PHP 手动 GZip 编码
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PHP Manual GZip Encoding
提问by M.Alnashmi
I was testing my website with Page Speed and the result was around 70/100. Enable Compression was the first and most important factor in slowing it down.
我正在用 Page Speed 测试我的网站，结果大约是 70/100。启用压缩是降低速度的第一个也是最重要的因素。
I know that I can do that by modifying the php.ini to automatically do that but I was more interested in the manual method (gzencode).
我知道我可以通过修改 php.ini 来自动执行此操作，但我对手动方法 ( gzencode)更感兴趣。
The problem is either all browsers fail in opening the website (Firefox: "The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.", Chrome: "303, ERR Content Encoding", etc.) or they display the encoded string.
问题是所有浏览器都无法打开网站（Firefox：“您尝试查看的页面无法显示，因为它使用了无效或不受支持的压缩形式。”，Chrome：“303，ERR 内容编码”等。 ) 或者它们显示编码的字符串。
Live Headers shows that the browser accepts the encoding, and the response has the content type set, but it still fails.
Live Headers 显示浏览器接受编码，并且响应设置了内容类型，但仍然失败。
GET / HTTP/1.1
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Encoding: gzip,deflate
HTTP/1.1 200 OK
Content-Encoding: gzip
Content-Length: 5827
Vary: Accept-Encoding
private function _compress($data) {
//return trim(preg_replace(array('/\>[^\S ]+/s','/[^\S ]+\</s','/(\s)+/s'), array('>','<','\1'), $data));
$supportsGzip = strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== false;
ob_start();
if ($supportsGzip) {
echo gzencode(trim(preg_replace('/\s+/', ' ', $data)), 9);
} else {
echo $data;
}
$content = ob_get_contents();
header("content-type: text/html; charset: UTF-8");
header("cache-control: must-revalidate");
$offset = 60 * 60;
$expire = "expires: " . gmdate("D, d M Y H:i:s", time() + $offset) . " GMT";
header($expire);
header('Content-Length: ' . strlen($content));
header('Vary: Accept-Encoding');
ob_end_clean();
echo $content;
}
If I change the Content-Encoding to zlib, I get the encoded string:
如果将 Content-Encoding 更改为 zlib，则会得到编码字符串：
????????Z?s???W^‘￥2o‘¨/–-?–ú?‰_?μ??ú_v I°I?!A?j–?on??b·?%íú?2n???‘t?=¤L)',?Iw>?Eax?á?÷°ùT?O??????tl??μ·? $k??? ?^?<ü??\?? ?o—\??6???”^?0z?^?Wê ?m4?j?°…X?'??|?nS·]#ì?F-|8LRPL2ìIè?52-\é\?m?=Fà?J5"ù—RóY?3CyéZ([ù?b%1′Yy??á?cx}±iD′??KV#4”á§x>?°à?íò ?p????1?ì?‘@?m
I don't really care anymore about getting the compression as much as I want to know why its not working.
我真的不再关心压缩了，因为我想知道它为什么不起作用。
Cheers,
干杯，
回答by Craig Sefton
Well, I think it's because you're trying to compress an empty string.
好吧，我认为这是因为您试图压缩一个空字符串。
I took your script as you gave it, and ran it in FF and IE.
我拿了你给的脚本，并在 FF 和 IE 中运行它。
Both failed, and FF said that there was an issue (like you described).
都失败了，FF 说有问题（就像你描述的那样）。
However, I then noticed $data is an empty string.
但是，我随后注意到 $data 是一个空字符串。
When I set $data = "Some test data.";at the top of the file it worked immediately (browser displayed "Some test data."), and checking in Firebug, I can see the correct headers.
当我$data = "Some test data.";在文件顶部设置它时它立即工作（浏览器显示“一些测试数据。”），并检查 Firebug，我可以看到正确的标题。
Content-Encoding gzip
Content-Length 68
Vary Accept-Encoding
Content-Type text/html
Edit:Also, just to point out, your if ($supportsGzip) {is a bit odd, because your else condition should actually echo out $data, not $content.
编辑：另外，要指出的是，您的 if ($supportsGzip) {情况有点奇怪，因为您的 else 条件实际上应该回显出来$data，而不是$content.
Edit:Okay, based on your revised function above, there are two key problems.
编辑：好的，根据你上面修改的函数，有两个关键问题。
The primary problem has to do with the fact that you're wiping out your headers by calling ob_end_clean(). A comment on the PHP Docsstates that "ob_end_clean() does discard headers".
主要问题与您通过调用ob_end_clean(). PHP Docs上的评论指出“ob_end_clean() 确实会丢弃标头”。
This means any headers you set before calling ob_end_clean()will get wiped. Also, your revised function doesn't send a gzip encoding header, either.
这意味着您在调用之前设置的任何标头都ob_end_clean()将被擦除。此外，您修改后的函数也不会发送 gzip 编码标头。
I must say that there is probably no need to even use ob_start and related functions here, either. Try the following:
我必须说，这里可能甚至不需要使用 ob_start 和相关函数。请尝试以下操作：
function _compress( $data ) {
$supportsGzip = strpos( $_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip' ) !== false;
if ( $supportsGzip ) {
$content = gzencode( trim( preg_replace( '/\s+/', ' ', $data ) ), 9);
header('Content-Encoding: gzip');
} else {
$content = $data;
}
$offset = 60 * 60;
$expire = "expires: " . gmdate("D, d M Y H:i:s", time() + $offset) . " GMT";
header("content-type: text/html; charset: UTF-8");
header("cache-control: must-revalidate");
header( $expire );
header( 'Content-Length: ' . strlen( $content ) );
header('Vary: Accept-Encoding');
echo $content;
}
_compress( "Some test data" );
This works in IE and FF, but I didn't have time to test other browsers.
这适用于 IE 和 FF，但我没有时间测试其他浏览器。
If you really must use ob_start and related functions, make sure you set your headers after you call ob_end_clean().
如果您确实必须使用 ob_start 和相关函数，请确保在调用ob_end_clean().
回答by daschl
I'd suggest to use http://php.net/manual/de/function.ob-gzhandler.php, this works out of the box for me:
我建议使用http://php.net/manual/de/function.ob-gzhandler.php，这对我来说是开箱即用的：
In my index.php I just place this before some output:
在我的 index.php 中，我只是将它放在一些输出之前：
/**
* Enable GZIP-Compression for Browser that support it.
*/
ob_start("ob_gzhandler");
And it encodes it!
它编码它！
回答by Jens Roland
A few things:
一些东西：
You probably want to add another header: header('Content-Encoding: gzip');
You are using ob_end_clean, which deletes all echoed/printed content without sending it to the browser. Depending on what you're trying to do, you may want to use ob_flush instead.
To make sure your output is buffered and handled (and compressed if you use PHP's output buffering compression), make sure all echo/print statements are placed BETWEEN the ob_start and ob_flush sttements.
您可能想添加另一个标题： header('Content-Encoding: gzip');
您正在使用 ob_end_clean，它会删除所有回显/打印的内容，而不将其发送到浏览器。根据您要执行的操作，您可能希望改用 ob_flush。
为了确保你的输出被缓冲和处理（如果你使用 PHP 的输出缓冲压缩，则被压缩），确保所有的 echo/print 语句都放在 ob_start 和 ob_flush 语句之间。
--and then try it again :)
--然后再试一次:)
