Share the method of caching the PHP website to speed up the opening speed_PHP tutorial

Notes:
1. The compressed files are cached on the server. Accessing them again reduces re-compression time and CPU usage.
2. By setting the client file cache time to reduce the number of re-requests, it can be reduced by more than 85%.
3. Because the image is already in a compressed format, only the client cache time is set and no compression is performed.

Usage:
1. The server must support gzip and Rewrite functions.
2. Add the following code in the line below "RewriteBase /" in the .htacess file, as shown in the picture
RewriteRule (.*.css$|.*.js$|.*.jpg$|.*.gif $|.*.png$) gzip.php?$1 [L]
3. Upload gzip.php to the root directory
4. Create a cache folder in the root directory to ensure it is readable and writable.

Copy code The code is as follows:

/**
* @author Seraphim
* @copyright 2012
*/
//
function sendheader($last_modified , $p_type, $content_length = 0)
{
// Set the client cache validity time
header("Expires: " . gmdate("D, d M Y H:i:s", time() + 15360000) . "GMT");
header("Cache-Control: max-age=315360000");
header("Pragma: ");
//Set the last modification time
header("Last-Modified: " . $last_modified);
//Set file type information
header($p_type);
header("Content-Length: " . $content_length);
}
define('ABSPATH', dirname(__file__) . '/');
$cache = true;
$cachedir = 'cache/'; //The directory where the gz file is stored, ensure it is writable
if (empty($_SERVER['QUERY_STRING']))
exit();
$gzip = strstr($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip');
if (empty ($gzip))
$cache = false;
$key = array_shift(explode('?', $_SERVER['QUERY_STRING']));
$key = str_replace('../' , '', $key);
$filename = ABSPATH . $key;
$symbol = '_';
$rel_path = str_replace(ABSPATH, '', dirname($filename));
$namespace = str_replace('/', $symbol, $rel_path);
$cache_filename = ABSPATH . $cachedir . $namespace . $symbol . basename($filename) .
'.gz'; / /Generate gz file path
$ext = array_pop(explode('.', $filename)); //Judge file type information based on suffix
$type = "Content-type: text/html"; // Default file type
switch ($ext)
{
case 'css':
$type = "Content-type: text/css";
break;
case ' js':
$type = "Content-type: text/javascript";
break;
case 'gif':
$cache = false;
$type = "Content-type : image/gif";
break;
case 'jpg':
$cache = false;
$type = "Content-type: image/jpeg";
break;
case 'png':
$cache = false;
$type = "Content-type: image/png";
break;
default:
exit();
}
if ($cache)
{
if (file_exists($cache_filename))
{ // If gz file exists
$mtime = filemtime($cache_filename);
$ gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';
if ((isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && array_shift(explode(';', $_SERVER ['HTTP_IF_MODIFIED_SINCE'])) ==
$gmt_mtime))
{
// Consistent with the file modification date in the browser cache, returns 304
header("HTTP/1.1 304 Not Modified ");
// Send client header
header("Content-Encoding :gzip");
sendheader($gmt_mtime, $type);
}
else
{
// Read gz file output
$content = file_get_contents($cache_filename);
// Send client header
sendheader($gmt_mtime, $type, strlen($content));
header("Content-Encoding: gzip");
// Send data
echo $content;
}
}
else
if (file_exists($filename))
{ // There is no corresponding gz file
$mtime = mktime();
$gmt_mtime = gmdate('D, d M Y H:i:s', $mtime) . ' GMT';
// Read the file
$content = file_get_contents($filename);
// Remove the blank part
// $content = ltrim($content);
// Compress the file content
$content = gzencode($content, 9, $gzip ? FORCE_GZIP : FORCE_DEFLATE);
//Send client header
sendheader($gmt_mtime, $type, strlen($content));
header("Content-Encoding: gzip");
// Send data
echo $content;
// Write file
file_put_contents($cache_filename, $content);
}
else
{
header("HTTP/1.0 404 Not Found");
}
}
else
{ // Process output in Gzip mode. The principle is basically the same as above
if (file_exists($filename))
{
$mtime = filemtime($filename);
$gmt_mtime = gmdate('D, d M Y H:i:s', $ mtime) . ' GMT';
if ((isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && array_shift(explode(';', $_SERVER['HTTP_IF_MODIFIED_SINCE'])) ==
$gmt_mtime))
{
// Consistent with the file modification date in the browser cache, returns 304
header("HTTP/1.1 304 Not Modified");
// Send client header
sendheader ($gmt_mtime, $type, strlen($content));
header("Content-Encoding :gzip");
}
else
{
// Read file output
$content = file_get_contents($filename);
// Send client header
sendheader($gmt_mtime, $type, strlen($content));
// Send data
echo $ content;
}
}
else
{
header("HTTP/1.0 404 Not Found");
}
}
?>

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