gzdecode
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.
gzdeflate
(PHP 4 >= 4.0.4, PHP 5)
gzdeflate — Comprime una stringa con il metodo DEFLATE
Descrizione
string gzdeflate
( string
$data
[, int $level = -1
] )
Questa funzione restituisce una versione compressa di
data utilizzando il formato dati DEFLATE.
Per i dettagli sull'algoritmo di compressione DEFLATE vedere il documento "» DEFLATE Compressed Data Format Specification version 1.3" (RFC 1951).
Elenco dei parametri
-
data -
I dati da comprimere.
-
level -
Il livello di compressione. Varia tra 0 (nessuna compressione) fino a 9 (compressione massima). Se non viene specificato, il livello di compressione di default sarà quello di default della libreria zlib.
Valori restituiti
La stringa compressa o FALSE in caso di errore.
Esempi
Example #1 Esempio di gzdeflate()
<?php
$compressed = gzdeflate('Compress me', 9);
echo $compressed;
?>
Vedere anche:
- gzinflate() - Inflate a deflated string
- gzcompress() - Comprime una stringa
- gzuncompress() - Uncompress a compressed string
- gzencode() - Crea una stringa compressa con gzip
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User Contributed Notes
gzdeflate - [6 notes]
anonymous at php dot net ¶
3 years ago
robin ¶
3 years ago
running 50000 repetitions on various content, i found that gzdeflate() and gzcompress() both performed equally fast regardless content and compression level, but gzinflate() was always about twice as fast as gzuncompress().
tomas at slax dot org ¶
4 years ago
gzcompress() is the same like gzdefflate(), it produces identical data and its speed is the same as well. The only difference is that gzcompress produces 6 bytes bigger result (2 extra bytes at the beginning and 4 extra bytes at the end).
giunta dot gaetano at sea-aeroportimilano dot it ¶
6 years ago
Take care that that "PHP deflate" != "HTTP deflate".
The deflate encoding used in HTTP is actually zlib encoded.
This is what PHP functions return:
gzencode() == gzip
gzcompress() == zlib (aka. HTTP deflate)
gzdeflate() == *raw* deflate encoding
denis dot noessler at red-at dot de ¶
9 years ago
if you have compressed data which is greater than 2 MB (system dependent), you will receive a buffer error by calling the function gzinflate().
be sure to to compress your data by a lower compression level, like 1.
i.e.: gzdeflate($sData, 1);
romain dot lalaut at laposte dot net ¶
5 years ago
@ 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]."