# Examples

Example #1 Cancelling a request

`<?php
/* Is called when eio_nop() finished */
function my_nop_cb($data, $result) {
echo "my_nop ", $data, "\n";
}
// This eio_nop() call will be cancelled
$req = eio_nop(EIO_PRI_DEFAULT, "my_nop_cb", "1");
var_dump($req);
eio_cancel($req);
// This time eio_nop() will be processed
eio_nop(EIO_PRI_DEFAULT, "my_nop_cb", "2");
// Process requests
eio_event_loop();
?>`

The above example will output something similar to:

    resource(4) of type (EIO Request Descriptor)
    my_nop 2

Example #2 Calling eio_chmod()

`<?php
$temp_filename = dirname(__FILE__) ."/eio-temp-file.tmp";
touch($temp_filename);
/* Is called when eio_chmod() finished */
function my_chmod_callback($data, $result) {
global $temp_filename;
if ($result == 0 && !is_readable($temp_filename) && is_writable($temp_filename)) {
echo "eio_chmod_ok";
}
@unlink($temp_filename);
}
eio_chmod($temp_filename, 0200, EIO_PRI_DEFAULT, "my_chmod_callback");
eio_event_loop();
?>`

The above example will output something similar to:

    eio_chmod_ok

Example #3 Making a custom request

`<?php
/* Callback for the custom callback */
function my_custom_callback($data, $result) {
var_dump($data);
var_dump(count($result));
var_dump($result['data_modified']);
var_dump($result['result']);
}
/* The custom request */
function my_custom($data) {
var_dump($data);
$result = array(
'result' => 1001,
'data_modified' => "my custom data",
);
return $result;
}
$data = "my_custom_data";
$req = eio_custom("my_custom", EIO_PRI_DEFAULT, "my_custom_callback", $data);
var_dump($req);
eio_event_loop();
?>`

The above example will output something similar to:

    resource(4) of type (EIO Request Descriptor)
    string(14) "my_custom_data"
    string(14) "my_custom_data"
    int(2)
    string(14) "my custom data"
    int(1001)

Example #4 Grouping requests

`<?php
/*
* Create a group request to open, read and close a file
*/
$temp_filename = dirname(__FILE__) ."/eio-file.tmp";
$fp = fopen($temp_filename, "w");
fwrite($fp, "some data");
fclose($fp);
/* Is called when the group requests are done */
function my_grp_done($data, $result) {
global $temp_filename;
var_dump($result == 0);
@unlink($temp_filename);
}
/* Is called when eio_open() done */
function my_grp_file_opened_callback($data, $result) {
global $my_file_fd, $grp;
$my_file_fd = $result;
var_dump($result > 0);
// Create eio_read() request and add it to the group
$req = eio_read($my_file_fd, 4, 0, EIO_PRI_DEFAULT, "my_grp_file_read_callback");
eio_grp_add($grp, $req);
}
/* Is called when eio_read() done */
function my_grp_file_read_callback($data, $result) {
global $my_file_fd, $grp;
var_dump($result);
// Create eio_close() request and add it to the group
$req = eio_close($my_file_fd);
eio_grp_add($grp, $req);
}
$grp = eio_grp("my_grp_done", "my_grp_data");
// Create eio_open() request and add it to the group
$req = eio_open($temp_filename, EIO_O_RDWR | EIO_O_APPEND , NULL,
EIO_PRI_DEFAULT, "my_grp_file_opened_callback", NULL);
eio_grp_add($grp, $req);
var_dump($grp);
eio_event_loop();
?>`

The above example will output something similar to:

    resource(6) of type (EIO Group Descriptor)
    bool(true)
    string(4) "some"
    bool(true)

Example #5 Using eio with libevent extension

`<?php
function my_eio_poll($fd, $events, $arg) {
/* Some libevent regulation might go here .. */
if (eio_nreqs()) {
eio_poll();
}
/* .. and here */
}
function my_nop_cb($d, $r) {
var_dump($r); var_dump($d);
}
$base = event_base_new();
$event = event_new();
$fd = eio_get_event_stream();
var_dump($fd);
eio_nop(EIO_PRI_DEFAULT, "my_nop_cb", "nop data");
eio_mkdir("/tmp/abc-eio-temp", 0750, EIO_PRI_DEFAULT, "my_nop_cb", "nop data");
/* some other eio_* calls here ... */
// set event flags
event_set($event, $fd, EV_READ /*| EV_PERSIST*/, "my_eio_poll", array($event, $base));
// set event base
event_base_set($event, $base);
// enable event
event_add($event);
// start event loop
event_base_loop($base);
/* The same will be available via buffered libevent interface */
?>`

The above example will output something similar to:

    int(3)
    int(0)
    string(8) "nop data"
    int(0)
    string(10) "mkdir data"

Example #6 Using eio with event extension

`<?php
$base = new EventBase();
// Retrieve eio polling stream.
// Note, this variable should be alive as long as the event loop is running.
$eio_stream = eio_get_event_stream();
// Bind eio polling stream to the event loop.
$poll_event = new Event($base, $eio_stream, Event::READ, function () {
if (eio_nreqs()) {
eio_poll();
}
});
$poll_event->add();
// Add eio jobs
eio_nop(EIO_PRI_DEFAULT, function () {
echo "eio_nop\n";
});
// Add events
$timer = Event::timer($base, function () {
echo "2 seconds elapsed\n";
});
$timer->add(2);
// Dispatch events.
$base->dispatch();
?>`

The above example will output something similar to:

    eio_nop
    2 seconds elapsed