Use a sqlite manager per stream that's kept around forever

src/Speckle.Sdk/SQLite/SqLiteJsonCacheManagerFactory.cs

@@ -1,4 +1,5 @@
-using Speckle.InterfaceGenerator;
+using System.Collections.Concurrent;
+using Speckle.InterfaceGenerator;
 using Speckle.Sdk.Logging;
 using Speckle.Sdk.Serialisation.Utilities;
 
@@ -8,12 +9,21 @@ namespace Speckle.Sdk.SQLite;
 public class SqLiteJsonCacheManagerFactory : ISqLiteJsonCacheManagerFactory
 {
   public const int INITIAL_CONCURRENCY = 4;
+
+  private readonly ConcurrentDictionary<string, ISqLiteJsonCacheManager> _cachedManagers = new();
 
   private ISqLiteJsonCacheManager Create(string path, int concurrency) => new SqLiteJsonCacheManager(path, concurrency);
 
   public ISqLiteJsonCacheManager CreateForUser(string scope) =>
     Create(Path.Combine(SpecklePathProvider.UserApplicationDataPath(), "Speckle", $"{scope}.db"), 1);
 
-  public ISqLiteJsonCacheManager CreateFromStream(string streamId) =>
-    Create(SqlitePaths.GetDBPath(streamId), INITIAL_CONCURRENCY);
+  public ISqLiteJsonCacheManager CreateFromStream(string streamId)
+  {
+    if (!_cachedManagers.TryGetValue(streamId, out var manager))
+    {
+      manager = Create(SqlitePaths.GetDBPath(streamId), INITIAL_CONCURRENCY);
+      _cachedManagers.TryAdd(streamId, manager);
+    }
+    return manager;
+  }
 }

src/Speckle.Sdk/ServiceRegistration.cs

@@ -97,6 +97,8 @@ SpeckleSdkOptions speckleSdkOptions
       typeof(Client)
     );
     serviceCollection.AddMatchingInterfacesAsTransient(typeof(GraphQLRetry).Assembly);
+    //we want to make sqlite pools be singletons per stream so needs a singleton factory
+    serviceCollection.TryAddSingleton<ISqLiteJsonCacheManagerFactory, SqLiteJsonCacheManagerFactory>();
     return serviceCollection;
   }