如何限制API调用？

Question

Reading it at http://blog.programmableweb.com/2007/04/02/12-ways-to-limit-an-api/ I wondered how to accomplish time based limits (ie. 1 call per second). Well, if authentication required, the way is to compare the seconds tracked by PHP's time function (for instance, if ($previous_call_time == $current_call_time) { ... })? Any other suggestions?

Answer 1

Use a simple cache:

if(filemtime("cache.txt") < (int)$_SERVER["REQUEST_TIME"] - 3600) { // 3600 is one hour in seconds
    $data = file_get_contents("http://remote.api/url/goes/here");
    file_put_contents("cache.txt", $data);
} else
    $data = file_get_contents("cache.txt");

Something like this will save the value of the API and let you get the information whenever you want while still limiting how often you actually pull date from the feed.

Hope this helps!