Finish challenge redislabs-training#7

quinluong · Feb 8, 2023 · 26d1bf2 · 26d1bf2
1 parent 0890554
commit 26d1bf2
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Showing 3 changed files with 40 additions and 4 deletions.
diff --git a/src/main/java/com/redislabs/university/RU102J/dao/RateLimiterSlidingDaoRedisImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/RateLimiterSlidingDaoRedisImpl.java
@@ -1,11 +1,17 @@
 package com.redislabs.university.RU102J.dao;
 
+import java.time.Instant;
+import java.time.ZonedDateTime;
+import java.util.UUID;
+import redis.clients.jedis.Jedis;
 import redis.clients.jedis.JedisPool;
+import redis.clients.jedis.Response;
+import redis.clients.jedis.Transaction;
 
 public class RateLimiterSlidingDaoRedisImpl implements RateLimiter {
 
     private final JedisPool jedisPool;
-    private final long windowSizeMS;
+    private final long windowSizeMS; // in milli
     private final long maxHits;
 
     public RateLimiterSlidingDaoRedisImpl(JedisPool pool, long windowSizeMS,
@@ -20,5 +26,29 @@ public RateLimiterSlidingDaoRedisImpl(JedisPool pool, long windowSizeMS,
     public void hit(String name) throws RateLimitExceededException {
         // START CHALLENGE #7
         // END CHALLENGE #7
+
+        String key = RedisSchema.getRateLimiterSlidingKey(windowSizeMS, name, maxHits);
+        Instant instant = ZonedDateTime.now().toInstant();
+        long currTimestampInMilli = instant.toEpochMilli();
+        long milestoneTimestampInMilli = currTimestampInMilli - windowSizeMS;
+        String randomNumber = UUID.randomUUID().toString();
+
+        try (Jedis jedis = jedisPool.getResource()) {
+            Transaction multi = jedis.multi();
+
+            multi.zadd(
+                    key,
+                    currTimestampInMilli,
+                    randomNumber
+            );
+            multi.zremrangeByScore(key, 0, milestoneTimestampInMilli);
+            Response<Long> hits = multi.zcard(key);
+
+            multi.exec();
+
+            if (hits.get() > maxHits) {
+                throw new RateLimitExceededException();
+            }
+        }
     }
 }
diff --git a/src/main/java/com/redislabs/university/RU102J/dao/RedisSchema.java b/src/main/java/com/redislabs/university/RU102J/dao/RedisSchema.java
@@ -42,6 +42,12 @@ static String getRateLimiterKey(String name, int minuteBlock,
                 String.valueOf(minuteBlock) + ":" +
                 String.valueOf(maxHits));
     }
+
+    static String getRateLimiterSlidingKey(long windowSize, String name, long maxHits) {
+        return KeyHelper.getKey(
+                String.format("limiter:%s:%s:%s", windowSize, name, maxHits)
+        );
+    }
 
     // sites:geo
     // Redis type: geo

diff --git a/src/test/java/com/redislabs/university/RU102J/dao/RateLimiterSlidingDaoRedisImplTest.java b/src/test/java/com/redislabs/university/RU102J/dao/RateLimiterSlidingDaoRedisImplTest.java
@@ -47,7 +47,7 @@ public void flush() {
         keyManager.deleteKeys(jedis);
     }
 
-    @Ignore
+//    @Ignore
     @Test
     public void hit() {
         int exceptionCount = 0;
@@ -64,7 +64,7 @@ public void hit() {
         assertThat(exceptionCount, is(0));
     }
 
-    @Ignore
+//    @Ignore
     @Test
     public void hitOutsideLimit() {
         int exceptionCount = 0;
@@ -81,7 +81,7 @@ public void hitOutsideLimit() {
         assertThat(exceptionCount, is(2));
     }
 
-    @Ignore
+//    @Ignore
     @Test
     public void hitOutsideWindow() throws InterruptedException {
         int exceptionCount = 0;