What are the differences and connections between curl_upkeep() and curl_reset()

curl_upkeep() is a relatively rare cURL function that is used to handle and its related connection information so that the connection is not closed prematurely between multiple requests. Its purpose is to multiplex connections in multiple requests, avoiding re-establishing the connection every time it requests, thereby improving efficiency.

effect :

• Reduce re-establishment of connections by maintaining existing cURL handles.

• Suitable for interaction with the same server when multiple requests are required to be made frequently in a short period of time.

Use scenarios :

• If you need to send multiple requests to a server through the same connection, instead of reopening the connection every time you request, using curl_upkeep() can reduce the overhead.

• In an HTTP keep-alive environment, curl_upkeep() can keep the connection active for reuse next time.

Here is a sample code using curl_upkeep() :

 <?php
$ch = curl_init(); // initialization cURL Handle
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/data"); // set up URL
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); // Return result

// Make the first request
$response = curl_exec($ch);
echo "First request result: $response";

// use curl_upkeep Maintain connection
curl_upkeep($ch); 

// Make a second request，Reuse existing connections
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/otherdata");
$response = curl_exec($ch);
echo "The result of the second request: $response";

// closure cURL Handle
curl_close($ch);
?>

2. The role and usage scenarios of curl_reset() function

The curl_reset() function is used to reset a cURL handle and return it to its initialized state. Unlike curl_upkeep() maintains a connection, curl_reset() completely resets the current cURL handle, which means that all options will be cleared and the connection information will be lost.

effect :

• Clear the configuration of the cURL handle, reset all options, and return to the initial state.

• Used when you need to reconfigure the cURL handle without closing the handle.

Use scenarios :

• When you use a cURL handle to send multiple different requests and need to clear the previous configuration between each request, you can use curl_reset() .

• If you plan to reconfigure the options for cURL handles, such as changing the request URL or changing other settings without wishing to retain the previous configuration.

Here is a sample code using curl_reset() :

 <?php
$ch = curl_init(); // initialization cURL Handle

// First request
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/data");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($ch);
echo "First request result: $response";

// use curl_reset 重置Handle
curl_reset($ch);

// Second request，Reconfigure options
curl_setopt($ch, CURLOPT_URL, "http://m66.net/api/otherdata");
$response = curl_exec($ch);
echo "The result of the second request: $response";

// closure cURL Handle
curl_close($ch);
?>

3. The difference between curl_upkeep() and curl_reset()

4. Summary

• curl_upkeep() is mainly used to maintain existing connection information, so that multiple requests can reuse connections, reduce the time for connection establishment, and is suitable for use when multiple requests to the same server.

• curl_reset() is used to reset the cURL handle and clear the previous configuration, suitable for scenarios where different configurations are required for each request.

Understanding the difference between the two and choosing the right function according to your needs can effectively improve your program efficiency and code clarity.