求基于PHP标准Socket函数的SignalR客户端示例（对接socket.bittrex.com）

Hey Marcel, great job getting the initial connection to Bittrex's SignalR socket working! Let's break down exactly how to subscribe to topics and process those real-time updates using PHP's built-in socket functions. Bittrex uses SignalR over WebSockets with the JSON protocol, so we'll need to handle WebSocket framing, SignalR handshake, subscription messages, and incoming update parsing.

Step 1: Confirm the WebSocket Handshake #

Since you already got a "Success" response, you probably have this covered, but let's recap to make sure. First, you need to initiate a WebSocket connection to Bittrex's SignalR endpoint. Here's the basic handshake code:

$socket = stream_socket_client('ssl://socket.bittrex.com:443', $errno, $errstr, 30);
if (!$socket) {
    die("$errstr ($errno)");
}

$handshakeKey = base64_encode(random_bytes(16));
$handshake = "GET /signalr/connect?transport=webSockets&clientProtocol=1.5 HTTP/1.1\r\n";
$handshake .= "Host: socket.bittrex.com\r\n";
$handshake .= "Upgrade: websocket\r\n";
$handshake .= "Connection: Upgrade\r\n";
$handshake .= "Sec-WebSocket-Key: $handshakeKey\r\n";
$handshake .= "Sec-WebSocket-Version: 13\r\n\r\n";

fwrite($socket, $handshake);
$response = fread($socket, 1024);

// Verify we got the correct handshake response
if (strpos($response, '101 Switching Protocols') === false) {
    die("Handshake failed: $response");
}

Step 2: Send a SignalR Subscription Message #

Once connected, you need to send a JSON-formatted message to subscribe to your target market (like BTC-USD). First, let's create a helper function to pack messages into valid WebSocket frames:

function webSocketEncode($data) {
    $length = strlen($data);
    $frame = chr(0x81); // FIN flag + Text frame type

    if ($length <= 125) {
        $frame .= chr($length);
    } elseif ($length > 125 && $length < 65536) {
        $frame .= chr(126);
        $frame .= pack('n', $length);
    } else {
        $frame .= chr(127);
        $frame .= pack('J', $length);
    }

    return $frame . $data;
}

Now send the subscription message to Bittrex's c2 hub (their official SignalR hub name):

$subscribeMsg = json_encode([
    'H' => 'c2',          // Bittrex's SignalR hub name
    'M' => 'SubscribeToExchangeDeltas', // Subscription method
    'A' => ['BTC-USD'],  // Array of markets to subscribe to
    'I' => 1             // Unique message ID (can be any integer)
]);

fwrite($socket, webSocketEncode($subscribeMsg));

Step 3: Listen for and Process Real-Time Updates #

Next, we need a helper to decode incoming WebSocket frames, then set up a loop to listen for updates:

function webSocketDecode($data) {
    $length = ord($data[1]) & 127;
    if ($length == 126) {
        $payloadOffset = 4;
        $payloadLength = unpack('n', substr($data, 2, 2))[1];
    } elseif ($length == 127) {
        $payloadOffset = 10;
        $payloadLength = unpack('J', substr($data, 2, 8))[1];
    } else {
        $payloadOffset = 2;
        $payloadLength = $length;
    }

    return substr($data, $payloadOffset, $payloadLength);
}

// Start listening for updates
echo "Listening for Bittrex BTC-USD updates...\n\n";
while (!feof($socket)) {
    $buffer = fread($socket, 4096);
    if (empty($buffer)) continue;

    $decodedMsg = webSocketDecode($buffer);
    if (empty($decodedMsg)) continue;

    $signalRData = json_decode($decodedMsg, true);
    if (!$signalRData) continue;

    // Process real-time update messages
    if (isset($signalRData['M'])) {
        foreach ($signalRData['M'] as $method) {
            if ($method['M'] == 'updateExchangeState') {
                $marketUpdate = $method['A'][0];
                echo date('Y-m-d H:i:s') . " | {$marketUpdate['MarketName']}\n";
                echo "Bid: {$marketUpdate['Bid']} | Ask: {$marketUpdate['Ask']} | Last Trade: {$marketUpdate['Last']}\n";
                echo "-------------------------\n";
            }
        }
    }
}

fclose($socket);

Full Working Example #

Putting it all together, here's a complete script you can run:

<?php

function webSocketEncode($data) {
    $length = strlen($data);
    $frame = chr(0x81);

    if ($length <= 125) {
        $frame .= chr($length);
    } elseif ($length > 125 && $length < 65536) {
        $frame .= chr(126);
        $frame .= pack('n', $length);
    } else {
        $frame .= chr(127);
        $frame .= pack('J', $length);
    }

    return $frame . $data;
}

function webSocketDecode($data) {
    $length = ord($data[1]) & 127;
    if ($length == 126) {
        $payloadOffset = 4;
        $payloadLength = unpack('n', substr($data, 2, 2))[1];
    } elseif ($length == 127) {
        $payloadOffset = 10;
        $payloadLength = unpack('J', substr($data, 2, 8))[1];
    } else {
        $payloadOffset = 2;
        $payloadLength = $length;
    }

    return substr($data, $payloadOffset, $payloadLength);
}

// Initialize connection
$socket = stream_socket_client('ssl://socket.bittrex.com:443', $errno, $errstr, 30);
if (!$socket) {
    die("$errstr ($errno)");
}

// Perform WebSocket handshake
$handshakeKey = base64_encode(random_bytes(16));
$handshake = "GET /signalr/connect?transport=webSockets&clientProtocol=1.5 HTTP/1.1\r\n";
$handshake .= "Host: socket.bittrex.com\r\n";
$handshake .= "Upgrade: websocket\r\n";
$handshake .= "Connection: Upgrade\r\n";
$handshake .= "Sec-WebSocket-Key: $handshakeKey\r\n";
$handshake .= "Sec-WebSocket-Version: 13\r\n\r\n";

fwrite($socket, $handshake);
$response = fread($socket, 1024);

if (strpos($response, '101 Switching Protocols') === false) {
    die("Handshake failed: $response");
}

// Send subscription message
$subscribeMsg = json_encode([
    'H' => 'c2',
    'M' => 'SubscribeToExchangeDeltas',
    'A' => ['BTC-USD'],
    'I' => 1
]);
fwrite($socket, webSocketEncode($subscribeMsg));

// Listen for updates
echo "Listening for Bittrex updates...\n\n";
while (!feof($socket)) {
    $buffer = fread($socket, 4096);
    if (empty($buffer)) continue;

    $decoded = webSocketDecode($buffer);
    if (empty($decoded)) continue;

    $signalRMsg = json_decode($decoded, true);
    if (!$signalRMsg) continue;

    if (isset($signalRMsg['M'])) {
        foreach ($signalRMsg['M'] as $method) {
            if ($method['M'] == 'updateExchangeState') {
                $data = $method['A'][0];
                echo date('Y-m-d H:i:s') . " | {$data['MarketName']}\n";
                echo "Bid: {$data['Bid']} | Ask: {$data['Ask']} | Last: {$data['Last']}\n";
                echo "-------------------------\n";
            }
        }
    }
}

fclose($socket);
?>

Quick Notes #

• Other Subscription Methods: Try SubscribeToSummaryDeltas for market summary updates, or SubscribeToOrderBookDeltas for order book changes—just adjust the M value in the subscription message.
• Error Handling: Add reconnection logic if the socket drops, and validate JSON responses to avoid crashes.
• Rate Limits: Bittrex enforces SignalR connection limits, so avoid spamming subscription requests.

内容的提问来源于stack exchange，提问作者Marcel Molenaar