NSOutputStream 或twistedreactor合并TCP数据包数据

发布于 2024-11-06 05:51:57 字数 1189 浏览 2 评论 0原文

我正在为与 Python Twisted 后端交互的 iPhone 应用程序编写一些网络代码。我最近遇到了一个问题，似乎我的 NSOutputStream 使发送时的有效负载加倍，或者扭曲使接收时的有效负载加倍。

我正在使用“Apple 推荐”风格的 TCP 套接字，EG 非轮询。

流程如下：
客户
   - NSStreamEventHasSpaceAvailable: 发送 X 字节数据的数据包
   - NSStreamEventHasSpaceAvailable: 发送另一个 Y 字节数据包
服务器
   - Twisted 接收大小为 (X + Y) 字节的数据包

我确保如果 outputStream 的状态为“，则明确不发送数据” NSStreamStatusWriting”。还要确保如果未抛出 NSStreamEventHasSpaceAvailable 则不允许从客户端发送数据。

关于可能导致有效负载加倍/合并的任何想法？ Twisted 代码相当简单，使用我的协议中的标准 dataReceived：

    def dataRecieved(self, data):
        # do logic in order to decide how to handle data
        # ...
        # print of len(data) here reveals merged packet size

iOS 代码也相当标准：

    if (eventCode == NSStreamEventHasSpaceAvailable)
    {
        [outputStream write:[packet getData] maxLength:[packet getPacketSize]];
    }
    // [packet getData] simply returns a standard UInt8 array. 
    // [packet getPacketSize] returns the size of that array.

当连续调用上述 iOS 代码两次时（例如，依次发送两个数据包），扭曲的代码报告合并数据的大小。

预先感谢您的任何意见或建议。

原文

I'm working on some networking code for an iPhone application that interfaces with a Python Twisted backend. I've been running into a problem recently where it appears as though either my NSOutputStream is doubling up the payload on send OR twisted is doubling up the payload on receive.

I'm using the "Apple Recommended" style of TCP sockets, E.G. non-polling.

The process is as follows:
CLIENT
    - NSStreamEventHasSpaceAvailable: send a packet of X bytes of data
    - NSStreamEventHasSpaceAvailable: send another packet of Y bytes of data
SERVER
    - Twisted receives packet of size (X + Y) bytes

I'm making sure I explicitly don't send data if the status of the outputStream is "NSStreamStatusWriting". Also ensuring that data is not allowed to be sent from the client if NSStreamEventHasSpaceAvailable has not been thrown.

Any ideas as to what may be causing this double-up/merger of the payload? The Twisted code is fairly straight-forward, using the standard dataReceived in my Protocol:

    def dataRecieved(self, data):
        # do logic in order to decide how to handle data
        # ...
        # print of len(data) here reveals merged packet size

iOS code is fairly standard as well:

    if (eventCode == NSStreamEventHasSpaceAvailable)
    {
        [outputStream write:[packet getData] maxLength:[packet getPacketSize]];
    }
    // [packet getData] simply returns a standard UInt8 array. 
    // [packet getPacketSize] returns the size of that array.

When the above iOS code is called twice in a row (e.g., sending two packets one after another), the twisted code reports the merged data size.

Thanks in advance for any advice or suggestions.

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