From f7539b5374a80ad5ebfd93dfa6aa22c8c7e76732 Mon Sep 17 00:00:00 2001
From: Laura Hausmann <laura@hausmann.dev>
Date: Sun, 28 Jan 2024 02:49:30 +0100
Subject: [PATCH] Fix cache serializer

---
 .../Extensions/DistributedCacheExtensions.cs  | 22 +++++++++++--------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/Iceshrimp.Backend/Core/Extensions/DistributedCacheExtensions.cs b/Iceshrimp.Backend/Core/Extensions/DistributedCacheExtensions.cs
index a3dd6bde..29b7defd 100644
--- a/Iceshrimp.Backend/Core/Extensions/DistributedCacheExtensions.cs
+++ b/Iceshrimp.Backend/Core/Extensions/DistributedCacheExtensions.cs
@@ -6,15 +6,20 @@ namespace Iceshrimp.Backend.Core.Extensions;
 public static class DistributedCacheExtensions {
 	//TODO: named caches, CacheService?
 	//TODO: thread-safe locks to prevent fetching data more than once
+	//TODO: sliding window ttl?
 
 	public static async Task<T?> Get<T>(this IDistributedCache cache, string key) {
 		var buffer = await cache.GetAsync(key);
-		if (buffer == null) return default;
+		if (buffer == null || buffer.Length == 0) return default;
 
 		var stream = new MemoryStream(buffer);
-		var data   = await JsonSerializer.DeserializeAsync<T>(stream);
-
-		return data != null ? (T)data : default;
+		try {
+			var data = await JsonSerializer.DeserializeAsync<T>(stream);
+			return data != null ? (T)data : default;
+		}
+		catch {
+			return default;
+		}
 	}
 
 	public static async Task<T> Fetch<T>(this IDistributedCache cache, string key, TimeSpan ttl,
@@ -28,11 +33,10 @@ public static class DistributedCacheExtensions {
 	}
 
 	public static async Task Set<T>(this IDistributedCache cache, string key, T data, TimeSpan ttl) {
-		using var ms = new MemoryStream();
-		await JsonSerializer.SerializeAsync(ms, data);
-		var buffer = new Memory<byte>();
-		_ = await ms.ReadAsync(buffer);
+		using var stream = new MemoryStream();
+		await JsonSerializer.SerializeAsync(stream, data);
+		stream.Position = 0;
 		var options = new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = ttl };
-		await cache.SetAsync(key, buffer.ToArray(), options);
+		await cache.SetAsync(key, stream.ToArray(), options);
 	}
 }
\ No newline at end of file