(PECL memcached >= 2.0.0)
Memcached::getAllKeys — Gets the keys stored on all the servers
Memcached::getAllKeys() queries each memcache server and retrieves an array of all keys stored on them at that point in time. This is not an atomic operation, so it isn't a truly consistent snapshot of the keys at point in time. As memcache doesn't guarantee to return all keys you also cannot assume that all keys have been returned.
注意:
This method is intended for debugging purposes and should not be used at scale!
此函数没有参数。
Returns the keys stored on all the servers on success 或者在失败时返回 false.
// initiate the memcached instance
$cache = new \Memcached();
$cache->addServer('localhost', '11211');
// get all stored memcached items
$keys = $cache->getAllKeys();
$cache->getDelayed($keys);
$store = $cache->fetchAll();
// delete by regex keys
$keys = $cache->getAllKeys();
$regex = 'product_.*';
foreach($keys as $item) {
if(preg_match('/'.$regex.'/', $item)) {
$cache->delete($item);
}
}First I use the lastest memcached version 1.4.25, but unfortunately I found memcached::getAllkeys do not work with it, though i follow the others suggestion to disable Memcached::OPT_BINARY_PROTOCOL. So i try to use history versions, when i use memcached version 1.4.17, it works./**
* Get all memcached keys. Special function because getAllKeys() is broken since memcached 1.4.23. Should only be needed on php 5.6
*
* cleaned up version of code found on Stackoverflow.com by Maduka Jayalath
*
* @return array|int - all retrieved keys (or negative number on error)
*/
public function getMemcachedKeys($host = '127.0.0.1', $port = 11211)
{
$mem = @fsockopen($host, $port);
if ($mem === false)
{
return -1;
}
// retrieve distinct slab
$r = @fwrite($mem, 'stats items' . chr(10));
if ($r === false)
{
return -2;
}
$slab = [];
while (($l = @fgets($mem, 1024)) !== false)
{
// finished?
$l = trim($l);
if ($l == 'END')
{
break;
}
$m = [];
// <STAT items:22:evicted_nonzero 0>
$r = preg_match('/^STAT\sitems\:(\d+)\:/', $l, $m);
if ($r != 1)
{
return -3;
}
$a_slab = $m[1];
if (!array_key_exists($a_slab, $slab))
{
$slab[$a_slab] = [];
}
}
reset($slab);
foreach ($slab as $a_slab_key => &$a_slab)
{
$r = @fwrite($mem, 'stats cachedump ' . $a_slab_key . ' 100' . chr(10));
if ($r === false)
{
return -4;
}
while (($l = @fgets($mem, 1024)) !== false)
{
// finished?
$l = trim($l);
if ($l == 'END')
{
break;
}
$m = [];
// ITEM 42 [118 b; 1354717302 s]
$r = preg_match('/^ITEM\s([^\s]+)\s/', $l, $m);
if ($r != 1)
{
return -5;
}
$a_key = $m[1];
$a_slab[] = $a_key;
}
}
// close the connection
@fclose($mem);
unset($mem);
$keys = [];
reset($slab);
foreach ($slab AS &$a_slab)
{
reset($a_slab);
foreach ($a_slab AS &$a_key)
{
$keys[] = $a_key;
}
}
unset($slab);
return $keys;
}The right way to dump slab keys seems to be by using lru_crawler metadump instead of stats cachedump, see https://github.com/memcached/memcached/issues/405
<?php
function getAllKeys(string $host, int $port): array
{
$sock = fsockopen($host, $port, $errno, $errstr);
if ($sock === false) {
throw new Exception("Error connection to server {$host} on port {$port}: ({$errno}) {$errstr}");
}
if (fwrite($sock, "stats items\n") === false) {
throw new Exception("Error writing to socket");
}
$slabCounts = [];
while (($line = fgets($sock)) !== false) {
$line = trim($line);
if ($line === 'END') {
break;
}
// STAT items:8:number 3
if (preg_match('!^STAT items:(\d+):number (\d+)$!', $line, $matches)) {
$slabCounts[$matches[1]] = (int)$matches[2];
}
}
foreach ($slabCounts as $slabNr => $slabCount) {
if (fwrite($sock, "lru_crawler metadump {$slabNr}\n") === false) {
throw new Exception('Error writing to socket');
}
$count = 0;
while (($line = fgets($sock)) !== false) {
$line = trim($line);
if ($line === 'END') {
break;
}
// key=foobar exp=1596440293 la=1596439293 cas=8492 fetch=no cls=24 size=14908
if (preg_match('!^key=(\S+)!', $line, $matches)) {
$allKeys[] = $matches[1];
$count++;
}
}
// if ($count !== $slabCount) {
// throw new Exception("Surprise, got {$count} keys instead of {$slabCount} keys");
// }
}
if (fclose($sock) === false) {
throw new Exception('Error closing socket');
}
return $allKeys;
}This command returns always FALSE when binary protocol in use (Memcached::OPT_BINARY_PROTOCOL = true). Without binary protocol it works.I got this answer..
My libmemcached version is 1.0.18. php-memcached version is 2.2.0
In Libmemcached at memcache.h line 84:
#define MAX_NUMBER_OF_SLAB_CLASSES (63 + 1)
Modify it to 201, compile again. It's ok.
主要还是版本不兼容造成的。libmemchaed里的一个bug，
memcached_return_t这个方法里的for循环，最大数是200，和上面的常量64定义不一致造成的。