Question

我有一个WCF服务，允许我以块的形式上传文件。我想知道的是，这个代码是否会导致上传的流在任何情况下仅部分附加到目标流？

我的日志告诉我所有发送的流都是512000字节（我在客户端设置），到目前为止我已经从9个块中发送了6个块。但在服务器上，文件大小为2634325.这意味着发送的最后一个块（第6个）保存不完整。

导致此行为的原因是什么？我该怎么做才能避免这种情况？

或者这是否完全安全，我应该在其他地方寻找错误？

public void UploadChunk ( RemoteFileChunk file )
{
    /// this file is not touched by anyone else
    var uploadPath = @"C:\some path\some.file";

    using ( var targetStream = new FileStream(uploadPath, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None) )
    { 
        if ( targetStream.Length == file.ChunkNumber * Helper.ChunkSize )
        {
            /// ---- streaming operation is here ----
            targetStream.Position = targetStream.Length;
            file.Stream.CopyTo(targetStream);
            file.Stream.Close();
            /// -------------------------------------
        }
        else throw new FaultException<DataIntegrityException>(new DataIntegrityException
        {
            CurrentIndex = targetStream.Length,
            RequestedIndex = file.ChunkNumber * Helper.ChunkSize,
            Message = string.Format("{0}th chunk index requested when there already {1} chunks exist.", file.ChunkNumber, targetStream.Length / Helper.ChunkSize)
        });
    }
}

以下是客户端文件上传代码段：

var buffer = new byte[ChunkIndex != NumberOfChunks - 1 ? Helper.ChunkSize : LastPieceLen];

using ( var file = new FileStream(Info.FullName, FileMode.Open, FileAccess.Read, FileShare.None) )
{
    file.Position = (long)ChunkIndex * Helper.ChunkSize;
    file.Read(buffer, 0, buffer.Length);
}

var chunk = new MemoryStream(buffer);

chunk.Position = 0;
Service.StreamingEnd.UploadChunk(new RemoteFileChunk(FileId, CF.Id, VersionDate, ChunkIndex, chunk.Length, Sessions.Get(), chunk));

Answer 1

看看if语句 - 最后的块是否保证恰好是块大小？如果您上传的文件大小不是块大小的倍数会怎样？

Stream.CopyTo（）方法可以保存流不完整吗？

1 个答案: