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flatbuffers

How exactly do references in flatbuffers work?


According to the "Writing a schema" guide for Google FlatBuffers it is possible to share data using references: "Remember that you can share data (refer to the same string/table within a buffer), so factoring out repeating data into its own data structure may be worth it."

However, I don't quite understand how this is meant to be accomplished. I have a flatbuffer that I'm trying to reverse engineer and I discovered that there are multiple offsets pointing to the same string value. When I compile the decoded JSON file again, there are multiple occurences of that string. What exactly do I have to specify in the schema file to prevent this?

Thank you :)


Solution

  • JSON has no way to represent such references, so a buffer is "flattened" to a tree when output as JSON. Only at the binary level can a FlatBuffer represent a DAG. You can construct such a DAG simply by using a child offset twice in parent(s) while serializing.