Implement copyslot by youknowone · Pull Request #6505 · RustPython/RustPython

youknowone · 2025-12-25T01:37:01Z

Benchmark	OLD	NEW	Speedup
fannkuch	1.56s	1.50s	+4%
nbody	0.15s	0.14s	+7%
pystone	0.88s	0.85s	+3%

Summary by CodeRabbit

Refactor
- Optimized method slot resolution by replacing dynamic inheritance chain traversals with direct class slot access across core protocol systems.
- Restructured sequence and mapping protocol methods from static method references to dynamic slot-based access.
- Streamlined internal protocol method dispatch mechanisms.
Bug Fixes
- Enforced stricter type validation for __str__ and __bool__ special methods to prevent returning incorrect types.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

coderabbitai · 2025-12-25T01:37:05Z

Caution

Review failed

The pull request is closed.

📝 Walkthrough

Walkthrough

This PR refactors protocol access patterns across the VM, replacing MRO-based slot lookups with direct class slot access. It introduces new unchecked accessors for sequences and mappings, restructures PyNumber/PySequence/PyMapping with slot-based designs, removes cached protocol methods from heap types, and adds slot inheritance helpers to simplify type initialization.

Changes

Cohort / File(s)	Summary
Core Protocol Restructuring `crates/vm/src/protocol/number.rs`, `crates/vm/src/protocol/sequence.rs`, `crates/vm/src/protocol/mapping.rs`	Introduced `PySequenceSlots` and `PyMappingSlots` structures for atomic slot storage. Renamed `to_number()` to `number()` and restructured `PyNumber` from tuple-newtype to named-field struct. Updated `PySequence` and `PyMapping` to use slot-based dispatch instead of static method references. Added `sequence_unchecked()`, `try_sequence()`, `mapping_unchecked()`, and `try_mapping()` accessors on `PyObject`.
Type System and Slot Management `crates/vm/src/types/slot.rs`, `crates/vm/src/builtins/type.rs`, `crates/vm/src/class.rs`	Changed `as_sequence` and `as_mapping` fields in `PyTypeSlots` from `PointerSlot` to `PySequenceSlots`/`PyMappingSlots`. Removed `sequence_methods` and `mapping_methods` fields from `HeapTypeExt`. Removed `mro_find_map` method and added slot inheritance helpers (`inherit_slots`, `inherit_readonly_slots`, `inherit_number_slots`, etc.). Updated type initialization to inherit slots from base types. Added wrappers for `__str__` and `__bool__` enforcement.
Object Protocol Implementation `crates/vm/src/protocol/object.rs`, `crates/vm/src/object/core.rs`	Replaced MRO-based slot lookups with direct `obj.class().slots.X.load()` access patterns across attribute access, item operations, comparisons, repr, hash, and length operations. Updated descriptor lookups to use direct slot access instead of MRO traversal.
VM Operations and Execution `crates/vm/src/vm/vm_ops.rs`, `crates/vm/src/vm/method.rs`, `crates/vm/src/vm/vm_object.rs`, `crates/vm/src/frame.rs`	Replaced MRO-based lookups for number operation slots, descriptor getters, and attribute access with direct slot retrieval. Updated arithmetic and comparison operator paths to use direct slot access. Simplified method resolution in ExecutingFrame.
Protocol Implementations `crates/vm/src/protocol/callable.rs`, `crates/vm/src/protocol/iter.rs`, `crates/vm/src/protocol/buffer.rs`	Changed call and iterator slot lookups from MRO-based search to direct class slot access. Updated `PyCallable::new`, `PyIter::check`, and buffer protocol to use `obj.class().slots.X.load()` directly.
Function Protocol `crates/vm/src/function/protocol.rs`	Removed `methods` field from `ArgMapping` struct. Changed constructor from `with_methods(obj, methods)` to `new(obj)`. Updated `mapping()` method to use `self.obj.mapping_unchecked()`. Simplified `TryFromObject` implementation for `ArgMapping` by removing methods validation step.
Builtin Types `crates/vm/src/builtins/bool.rs`, `crates/vm/src/builtins/classmethod.rs`, `crates/vm/src/builtins/dict.rs`, `crates/vm/src/builtins/iter.rs`, `crates/vm/src/builtins/list.rs`, `crates/vm/src/builtins/mappingproxy.rs`, `crates/vm/src/builtins/weakproxy.rs`	Updated containment and sequence access patterns to use `sequence_unchecked()` instead of `to_sequence()`. Removed `PySequenceMethods` caching in `PySequenceIterator`. Updated `PyClassMethod` pyclass attribute to include `Initializer`. Changed mapping proxy construction to use `ArgMapping::new()` and direct slot validation.
Standard Library `crates/stdlib/src/sqlite.rs`, `crates/vm/src/stdlib/builtins.rs`, `crates/vm/src/stdlib/ctypes/structure.rs`, `crates/vm/src/stdlib/ctypes/union.rs`, `crates/vm/src/stdlib/typing.rs`	Updated numeric access from `to_number()` to `number()` in SQLite collation. Changed eval globals mapping check to use `mapping_unchecked().check()`. Replaced MRO-based descriptor lookups in ctypes with direct slot access. Added `init()` function for typing module initialization.
Module Exports `crates/vm/src/protocol/mod.rs`, `crates/vm/src/types/structseq.rs`, `crates/vm/src/types/zoo.rs`	Added `PyMappingSlots` and `PySequenceSlots` to public protocol exports. Updated struct sequence slot initialization to use `copy_from()` for direct slot population. Added typing module initialization to TypeZoo.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~50 minutes

Possibly related PRs

iter with slot-wrapper #6488: Modifies iterator slot-wrapper machinery and class slot handling in parallel with changes to iter initialization and PySequenceIterator refactoring.
disallow __new__, __init__ #6446: Updates pyclass initialization with Constructor/Initializer traits, aligning with the classmethod attribute changes and slot-based initialization patterns in this PR.
ctypes overhaul #6450: Modifies ctypes implementation (PyCStructType, PyCUnionType) descriptor handling, which overlaps with the descriptor slot lookup refactoring in this PR.

Suggested reviewers

ShaharNaveh
arihant2math
coolreader18

🐰 Protocol slots now shimmer bright,
Direct access replaces MRO's flight,
Unchecked pathways swift and clean,
Type slots wired, a cleaner scene,
The rabbit hops through refactored light!

✨ Finishing touches

📝 Generate docstrings

🧪 Generate unit tests (beta)

Create PR with unit tests
Post copyable unit tests in a comment

📜 Recent review details

Configuration used: Path: .coderabbit.yml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 7eb0fe4 and c83101f.

⛔ Files ignored due to path filters (1)

Lib/test/test_typing.py is excluded by !Lib/**

📒 Files selected for processing (32)

crates/stdlib/src/sqlite.rs
crates/vm/src/builtins/bool.rs
crates/vm/src/builtins/classmethod.rs
crates/vm/src/builtins/dict.rs
crates/vm/src/builtins/iter.rs
crates/vm/src/builtins/list.rs
crates/vm/src/builtins/mappingproxy.rs
crates/vm/src/builtins/object.rs
crates/vm/src/builtins/type.rs
crates/vm/src/builtins/weakproxy.rs
crates/vm/src/class.rs
crates/vm/src/frame.rs
crates/vm/src/function/protocol.rs
crates/vm/src/object/core.rs
crates/vm/src/protocol/buffer.rs
crates/vm/src/protocol/callable.rs
crates/vm/src/protocol/iter.rs
crates/vm/src/protocol/mapping.rs
crates/vm/src/protocol/mod.rs
crates/vm/src/protocol/number.rs
crates/vm/src/protocol/object.rs
crates/vm/src/protocol/sequence.rs
crates/vm/src/stdlib/builtins.rs
crates/vm/src/stdlib/ctypes/structure.rs
crates/vm/src/stdlib/ctypes/union.rs
crates/vm/src/stdlib/typing.rs
crates/vm/src/types/slot.rs
crates/vm/src/types/structseq.rs
crates/vm/src/types/zoo.rs
crates/vm/src/vm/method.rs
crates/vm/src/vm/vm_object.rs
crates/vm/src/vm/vm_ops.rs

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

github-actions · 2025-12-25T07:00:45Z

Code has been automatically formatted

The code in this PR has been formatted using cargo fmt --all.
Please pull the latest changes before pushing again:

git pull origin copyslot

youknowone force-pushed the copyslot branch 6 times, most recently from 86969fb to f6602a7 Compare December 25, 2025 04:29

youknowone added 6 commits December 25, 2025 15:32

strwrapper

bdaadd4

impl copyslot

7b08c72

toggle sbuslot

71df458

fix typing::init

099d9a4

bool_wrapper

97c4949

apply pointerslot

0c70347

youknowone force-pushed the copyslot branch from f6602a7 to f5ca8a0 Compare December 25, 2025 06:32

youknowone added 2 commits December 25, 2025 15:55

align PyNumber

6e6df1e

apply buffer

4448d7f

youknowone force-pushed the copyslot branch from f5ca8a0 to 4448d7f Compare December 25, 2025 06:55

Auto-format: cargo fmt --all

c83101f

youknowone marked this pull request as ready for review December 25, 2025 07:56

youknowone merged commit 151f074 into RustPython:main Dec 25, 2025
12 of 13 checks passed

youknowone deleted the copyslot branch December 25, 2025 07:56

This was referenced Jan 19, 2026

_abc, _typing and update typing,test_types from 3.14.2 #6797

Merged

Remove Copy from PyPayload #6865

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Implement copyslot#6505

Implement copyslot#6505
youknowone merged 9 commits intoRustPython:mainfrom
youknowone:copyslot

youknowone commented Dec 25, 2025 •

edited by coderabbitai bot

Loading

Uh oh!

coderabbitai bot commented Dec 25, 2025 •

edited

Loading

Review failed

Walkthrough

Changes

Estimated code review effort

Possibly related PRs

Suggested reviewers

Uh oh!

github-actions bot commented Dec 25, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

Conversation

youknowone commented Dec 25, 2025 • edited by coderabbitai bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary by CodeRabbit

Uh oh!

coderabbitai bot commented Dec 25, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Review failed

Walkthrough

Changes

Estimated code review effort

Possibly related PRs

Suggested reviewers

Uh oh!

github-actions bot commented Dec 25, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

youknowone commented Dec 25, 2025 •

edited by coderabbitai bot

Loading

coderabbitai bot commented Dec 25, 2025 •

edited

Loading