add : 频率锁

src/Lock/FrequencyLockUtil.php

+<?php
+
+namespace Api\PhpUtils\Lock;
+
+/**
+ * Redis 频率锁
+ */
+use Api\PhpUtils\Redis\RedisUtil;
+
+class FrequencyLockUtil
+{
+
+    const MIN_FREQUENCY_SECONDS = 30;   // 频率锁默认最小间隔秒数
+    const MIN_FREQUENCY_TIMES   = 1;   // 频率锁默认最小间隔秒数内最大访问次数
+
+    const PREFIX_FREQUENCY_LOCK = 'flk:';
+
+    private static $handler = null;
+
+    private static function initCache()
+    {
+        if (empty(self::$handler)){
+            //获取连接句柄, 使用gateway的codis
+            self::$handler = RedisUtil::getInstance('cache', ['serializer' => 'none']);
+        }
+    }
+
+    /**
+     * 频率锁, 每$expire秒钟允许$times次$key访问
+     *
+     * @param string $key   锁定的key
+     * @param int $times    允许访问次数
+     * @param int $expire   锁定时长,秒数
+     * @return boolean
+     */
+    public static function isLocked($key, $times = self::MIN_FREQUENCY_TIMES, $expire = self::MIN_FREQUENCY_SECONDS)
+    {
+        $key = self::PREFIX_FREQUENCY_LOCK . $key;
+        self::initCache();
+        $current_times = self::$handler->incr($key);
+        if ($current_times == 1) {
+            self::$handler->expire($key, $expire);
+        }
+        return ($current_times > $times) ? false : true;
+    }
+    
+    /**
+     * 频次减少
+     * @param  string $key   锁定的key
+     * @param  int $number   减少的值
+     * @return void
+     */
+    public static function decr($key, $number = 1)
+    {
+        $key = self::PREFIX_FREQUENCY_LOCK . $key;
+        self::initCache();
+        return self::$handler->decrby($key, $number);
+    }
+
+    /**
+     * 频次重置(测试用)
+     * @param string $key
+     */
+    public static function reset($key)
+    {
+        $key = self::PREFIX_FREQUENCY_LOCK . $key;
+        self::initCache();
+        return self::$handler->del($key);
+    }
+
+    /**
+     * 已经使用次数
+     * @param string $key
+     * @return int
+     */
+    public static function get($key)
+    {
+        $key = self::PREFIX_FREQUENCY_LOCK . $key;
+        self::initCache();
+        $times = self::$handler->get($key);
+        return intval($times);
+    }
+}