使用PHP访问没有数据库的计数器 [英] Visits counter without database with PHP

问题描述

我只有一个网页，我想跟踪它在不使用数据库的情况下被访问了多少次.

I have a single webpage and i would like to track how many times it's visited without using a database.

我考虑过XML，每次用户访问页面时都会更新文件:

I thought about XML, updating a file every time a user visits the page:

<?xml version='1.0' encoding='utf-8'?>
<counter>8</counter>

然后，我认为最好在一个单独的文件中声明一个PHP计数器，然后在用户每次访问该页面时对其进行更新.

Then i thought it could have been a better idea to declare a PHP counter in a separate file and then update it everytime a user visits the page.

counter.php

counter.php

<?php
    $counter = 0;
?>

update_counter.php:

update_counter.php:

<?php
    include "counter.php";
    $counter += 1;
    $var = "<?php\n\t\$counter = $counter;\n?>";
    file_put_contents('counter.php', $var);
?>

这样，每次访问update_counter.php时，counter.php文件中的变量都会增加.

With this, everytime update_counter.php is visited, the variable in the counter.php file is incremented.

无论如何，我注意到，如果counter.php文件具有$counter = 5，并且恰好同时有1000位用户访问了update_counter.php文件，则该文件将同时被读取1000次(因此值5会在所有请求中读取)，counter.php文件将更新为值5+1 (=6)而不是1005.

Anyway, i noticed that if the counter.php file has $counter = 5 and the update_counter.php file is visited by i.e. 1000 users at the exact same time, the file gets read 1000 times at the same time (so the the value 5 gets read in all requests) the counter.php file will be updated with value 5+1 (=6) instead of 1005.

有没有一种方法可以使它在不使用数据库的情况下正常工作?

Is there a way to make it work without using database?

推荐答案

您可以使用flock()来锁定文件，以便其他进程不写入该文件.

You can use flock() which will lock the file so that other processes are not writing to the file.

已更新为使用fread()而不是include()

$fp = fopen("counter.txt", "r+");

while(!flock($fp, LOCK_EX)) {  // acquire an exclusive lock
    // waiting to lock the file
}

$counter = intval(fread($fp, filesize("counter.txt")));
$counter++;

ftruncate($fp, 0);      // truncate file
fwrite($fp, $counter);  // set your data
fflush($fp);            // flush output before releasing the lock
flock($fp, LOCK_UN);    // release the lock

fclose($fp);

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