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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision: 328913 $ -->
<phpdoc:classref xml:id="class.evstat" xmlns:phpdoc="http://php.net/ns/phpdoc" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xi="http://www.w3.org/2001/XInclude">
<title>The EvStat class</title>
<titleabbrev>EvStat</titleabbrev>
<partintro>
<!-- {{{ EvStat intro -->
<section xml:id="evstat.intro">
&reftitle.intro;
<para>
<classname>EvStat</classname>
monitors a file system path for attribute changes. It calls
<emphasis>stat()</emphasis>
on that path in regular intervals(or when the OS signals it changed) and
sees if it changed compared to the last time, invoking the callback if it
did.
</para>
<para>
The path does not need to exist: changing from "path exists" to "path does
not exist" is a status change like any other. The condition "path does not
exist" is signified by the
<constant>'nlink'</constant>
item being 0(returned by
<methodname>EvStat::attr</methodname>
method).
</para>
<para>
The path must not end in a slash or contain special components such as
<constant>'.'</constant>
or
<constant>..</constant>
. The path should be absolute: if it is relative and the working directory
changes, then the behaviour is undefined.
</para>
<para>
Since there is no portable change notification interface available, the
portable implementation simply calls
<emphasis>stat()</emphasis>
regularly on the path to see if it changed somehow. For this case a
recommended polling interval can be specified. If one specifies a polling
interval of
<constant>0.0 </constant>
(highly recommended) then a suitable, unspecified default value will be
used(which could be expected to be around 5 seconds, although this might
change dynamically).
<emphasis>libev</emphasis>
will also impose a minimum interval which is currently around
<constant>0.1</constant>
, but that’s usually overkill.
</para>
<para>
This watcher type is not meant for massive numbers of
<classname>EvStat</classname>
watchers, as even with OS-supported change notifications, this can be
resource-intensive.
</para>
</section>
<!-- }}} -->
<section xml:id="evstat.synopsis">
&reftitle.classsynopsis;
<!-- {{{ Synopsis -->
<classsynopsis>
<ooclass>
<classname>EvStat</classname>
</ooclass>
<!-- {{{ Class synopsis -->
<classsynopsisinfo>
<ooclass>
<classname>EvStat</classname>
</ooclass>
<ooclass>
<modifier>extends</modifier>
<classname>EvWatcher</classname>
</ooclass>
</classsynopsisinfo>
<!-- }}} -->
<classsynopsisinfo role="comment">&Properties;</classsynopsisinfo>
<fieldsynopsis>
<modifier>public</modifier>
<varname linkend="evstat.props.path">path</varname>
</fieldsynopsis>
<fieldsynopsis>
<modifier>public</modifier>
<varname linkend="evstat.props.interval">interval</varname>
</fieldsynopsis>
<classsynopsisinfo role="comment">&InheritedProperties;</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('evwatcher.synopsis')/descendant::db:fieldsynopsis)" />
<classsynopsisinfo role="comment">&Methods;</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.evstat')/db:refentry/db:refsect1[@role='description']/descendant::db:methodsynopsis[1])" />
<classsynopsisinfo role="comment">&InheritedMethods;</classsynopsisinfo>
<xi:include xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('class.evwatcher')/db:refentry/db:refsect1[@role='description']/descendant::db:methodsynopsis[1])" />
</classsynopsis>
<!-- }}} -->
</section>
<!-- {{{ EvStat properties -->
<section xml:id="evstat.props">
&reftitle.properties;
<variablelist>
<varlistentry xml:id="evstat.props.interval">
<term>
<varname>interval</varname>
</term>
<listitem>
<para>
<emphasis>Readonly</emphasis>
. Hint on how quickly a change is expected to be detected and should
normally be specified as
<constant>0.0</constant>
to let
<emphasis>libev</emphasis>
choose a suitable value.
</para>
</listitem>
</varlistentry>
<varlistentry xml:id="evstat.props.path">
<term>
<varname>path</varname>
</term>
<listitem>
<para>
<emphasis>Readonly</emphasis>
. The path to wait for status changes on.
</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<!-- }}} -->
</partintro>
&reference.ev.entities.evstat;
</phpdoc:classref>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
