Speed up querystring callback dispatch

[Kludex]

Summary

• resolve QuerystringParser callbacks through fixed callback keys once per input chunk instead of using BaseParser.callback() for every event
• use shared no-op defaults to eliminate repeated optional-callback checks
• avoid callback-name construction and an extra Python method call on each parsed field event
• preserve zero-length data suppression and support omitted callbacks through shared no-op functions

Performance

The latest CodSpeed simulation reports a 70.17% efficiency improvement for test_querystring_large_form, from 912.9 µs to 536.5 µs. A same-environment local wall-time benchmark on Python 3.13 improved from approximately 80 µs to 49 µs (about 39%). The other four CodSpeed benchmarks are unchanged.

Validation

• 160 tests pass
• 100% statement coverage
• Ruff passes
• mypy passes
• source distribution check passes

[codspeed-hq]

Merging this PR will improve performance by 70.17%

⚡ 1 improved benchmark
✅ 4 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	test_querystring_large_form	912.9 µs	536.5 µs	+70.17%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing speed-up-querystring-callback-dispatch (f219559) with main (a034d65)}

[Kludex]

Thanks. The final revision retains the improvement: CodSpeed reports a 70.17% efficiency improvement for test_querystring_large_form (912.9 µs to 536.5 µs), with the other four benchmarks unchanged. The PR description is up to date; no code change is needed.

[cubic-dev-ai]

No issues found across 3 files

_{Re-trigger cubic}

[Kludex]

Updated callback dispatch in b1c3c9e to use shared _noop_event and _noop_data defaults, removing repeated is not None checks without allocating lambdas. Follow-up de37a65 resolves callbacks once per chunk, preserves explicit-None compatibility, and tests both omitted and None callbacks. Local lint, mypy, and all 160 tests pass with 100% statement coverage.

[cubic-dev-ai]

All reported issues were addressed across 1 file (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>

[cubic-dev-ai]

All reported issues were addressed across 2 files (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

Re-trigger cubic</sub>