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cschemaflatbuffers

how to declare pointer type in flatbuffers schema file?

I am learning flatbuffers and I wish to use them in C. What I'm trying to do is writing a schema file for my structs. this is one of my structs:

typedef struct
{
    unsigned short request_number;
    unsigned short length;
    unsigned short height;
    unsigned char   *buffer;
} CASH_RECEIPT_REQUEST;

How can i write the pointer unsigned char *buffer in my schema file?

Solution

  • Pointer sizes are platform dependent. If you decide use it on 64-bit processor with 8 bytes size pointers you can use ulong (as schema specifies in here) ulong size is 8 bytes. So at the parsing side you can typecast the ulong (In other words unsigned long) to char* type to obtain the correct pointer value. Sample schema for your example looks like this

    CASH_RECEIPT_REQUEST {
  request_number:ushort;
  length:ushort;
  height:ushort;
  buffer:ulong;
}