questlab/www/analytics/core/ProxyHttp.php
2014-05-03 22:37:04 +02:00

232 lines
9.1 KiB
PHP

<?php
/**
* Piwik - Open source web analytics
*
* @link http://piwik.org
* @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
*
*/
namespace Piwik;
/**
* Http helper: static file server proxy, with compression, caching, isHttps() helper...
*
* Used to server piwik.js and the merged+minified CSS and JS files
*
*/
class ProxyHttp
{
/**
* Returns true if the current request appears to be a secure HTTPS connection
*
* @return bool
*/
public static function isHttps()
{
return Url::getCurrentScheme() === 'https';
}
/**
* Serve static files through php proxy.
*
* It performs the following actions:
* - Checks the file is readable or returns "HTTP/1.0 404 Not Found"
* - Returns "HTTP/1.1 304 Not Modified" after comparing the HTTP_IF_MODIFIED_SINCE
* with the modification date of the static file
* - Will try to compress the static file according to HTTP_ACCEPT_ENCODING. Compressed files are store in
* the /tmp directory. If compressing extensions are not available, a manually gzip compressed file
* can be provided in the /tmp directory. It has to bear the same name with an added .gz extension.
* Using manually compressed static files requires you to manually update the compressed file when
* the static file is updated.
* - Overrides server cache control config to allow caching
* - Sends Very Accept-Encoding to tell proxies to store different version of the static file according
* to users encoding capacities.
*
* Warning:
* Compressed filed are stored in the /tmp directory.
* If this method is used with two files bearing the same name but located in different locations,
* there is a risk of conflict. One file could be served with the content of the other.
* A future upgrade of this method would be to recreate the directory structure of the static file
* within a /tmp/compressed-static-files directory.
*
* @param string $file The location of the static file to serve
* @param string $contentType The content type of the static file.
* @param bool $expireFarFuture Day in the far future to set the Expires header to.
* Should be set to false for files that should not be cached.
*/
public static function serverStaticFile($file, $contentType, $expireFarFutureDays = 100)
{
if (file_exists($file)) {
// conditional GET
$modifiedSince = '';
if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) {
$modifiedSince = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
// strip any trailing data appended to header
if (false !== ($semicolon = strpos($modifiedSince, ';'))) {
$modifiedSince = substr($modifiedSince, 0, $semicolon);
}
}
$fileModifiedTime = @filemtime($file);
$lastModified = gmdate('D, d M Y H:i:s', $fileModifiedTime) . ' GMT';
// set HTTP response headers
self::overrideCacheControlHeaders('public');
@header('Vary: Accept-Encoding');
@header('Content-Disposition: inline; filename=' . basename($file));
if ($expireFarFutureDays) {
// Required by proxy caches potentially in between the browser and server to cache the request indeed
@header("Expires: " . gmdate('D, d M Y H:i:s', time() + 86400 * (int)$expireFarFutureDays) . ' GMT');
}
// Returns 304 if not modified since
if ($modifiedSince === $lastModified) {
self::setHttpStatus('304 Not Modified');
} else {
// optional compression
$compressed = false;
$encoding = '';
$compressedFileLocation = AssetManager::getInstance()->getAssetDirectory() . '/' . basename($file);
$phpOutputCompressionEnabled = ProxyHttp::isPhpOutputCompressed();
if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) && !$phpOutputCompressionEnabled) {
$acceptEncoding = $_SERVER['HTTP_ACCEPT_ENCODING'];
if (extension_loaded('zlib') && function_exists('file_get_contents') && function_exists('file_put_contents')) {
if (preg_match('/(?:^|, ?)(deflate)(?:,|$)/', $acceptEncoding, $matches)) {
$encoding = 'deflate';
$filegz = $compressedFileLocation . '.deflate';
} else if (preg_match('/(?:^|, ?)((x-)?gzip)(?:,|$)/', $acceptEncoding, $matches)) {
$encoding = $matches[1];
$filegz = $compressedFileLocation . '.gz';
}
if (!empty($encoding)) {
// compress-on-demand and use cache
if (!file_exists($filegz) || ($fileModifiedTime > @filemtime($filegz))) {
$data = file_get_contents($file);
if ($encoding == 'deflate') {
$data = gzdeflate($data, 9);
} else if ($encoding == 'gzip' || $encoding == 'x-gzip') {
$data = gzencode($data, 9);
}
file_put_contents($filegz, $data);
}
$compressed = true;
$file = $filegz;
}
} else {
// manually compressed
$filegz = $compressedFileLocation . '.gz';
if (preg_match('/(?:^|, ?)((x-)?gzip)(?:,|$)/', $acceptEncoding, $matches) && file_exists($filegz) && ($fileModifiedTime < @filemtime($filegz))) {
$encoding = $matches[1];
$compressed = true;
$file = $filegz;
}
}
}
@header('Last-Modified: ' . $lastModified);
if (!$phpOutputCompressionEnabled) {
@header('Content-Length: ' . filesize($file));
}
if (!empty($contentType)) {
@header('Content-Type: ' . $contentType);
}
if ($compressed) {
@header('Content-Encoding: ' . $encoding);
}
if (!_readfile($file)) {
self::setHttpStatus('505 Internal server error');
}
}
} else {
self::setHttpStatus('404 Not Found');
}
}
/**
* Test if php output is compressed
*
* @return bool True if php output is (or suspected/likely) to be compressed
*/
public static function isPhpOutputCompressed()
{
// Off = ''; On = '1'; otherwise, it's a buffer size
$zlibOutputCompression = ini_get('zlib.output_compression');
// could be ob_gzhandler, ob_deflatehandler, etc
$outputHandler = ini_get('output_handler');
// output handlers can be stacked
$obHandlers = array_filter(ob_list_handlers(), function ($var) {
return $var !== "default output handler";
});
// user defined handler via wrapper
if (!defined('PIWIK_TEST_MODE')) {
$autoPrependFile = ini_get('auto_prepend_file');
$autoAppendFile = ini_get('auto_append_file');
}
return !empty($zlibOutputCompression) ||
!empty($outputHandler) ||
!empty($obHandlers) ||
!empty($autoPrependFile) ||
!empty($autoAppendFile);
}
/**
* Workaround IE bug when downloading certain document types over SSL and
* cache control headers are present, e.g.,
*
* Cache-Control: no-cache
* Cache-Control: no-store,max-age=0,must-revalidate
* Pragma: no-cache
*
* @see http://support.microsoft.com/kb/316431/
* @see RFC2616
*
* @param string $override One of "public", "private", "no-cache", or "no-store". (optional)
*/
public static function overrideCacheControlHeaders($override = null)
{
if ($override || self::isHttps()) {
@header('Pragma: ');
@header('Expires: ');
if (in_array($override, array('public', 'private', 'no-cache', 'no-store'))) {
@header("Cache-Control: $override, must-revalidate");
} else {
@header('Cache-Control: must-revalidate');
}
}
}
/**
* Set response header, e.g., HTTP/1.0 200 Ok
*
* @param string $status Status
* @return bool
*/
protected static function setHttpStatus($status)
{
if (substr_compare(PHP_SAPI, '-fcgi', -5)) {
@header($_SERVER['SERVER_PROTOCOL'] . ' ' . $status);
} else {
// FastCGI
@header('Status: ' . $status);
}
}
}