<?php
/*
* This file is part of the Predis package.
*
* (c) Daniele Alessandri <suppakilla@gmail.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
require __DIR__.'/shared.php';
use Predis\Collection\Iterator;
// Starting from Redis 2.8, clients can iterate incrementally over collections
// without blocking the server like it happens when a command such as KEYS is
// executed on a Redis instance storing millions of keys. These commands are:
//
// - SCAN (iterates over the keyspace)
// - SSCAN (iterates over members of a set)
// - ZSCAN (iterates over members and ranks of a sorted set)
// - HSCAN (iterates over fields and values of an hash).
// Predis provides a specialized abstraction for each command based on standard
// SPL iterators making it possible to easily consume SCAN-based iterations in
// your PHP code.
//
// See http://redis.io/commands/scan for more details.
//
// Create a client using `2.8` as a server profile (needs Redis 2.8!)
$client = new Predis\Client($single_server, array('profile' => '2.8'));
// Prepare some keys for our example
$client->del('predis:set', 'predis:zset', 'predis:hash');
for ($i = 0; $i < 5; ++$i) {
$client->sadd('predis:set', "member:$i");
$client->zadd('predis:zset', -$i, "member:$i");
$client->hset('predis:hash', "field:$i", "value:$i");
}
// === Keyspace iterator based on SCAN ===
echo 'Scan the keyspace matching only our prefixed keys:', PHP_EOL;
foreach (new Iterator\Keyspace($client, 'predis:*') as $key) {
echo " - $key", PHP_EOL;
}
/* OUTPUT
Scan the keyspace matching only our prefixed keys:
- predis:zset
- predis:set
- predis:hash
*/
// === Set iterator based on SSCAN ===
echo 'Scan members of `predis:set`:', PHP_EOL;
foreach (new Iterator\SetKey($client, 'predis:set') as $member) {
echo " - $member", PHP_EOL;
}
/* OUTPUT
Scan members of `predis:set`:
- member:1
- member:4
- member:0
- member:3
- member:2
*/
// === Sorted set iterator based on ZSCAN ===
echo 'Scan members and ranks of `predis:zset`:', PHP_EOL;
foreach (new Iterator\SortedSetKey($client, 'predis:zset') as $member => $rank) {
echo " - $member [rank: $rank]", PHP_EOL;
}
/* OUTPUT
Scan members and ranks of `predis:zset`:
- member:4 [rank: -4]
- member:3 [rank: -3]
- member:2 [rank: -2]
- member:1 [rank: -1]
- member:0 [rank: 0]
*/
// === Hash iterator based on HSCAN ===
echo 'Scan fields and values of `predis:hash`:', PHP_EOL;
foreach (new Iterator\HashKey($client, 'predis:hash') as $field => $value) {
echo " - $field => $value", PHP_EOL;
}
/* OUTPUT
Scan fields and values of `predis:hash`:
- field:0 => value:0
- field:1 => value:1
- field:2 => value:2
- field:3 => value:3
- field:4 => value:4
*/
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