Add CacheRateLimiter

src/Support/CacheRateLimiter.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Msr\LaravelBitunixApi\Support;
+
+use Illuminate\Contracts\Cache\Repository;
+use Msr\LaravelBitunixApi\Contracts\RateLimiterContract;
+
+class CacheRateLimiter implements RateLimiterContract
+{
+    public function __construct(
+        protected Repository $cache,
+    ) {
+    }
+
+    public function throttle(
+        string $bucket,
+        string $identity,
+        int $maxRequests,
+        float $perSeconds
+    ): void {
+        if ($maxRequests <= 0 || $perSeconds <= 0) {
+            return;
+        }
+
+        $cacheKey = $this->makeCacheKey($bucket, $identity);
+        $minIntervalMicroseconds = (int) (($perSeconds / $maxRequests) * 1_000_000);
+
+        $lastRequestAt = $this->cache->get($cacheKey);
+
+        if (is_numeric($lastRequestAt)) {
+            $elapsedMicroseconds = (int) ((microtime(true) - (float) $lastRequestAt) * 1_000_000);
+
+            if ($elapsedMicroseconds < $minIntervalMicroseconds) {
+                $sleepMicroseconds = $minIntervalMicroseconds - $elapsedMicroseconds;
+
+                if ($sleepMicroseconds > 0) {
+                    usleep($sleepMicroseconds);
+                }
+            }
+        }
+
+        $this->cache->put(
+            $cacheKey,
+            microtime(true),
+            now()->addSeconds((int) max(1, ceil($perSeconds * 2)))
+        );
+    }
+
+    protected function makeCacheKey(string $bucket, string $identity): string
+    {
+        return sprintf(
+            'laravel_bitunix_api:rate_limit:%s:%s',
+            $bucket,
+            sha1($identity)
+        );
+    }
+}