PHP redis SCAN、SSCAN、ZSCAN、HSCAN

• SCAN cursor [MATCH pattern] [COUNT count]
• 作用：迭代当前数据库中的数据库键
• SCAN 使用 demo

<?php
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
/* Options for the SCAN family of commands, indicating whether to abstract
   empty results from the user.  If set to SCAN_NORETRY (the default), phpredis
   will just issue one SCAN command at a time, sometimes returning an empty
   array of results.  If set to SCAN_RETRY, phpredis will retry the scan command
   until keys come back OR Redis returns an iterator of zero */
$redis->setOption(Redis::OPT_SCAN, Redis::SCAN_RETRY);
$iterator = null;
$count = 1000; // 测试时redis中大概有20w个key，用时约2s，当count为500时用时约4s，count越大时扫描用时越短（当然需要根据你的业务需要来定）
$prefix = date('Ymd');
$time1 = msectime();
$total = [];
while ($arrKeys = $redis->scan($iterator, $prefix . '*', $count)) {
    $arrValues = $redis->mget($arrKeys);
    $ret = array_combine($arrKeys, $arrValues);
    $total = array_merge($total, $ret);
}
$time2 = msectime();
$time = $time2 - $time1;
echo 'time : ' . $time  . ' ms; total keys : ' . count($total) . PHP_EOL;
// time : 2009 ms; total keys : 129798  （用时2009 ms，20w中共有129798个前缀为$prefix的key）
function msectime() {
    list($msec, $sec) = explode(' ', microtime());
    $msectime = (float)sprintf('%.0f', (floatval($msec) + floatval($sec)) * 1000);
    return $msectime;
}

• SCAN cursor [MATCH pattern] [COUNT count]
• 作用：用于迭代集合键中的元素
• SSCAN使用demo

<?php
$iterator = null;
$count = 1000;
$mainKey = date('Ymd');
$prefix = $mainKey;
$total = [];
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
$redis->setOption(Redis::OPT_SCAN, Redis::SCAN_RETRY);
$time1 = msectime();
while ($arrKeys = $redis->sscan($mainKey, $iterator, $prefix . '*', $count)) { // 匹配前缀为当前日期的key
    $total += $arrKeys;
}
$time2 = msectime();
$time = $time2 - $time1;
echo 'use time : ' . $time  . ' ms; total keys : ' . count($total) . PHP_EOL;
// use time : 649 ms; total keys : 90010 （这个集合中有20w个元素）
....... other code ......

• ZSCAN cursor [MATCH pattern] [COUNT count]
• 作用：用于迭代有序集合中的元素
• ZSCAN使用demo

<?php
$iterator = null;
$count = 1000;
$mainKey = 'test';
$prefix = '10';
$total = [];
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
$redis->setOption(Redis::OPT_SCAN, Redis::SCAN_RETRY);
$time1 = msectime();
while ($arrKeys = $redis->zscan($mainKey, $iterator, $prefix . '*', $count)) { // 匹配key前缀是 10 的所有key
    var_dump($arrKeys);
    $total += $arrKeys;
}
$time2 = msectime();
$time = $time2 - $time1;
echo 'use time : ' . $time  . ' ms; total keys : ' . count($total) . PHP_EOL;
// use time : 317 ms; total keys : 1111 （这个集合中有10w个元素）
...... other code ......

• HSCAN cursor [MATCH pattern] [COUNT count]
• 作用：用于迭代哈希中的元素
• HSACN 使用demo

<?php
$iterator = null;
$count = 1000;
$mainKey = 'my_hash_key';
$match = "*key*";
$total = [];
$redis = new Redis();
$redis->connect('127.0.0.1', 6379);
$redis->setOption(Redis::OPT_SCAN, Redis::SCAN_RETRY);
$time1 = msectime();
while ($arrKeys = $redis->hscan($mainKey, $iterator, $match, $count)) { // 匹配含有'key'的键
    var_dump($arrKeys);
    $total += $arrKeys;
}
$time2 = msectime();
$time = $time2 - $time1;
echo 'use time : ' . $time  . ' ms; total keys : ' . count($total) . PHP_EOL;
// use time : 1484 ms; total keys : 100000
...... other code ......

$pipe = $redis->multi(Redis::PIPELINE);
for ($i = 0; $i < 100000; $i++) {
    $redis->zAdd($key, $i, $i);
}
$curValues = $pipe->exec();
$val = $redis->zRange($key, 0, -1, true);
var_dump($val);

• redis 指令参考 scan