Php/docs/class.evstat
(PECL ev >= 0.2.0)
Introduction
EvStat monitors a file system path for attribute changes. It calls stat() 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.
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
'nlink'
item being 0(returned by
EvStat::attr()
method).
The path must not end in a slash or contain special components such as
'.'
or
..
. The path should be absolute: if it is relative and the working directory
changes, then the behaviour is undefined.
Since there is no portable change notification interface available, the
portable implementation simply calls
stat()
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
0.0
(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).
libev
will also impose a minimum interval which is currently around
0.1
, but that’s usually overkill.
This watcher type is not meant for massive numbers of EvStat watchers, as even with OS-supported change notifications, this can be resource-intensive.
Class synopsis
EvStat extends EvWatcher {
public
$path
public
$interval
/* Inherited properties */
public
$is_active
public
$data
public
$is_pending
public
$priority
/* Methods */
public attr ( ) : array
public
__construct
(
string
$path
,
float
$interval
,
callable
$callback
[,
mixed
$data
= NULL
[,
int
$priority
= 0
]] )
final
public
static
createStopped
(
string
$path
,
float
$interval
,
callable
$callback
[,
mixed
$data
= NULL
[,
int
$priority
= 0
]] ) : void
public prev ( ) : void
public
set
(
string
$path
,
float
$interval
) : void
public stat ( ) : bool
/* Inherited methods */
public EvWatcher::clear ( ) : int
abstract public EvWatcher::__construct ( )
public
EvWatcher::feed
(
int
$revents
) : void
public EvWatcher::getLoop ( ) : EvLoop
public
EvWatcher::invoke
(
int
$revents
) : void
public
EvWatcher::keepalive
([
bool
$value
] ) : bool
public
EvWatcher::setCallback
(
callable
$callback
) : void
public EvWatcher::start ( ) : void
public EvWatcher::stop ( ) : void
}
Properties
interval- Readonly . Hint on how quickly a change is expected to be detected and should normally be specified as
0.0to let libev choose a suitable value. path- Readonly . The path to wait for status changes on.
Table of Contents
- EvStat::attr — Returns the values most recently detected by Ev
- EvStat::__construct — Constructs EvStat watcher object
- EvStat::createStopped — Create a stopped EvStat watcher object
- EvStat::prev — Returns the previous set of values returned by EvStat::attr
- EvStat::set — Configures the watcher
- EvStat::stat — Initiates the stat call
/* Properties */