[bompus]

Syncing one changed file in CPython takes about 3% less on Node (5.33 s to 5.15 s on the second sync) and its retry phase 9–10% less (2.29 s to 2.08 s, 2.19 s to 1.96 s); Bun's sync time shows no clear change.

Metric, CPython (3,710 files), median of 4 runs per build	Before	After	Change
Retry phase, first sync, Node	2.29 s	2.08 s	9% lower (ranges do not overlap)
Retry phase, second sync, Node	2.19 s	1.96 s	10% lower (ranges do not overlap)
One-file sync, second sync, Node	5.33 s	5.15 s	3% lower (ranges do not overlap)
One-file sync, first sync, Node	5.45 s	5.25 s	no clear change (ranges overlap)
One-file sync, Bun (both syncs)	5.59 s, 5.41 s	5.74 s, 5.33 s	no clear change (first sync 2.8% slower, inside the 3% band)
Retry phase, Bun	2.29 s, 2.20 s	2.04 s, 2.02 s	11% and 8% lower; ranges overlap on the first sync
Full index, Node / Bun	36.16 s / 39.59 s	34.92 s / 39.49 s	no clear change
Full index, Django (guard, Node, 2 runs per build)	12.27 s	12.44 s	no clear change

The small size is expected: this removes part of the two slow scans from the earlier fix (#493), not the scans themselves. Figures are from codegraph sync after appending one line to Lib/os.py on a fresh index, builds alternated B F F B B F F B; the preset rule (median gain above 3% and non-overlapping ranges) was declared before the runs.

What changes

python_bases resolves a class's base classes from its header and file. The scan that looks for a descendant of a class (see #493) calls it for every class that has a method of the name being linked, again for each such reference. A class's bases depend only on that class, so they are now kept by class id for the rest of the run (py_bases_memo, beside the existing py_descendants_memo). 8 lines of Rust.

Checks

• The graph is unchanged: on CPython (167,929 nodes, 600,467 edges, 364,595 unresolved references) and Django (62,500, 185,361, 144,585), no edge row, node row or unresolved reference differs between the builds in either direction.
• Full vitest suite on this head: 702 files, 8,952 passed, 39 skipped, 0 failed; no Native stack trace or Worker exited unexpectedly in the raw output. Kernel golden dumps unchanged.
• README: checked "About this fork". The rows that compare the CPython one-file sync with upstream are still out of date in the fork's disfavor (see perf(kernel): read a plain Python import line instead of re-parsing the file for each package-import base #493); this change moves the fork's figure by about 3%, so they are unchanged and wait for the fork-against-upstream re-run. CHANGELOG entry added under Fixes.

Not covered: the other slow parts of the retry phase (the first use of the attribute-writer index, about 0.34 s, and the descendant scan itself); other Python corpora; Windows and macOS.

---

Summary by cubic

Caches each Python class's resolved base classes so the descendant scan during a sync resolves them once per class instead of once per reference. Syncing one changed file in CPython drops the retry phase by 9–10% on Node (2.29 s/2.19 s to 2.08 s/1.96 s) and the one-file sync by about 3% (5.33 s to 5.15 s); Bun shows no clear change.

Benchmarks (CPython, 3,710 files, median of 4 alternating runs per build)

Metric, Node	Before	After
Retry phase, first sync	2.29 s	2.08 s
Retry phase, second sync	2.19 s	1.96 s
One-file sync, second sync	5.33 s	5.15 s

A full index and Bun's one-file sync stay within run-to-run variation. This removes part of the slow scans from #493, not the scans themselves.

Verification

• The graph is unchanged on CPython and Django: no edge, node, or unresolved reference differs.
• Full vitest suite passes (8,952 passed, 0 failed) and kernel golden dumps are unchanged; a CHANGELOG entry is added under Fixes.

^{Written for commit 797b94f. Summary will update on new commits.}

Summary by CodeRabbit

• Performance
  • Improved Python analysis performance, reducing CPython retry-phase time from 2.29 seconds to 2.08 seconds and one-file sync time from 5.33 seconds to 5.15 seconds in reported benchmarks.
  • Full-index timing remained within normal run-to-run variation, and no graph output differences were observed in CPython or Django benchmarks. No clear sync-time change was measured with Bun.

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Reviewing files that changed from the base of the PR and between dfdf4a3 and 797b94f.

📒 Files selected for processing: 3

• CHANGELOG.md
• codegraph-kernel/src/resolve/member_fn_ref.rs
• codegraph-kernel/src/resolve/mod.rs

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📝 Walkthrough

The resolver now caches resolved Python base classes by class ID for the duration of a run. The changelog reports benchmark results and states that graph results did not change.

Changes: Python base-class memoization

Layer / File(s)	Summary
Add and use the base-class memo codegraph-kernel/src/resolve/mod.rs, codegraph-kernel/src/resolve/member_fn_ref.rs, CHANGELOG.md	KernelResolver initializes a per-class memo. python_bases returns cached bases when available and stores resolved bases after a cache miss. The changelog reports benchmark results and unchanged-graph claims.

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to 797b9

This change reuses resolved Python bases within a resolution run. The resolver lifecycle prevents changed class bases from reusing a prior run’s cache, so no actionable merge-blocking risk remains.

Security architecture risk: 🔵 Low · up to 797b9

The cache is temporary, and normal indexing and synchronization paths discard it. No new permissions or external access were identified. Cache validity when callers retain an instance across intervening data changes remains unverified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The newly cached state is confined to an individual resolver instance and its inheritance lookups; the added memo is not a process-global or cross-project cache.

Trust Boundaries and Controls

• inferred — The inspected change reuses existing source-reading and import/class lookup paths rather than granting new authority. No introduced execution or privilege transition was identified along this changed path.

Resilience and Maintainability Implications

• observed — runPostExtract retains a kernel that was already open, and its cache-clearing routine does not reset native memos. Normal sync cleanup closes the kernel, but validity under atypical retention across mutations remains unverified; this is not a demonstrated PR-introduced security condition.

Pre-merge checks: 6

Passed checks: 6 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: caching Python class base resolution once per class during syncing.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Suppressions Explained		The pull request adds only a changelog entry and Python-base memoization. The changed Rust lines add a cache lookup, cache insertion, a field, and initialization. No changed line adds or broadens a li…
User-Visible Changes Documented		PASS. The pull request changes only Python base-resolution memoization and adds a CHANGELOG entry. The diff adds no CLI command or flag, MCP tool or argument, supported language or framework, agent ta…

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