[connortsui20]

Tracking Issue: #10701

Bottom of the decimal Widen stack. #11002 builds on it. No release gate.

Summary

A plugin can need another encoding's wire form without taking over its reader. serialized_ids() currently serves both jobs, so a Widen writer cannot emit a narrow decimal node while preserving the decimal reader.

Changes

Reader registration now uses read_ids(), while serialization validates its output against write_ids(). A writing session does not need a reader for every ID it writes. Existing plugins keep their current IDs, and tests cover reader ownership and the two validation contracts. LayoutPlugin is unchanged.

API Changes

Replaces ArrayPlugin::serialized_ids() with required read_ids() and write_ids() methods, with no defaults. Read IDs stay ordered oldest to newest.

[codspeed]

Merging this PR will regress 1 benchmark

2 warnings

⚠️ Walltime results may be unreliable

Some benchmarks used the Walltime instrument outside CodSpeed Macro Runners, which can make the results inconsistent.

Learn more about Macro Runners

See affected benchmarks

⚠️ 3 benchmarks with a significant change ran in a different software environment

Their base and head results were measured with a different OS or toolchain, such as compiler, runtime or library versions, so the changes might come from this difference rather than from the code. Open an affected benchmark to see what changed.

See affected benchmarks

⚡ 4 improved benchmarks
❌ 1 regressed benchmark
✅ 2313 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	CPU Simulation	take_filter_primitive_small_uncached_random_mask_random_indices[4096, 10]	20.7 µs	24.4 µs	-15.08%
⚡	CPU Simulation	filter_powerlaw_by_random[10000]	1,300.8 ns	358.1 ns	×3.6
⚡	CPU Simulation	test_repeated_scan_filter[int]	2.4 ms	2.1 ms	+13.04%
⚡	CPU Simulation	test_scan_filter_to_arrow_array[int]	2.8 ms	2.5 ms	+11.23%
⚡	CPU Simulation	test_scan_filter[int]	2.9 ms	2.6 ms	+11%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing ct/array-plugin-read-write-ids (9556b96) with develop (493967c)}

[joseph-isaacs]

What are examples of the difference?

[connortsui20]

@joseph-isaacs look at the next PR #11002