Node.js与PHP本地通信策略：WebSockets的有效性与考量

<?php

// Node.js WebSocket服务器地址和端口
$host = '127.0.0.1';
$port = 8080; // 假设Node.js WebSocket服务器监听在8080端口

// 构造WebSocket握手请求头
$key = base64_encode(openssl_random_pseudo_bytes(16));
$headers = [
    "GET / HTTP/1.1",
    "Host: {$host}:{$port}",
    "Upgrade: websocket",
    "Connection: Upgrade",
    "Sec-WebSocket-Key: {$key}",
    "Sec-WebSocket-Version: 13",
    "Origin: http://example.com", // 可以是任意有效的源
    "\r\n" // 额外的空行表示HTTP头结束
];
$headerString = implode("\r\n", $headers);

// 连接到Node.js服务器
$errno = $errstr = null;
$socket = stream_socket_client("tcp://{$host}:{$port}", $errno, $errstr, 30);

if (!$socket) {
    die("Failed to connect: {$errstr} ({$errno})\n");
}

// 发送WebSocket握手请求
fwrite($socket, $headerString);

// 读取服务器响应，验证握手
$response = fread($socket, 2048); // 读取握手响应
if (strpos($response, 'HTTP/1.1 101 Switching Protocols') === false) {
    die("WebSocket handshake failed.\n");
}

// 假设握手成功，现在可以发送和接收WebSocket数据帧
// 示例：发送JSON数据
$message = json_encode(['action' => 'getData', 'params' => ['userId' => 123]]);
$encodedMessage = mask(opcode(1, $message)); // opcode 1 for text frame

fwrite($socket, $encodedMessage);

// 读取服务器响应
$responseFrame = fread($socket, 8192); // 读取响应帧
$decodedResponse = unmask($responseFrame); // 解码响应帧
$data = json_decode($decodedResponse, true);

echo "Received from Node.js: " . print_r($data, true) . "\n";

// 关闭连接
fclose($socket);

// 辅助函数：WebSocket数据帧编码
function opcode($opcode, $data) {
    $b1 = 0x80 | ($opcode & 0x0f); // FIN bit + opcode
    $length = strlen($data);

    if ($length <= 125) {
        $header = pack('C2', $b1, $length);
    } elseif ($length > 125 && $length < 65536) {
        $header = pack('C2n', $b1, 126, $length);
    } else {
        $header = pack('C2NN', $b1, 127, $length);
    }
    return $header . $data;
}

// 辅助函数：WebSocket数据帧掩码（客户端发送时需要）
function mask($payload) {
    $masks = openssl_random_pseudo_bytes(4);
    $data = '';
    for ($i = 0; $i < strlen($payload); $i++) {
        $data .= $payload[$i] ^ $masks[$i % 4];
    }
    return pack('C', 0x80 | 0x01) . pack('C', strlen($payload) | 0x80) . $masks . $data;
}

// 辅助函数：WebSocket数据帧解码（服务器接收时需要，这里用于客户端接收后解码）
function unmask($payload) {
    $length = ord($payload[1]) & 127;
    if ($length == 126) {
        $masks = substr($payload, 4, 4);
        $data = substr($payload, 8);
    } elseif ($length == 127) {
        $masks = substr($payload, 10, 4);
        $data = substr($payload, 14);
    } else {
        $masks = substr($payload, 2, 4);
        $data = substr($payload, 6);
    }

    $text = '';
    for ($i = 0; $i < strlen($data); $i++) {
        $text .= $data[$i] ^ $masks[$i % 4];
    }
    return $text;
}
?>