[perf-scan] 2026-11-10 -- performance opportunities found

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
67/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Active
Tech stack
git, python
Domain
cli, performance

Research direction

Read src/apm_cli/deps/tiered_ref_resolver.py around lines 335–352 and trace how it checks heads, tags, and bare refs. Confirm the lookup behavior with the relevant resolver tests, then reduce the subprocess calls while preserving candidate order and short-circuiting; done when the tests pass and each ref needs at most one subprocess.

Written by the indexing model from the issue text.

Description

type/automation type/performance

Performance Scan - 2026-11-10

Automated scan of src/apm_cli/ for algorithmic performance anti-patterns.
1 finding(s) identified (low priority).

Findings
[F] Sequential subprocess fallbacks -- src/apm_cli/deps/tiered_ref_resolver.py:335-352
  • Current: up to 3 sequential git rev-parse --verify subprocess spawns per ref (heads, tags, bare ref), each ~ms of process startup, per dependency.
  • Proposed: 1 subprocess per ref.
  • Fix: Use a single git rev-parse --verify --quiet call (or git for-each-ref/show-ref once per bare repo and cache) instead of spawning up to three processes. Low priority: candidates short-circuit on first hit and iterations are order-dependent.
Scan coverage
  • src/apm_cli/ (507 files scanned)
  • Patterns checked: A (quadratic loops), B (linear scan in loop),
    C (unconditional expensive ops), D (redundant config parsing),
    E (heavy top-level imports; commands/ already use lazy imports for heavy modules), F (sequential independent I/O)

Generated by Daily Performance Scanner · copilot · auto · 17.6 AIC · ⌖ 0.565 AIC · ⊞ 5.8K · ◷

  • expires on Nov 17, 2026, 1:24 AM UTC
Dominant language
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Merged PRs (30d)
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