Files
dmlc--dgl/python/dgl/function/reducer.py
T
2026-07-13 13:35:51 +08:00

83 lines
1.9 KiB
Python

"""Built-in reducer function."""
# pylint: disable=redefined-builtin
from __future__ import absolute_import
import sys
from .base import BuiltinFunction
class ReduceFunction(BuiltinFunction):
"""Base builtin reduce function class."""
@property
def name(self):
"""Return the name of this builtin function."""
raise NotImplementedError
class SimpleReduceFunction(ReduceFunction):
"""Builtin reduce function that aggregates a single field into another
single field."""
def __init__(self, name, msg_field, out_field):
self._name = name
self.msg_field = msg_field
self.out_field = out_field
@property
def name(self):
return self._name
###############################################################################
# Generate all following reducer functions:
# sum, max, min, mean, prod
def _gen_reduce_builtin(reducer):
docstring = """Builtin reduce function that aggregates messages by {0}.
Parameters
----------
msg : str
The message field.
out : str
The output node feature field.
Examples
--------
>>> import dgl
>>> reduce_func = dgl.function.{0}('m', 'h')
The above example is equivalent to the following user defined function
(if using PyTorch):
>>> import torch
>>> def reduce_func(nodes):
>>> return {{'h': torch.{0}(nodes.mailbox['m'], dim=1)}}
""".format(
reducer
)
def func(msg, out):
return SimpleReduceFunction(reducer, msg, out)
func.__name__ = str(reducer)
func.__qualname__ = str(reducer)
func.__doc__ = docstring
return func
__all__ = []
def _register_builtin_reduce_func():
"""Register builtin reduce functions"""
for reduce_op in ["max", "min", "sum", "mean"]:
builtin = _gen_reduce_builtin(reduce_op)
setattr(sys.modules[__name__], reduce_op, builtin)
__all__.append(reduce_op)
_register_builtin_reduce_func()