7: Convert AST nodes to frozen dataclasses (70% faster decode, 40% faster parsing) #256
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Introduce benchmarks using a large (~117KB) GraphQL query to measure parse and pickle serialization performance. These provide a baseline for comparing serialization approaches in subsequent commits. Baseline performance (measrued on a Macbook Pro M4 Max): - Parse: 81ms - Pickle encode: 24ms - Pickle decode: 42ms - Roundtrip: 71ms
Prepares AST for immutability by using tuples instead of lists for collection fields. This aligns with the JavaScript GraphQL library which uses readonly arrays, and enables future frozen datastructures.
Python 3.9 reaches end-of-life October 2025. Python 3.10 adoption is now mainstream - major frameworks (strawberry, Django 5.0, FastAPI) require it. This enables modern Python features: - Dataclasses with `kw_only` - Union types with `|` syntax (PEP 604) - isinstance() with union types directly - match statements for pattern matching
Modifies the AST visitor to use copy-on-write semantics when applying edits. Instead of mutating nodes in place, the visitor now creates new node instances with the edited values. This prepares for frozen AST nodes while maintaining backwards compatibility. The visitor accumulates edits and applies them by constructing new nodes, enabling the transition to immutable data structures.
- Update test_visitor.py to properly type-annotate the visitor class attribute and add assertion before using selection_set - Update test_schema_parser.py to use more precise types that match GraphQL spec: - NonNullTypeNode's inner type can only be NamedTypeNode or ListTypeNode - Schema definitions use ConstDirectiveNode, not DirectiveNode - Default values use ConstValueNode, not ValueNode - OperationTypeDefinition's type_ must be NamedTypeNode
- Handle token.value being str | None by using `or ""` fallback - Fix parse_variable_definition to not use `and` for side effects - Use properly typed variable in parse_nullability_assertion - These fixes prepare for stricter type checking in frozen dataclasses
…r parsing) Refactor all of the GraphQL AST Nodes to use Python dataclasses to provide better type safety, immutability guarantees, and cleaner code while maintaining backwards compatibility with existing APIs. Benchmark comparison (837f604 base vs dataclasses): | Benchmark | Base | Dataclass | Change | |---------------------------------|--------|------------|-----------------| | test_parse_large_query | 33,108 | 18,689 | 44% faster | | test_parse_kitchen_sink | 577 | 361 | 37% faster | | test_pickle_large_query_decode | 18,520 | 5,549 | 70% faster (3x) | | test_pickle_large_query_encode | 9,038 | 4,117 | 54% faster (2x) | | test_pickle_large_query_round | 28,048 | 10,206 | 64% faster (3x) | | test_many_repeated_fields | 15,918 | 14,909 | 6% faster | | test_execute_basic_sync | 310 | 292 | 6% faster | | test_execute_basic_async | 354 | 338 | 5% faster |
CodSpeed Performance ReportMerging this PR will degrade performance by 23.43%Comparing Summary
Performance Changes
|
Member
|
Baseline performance (before PR #250):
Performance (after PR #256):
(mean benchmark time in ms) |
Member
|
Thanks @corydolphin . These are in fact impressive gains in parsing and deser of large queries. Codspeed complains about a degredation in the "validate introspection query" benchmark. I think this is just because of the high variability in this test. Can you double check that it's not caused by this PR? Generally, I think we should split some of the benchmarks and have created issue #257 to remember. I will already merge and fix the linting error later. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Refactor all of the GraphQL AST Nodes to use Python dataclasses to provide
better type safety, immutability guarantees, and cleaner code while maintaining
backwards compatibility with existing APIs.
Benchmark comparison (837f604 base vs dataclasses):