocket server will send
    // an info message that contains the actual version of the websocket stream.
    // Receive that message..
    ws.readFrame() catch {
        std.debug.print("Failed to receive a frame\n", .{});
        std.debug.print("ReadFrame fail reason = {d}\n", .{ws.getReadFrameFailReason()});
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        return;
    };

    // We should get this:
    // {"event":"info","version":1.1,"platform":{"status":1}}
    std.debug.print("{s}\n", .{try ws.getFrameData(alloc)});

    // Subscribe to the BTCUSD ticker feed.
    // See https://docs.bitfinex.com/docs for more information.
    const json1 = try chilkat.JsonObject.init();
    defer json1.deinit();
    json1.appendString("event", "subscribe") catch {};
    json1.appendString("channel", "ticker") catch {};
    json1.appendString("pair", "BTCUSD") catch {};

    const final_frame = true;
    try ws.sendFrame(try json1.emit(alloc), final_frame);

    // Subscribe to the ETHUSD ticker feed.
    const json2 = try chilkat.JsonObject.init();
    defer json2.deinit();
    json2.appendString("event", "subscribe") catch {};
    json2.appendString("channel", "ticker") catch {};
    json2.appendString("pair", "ETHUSD") catch {};

    try ws.sendFrame(try json2.emit(alloc), final_frame);

    // Begin reading the ticker feed.
    // / This will include a single confirmation response for each subscription.

    // We'll just read the 1st 5 updates and then exit..
    var num_updates_received: i32 = 0;
    while (num_updates_received < 7) {
        ws.readFrame() catch {
            std.debug.print("Failed to receive a frame\n", .{});
            std.debug.print("ReadFrame fail reason = {d}\n", .{ws.getReadFrameFailReason()});
            std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
            return;
        };

        // The responses we desire are in Text frames, where the opcode = 1.
        if (ws.getFrameOpcodeInt() == 1) {
            const received_text = try ws.getFrameData(alloc);
            std.debug.print("{s}\n", .{received_text});
            // Should receive a line of text such as this:
            // [2751,7349,36.34269559,7349.1,41.01777063,-116.2,-0.0156,7349.1,22188.26055319,7560,7270.5]
            // Initially, a single confirmation response for each subscription would be received, such as this:
            // {"event":"subscribed","channel":"ticker","chanId":810,"pair":"BTCUSD"}
            num_updates_received = num_updates_received + 1;
        }
    }

    // This is sample output:
    // You can see that the 1st message received is the subscription confirmation for the BTCUSD subscribe request.
    // The next message is a BTCUSD ticker update.
    // The next message is the confirmation for the ETHUSD subscription.
    // The next message is an ETHUSD update.
    // The BTCUSD channel ID is "537", and the ETHUSD channel ID is "700".  The channel IDs are provided in the
    // subscription confirmation messages.  Each ticker update begins with the channel ID..

    // {"event":"subscribed","channel":"ticker","chanId":537,"pair":"BTCUSD"}
    // [537,6457.9,79.59102302,6458,22.49395741,-24.1,-0.0037,6457.9,13644.52820029,6540,6370.76958739]
    // {"event":"subscribed","channel":"ticker","chanId":700,"pair":"ETHUSD"}
    // [700,496.9,247.24493326,496.92,284.09636979,-2.47,-0.0049,496.9,74154.05945261,502.85,486.96]
    // [537,"hb"]
    // [700,"hb"]
    // [700,496.92,233.34338276,496.93,431.78867277,-2.45,-0.0049,496.92,74167.99173586,502.85,486.96]

    // Close the websocket connection.
    ws.sendClose(true, 1000, "Closing this websocket.") catch {
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        return;
    };

    // Read the Close response.
    ws.readFrame() catch {
        std.debug.print("ReadFrame fail reason = {d}\n", .{ws.getReadFrameFailReason()});
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Success.\n", .{});
}