Game State Encoder Library

This library will encode and decode data as per the specification documented here: https://github.com/fluffy/draft-jennings-game-state-over-rtp.

To use the library, one instantiates an object of type gs::Encoder. This object will accept any one of defined object types and encode that by calling the gs::Serializer object. The gs::Serializer object, in turn, invokes functions in the DataBuffer object to serialize the primitive data types.

Deserialization of data is via the gs::Decoder object. It accepts a DataBuffer and all objects found in the buffer are deserialized into a vector of GSObjects. The gs::Decoder will utilize the gs::Serializer, which in turn calls functions in the DataBuffer object to extract primitive types.

Building

( mkdir build ; cd build ; cmake .. ; make ) 

C Interface

The C interface has the following encoder (serialization) functions:

• GSEncoderInit()
• GSEncoderDataLength()
• GSEncodeObject()
• GetEncoderError()
• GSEncoderDestroy()

One would call GSEncoderInit() with a pointer to the raw buffer and a buffer length. That will create a context that is used with other calls.

A GS_Object is populated and passed into GSEncodeObject(), which will return 1 on success, 0 if the buffer cannot hold more data, or -1 on error. On error, one can check the error string. Calling the GSEncoderDataLength() will return the number of octets serialized into the buffer. GSEncodeObject() may be called repeatedly until there is no more room in the buffer.

GSEEncoderDestroy() will destroy the encoder context and any associated data, so be sure to call GSEncoderDataLength() before GSEEncoderDestroy().

The C interface has the following decoder (deserialization) functions:

• GSDecoderInit()
• GSDecodeObject()
• GetDecoderError()
• GSDecoderDestroy()

One would call GSDecoderInit() with a pointer to the buffer holding the object(s) to deserialize and a buffer length. That will create a context that is used with other calls.

One then calls GSDecodeObject() with a pointer to a GS_Object type. The structured will be zero-initialized by this API call, so the caller need not initialize it. The result result will be 1 if successful, 0 if there are no more objects to deserialize from the buffer, or -1 if there is an error. On error, one can check the error string. GSDecodeObject() may be called repeatedly until there are no more objects to decode.

As a part of the decode process, some data may be dynamically allocated on the heap with pointers assigned inside the GS_Object. Pointers to any such data are stored with the decoder context and will be freed when GSEDecoderDestroy() is called. One may assume pointers remain valid until GSEDecoderDestroy() is called.

GSEDecoderDestroy() will destroy the decoder context and any associated data.