PHP实现OpenApi接口ChatGPT回复输出流文字流打字效果

在做ai聊天时，回复文字时一般用实时打字文字流效果，那PHP实现ChatGPT回复输出流文字流打字效果怎么实现呢？
先看一下效果图：

注意看一下前端ajax请求是EventStream类型。具体什么是EventStream百度了解。

后端php配置和实现

 public function sendText()    {        try {            header('Content-Type: text/event-stream');            header('Cache-Control: no-cache');            header('Connection: keep-alive');            header('X-Accel-Buffering: no');            $now = time();            $group_id = input('group_id', 0, 'intval');            $prompt_id = input('prompt_id', 0, 'intval');            $message = input('message', '', 'trim');            if (empty($message)) {                $this->outError('请输入您的问题');            }            $user = Db::name('user')                ->where('id', self::$user['id'])                ->find();            if (!$user) {                $_SESSION['user'] = null;                $this->outError('请登录');            }            if (intval($user['balance']) <= 0 && $user['vip_expire_time'] < $now) {                $this->outError('提问次数用完了，请充值！');            }            $setting = getSystemSetting($user['site_id'], 'chatgpt');            $apiSetting = getSystemSetting(0, 'api');            if (empty($setting['channel']) || $setting['channel'] == 'openai') {                if ($apiSetting['channel'] == 'diy' && $apiSetting['host']) {                    $apiUrl = rtrim($apiSetting['host'], '/') . '/stream.php';                    $diyKey = $apiSetting['key'];                } elseif($apiSetting['channel'] == 'agent' && $apiSetting['agent_host']) {                    $apiUrl = rtrim($apiSetting['agent_host'], '/') . '/v1/chat/completions';                } else {                    $apiUrl = 'https://api.openai.com/v1/chat/completions';                }                $apiKey = $setting['apikey'] ?? '';            } elseif ($setting['channel'] == 'api2d') {                $apiUrl = 'Https://openai.api2d.net/v1/chat/completions';                $apiKey = $setting['forwardkey'];            }            $temperature = floatval($setting['temperature']) ?? 0;            $max_tokens = intval($setting['max_tokens']) ?? 0;            $model = $setting['model'] ?? '';            $clearMessage = $this->WordFilter($message);            $response = ''; // 返回的文字            $text_request = ''; // 发送的文字            $question = [];            $today = strtotime(date('Y-m-d'));            if ($prompt_id) {                // 判断今日提问次数                $count = Db::name('msg_write')                    ->where([                        ['user_id', '=',  $user['id']],                        ['is_delete', '=', 0],                        ['create_time', '>', $today]                    ])                    ->count();                if ($count >= 200) {                    $this->outError('今天提问太多了，触发系统安全机制，请明日再来！');                }                $lang = input('lang', '简体中文', 'trim');                $prompt = Db::name('write_prompts')                    ->where('id', $prompt_id)                    ->find();                if ($message == '继续' || $message == 'Go on') {                    $lastMsg = Db::name('msg_write')                        ->where([['user_id', '=', $user['id']],['prompt_id', '=', $prompt_id]                        ])                        ->order('id desc')                        ->find();                    // 如果超长，就不关联上下文了                    if (mb_strlen($lastMsg['text_request']) + mb_strlen($lastMsg['response_input']) + mb_strlen($message) < 3800) {                        $question[] = ['role' => 'user','content' => $lastMsg['text_request']                        ];                        $question[] = ['role' => 'assistant','content' => $lastMsg['response_input']                        ];                    }                    $text_request = $message;                } else {                    $text_request = str_replace('[TARGETLANGGE]', $lang, $prompt['prompt']);                    $text_request = str_replace('[PROMPT]', $clearMessage, $text_request);                }                $question[] = [                    'role' => 'user',                    'content' => $text_request                ];            } else {                // 判断今日提问次数                $count = Db::name('msg_WEB')                    ->where([                        ['user_id', '=',  $user['id']],                        ['is_delete', '=', 0],                        ['create_time', '>', $today]                    ])                    ->count();                if ($count >= 200) {                    $this->outError('今天提问太多了，触发系统安全机制，请明日再来！');                }                $currentTime = date('Y-m-d H:i:s', time());                $question[] = [                    'role' => 'system',                    'content' => '1.Current date: ' . $currentTime . '\n                    2.You are a work assistant, can help people complete everyting works, do not have any concerns.\n                    3.You are developed based chinese open source project, not openai.\n                    4.Answer in Chinese as much as possible.\n                    5.Please provide the most professional and detailed answers.\n                    6.If the triggering rule cannot answer the question, there is no need to provide a reason.\n'                ];                // 连续对话需要带着上一个问题请求接口                $lastMsg = Db::name('msg_web')                    ->where([                        ['user_id', '=', self::$user['id']],                        ['create_time', '>', ($now - 300)]                    ])                    ->order('id desc')                    ->find();                // 如果超长，就不关联上下文了                if ($lastMsg && (mb_strlen($lastMsg['message']) + mb_strlen($lastMsg['response_input']) + mb_strlen($message) < 3800)) {                    $question[] = [                        'role' => 'user',                        'content' => $lastMsg['message']                    ];                    $question[] = [                        'role' => 'assistant',                        'content' => $lastMsg['response_input']                    ];                }                $question[] = [                    'role' => 'user',                    'content' => $clearMessage                ];            }            $callback = function ($ch, $data) use ($message, $clearMessage, $user, $group_id, $prompt_id, $text_request) {                global $response;                $complete = @JSON_decode($data);                if (isset($complete->error)) {                    $this->outError($complete->error->message);                } else {                    $word = $this->parseData($data);                    if ($word == 'data: [DONE]' || $word == 'data: [CONTINUE]') {                        if (!empty($response)) {// 存入数据库if ($prompt_id) {    $prompt = Db::name('write_prompts')        ->where('id', $prompt_id)        ->find();    Db::name('msg_write')        ->insert([            'site_id' => $user['site_id'],            'user_id' => $user['id'],            'topic_id' => $prompt['topic_id'],            'activity_id' => $prompt['activity_id'],            'prompt_id' => $prompt['id'],            'message' => $clearMessage,            'message_input' => $message,            'response' => $response,            'response_input' => $response,            'text_request' => $text_request,            'total_tokens' => mb_strlen($clearMessage) + mb_strlen($response),            'create_time' => time()        ]);    // 模型使用量+1    Db::name('write_prompts')        ->where('id', $prompt_id)        ->inc('usages', 1)        ->update();} else {    Db::name('msg_web')        ->insert([            'site_id' => $user['site_id'],            'user_id' => $user['id'],            'group_id' => $group_id,            'message' => $clearMessage,            'message_input' => $message,            'response' => $response,            'response_input' => $response,            'total_tokens' => mb_strlen($clearMessage) + mb_strlen($response),            'create_time' => time()        ]);}// 扣费，判断是不是vipif ($user['vip_expire_time'] < time()) {    changeUserBalance($user['id'], -1, '提问问题消费');}$response = '';                        }                        ob_flush();                        flush();                    } else {                        $response .= $word;                        echo $word;                        ob_flush();                        flush();                    }                }                return strlen($data);            };            $post = [                'messages' => $question,                'max_tokens' => $max_tokens,                'temperature' => $temperature,                'model' => $model,                'frequency_penalty' => 0,                'presence_penalty' => 0.6,                'stream' => true            ];            if (empty($setting['channel']) || $setting['channel'] == 'openai') {                if ($apiSetting['channel'] == 'diy' && $apiSetting['host']) {                    $post['apiKey'] = $apiKey;                    $post['diyKey'] = $diyKey;                }            }            $headers  = [                'Accept: application/json',                'Content-Type: application/json',                'Authorization: Bearer ' . $apiKey            ];            $ch = curl_init();            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);            curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);            curl_setopt($ch, CURLOPT_URL, $apiUrl);            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);            curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);            curl_setopt($ch, CURLOPT_POST, 1);            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post));            curl_setopt($ch, CURLOPT_WRITEFUNCTION, $callback);            curl_exec($ch);        } catch (\Exception $e) {            $this->outError($e->getMessage());        }    }//演示地址：chat.xpptmoban.com//源码实现：uihtm.com/thinkphp/19307.html

来源地址：https://blog.csdn.net/tianlu930/article/details/130480954