1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
=Deflatemod=
Deflatemod is in beta version. Submit your bugs and feature wishes [[http://ocsigen.org/trac|here]].
== Usage ==
=== What is deflatemod?
Deflatemod is a module for Ocsigen that allows you to
deflate content, using HTTP/1.1 mechanism. It supports gzip as well as
deflate.
=== What do I need to use deflatemod?
You need the camlzip library by Xavier Leroy and a working Ocsigen
installation.
=== How do I use deflatemod?
First, load the extension in the configuration file:
{{{
<extension findlib-package="ocsigenserver.ext.deflatemod" />
}}}
Alternatively, if you do not want to use findlib, you need to:
* load camlzip
{{{
<extension module="/path/to/camlzip.cma" />
}}}
* then load deflatemod
{{{
<extension module="/path/to/deflatemod.cmo" />
}}}
=== How do I configure deflatemod?
Again, the options are in ocsigen.conf. You can set a few options globally, in the extension tag:
* the compress level: from 0 (no compression) to 9. The higher, the
better compression rate you achieve. Conversely, the lower, the faster
it is. Default is 6.
* the buffer size: default is 1024. You shouldn't need to change this
one, but you can still try a few other values (any feedback welcomed).
For example:
{{{
<extension module="/home/gabriel/ocsigen/extensions/deflatemod.cmo">
<compress level="6" />
<buffer size="1024" />
</extension>
}}}
Next, you '''have to''' specify which pages you whish to deflate, in which host/site (otherwise, deflatemod won't compress anything). See next question to do that.
=== I want to deflate only some files. Is it possible?
To some extent, yes. You can '''exclude''' some files and deflate every other, according to their mime-type or extension (''ie.'' the end of the '''url''' in fact, not really the file name on the disk).
Here is an example:
{{{
<host>
<site>
<!-- ... -->
</site>
<deflate compress="allbut">
<!-- deflate everything but *.tar.gz files and image/* files -->
<extension>.tar.gz</extension>
<type>image/*</type>
</deflate>
</host>
}}}
As you can see, you must put the <deflate> tag at the very end of the <host> element. Indeed, Ocsigen deals with extensions sequentially, so if you put <site> or other elements '''after''' <deflatemod>, they won't be compressed.
Conversely, you can choose to deflate '''only''' some files, based
on their mime-types or extension:
{{{
<host>
<site>
<!-- ... -->
</site>
<deflate compress="only">
<!-- deflate only text/html files -->
<type>text/html</type>
</deflate>
</host>
}}}
Warning: you can use only one contenttype tag! So you must choose,
either the "only" or the "allbut" way.
Limitations: you cannot filter by directory or by filename extension (remember extension is the url's extension). If you really need it, please fill a bug report or send a patch.
== Technical questions ==
=== How can I choose the content-encoding (gzip or deflate)?
You can't. Deflatemod follows the RFC and chooses automatically the
right encoding, based upon Accept-encoding header sent by the client.
=== Does deflatemod support transfert-encoding?
No, it doesn't. Content-encoding is definitely a better solution,
providing end to end compression at the content-level.
=== How does deflatemod deal with the content-length header?
As it cannot compute the new content-length, deflatemod uses
chunked-encoding. This is the recommended way to go.
//Page written by Gabriel Kerneis//
|
