Flatbuffers：在 C++ 中写入读取二进制文件问题？

Question

My schema, encoder and decoder looks as below.

Schema :

namespace Myclient.sample;
table Person {
  age: short;
}
root_type Person;

Encoder:

int main(int argc, char *argv[])
{            
        flatbuffers::FlatBufferBuilder builder(1024);
        auto name = builder.CreateString("Mr Test");
        PersonBuilder mybuilder(builder);
        mybuilder.add_age(20);
        auto orc = mybuilder.Finish();
        builder.Finish(orc);
        uint8_t *buf = builder.GetBufferPointer();
        int size = builder.GetSize();
        ofstream wf(argv[1], ios::out | ios::binary);           
        wf.write((char*) &buf, size);   // overwrite
        wf.close();            
        return 0;
}

Decoder:

int main(int argc, char *argv[])
{
    //Read BIN file
    std::ifstream infile;
    infile.open(argv[1], std::ios::binary | std::ios:: in);
    infile.seekg(0, std::ios::end);
    int length = infile.tellg();
    infile.seekg(0, std::ios::beg);
    char *data = new char[length];
    infile.read(data, length);
    infile.close();

    flatbuffers::Verifier verifier(reinterpret_cast< unsigned char*> (data), length);
    bool ok = VerifyPersonBuffer(verifier);

    cout << "   verify value2: " << ok << endl;
    auto per = GetPerson(data);
    if (per)
    {
        cout << " person decoded" << endl;
        cout << "age is " << per->age() << endl;
    }
    return 0;
}

output of decoder: verify value2: 0 person decoded

Issue: could not decoded. is there any issue with biniary file read write, or schema definition. please help. Thanks.

Answer 1

wf.write((char*) &buf, size); will happily write the address of buf to that file followed by a large amount of garbage. The compiler was trying to warn you but you shut it up without reading the error. Change to buf and at least that problem is solved.