Copy stream and seek stream position to start

framework/src/Volo.Abp.BlobStoring.Aliyun/Volo/Abp/BlobStoring/Aliyun/AliyunBlobProvider.cs

@@ -86,9 +86,7 @@ namespace Volo.Abp.BlobStoring.Aliyun
                 return null;
             }
             var result = ossClient.GetObject(containerName, blobName);
-            var memoryStream = new MemoryStream();
+            return await TryCopyToMemoryStreamAsync(result.Content, args.CancellationToken);
-            await result.Content.CopyToAsync(memoryStream);
-            return memoryStream;
         }
 
         protected virtual string GetContainerName(BlobProviderArgs args)

framework/src/Volo.Abp.BlobStoring.Aws/Volo/Abp/BlobStoring/Aws/AwsBlobProvider.cs

@@ -103,9 +103,7 @@ namespace Volo.Abp.BlobStoring.Aws
                     Key = blobName
                 });
 
-                var memoryStream = new MemoryStream();
+                return await TryCopyToMemoryStreamAsync(response.ResponseStream, args.CancellationToken);
-                await response.ResponseStream.CopyToAsync(memoryStream);
-                return memoryStream;
             }
         }
 

framework/src/Volo.Abp.BlobStoring.Azure/Volo/Abp/BlobStoring/Azure/AzureBlobProvider.cs

@@ -67,9 +67,7 @@ namespace Volo.Abp.BlobStoring.Azure
 
             var blobClient = GetBlobClient(args, blobName);
             var download = await blobClient.DownloadAsync();
-            var memoryStream = new MemoryStream();
+            return await TryCopyToMemoryStreamAsync(download.Value.Content, args.CancellationToken);
-            await download.Value.Content.CopyToAsync(memoryStream);
-            return memoryStream;
         }
 
         protected virtual BlobClient GetBlobClient(BlobProviderArgs args, string blobName)

framework/src/Volo.Abp.BlobStoring.FileSystem/Volo/Abp/BlobStoring/FileSystem/FileSystemBlobProvider.cs

@@ -74,9 +74,7 @@ namespace Volo.Abp.BlobStoring.FileSystem
                 {
                     using (var fileStream = File.OpenRead(filePath))
                     {
-                        var memoryStream = new MemoryStream();
+                        return await TryCopyToMemoryStreamAsync(fileStream, args.CancellationToken);
-                        await fileStream.CopyToAsync(memoryStream, args.CancellationToken);
-                        return memoryStream;
                     }
                 });
         }

framework/src/Volo.Abp.BlobStoring.Minio/Volo/Abp/BlobStoring/Minio/MinioBlobProvider.cs

@@ -75,20 +75,13 @@ namespace Volo.Abp.BlobStoring.Minio
                 return null;
             }
 
-            var memoryStream = new MemoryStream();
+            Stream blobStream = null;
             await client.GetObjectAsync(containerName, blobName,  (stream) =>
             {
-                    if (stream != null)
+                blobStream = stream;
-                    {
-                        stream.CopyTo(memoryStream);
-                    }
-                    else
-                    {
-                        memoryStream = null;
-                    }
             });
 
-            return memoryStream;
+            return await TryCopyToMemoryStreamAsync(blobStream, args.CancellationToken);
         }
 
         protected virtual MinioClient GetMinioClient(BlobProviderArgs args)

framework/src/Volo.Abp.BlobStoring/Volo/Abp/BlobStoring/BlobContainer.cs

@@ -194,14 +194,14 @@ namespace Volo.Abp.BlobStoring
                 var blobNormalizeNaming =
                     BlobNormalizeNamingService.NormalizeNaming(Configuration, ContainerName, name);
 
-                return TrySeekStreamToBegin(await Provider.GetOrNullAsync(
+                return await Provider.GetOrNullAsync(
                     new BlobProviderGetArgs(
                         blobNormalizeNaming.ContainerName,
                         Configuration,
                         blobNormalizeNaming.BlobName,
                         CancellationTokenProvider.FallbackToProvider(cancellationToken)
                     )
-                ));
+                );
             }
         }
 
@@ -214,14 +214,5 @@ namespace Volo.Abp.BlobStoring
 
             return CurrentTenant.Id;
         }
-
-        protected virtual Stream TrySeekStreamToBegin(Stream stream)
-        {
-            if (stream != null && stream.CanSeek)
-            {
-                stream.Seek(0, SeekOrigin.Begin);
-            }
-            return stream;
-        }
     }
 }

framework/src/Volo.Abp.BlobStoring/Volo/Abp/BlobStoring/BlobProviderBase.cs

@@ -1,4 +1,5 @@
 using System.IO;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Volo.Abp.BlobStoring
@@ -12,5 +13,18 @@ namespace Volo.Abp.BlobStoring
         public abstract Task<bool> ExistsAsync(BlobProviderExistsArgs args);
 
         public abstract Task<Stream> GetOrNullAsync(BlobProviderGetArgs args);
+
+        protected virtual async Task<Stream> TryCopyToMemoryStreamAsync(Stream stream, CancellationToken cancellationToken = default)
+        {
+            if(stream == null)
+            {
+                return null;
+            }
+
+            var memoryStream = new MemoryStream();
+            await stream.CopyToAsync(memoryStream, cancellationToken);
+            memoryStream.Seek(0, SeekOrigin.Begin);
+            return memoryStream;
+        }
     }
 }