/**
* The scan command allows for efficient, non-blocking iteration of the entire keyspace. It works by using a cursor
* which is repeatedly passed to the command and updated by the Redis instance.
*
* See information at the official redis website:
*
* @link http://redis.io/commands/scan
*
* @param int $iterator a reference to the cursor, this variable will be updated automatically with the new cursor value once
* the method returns. when no more keys are available to the cursor it is reset to 0. this should be used as the indication
* to end an iteration.
* @param string $pattern an optional pattern which the returned keys have to match, defaults to no pattern at all
* @param int $count the optional maximal number of keys to return, defaults to 10
* @return string[] returns an array of strings (which may be empty if a pattern is used)
* @example
* <pre>
* $cursor = 0;
* while ($cursor != 0) {
* $result = $redis->scan($cursor)
* print_r($result);
* }
*/
public function scan(&$iterator, $pattern = '', $count = 10)
{
try {
return $this->client->scan($iterator, $pattern, $count);
} catch (Exception $e) {
// func_get_args() apparently resolves references in arguments. we however need to make sure to preserve it.
$args = func_get_args();
$args[0] =& $iterator;
return $this->handleException($e, __FUNCTION__, $args);
}
}
/**
* Test the scan family of commands
*/
public function testScan()
{
$this->redis->flushdb();
$keys = ['testScan', 'testScanHello', 'testScanHallo', 'testScanHaallo', 'testScanHoula', 'testScan2', 'testScanHello2', 'testScanHallo2', 'testScanHaallo2', 'testScanHoula2', 'testScan3', 'testScanHello3', 'testScanHallo3', 'testScanHaallo3', 'testScanHoula3'];
foreach ($keys as $key) {
$this->redis->set($key, 'someValue');
}
// a bit tricky to test, since we can't determine the outcome of a single iteration (or can we?)
// so we just iterate until the iterator is exhausted and then compare the final results
$iterator = 0;
// we unroll the iteration here, to have better control over the involved values
$result = $this->redis->scan($iterator);
$this->assertNotEmpty($result);
//$this->assertSame(10, count($result));
$this->assertNotSame(0, $iterator);
$result = array_merge($result, $this->redis->scan($iterator));
foreach ($keys as $key) {
$this->assertContains($key, $result);
}
$this->assertSame(15, count($result));
$this->assertSame(0, $iterator);
$result1 = $this->redis->scan($iterator, 'testScanH?llo', 20);
$this->assertContains('testScanHello', $result1);
$this->assertContains('testScanHallo', $result1);
$this->assertEquals(2, count($result1));
$this->assertSame(0, $iterator);
$result2 = $this->redis->scan($iterator, 'testScanH*llo', 20);
$this->assertContains('testScanHello', $result2);
$this->assertContains('testScanHallo', $result2);
$this->assertContains('testScanHaallo', $result2);
$this->assertEquals(3, count($result2));
$this->assertSame(0, $iterator);
$result3 = $this->redis->scan($iterator, 'testScanH[ae]llo', 20);
$this->assertContains('testScanHello', $result3);
$this->assertContains('testScanHallo', $result3);
$this->assertEquals(2, count($result3));
$this->assertSame(0, $iterator);
$result4 = $this->redis->scan($iterator, '*', 20);
$this->assertEquals(15, count($result4));
$this->assertSame(0, $iterator);
}
