Checkpointing

Checkpointing

Added on main via LIM-234 / GH#28 (save_state / load_state!).

API

snap = save_state(router::RegionRouter)  # -> NamedTuple (independent copies)
load_state!(router, snap)                # in-place restore
load_state(router, snap)                 # alias of load_state!

Snapshot contents

save_state copies:

Field	Purpose
n_regions, n_out	Dimension validation
region_names	Structural match check
adjacency_matrix	Structural match check
inhibition_matrix	Structural match check
routing_weights	Restored
readout_ema	Restored
spike_density	Restored
prev_routing_weights	Restored
prev_relevance	Restored
surprise	Restored
scratch	Restored (optional on older snaps)
tick_count	Restored

Array fields are copy so later update_routing! does not mutate the snapshot. Element types are immutable (Float32 / String).

Load validation

load_state! throws ArgumentError when:

• n_regions / n_out mismatch the target router
• required structural fields missing (region_names, adjacency_matrix, inhibition_matrix)
• array sizes wrong
• region_names / adjacency / inhibition values do not equal the target router

Structural fields are validated, not rewritten — the target router must already be configured for the same experiment labels and graph.

If scratch is absent from an older snapshot, the load path zeros the target scratch buffer for determinism.

Intended use

• Pause / resume long-running routing experiments
• Round-trip tests
• Reproducible restarts when the surrounding SNN state is also restored

Not a wire format or cross-language serialization standard — it is a Julia NamedTuple of copies. Callers that need disk I/O should serialize the snapshot themselves.

Tests

See test/test_nero.jl suites: round-trip, dimension mismatch, structural mismatch, load_state alias.

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Last updated: July 29, 2026 Updated by: Grok Build: Grok 4.5 Package tip reference: c9ff99c (main)