PHP fsockopen Is Slow

问题:

I'm playing around with the IMAP protocol in PHP using fsockopen to send and receive commands. My preliminary experiments work but are insanely slow. It takes about 2 minutes for the simple function below to run. I've tried several different IMAP servers and have gotten the same result. Can anyone tell me why this code is so slow?

<?php

function connectToServer($host, $port, $timeout) {
    // Connect to the server
    $conn = fsockopen($host, $port, $errno, $errstr, $timeout);

    // Write IMAP Command
    $command = "a001 CAPABILITY\r\n";

    // Send Command
    fputs($conn, $command, strlen($command));

    // Read in responses
    while (!feof($conn)) {
        $data .= fgets($conn, 1024);
    }

    // Display Responses
    print $data;

    // Close connection to server
    fclose($conn);
}

connectToServer('mail.me.com', 143, 30);

?>

This is the response I get back:

macinjosh:Desktop Josh$ php test.php
* OK [CAPABILITY mmp0613 IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ NAMESPACE UIDPLUS CHILDREN BINARY UNSELECT SORT LANGUAGE IDLE XSENDER X-NETSCAPE XSERVERINFO X-SUN-SORT X-SUN-IMAP X-ANNOTATEMORE X-UNAUTHENTICATE XUM1 AUTH=PLAIN STARTTLS] Messaging Multiplexor (Sun Java(tm) System Messaging Server 6.3-6.03 (built Jun  5 2008))
* CAPABILITY mmp0613 IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ NAMESPACE UIDPLUS CHILDREN BINARY UNSELECT SORT LANGUAGE IDLE XSENDER X-NETSCAPE XSERVERINFO X-SUN-SORT X-SUN-IMAP X-ANNOTATEMORE X-UNAUTHENTICATE XUM1 AUTH=PLAIN STARTTLS
a001 OK CAPABILITY completed

回答1:

It seems like feof won't return true until the remote side times out and closes the connection. The $timeout parameter that you are passing only applies to the initial connection attempt.

Try changing your while loop to print the status directly:

while (!feof($conn)) {
    print fgets($conn, 1024);
}

Or change your loop exit condition to break after its read the full reply. It would probably have to be smarter about the protocol.

Finally, I have to ask, why aren't you using PHP's built-in IMAP client?