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

351 lines
9.1 KiB
Python

# pylint: disable=invalid-name, unused-import
"""Function namespace."""
from __future__ import absolute_import
import ctypes
import sys
from .base import _FFI_MODE, _LIB, c_str, check_call, py_str, string_types
IMPORT_EXCEPT = RuntimeError if _FFI_MODE == "cython" else ImportError
try:
# pylint: disable=wrong-import-position
if _FFI_MODE == "ctypes":
raise ImportError()
if sys.version_info >= (3, 0):
from ._cy3.core import (
_set_class_function,
_set_class_module,
convert_to_dgl_func,
FunctionBase as _FunctionBase,
)
else:
from ._cy2.core import (
_set_class_function,
_set_class_module,
convert_to_dgl_func,
FunctionBase as _FunctionBase,
)
except IMPORT_EXCEPT:
# pylint: disable=wrong-import-position
from ._ctypes.function import (
_set_class_function,
_set_class_module,
convert_to_dgl_func,
FunctionBase as _FunctionBase,
)
FunctionHandle = ctypes.c_void_p
class Function(_FunctionBase):
"""The PackedFunc object.
Function plays an key role to bridge front and backend in DGL.
Function provide a type-erased interface, you can call function with positional arguments.
The compiled module returns Function.
DGL backend also registers and exposes its API as Functions.
For example, the developer function exposed in dgl.ir_pass are actually
C++ functions that are registered as PackedFunc
The following are list of common usage scenario of dgl.Function.
- Automatic exposure of C++ API into python
- To call PackedFunc from python side
- To call python callbacks to inspect results in generated code
- Bring python hook into C++ backend
See Also
--------
dgl.register_func: How to register global function.
dgl.get_global_func: How to get global function.
"""
pass # pylint: disable=unnecessary-pass
class ModuleBase(object):
"""Base class for module"""
__slots__ = ["handle", "_entry", "entry_name"]
def __init__(self, handle):
self.handle = handle
self._entry = None
self.entry_name = "__dgl_main__"
def __del__(self):
check_call(_LIB.DGLModFree(self.handle))
@property
def entry_func(self):
"""Get the entry function
Returns
-------
f : Function
The entry function if exist
"""
if self._entry:
return self._entry
self._entry = self.get_function(self.entry_name)
return self._entry
def get_function(self, name, query_imports=False):
"""Get function from the module.
Parameters
----------
name : str
The name of the function
query_imports : bool
Whether also query modules imported by this module.
Returns
-------
f : Function
The result function.
"""
ret_handle = FunctionHandle()
check_call(
_LIB.DGLModGetFunction(
self.handle,
c_str(name),
ctypes.c_int(query_imports),
ctypes.byref(ret_handle),
)
)
if not ret_handle.value:
raise AttributeError("Module has no function '%s'" % name)
return Function(ret_handle, False)
def import_module(self, module):
"""Add module to the import list of current one.
Parameters
----------
module : Module
The other module.
"""
check_call(_LIB.DGLModImport(self.handle, module.handle))
def __getitem__(self, name):
if not isinstance(name, string_types):
raise ValueError("Can only take string as function name")
return self.get_function(name)
def __call__(self, *args):
if self._entry:
return self._entry(*args)
f = self.entry_func
return f(*args)
def register_func(func_name, f=None, override=False):
"""Register global function
Parameters
----------
func_name : str or function
The function name
f : function, optional
The function to be registered.
override: boolean optional
Whether override existing entry.
Returns
-------
fregister : function
Register function if f is not specified.
Examples
--------
The following code registers my_packed_func as global function.
Note that we simply get it back from global function table to invoke
it from python side. However, we can also invoke the same function
from C++ backend, or in the compiled DGL code.
.. code-block:: python
targs = (10, 10.0, "hello")
@dgl.register_func
def my_packed_func(*args):
assert(tuple(args) == targs)
return 10
# Get it out from global function table
f = dgl.get_global_func("my_packed_func")
assert isinstance(f, dgl.nd.Function)
y = f(*targs)
assert y == 10
"""
if callable(func_name):
f = func_name
func_name = f.__name__
if not isinstance(func_name, str):
raise ValueError("expect string function name")
ioverride = ctypes.c_int(override)
def register(myf):
"""internal register function"""
if not isinstance(myf, Function):
myf = convert_to_dgl_func(myf)
check_call(
_LIB.DGLFuncRegisterGlobal(c_str(func_name), myf.handle, ioverride)
)
return myf
if f:
return register(f)
return register
def get_global_func(name, allow_missing=False):
"""Get a global function by name
Parameters
----------
name : str
The name of the global function
allow_missing : bool
Whether allow missing function or raise an error.
Returns
-------
func : dgl.Function
The function to be returned, None if function is missing.
"""
handle = FunctionHandle()
check_call(_LIB.DGLFuncGetGlobal(c_str(name), ctypes.byref(handle)))
if handle.value:
return Function(handle, False)
else:
if allow_missing:
return None
else:
raise ValueError("Cannot find global function %s" % name)
def list_global_func_names():
"""Get list of global functions registered.
Returns
-------
names : list
List of global functions names.
"""
plist = ctypes.POINTER(ctypes.c_char_p)()
size = ctypes.c_uint()
check_call(
_LIB.DGLFuncListGlobalNames(ctypes.byref(size), ctypes.byref(plist))
)
fnames = []
for i in range(size.value):
fnames.append(py_str(plist[i]))
return fnames
def extract_ext_funcs(finit):
"""
Extract the extension PackedFuncs from a C module.
Parameters
----------
finit : ctypes function
a ctypes that takes signature of DGLExtensionDeclarer
Returns
-------
fdict : dict of str to Function
The extracted functions
"""
fdict = {}
def _list(name, func):
fdict[name] = func
myf = convert_to_dgl_func(_list)
ret = finit(myf.handle)
_ = myf
if ret != 0:
raise RuntimeError("cannot initialize with %s" % finit)
return fdict
def _get_api(f):
flocal = f
flocal.is_global = True
return flocal
def _init_api(namespace, target_module_name=None):
"""Initialize api for a given module name
namespace : str
The namespace of the source registry
target_module_name : str
The target module name if different from namespace
"""
target_module_name = target_module_name if target_module_name else namespace
if namespace.startswith("dgl."):
return _init_api_prefix(target_module_name, namespace[4:])
else:
return _init_api_prefix(target_module_name, namespace)
def _init_api_prefix(module_name, prefix):
module = sys.modules[module_name]
name_list = []
for name in list_global_func_names():
if name.startswith("_") and not name.startswith("_deprecate"):
# internal APIs are ignored
continue
name_split = name.rsplit(".", 1)
if name_split[0] != prefix:
continue
if len(name_split) == 1:
print('Warning: invalid API name "%s".' % name)
continue
fname = name_split[1]
target_module = module
f = get_global_func(name)
ff = _get_api(f)
ff.__name__ = fname
ff.__doc__ = "DGL PackedFunc %s. " % fname
setattr(target_module, ff.__name__, ff)
name_list.append(fname)
return name_list
def _init_internal_api():
for name in list_global_func_names():
if not name.startswith("_") or name.startswith("_deprecate"):
# normal APIs are ignored
continue
target_module = sys.modules["dgl._api_internal"]
fname = name
if fname.find(".") != -1:
print('Warning: invalid API name "%s".' % fname)
continue
f = get_global_func(name)
ff = _get_api(f)
ff.__name__ = fname
ff.__doc__ = "DGL PackedFunc %s. " % fname
setattr(target_module, ff.__name__, ff)
_set_class_function(Function)