我对 ReactPHP、异步编程和软件开发完全陌生。我目前正在开发一个我想要异步的 API。 API 必须向外部 API 发出大量 API 请求。我的想法是在后台启动 API 请求，这样它就不会阻止进一步的客户端请求，但我无法使其正常工作。
在整个 API 中，我们必须向多个分发者发出请求，这些分发者都有不同的处理 API 请求的方式，因此我们必须单独实现每个分发者。
在 API 中我使用的是 ReactPHP EventLoop。
我正在使用 React\Promise ll()。因此我创建了 5 个测试 Promise 并将它们提供给 all():
信息：我使用 Guzzle 来执行请求，因为我必须将标头放入该特定分发者的curl 选项中。
private function requestProduct($id, $access_token, $request_url, $client_id)
{
$request_url = str_replace(' ','',$request_url);
$data = [
'currency' => 'EUR',
'limit' => 1,
'search' => $id
];
$request_url .= "search?" . http_build_query($data);
$this->setRequestUrl($request_url);
$header = [
"content-type: application/x-www-form-urlencode",
"accept: application/json",
"authorization: Bearer $access_token",
"client_id: $client_id"
];
// $this->setHeader($header);
$this->client = new Client();
for ($i = 0; $i < 5; $i++) {
$promises[] = new Promise(function ($resolve, $reject) use ($request_url, $header, $i) {
try {
echo "Starting async request {$i} to URL: {$request_url}" . PHP_EOL;
$this->client->getAsync($request_url, [
'curl' => [
CURLOPT_HTTPHEADER => $header,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => false,
]
])
->then(
function (ResponseInterface $response) use ($resolve, $i) {
$content = $response->getBody()->getContents();
$decodedResponse = json_decode($content, true);
if (json_last_error() !== JSON_ERROR_NONE) {
throw new Exception('Invalid JSON response');
}
echo "Request {$i} completed successfully." . PHP_EOL;
$resolve($decodedResponse);
},
function (Exception $e) use ($reject, $i) {
echo "Error during async GET request {$i}: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
);
} catch (Exception $e) {
echo "Unexpected error in request {$i}: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
});
}
echo "Waiting for all promises to resolve" . PHP_EOL;
// Wait for all promises to resolve
return all($promises)
->then(function($responses) {
$result = [];
echo "All Promises resolved" . PHP_EOL;
echo gettype($responses) . PHP_EOL;
foreach ($responses as $i => $response) {
// print_r($response);
$result[$i] = $response['status'];
echo "Result {$i} decoded" . PHP_EOL;
}
print_r($result);
return $result;
})
->catch(function($error) {
echo "An error occurred: {$error->getMessage()}" . PHP_EOL;
throw new Exception("Error in all()", 500);
});
}
该函数在名为 getProductByMpn 的函数中被调用。
从 all() 返回的 Promise 应该在控制器中解决。
public function getProductByMpn($request)
{
try {
$body = $request->getParsedBody();
$distributor = DistributorHelper::getDistributorNameFromPath($request);
$distributorID = $body['linr'];
$mpn = $body['mpn'] ?? null;
if (!$distributor || !$mpn || !$distributorID) {
throw new Exception('Missing distributor, distributor ID or mpn', 400);
}
return $this->distributorService
->getProductByMpn($distributor, $mpn, $distributorID)
->then(function ($response) {
echo "Response successful". PHP_EOL;
return JsonResponse::ok($response);
})
->catch(function ($error) {
echo "Error in getProductByMpn: {$error->getMessage()}" . PHP_EOL;
throw new Exception("Error in getProductByMpn: {$error->getMessage()}", 500);
});
} catch (Exception $e) {
return JsonResponse::individual($e->getCode(), ['error' => $e->getMessage()]);
}
}
现在的问题是它没有解决。相反，它似乎卡在某个地方了。我认为我在解决 Promise 时做错了什么，但我找不到错误。
我还尝试了一个 API 请求，它工作得很好：
private function requestProduct($id, $access_token, $request_url, $client_id)
{
$request_url = str_replace(' ','',$request_url);
$data = [
'currency' => 'EUR',
'limit' => 1,
'search' => $id
];
$request_url .= "search?" . http_build_query($data);
$this->setRequestUrl($request_url);
$header = [
"content-type: application/x-www-form-urlencode",
"accept: application/json",
"authorization: Bearer $access_token",
"client_id: $client_id"
];
// $this->setHeader($header);
$this->client = new Client();
return new Promise(function ($resolve, $reject) use ($request_url, $header) {
try {
echo "Starting async request to URL: {$request_url}" . PHP_EOL;
$this->client->getAsync($request_url, [
'curl' => [
CURLOPT_HTTPHEADER => $header,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => false,
]
])
->then(
function (ResponseInterface $response) use ($resolve) {
$content = $response->getBody()->getContents();
// echo "Response received: $content" . PHP_EOL;
$decodedResponse = json_decode($content, true);
if (json_last_error() !== JSON_ERROR_NONE) {
throw new Exception('Invalid JSON response');
}
$resolve($decodedResponse);
},
function (Exception $e) use ($reject) {
echo "Error during async GET request: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
)
->wait(); // has to stand here to resolve correctly?
} catch (Exception $e) {
echo "Unexpected error: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
});
}
有趣的是，当我将它们混合在一起时，all() 函数工作正常并打印出结果。
这就是混合函数。我认为这与单个 Promise 中的 wait() 有关。当 Promise 没有 wait() 时，它也不起作用。
private function requestProduct($id, $access_token, $request_url, $client_id)
{
$request_url = str_replace(' ','',$request_url);
$data = [
'currency' => 'EUR',
'limit' => 1,
'search' => $id
];
$request_url .= "search?" . http_build_query($data);
$this->setRequestUrl($request_url);
$header = [
"content-type: application/x-www-form-urlencode",
"accept: application/json",
"authorization: Bearer $access_token",
"client_id: $client_id"
];
// $this->setHeader($header);
$this->client = new Client();
for ($i = 0; $i < 5; $i++) {
$promises[] = new Promise(function ($resolve, $reject) use ($request_url, $header, $i) {
try {
echo "Starting async request {$i} to URL: {$request_url}" . PHP_EOL;
$this->client->getAsync($request_url, [
'curl' => [
CURLOPT_HTTPHEADER => $header,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => false,
]
])
->then(
function (ResponseInterface $response) use ($resolve, $i) {
$content = $response->getBody()->getContents();
$decodedResponse = json_decode($content, true);
if (json_last_error() !== JSON_ERROR_NONE) {
throw new Exception('Invalid JSON response');
}
echo "Request {$i} completed successfully." . PHP_EOL;
$resolve($decodedResponse);
},
function (Exception $e) use ($reject, $i) {
echo "Error during async GET request {$i}: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
);
} catch (Exception $e) {
echo "Unexpected error in request {$i}: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
});
}
echo "Waiting for all promises to resolve" . PHP_EOL;
// Wait for all promises to resolve
all($promises)
->then(function($responses) {
$result = [];
echo "All Promises resolved" . PHP_EOL;
echo gettype($responses) . PHP_EOL;
foreach ($responses as $i => $response) {
// print_r($response);
$result[$i] = $response['status'];
echo "Result {$i} decoded" . PHP_EOL;
}
print_r($result);
return $result;
})
->catch(function($error) {
echo "An error occurred: {$error->getMessage()}" . PHP_EOL;
throw new Exception("Error in all()", 500);
});
return new Promise(function ($resolve, $reject) use ($request_url, $header) {
try {
echo "Starting async request to URL: {$request_url}" . PHP_EOL;
$this->client->getAsync($request_url, [
'curl' => [
CURLOPT_HTTPHEADER => $header,
CURLOPT_SSL_VERIFYPEER => false,
CURLOPT_SSL_VERIFYHOST => false,
]
])
->then(
function (ResponseInterface $response) use ($resolve) {
$content = $response->getBody()->getContents();
// echo "Response received: $content" . PHP_EOL;
$decodedResponse = json_decode($content, true);
if (json_last_error() !== JSON_ERROR_NONE) {
throw new Exception('Invalid JSON response');
}
$resolve($decodedResponse);
},
function (Exception $e) use ($reject) {
echo "Error during async GET request: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
)
->wait(); // has to stand here to resolve correctly?
} catch (Exception $e) {
echo "Unexpected error: {$e->getMessage()}" . PHP_EOL;
$reject($e);
}
});
}
all() 的结果符合预期。它打印出每个请求的结果。
是否有另一种方法可以在不使用 wait() 的情况下解决 Promise 以及如何使用 all() 正确解决 Promise？
Guzzle 默认使用
cURLGuzzle 需要 cURL 吗？
不。 Guzzle 可以使用任何 HTTP 处理程序来发送请求。这意味着 Guzzle 可以与 cURL、PHP 的流包装器、套接字和非阻塞库（如 React）一起使用。您只需配置 HTTP 处理程序即可使用不同的发送请求的方法。
您的示例可能不起作用，因为您正在混合基于
cURL您的最后一个示例之所以有效，是因为您直接在
Guzzle 的承诺上调用
wait，这会阻塞直到请求完成。
一种解决方案是使用将 Guzzle 与 ReactPHP 的事件循环集成的库，例如https://github.com/WyriHaximus/react-guzzle-psr7/.
或者，您可以使用 ReactPHP 的 HTTP 客户端而不是 Guzzle。它还支持设置标头（https://reactphp.org/http/#withheader）：
withHeader()方法可用于为所有后续请求添加请求标头。withHeader(string $header, string $value): Browser$browser = $browser->withHeader('User-Agent', 'ACME'); $browser->get($url)->then(…);