gzdecode
running 50000 repetitions on various content, i found that gzdeflate() and gzcompress() both performed equally fast regardless content and compression level, but gzinflate() was always about twice as fast as gzuncompress().
gzdeflate
(PHP 4 >= 4.0.4, PHP 5)
gzdeflate — 文字列を deflate 圧縮する
説明
string gzdeflate
( string $data
[, int $level = -1
] )
この関数は、DEFLATE データフォーマットを用いて 与えられた文字列を圧縮します。
DEFLATE 圧縮アルゴリズムについての詳細は、 "» DEFLATE Compressed Data Format Specification version 1.3" (RFC 1951) を参照ください。
パラメータ
- data
-
収縮させるデータ
- level
-
圧縮レベル。圧縮しない場合に0、最大限の圧縮をする場合に9を指定可能です。 指定しない場合、デフォルトの圧縮レベルは zlib ライブラリのデフォルト圧縮レベルになります。
返り値
収縮された文字列、もしくはエラーの場合 FALSE 。
例
例1 gzdeflate() の例
<?php
$compressed = gzdeflate('Compress me', 9);
echo $compressed;
?>
参考
- gzinflate() - deflate圧縮された文字列を解凍する
- gzcompress() - 文字列を圧縮する
- gzuncompress() - 圧縮された文字列を解凍する
- gzencode() - gzip 圧縮された文字列を作成する
add a note
User Contributed Notes
gzdeflate
robin
26-Feb-2010 05:46
anonymous at php dot net
04-Jun-2009 05:20
gzcompress produces longer data because it embeds information about the encoding onto the string. If you are compressing data that will only ever be handled on one machine, then you don't need to worry about which of these functions you use. However, if you are passing data compressed with these functions to a different machine you should use gzcompress.
tomas at slax dot org
03-Oct-2008 05:13
gzcompress() is the same like gzdefflate(), it produces identical data and its speed is the same as well. The only difference is that gzcompress produces 6 bytes bigger result (2 extra bytes at the beginning and 4 extra bytes at the end).
romain dot lalaut at laposte dot net
08-Oct-2007 07:20
@ giunta dot gaetano at sea-aeroportimilano dot it
No, gzdeflate() implements rfc1951.
And rf2616 (http 1.1 specs) says "deflate : The "zlib" format defined in RFC 1950 [31] in combination with the "deflate" compression mechanism described in RFC 1951 [29]."
giunta dot gaetano at sea-aeroportimilano dot it
21-Aug-2006 05:22
Take care that that "PHP deflate" != "HTTP deflate".
The deflate encoding used in HTTP is actually zlib encoded.
This is what PHP functions return:
gzencode() == gzip
gzcompress() == zlib (aka. HTTP deflate)
gzdeflate() == *raw* deflate encoding
denis dot noessler at red-at dot de
17-Jun-2003 03:26
if you have compressed data which is greater than 2 MB (system dependent), you will receive a buffer error by calling the function gzinflate().
be sure to to compress your data by a lower compression level, like 1.
i.e.: gzdeflate($sData, 1);