PHPRedis Scan不返回下一个光标

编程问答 2022-06-07

问题描述

在Laravel应用程序中，我曾经使用predis/predis包来使用Redis进行缓存。最近，按照文档中的建议，我已切换到PHPRedis，但是我使用SCAN的部分代码已损坏。在predis中，当我使用像这样的扫描时：

Redis::scan(0,'match',$pattern //Test:*);

我曾经得到这样的结果：

[
     "253952",[
       "Test::296589","Test::299112","Test::332487","Test::320358",],]

在这种情况下，我可以传递253952作为下一个光标，以便再次扫描以获取下一个批次Redis::scan(253952,$pattern //Test:*); 我可以在while循环中运行它，直到到达终点：

$all_keys = [];
$keys = RedisManager::scan(0,$pattern);
while ($keys[0] !== "0") {
   foreach($keys[1] as $key) {
      $all_keys[] = $key;
   }
 $keys = RedisManager::scan($keys[0],$pattern);
}

自从我切换到PHPredis以来，我无法再遍历该列表。首先，语法似乎有所不同：

$it=null;
$keys = RedisManager::scan($it,$pattern);

我不确定将null作为迭代器传递给第一个参数有什么意义。它也只返回：

[
 "Test::296589","Test::299112"
]

这只是结果的一部分。它不会给我一切，也不会给我下一个光标。有人可以指引我正确的方向吗？

解决方法

我在本地切换到Phpredis，并使其与以下代码段一起使用。 documentation指出扫描的用法不同。

$redis = RedisManager::connection(); // initialize

$redis->setOption(\Redis::OPT_SCAN,\Redis::SCAN_RETRY); // please check documentation for other option
$keyList = [];
$iterator = null;

// you may update the count or match options according to your needs
while ($keys = $redis->scan($iterator,['match' => 'Test:*','count' => 20])) {
    $iterator = $keys[0];
    foreach ($keys[1] as $key) {
        $keyList[] = $key;
    }
}

return $keyList;

在调试或开发时，使用monitor命令将很有用。在该代码段运行时，它会打印出这样的内容； 

1603241935.261667 [0 127.0.0.1:52536] "SCAN" "0" "COUNT" "20" "MATCH" "Test:*"
1603241935.262241 [0 127.0.0.1:52536] "SCAN" "48" "COUNT" "20" "MATCH" "Test:*"
1603241935.263421 [0 127.0.0.1:52536] "SCAN" "424" "COUNT" "20" "MATCH" "Test:*"
1603241935.264476 [0 127.0.0.1:52536] "SCAN" "260" "COUNT" "20" "MATCH" "Test:*"
1603241935.265508 [0 127.0.0.1:52536] "SCAN" "100" "COUNT" "20" "MATCH" "Test:*"
1603241935.266405 [0 127.0.0.1:52536] "SCAN" "460" "COUNT" "20" "MATCH" "Test:*"
1603241935.267137 [0 127.0.0.1:52536] "SCAN" "258" "COUNT" "20" "MATCH" "Test:*"
1603241935.268271 [0 127.0.0.1:52536] "SCAN" "402" "COUNT" "20" "MATCH" "Test:*"
1603241935.269344 [0 127.0.0.1:52536] "SCAN" "42" "COUNT" "20" "MATCH" "Test:*"
1603241935.270328 [0 127.0.0.1:52536] "SCAN" "198" "COUNT" "20" "MATCH" "Test:*"
1603241935.275193 [0 127.0.0.1:52536] "SCAN" "342" "COUNT" "20" "MATCH" "Test:*"
1603241935.276690 [0 127.0.0.1:52536] "SCAN" "286" "COUNT" "20" "MATCH" "Test:*"
1603241935.279386 [0 127.0.0.1:52536] "SCAN" "510" "COUNT" "20" "MATCH" "Test:*"
1603241935.281084 [0 127.0.0.1:52536] "SCAN" "81" "COUNT" "20" "MATCH" "Test:*"
1603241935.282568 [0 127.0.0.1:52536] "SCAN" "41" "COUNT" "20" "MATCH" "Test:*"
1603241935.284090 [0 127.0.0.1:52536] "SCAN" "185" "COUNT" "20" "MATCH" "Test:*"
1603241935.285949 [0 127.0.0.1:52536] "SCAN" "117" "COUNT" "20" "MATCH" "Test:*"
1603241935.288443 [0 127.0.0.1:52536] "SCAN" "253" "COUNT" "20" "MATCH" "Test:*"
1603241935.293034 [0 127.0.0.1:52536] "SCAN" "147" "COUNT" "20" "MATCH" "Test:*"
1603241935.294957 [0 127.0.0.1:52536] "SCAN" "155" "COUNT" "20" "MATCH" "Test:*"
1603241935.296113 [0 127.0.0.1:52536] "SCAN" "199" "COUNT" "20" "MATCH" "Test:*"
1603241935.296456 [0 127.0.0.1:52536] "SCAN" "247" "COUNT" "20" "MATCH" "Test:*"
1603241935.296723 [0 127.0.0.1:52536] "SCAN" "223" "COUNT" "20" "MATCH" "Test:*"
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