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2026-03-10 13:31:25 +08:00

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Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
import ast
import inspect
import textwrap
from dataclasses import MISSING, Field, field, fields, is_dataclass
from typing import TYPE_CHECKING, Any, TypeVar
import regex as re
if TYPE_CHECKING:
from _typeshed import DataclassInstance
ConfigType = type[DataclassInstance]
else:
ConfigType = type
ConfigT = TypeVar("ConfigT", bound=ConfigType)
def config(cls: ConfigT) -> ConfigT:
"""
A decorator that ensures all fields in a dataclass have default values
and that each field has a docstring.
If a `ConfigT` is used as a CLI argument itself, the `type` keyword argument
provided by `get_kwargs` will be
`pydantic.TypeAdapter(ConfigT).validate_json(cli_arg)` which treats the
`cli_arg` as a JSON string which gets validated by `pydantic`.
Config validation is performed by the tools/validate_config.py
script, which is invoked during the pre-commit checks.
"""
return cls
def get_field(cls: ConfigType, name: str) -> Field:
"""Get the default factory field of a dataclass by name. Used for getting
default factory fields in `EngineArgs`."""
if not is_dataclass(cls):
raise TypeError("The given class is not a dataclass.")
cls_fields = {f.name: f for f in fields(cls)}
if name not in cls_fields:
raise ValueError(f"Field '{name}' not found in {cls.__name__}.")
named_field: Field = cls_fields[name]
if (default_factory := named_field.default_factory) is not MISSING:
return field(default_factory=default_factory)
if (default := named_field.default) is not MISSING:
return field(default=default)
raise ValueError(
f"{cls.__name__}.{name} must have a default value or default factory.")
def contains_object_print(text: str) -> bool:
"""
Check if the text looks like a printed Python object, e.g.
contains any substring matching the pattern: "at 0xFFFFFFF>"
We match against 0x followed by 2-16 hex chars (there's
a max of 16 on a 64-bit system).
Args:
text (str): The text to check
Returns:
result (bool): `True` if a match is found, `False` otherwise.
"""
pattern = r'at 0x[a-fA-F0-9]{2,16}>'
match = re.search(pattern, text)
return match is not None
def assert_hashable(text: str) -> bool:
if not contains_object_print(text):
return True
raise AssertionError(
f"vLLM tried to hash some configs that may have Python objects ids "
f"in them. This is a bug, please file an issue. "
f"Text being hashed: {text}")
def get_attr_docs(cls: type[Any]) -> dict[str, str]:
"""
Get any docstrings placed after attribute assignments in a class body.
https://davidism.com/mit-license/
"""
def pairwise(iterable):
"""
Manually implement https://docs.python.org/3/library/itertools.html#itertools.pairwise
Can be removed when Python 3.9 support is dropped.
"""
iterator = iter(iterable)
a = next(iterator, None)
for b in iterator:
yield a, b
a = b
try:
cls_node = ast.parse(textwrap.dedent(inspect.getsource(cls))).body[0]
except (OSError, KeyError, TypeError):
# HACK: Python 3.13+ workaround - set missing __firstlineno__
# Workaround can be removed after we upgrade to pydantic==2.12.0
with open(inspect.getfile(cls)) as f:
for i, line in enumerate(f):
if f"class {cls.__name__}" in line and ":" in line:
cls.__firstlineno__ = i + 1
break
cls_node = ast.parse(textwrap.dedent(inspect.getsource(cls))).body[0]
if not isinstance(cls_node, ast.ClassDef):
raise TypeError("Given object was not a class.")
out = {}
# Consider each pair of nodes.
for a, b in pairwise(cls_node.body):
# Must be an assignment then a constant string.
if (not isinstance(a, (ast.Assign, ast.AnnAssign))
or not isinstance(b, ast.Expr)
or not isinstance(b.value, ast.Constant)
or not isinstance(b.value.value, str)):
continue
doc = inspect.cleandoc(b.value.value)
# An assignment can have multiple targets (a = b = v), but an
# annotated assignment only has one target.
targets = a.targets if isinstance(a, ast.Assign) else [a.target]
for target in targets:
# Must be assigning to a plain name.
if not isinstance(target, ast.Name):
continue
out[target.id] = doc
return out
def is_init_field(cls: ConfigType, name: str) -> bool:
return next(f for f in fields(cls) if f.name == name).init