CODEWITHSUNDEEP
c++serializationthrift
Jack
Jack

Reputation: 5434

Apache Thrift serialization in C++

I’m having a lot of trouble serializing data. What am I doing wrong?

std::string serialize(ContactsList& obj, std::string filename) {
    shared_ptr<TMemoryBuffer> transportOut(new TMemoryBuffer());
    shared_ptr<TBinaryProtocol> protocolOut(new TBinaryProtocol(transportOut));
    obj.write(protocolOut);
    std::string serialized_string = transportOut->getBufferAsString();
    return serialized_string;
}

This is the method I call from another method. I expect to get back a serialized binary string which I can write out to disk. Inside this serialize method, I create a TMemory buffer, then I wrap it in a TBinaryProtocol, and then the object’s write method, which will write itself into the memory buffer. Then, I get that buffer back as a string. I’d then write out the serialized string to disk.

I get this error:

error: no matching function for call to ‘addressbook::ContactsList::write(boost::shared_ptr<apache::thrift::protocol::TBinaryProtocolT<apache::thrift::transport::TTransport> >&)

As well as this note:

note: no known conversion for argument 1 from ‘boost::shared_ptr<apache::thrift::protocol::TBinaryProtocolT<apache::thrift::transport::TTransport> >’ to ‘apache::thrift::protocol::TProtocol*

I'm using Apache Thrift 1.0-dev, C++ 98 if these things make a difference.

Upvotes: 3

Views: 5043

Answers (2)

Henrique Mendon&#231;a
Henrique Mendon&#231;a

Reputation: 584

In c++ you can use the TFileTransport and a Thrift protocol of your choice, i.e. TBinaryProtocol:

shared_ptr<TFileTransport> transport(new TFileTransport(filename));
shared_ptr<TBinaryProtocol> protocol(new TBinaryProtocol(transport));
yourObj.write(protocol.get()); // to write

or

yourObj.read(protocol.get()); // to read

to make sure the file exists you can use a open before:

open(filename.c_str(), O_CREAT|O_TRUNC|O_WRONLY, 0666); // create file

ps.: It's actually very similar in all other target languages.

Upvotes: 3

Sagar Padhye
Sagar Padhye

Reputation: 176

The ThriftObject.write() function expects an argument of type

apache::thrift::protocol::TProtocol*

i.e. a 'Raw' pointer of type TProtocol. The protocolOut object used here is of shared pointer of the type.

shared_ptr<TBinaryProtocol> protocolOut

The 'get()' method of shared_ptr gives the raw pointer being managed by the shared_ptr object. Hence using

obj.write(protocolOut.get());

should resolve the problem

Upvotes: 2

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