Fixed GetOrSet redis read. (#25)

* Fixed GetOrSet redis read.

* Changed implementation to avoid feedbackup/notification loop. Thanks @JoelNygren-Norce!

Author: aheintz

RedisBackedHzCache/RedisBackedHzCache.cs

@@ -219,6 +219,23 @@ public void Set<T>(string key, T value, TimeSpan ttl)
 
         public T GetOrSet<T>(string key, Func<string, T> valueFactory, TimeSpan ttl, long maxMsToWaitForFactory = 10000)
         {
+            var value = hzCache.Get<T>(key);
+            if (value != null)
+            {
+                return value;
+            }
+
+            if (options.useRedisAs2ndLevelCache)
+            {
+                var redisValue = GetRedisValue(key);
+                if (!redisValue.IsNull)
+                {
+                    var ttlValue = TTLValue.FromRedisValue<T>(Encoding.ASCII.GetBytes(redisValue.ToString()));
+                    hzCache.SetRaw(key, ttlValue);
+                    return (T)ttlValue.value;
+                }
+            }
+
             return hzCache.GetOrSet(key, valueFactory, ttl, maxMsToWaitForFactory);
         }
 
@@ -229,7 +246,8 @@ public IList<T> GetOrSetBatch<T>(IList<string> keys, Func<IList<string>, List<Ke
 
         public IList<T> GetOrSetBatch<T>(IList<string> keys, Func<IList<string>, List<KeyValuePair<string, T>>> valueFactory, TimeSpan ttl)
         {
-            using var activity = HzActivities.Source.StartActivityWithCommonTags(HzActivities.Names.GetOrSetBatch, HzActivities.Area.RedisBackedHzCache, key: string.Join(",", keys ?? new List<string>()));
+            using var activity = HzActivities.Source.StartActivityWithCommonTags(HzActivities.Names.GetOrSetBatch, HzActivities.Area.RedisBackedHzCache,
+                key: string.Join(",", keys ?? new List<string>()));
             Func<IList<string>, List<KeyValuePair<string, T>>> redisFactory = idList =>
             {
                 // Create a list of redis keys from the list of cache keys

RedisBackedHzCache/RedisBackedHzCacheAsync.cs

@@ -55,9 +55,26 @@ public Task SetAsync<T>(string key, T value, TimeSpan ttl)
             return hzCache.SetAsync(key, value, ttl);
         }
 
-        public Task<T> GetOrSetAsync<T>(string key, Func<string, Task<T>> valueFactory, TimeSpan ttl, long maxMsToWaitForFactory = 10000)
+        public async Task<T> GetOrSetAsync<T>(string key, Func<string, Task<T>> valueFactory, TimeSpan ttl, long maxMsToWaitForFactory = 10000)
         {
-            return hzCache.GetOrSetAsync(key, valueFactory, ttl, maxMsToWaitForFactory);
+            var value = await hzCache.GetAsync<T>(key);
+            if (value != null)
+            {
+                return value;
+            }
+
+            if (options.useRedisAs2ndLevelCache)
+            {
+                var redisValue = await GetRedisValueAsync(key);
+                if (!redisValue.IsNull)
+                {
+                    var ttlValue = await TTLValue.FromRedisValueAsync<T>(Encoding.ASCII.GetBytes(redisValue.ToString()));
+                    hzCache.SetRaw(key, ttlValue);
+                    return (T)ttlValue.value;
+                }
+            }
+
+            return await hzCache.GetOrSetAsync(key, valueFactory, ttl, maxMsToWaitForFactory);
         }
 
         public Task<IList<T>> GetOrSetBatchAsync<T>(IList<string> keys, Func<IList<string>, Task<List<KeyValuePair<string, T>>>> valueFactory)
@@ -67,7 +84,8 @@ public Task<IList<T>> GetOrSetBatchAsync<T>(IList<string> keys, Func<IList<strin
 
         public async Task<IList<T>> GetOrSetBatchAsync<T>(IList<string> keys, Func<IList<string>, Task<List<KeyValuePair<string, T>>>> valueFactory, TimeSpan ttl)
         {
-            using var activity = HzActivities.Source.StartActivityWithCommonTags(HzActivities.Names.GetOrSetBatch, HzActivities.Area.RedisBackedHzCache, async: true, key: string.Join(",", keys ?? new List<string>()));
+            using var activity = HzActivities.Source.StartActivityWithCommonTags(HzActivities.Names.GetOrSetBatch, HzActivities.Area.RedisBackedHzCache, async: true,
+                key: string.Join(",", keys ?? new List<string>()));
             Func<IList<string>, Task<List<KeyValuePair<string, T>>>> redisFactory = async idList =>
             {
                 // Create a list of redis keys from the list of cache keys
@@ -127,4 +145,4 @@ public Task<bool> RemoveAsync(string key)
             return hzCache.RemoveAsync(key);
         }
     }
-}
+}

UnitTests/IntegrationTests.cs

@@ -298,10 +298,11 @@ public async Task TestRedisGetOrSet()
             var v1 = c1.GetOrSet("1", _ => new Mocko(10), TimeSpan.FromMinutes(1));
             Assert.IsNotNull(v1);
             Assert.IsTrue(c1.Get<Mocko>("1").num == 10);
-            await Task.Delay(100);
-            var c21 = await c2.GetAsync<Mocko>("1");
+            await Task.Delay(200);
+            var c21 = await c2.GetOrSetAsync("1", _ => Task.FromResult(new Mocko(20)), TimeSpan.FromMinutes(1));
             Assert.IsTrue(c21.num == 10);
             Assert.IsTrue(c21.guid != v1.guid);
+            await c1.RemoveAsync("1");
         }