Fixed CosmosSqlMetadataProvider concurrency issue. (#2695)

The CosmosSqlMetdataProvider uses a standard dictionary although the
metadata provider is accessed and updated concurrently. This causes the
issue in #2694. I have updated the implementation to use a
ConcurrentDictionary.

Fixes #2694

Co-authored-by: Aniruddh Munde <[email protected]>

Author: 2 people

src/Core/Services/MetadataProviders/CosmosSqlMetadataProvider.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System.Collections.Concurrent;
 using System.Diagnostics.CodeAnalysis;
 using System.IO.Abstractions;
 using Azure.DataApiBuilder.Config.DatabasePrimitives;
@@ -26,7 +27,7 @@ public class CosmosSqlMetadataProvider : ISqlMetadataProvider
         private CosmosDbNoSQLDataSourceOptions _cosmosDb;
         private readonly RuntimeEntities _runtimeConfigEntities;
         private readonly bool _isDevelopmentMode;
-        private Dictionary<string, string> _partitionKeyPaths = new();
+        private ConcurrentDictionary<string, string> _partitionKeyPaths = new();
 
         /// <summary>
         /// This contains each entity into EDM model convention which will be used to traverse DB Policy filter using ODataParser
@@ -536,17 +537,21 @@ public IReadOnlyDictionary<string, DatabaseObject> GetEntityNamesAndDbObjects()
         /// <inheritdoc />
         public string? GetPartitionKeyPath(string database, string container)
         {
+            ArgumentNullException.ThrowIfNull(database);
+            ArgumentNullException.ThrowIfNull(container);
+
             _partitionKeyPaths.TryGetValue($"{database}/{container}", out string? partitionKeyPath);
             return partitionKeyPath;
         }
 
         /// <inheritdoc />
         public void SetPartitionKeyPath(string database, string container, string partitionKeyPath)
         {
-            if (!_partitionKeyPaths.TryAdd($"{database}/{container}", partitionKeyPath))
-            {
-                _partitionKeyPaths[$"{database}/{container}"] = partitionKeyPath;
-            }
+            ArgumentNullException.ThrowIfNull(database);
+            ArgumentNullException.ThrowIfNull(container);
+            ArgumentNullException.ThrowIfNull(partitionKeyPath);
+
+            _partitionKeyPaths.AddOrUpdate($"{database}/{container}", partitionKeyPath, (key, oldValue) => partitionKeyPath);
         }
 
         public bool TryGetEntityNameFromPath(string entityPathName, [NotNullWhen(true)] out string? entityName)