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

147 lines
4.4 KiB
Python

from __future__ import absolute_import
import importlib
import json
import logging
import os
import sys
from . import backend
from .set_default_backend import set_default_backend
_enabled_apis = set()
logger = logging.getLogger("dgl-core")
def _gen_missing_api(api, mod_name):
def _missing_api(*args, **kwargs):
raise ImportError(
'API "%s" is not supported by backend "%s".'
" You can switch to other backends by setting"
" the DGLBACKEND environment." % (api, mod_name)
)
return _missing_api
def load_backend(mod_name):
# Load backend does four things:
# (1) Import backend framework (PyTorch, MXNet, Tensorflow, etc.)
# (2) Import DGL C library. DGL imports it *after* PyTorch/MXNet/Tensorflow. Otherwise
# DGL will crash with errors like `munmap_chunk(): invalid pointer`.
# (3) Sets up the tensoradapter library path.
# (4) Import the Python wrappers of the backend framework. DGL does this last because
# it already depends on both the backend framework and the DGL C library.
if mod_name == "pytorch":
import torch
mod = torch
elif mod_name == "mxnet":
import mxnet
mod = mxnet
elif mod_name == "tensorflow":
import tensorflow
mod = tensorflow
else:
raise NotImplementedError("Unsupported backend: %s" % mod_name)
from .._ffi.base import load_tensor_adapter # imports DGL C library
version = mod.__version__
load_tensor_adapter(mod_name, version)
logger.debug("Using backend: %s" % mod_name)
mod = importlib.import_module(".%s" % mod_name, __name__)
thismod = sys.modules[__name__]
for api in backend.__dict__.keys():
if api.startswith("__"):
# ignore python builtin attributes
continue
if api == "data_type_dict":
# load data type
if api not in mod.__dict__:
raise ImportError(
'API "data_type_dict" is required but missing for'
' backend "%s".' % (mod_name)
)
data_type_dict = mod.__dict__[api]()
for name, dtype in data_type_dict.items():
setattr(thismod, name, dtype)
# override data type dict function
setattr(thismod, "data_type_dict", data_type_dict)
# for data types with aliases, treat the first listed type as
# the true one
rev_data_type_dict = {}
for k, v in data_type_dict.items():
if not v in rev_data_type_dict.keys():
rev_data_type_dict[v] = k
setattr(thismod, "reverse_data_type_dict", rev_data_type_dict)
# log backend name
setattr(thismod, "backend_name", mod_name)
else:
# load functions
if api in mod.__dict__:
_enabled_apis.add(api)
setattr(thismod, api, mod.__dict__[api])
else:
setattr(thismod, api, _gen_missing_api(api, mod_name))
def get_preferred_backend():
default_dir = None
if "DGLDEFAULTDIR" in os.environ:
default_dir = os.getenv("DGLDEFAULTDIR")
else:
default_dir = os.path.join(os.path.expanduser("~"), ".dgl")
config_path = os.path.join(default_dir, "config.json")
backend_name = None
if "DGLBACKEND" in os.environ:
backend_name = os.getenv("DGLBACKEND")
elif os.path.exists(config_path):
with open(config_path, "r") as config_file:
config_dict = json.load(config_file)
backend_name = config_dict.get("backend", "").lower()
if backend_name in ["tensorflow", "mxnet", "pytorch"]:
return backend_name
else:
print(
"DGL backend not selected or invalid. "
"Assuming PyTorch for now.",
file=sys.stderr,
)
set_default_backend(default_dir, "pytorch")
return "pytorch"
load_backend(get_preferred_backend())
def is_enabled(api):
"""Return true if the api is enabled by the current backend.
Parameters
----------
api : str
The api name.
Returns
-------
bool
True if the API is enabled by the current backend.
"""
return api in _enabled_apis
def to_dgl_nd(data):
return zerocopy_to_dgl_ndarray(data)
def from_dgl_nd(data):
return zerocopy_from_dgl_ndarray(data)