Cache client

WWTWebservices.Azure/AzurePlateTilePyramid.cs

@@ -1,26 +1,34 @@
 using Azure.Core;
 using Azure.Storage.Blobs;
 using System;
+using System.Collections.Concurrent;
 using System.IO;
 
 namespace WWTWebservices.Azure
 {
     public class AzurePlateTilePyramid : IPlateTilePyramid
     {
+        private readonly ConcurrentDictionary<string, BlobContainerClient> _containers;
         private readonly TokenCredential _credentials;
         private readonly string _storageUri;
 
         public AzurePlateTilePyramid(string storageUri, TokenCredential credentials)
         {
             _credentials = credentials;
             _storageUri = storageUri;
+            _containers = new ConcurrentDictionary<string, BlobContainerClient>();
         }
 
         public Stream GetStream(string plateName, int level, int x, int y)
         {
-            var name = Path.GetFileNameWithoutExtension(plateName).ToLowerInvariant();
-            var uri = new Uri($"{_storageUri}/{name}");
-            var container = new BlobContainerClient(uri, _credentials);
+            var container = _containers.GetOrAdd(plateName, c =>
+            {
+                var name = Path.GetFileNameWithoutExtension(plateName).ToLowerInvariant();
+                var uri = new Uri($"{_storageUri}/{name}");
+
+                return new BlobContainerClient(uri, _credentials);
+            });
+
             var client = container.GetBlobClient($"L{level}X{x}Y{y}.png");
             var download = client.Download();