505 2026 02 02 Sanitize Loop Canonicalization Bottleneck 85c933a3

Goal

Reduce message canonicalization overhead in run_cleanup_loop() by caching canonical messages per iteration: 1N conversions when no mutations occur, and 2N conversions in iterations that mutate messages (recompute after mutation).

Non-goals:

• Changing the cleanup logic or iteration cap
• Modifying CanonicalMessage structure
• Adding new cleanup functions

Scope & Assumptions

In Scope

• adapter.py:309-318 - find_dangling_tool_calls() double conversion
• sanitize.py:469-491 - Cache canonical messages at iteration start
• Pass pre-computed canonical list to cleanup functions

Out of Scope

• Performance of individual cleanup operations
• Changes to to_canonical() implementation
• CanonicalMessage class modifications

Assumptions

• CanonicalMessage instances are immutable within an iteration
• Messages may be deleted during cleanup, invalidating cache indices; cache must be recomputed after mutation
• Current API signatures can be extended with optional canonical cache parameter

Constraints

• Must maintain backward compatibility with existing function signatures
• No new dependencies
• Must pass existing tests

Deliverables (DoD)

1. Modified find_dangling_tool_calls() - Single conversion per message (2N to N)
2. Cache injection in run_cleanup_loop() - Convert once at iteration start, recompute after mutation (1N no-mutation / 2N with mutation)
3. Updated cleanup functions - Accept optional canonical cache parameter
4. 1 test - Verify conversion count reduction in no-mutation iterations

Readiness (DoR)

• Research document completed with line-level analysis
• Code verified to match research (no drift)
• Git branch ready (bottlenecks)
• tk CLI available

Milestones

• M1: Fix double conversion in find_dangling_tool_calls (adapter.py)
• M2: Add cache injection at iteration start (sanitize.py)
• M3: Test and verify reduction

Work Breakdown (Tasks)

Task 1: Fix Double Conversion in find_dangling_tool_calls

Owner: agent Dependencies: None Milestone: M1

What: Modify adapter.py:309-318 to convert each message once and extract both call_ids and return_ids from the same canonical instance.

Before:

for msg in messages:
    call_ids.update(get_tool_call_ids(msg))     # to_canonical(msg)
    return_ids.update(get_tool_return_ids(msg)) # to_canonical(msg) AGAIN

After:

for msg in messages:
    canonical = msg if isinstance(msg, CanonicalMessage) else to_canonical(msg)
    call_ids.update(canonical.get_tool_call_ids())
    return_ids.update(canonical.get_tool_return_ids())

Files:

• src/tunacode/utils/messaging/adapter.py:309-318

Acceptance:

• Each message converted at most once per call
• Function returns same results as before
• Existing tests pass

Task 2: Add Canonical Cache at Iteration Start

Owner: agent Dependencies: Task 1 Milestone: M2

What: At the start of each cleanup iteration in run_cleanup_loop(), convert messages once and pass the canonical list to find_dangling_tool_call_ids(). If any cleanup mutates messages, recompute the canonical list before subsequent cleanup steps.

Files:

• src/tunacode/core/agents/resume/sanitize.py:469-491

Acceptance:

• to_canonical_list() called once at iteration start
• Canonical list passed to find_dangling_tool_call_ids()
• Canonical cache recomputed after any mutation before later cleanup passes

Task 3: Update Cleanup Functions for Cache Passthrough

Owner: agent Dependencies: Task 2 Milestone: M2

What: Modify remove_empty_responses() and remove_consecutive_requests() to accept an optional canonical cache parameter, skipping their internal _canonicalize_messages() call when cache is provided.

Files:

• src/tunacode/core/agents/resume/sanitize.py:326-355 (remove_empty_responses)
• src/tunacode/core/agents/resume/sanitize.py:358-404 (remove_consecutive_requests)

Acceptance:

• Functions accept optional canonical_cache parameter
• When cache provided, internal conversion skipped
• Existing tests pass

Task 4: Write Verification Test

Owner: agent Dependencies: Task 3 Milestone: M3

What: Add one test that verifies conversion count reduction in a no-mutation iteration. Use a mock or counter to track to_canonical() calls.

Files:

• tests/unit/test_sanitize_canonicalization.py (new)

Acceptance:

• Test verifies N conversions per iteration when no mutations occur (1N, not 4N)
• Test passes

Risks & Mitigations

Test Strategy

• 1 new test: test_canonicalization_count_reduction - Verify conversion count is 1N (not 4N) in a no-mutation iteration using a mock counter on to_canonical().

References

• Research: memory-bank/research/2026-02-02_sanitize_loop_canonicalization_bottleneck.md
• adapter.py:309-318 - Double conversion bottleneck
• sanitize.py:469-491 - Cleanup loop

Tickets Created

Dependencies

bot-555f (ready)
    └── bot-30b4 (blocked by bot-555f)
        └── bot-11c6 (blocked by bot-30b4)
            └── bot-a9de (blocked by bot-11c6)