QDataStream won’t work with custom crafted char array
Hi guys. I have an application which consists of two primary modules. One is written in C, uses standard C runtime library and one written in Qt C++. They communicate with each other with IPC. C module creates a char array, fills it with data and sends to the module written in Qt. I want to deserialize received data using QDataStream, but my efforts didn’t yield any result yet. Here’s a simple example what I’m trying to achieve:
- unsigned int pointer = 0;
- const int IPC_MSG_LEN = 500;
- const int IPC_MSG_HEADER = 200;
- const int SOMETHING = 1443;
- char api = 55;
- char msg[IPC_MSG_LEN] = {0};
- memcpy_s(msg, IPC_MSG_LEN, &IPC_MSG_HEADER, sizeof(int));
- pointer = sizeof(unsigned int);
- memcpy_s(&msg[pointer], IPC_MSG_LEN - pointer, &api, sizeof(char));
- ++pointer;
- memcpy_s(&msg[pointer], IPC_MSG_LEN - pointer, &SOMETHING, sizeof(int));
- qint32 header = 0, aa = 0;
- qint8 t_api = 0;
- ds >> header; //Doesn't work
- ds >> t_api; //Works
- ds >> aa; //Doesn't work
As you can see, the code is pretty simple, but header and aa variables are deserialized to a random number. However t_api (one byte variable) has correct value assigned.
So what’s the problem with this code? Does QDataStream uses a private data format which is not compatible with the one I’m using? Should I write my own QIODevice implementation or there is a quick fix I’m not aware of? :)
Thanks, I appreciate your help.
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