CANParser: expose MessageState to Cython to eliminate data copying

[deanlee]

This PR greatly simplifies the update logic, resulting in reduced code complexity and eliminating unnecessary data copying.

Main Changes:

1. Removal of SignalValue Struct and CANParser::query_latest Function: These components, previously used for copying updated values to Cython, have been removed. This change streamlines the data flow between C++ and Cython.
2. Direct Exposure of MessageState to Cython: MessageState is now directly accessible from Cython, allowing values to be read straight from the C++ object. This eliminates the need for intermediate copying, optimizing performance and simplifying the overall code structure.

Additionally, this PR includes changes from #1381, where value dictionaries are now initialized directly from DBC messages, though it does not include the test_parser_empty_list() function.

Below are the performance benchmark results comparing this PR against the current master branch:

Benchmark (PR):

6000 CAN packets, 10 runs
272.64 mean ms, 278.98 max ms, 268.80 min ms, 2.98 std ms
0.0454 mean ms / CAN packet

Benchmark (Master):

6000 CAN packets, 10 runs
335.81 mean ms, 394.27 max ms, 312.58 min ms, 24.96 std ms
0.0560 mean ms / CAN packe

Most of the time is spent converting and copying messages from Python to C++. so while the current results don't show a massive improvement, after #1383 is merged, this PR could reduce the time per packet from 0.0318 ms to under 0.02 ms. I will run additional benchmarks to confirm once that change is integrated.

[sshane]

Benchmarks on a 3X:

PR:

6000 CAN packets, 10 runs
395.90 mean ms, 397.14 max ms, 394.55 min ms, 0.83 std ms
0.0660 mean ms / CAN packet

master (after bus/addr filter PR):

6000 CAN packets, 10 runs
437.80 mean ms, 440.19 max ms, 436.00 min ms, 1.38 std ms
0.0730 mean ms / CAN packet

[deanlee]

@sshane : FYI, this PR also resolves issue #1066, as it no longer relies on timestamps for updating the last values. Instead, it updates the updated_addresses set whenever a CAN signal is successfully parsed.

if (state_it->second.parse(can.nanos, frame.dat)) {
    updated_addresses.insert(state_it->first);
}

This approach ensures the updated values are tracked more reliably, independent of the timestamp.

I believe we can close issue #1066 once this is merged.

[sshane]

Nice clean up!

[sshane]

@deanlee do you mind making the same change with PlotJuggler? It used SignalValue which we removed

[deanlee]

@sshane : commaai/PlotJuggler#67 should work, However, since I'm still unable to build PlotJuggler, feel free to take over it if you'd like.