Streaming Data Types

FlatBuffers is the format chosen for the ISIS data streaming system, derived from the ESS messaging system.

Schema ids

Adding new schemas

Add .fbs file to `schemas directory

Check ess-streaming-data-types first; attempt not to diverge without reason. If a new schema is really needed, then add a new .fbs schema in the schemas directory.

Note: to generate code from .fbs schemas, you will need the flatc tool installed. It can be acquired from https://github.com/google/flatbuffers/releases .

Adding Python bindings

Python bindings have low-level code (autogenerated by flatc) in the fbschemas directory, but also manually-written convenience serializers and deserializers in the top-level of the python module.

When adding or modifying a schema:

• The low-level code must be generated by manually calling flatc --python schemas\some_schema.fbs and adding the resulting generated code to python/src/streaming_data_types/fbschemas.
• Manually-written serializers & deserializers will need to be updated, and added to the lists in __init__.py.

Rust bindings

Rust bindings have low-level code in flatbuffers_generated, and a small high-level wrapper to deserialize any message.

When adding or modifying a schema:

• The low-level code must be generated by calling generate_rust_bindings.py
• The wrapper (defined in lib.rs) will need to be updated with the new schema.