Files
codebase-memory-mcp/internal/cbm
Martin Vogel 51770de0b6 perf(ts): memoize expression-type evaluation per node
ts_eval_expr_type and ts_signature_for_call are mutually recursive: resolving
a call evaluates its argument expressions once per lookup path (method
dispatch + namespace fallback), and in tsc-compiled spread files the first
argument is itself the next nested Object.assign(...) call — the same subtree
re-evaluates once per enclosing level, 2^n total. The TS suite's
objectSpreadRepeatedComplexity.js (3.6 KB, 5 nodes) measured 20.4 s; with the
memo its eval cost is zero within measurement noise of a one-file control,
and the microsoft/TypeScript corpus drops 37.5 -> ~24 s warm (nodes
byte-identical, edges within the known scheduler jitter).

Expression types are position-pure within a file pass (one node = one scope
path; the per-file walk is single-threaded and deterministic), so one eval
per node is the correct semantics, not a cache trade-off. The memo is a
per-file, arena-backed, linear-probe table keyed on TSNode.id. Results
produced under a depth-cap or budget bail are never stored: both bail sites
bump a degradation counter, and a store only happens when the subtree
completed clean — a degraded UNKNOWN can therefore never shadow a later full
evaluation.

The regression guard asserts work, not wall-clock: the nested-Object.assign
shape must complete without exhausting the deterministic eval budget, read
back through a new CBM_ENABLE_TEST_SEAMS accessor pair. The seam lives in the
lsp_all unity object, so GRAMMAR_CFLAGS_TEST/TSAN now carry the seams define
(test artifacts always have seams; prod never does). Verified RED without the
memo (budget exhausted, suite 47.8 s) and green with it (3.2 s).

Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
2026-08-17 00:16:16 +02:00
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