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from __future__ import (print_function, division, unicode_literals,
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from ctypes import CDLL
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from ctypes.util import find_library
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from contextlib import contextmanager
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def load_library(name, signatures=None):
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Load the C library with the given ``name``.
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``name`` is a string containing a generic library name (as for
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:func:`ctypes.util.find_library`). If ``signatures`` is given, it must be
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a dictionary with signatures of functions of the library, see
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:func:`add_foreign_signatures` for details.
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Return a :class:`ctypes.CDLL` wrapping the library. Raise
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:exc:`~exceptions.ImportError`, if the library was not found.
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library_name = find_library(name)
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raise ImportError('No library named {0}'.format(name))
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library = CDLL(library_name)
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library = add_foreign_signatures(library, signatures)
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def add_foreign_signatures(library, signatures):
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Add ``signatures`` of a foreign ``library`` to the symbols defined in
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Add ``signatures`` of a foreign ``library`` to the symbols defined in this
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``library`` is a :class:`~ctypes.CDLL` object, wrapping a foreign
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library. ``signatures`` is a dictionary, which specifies signatures for
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symbols defined in this library. It maps the name of a function to a
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three element tuple ``(argument_types, return_type, error_checker)``.
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``argument_types`` is a list of argument types (see
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:attr:`~ctypes._FuncPtr.argtypes`), ``return_type`` is the return type
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(see :attr:`~ctypes._FuncPtr.restype`) and ``error_checker`` is a
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function used as error checker (see :attr:``~ctypes._FuncPtr.errcheck`).
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``error_checker`` may be ``None``, in which case no error checking
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``library`` is a :class:`~ctypes.CDLL` object, wrapping a foreign library.
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``signatures`` is a dictionary, which specifies signatures for symbols
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defined in this library. It maps the name of a function to a two or three
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component tuple ``(argument_types, return_type, error_checker)``, where
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``error_checker`` is optional and can be omitted. ``argument_types`` is a
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list of argument types (see :attr:`~ctypes._FuncPtr.argtypes`),
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``return_type`` is the return type (see :attr:`~ctypes._FuncPtr.restype`)
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and ``error_checker`` is a function used as error checker (see
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:attr:``~ctypes._FuncPtr.errcheck`). ``error_checker`` may be ``None``, in
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which case no error checking function is defined.
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Return the ``library`` object again.
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for name, signature in signatures.iteritems():
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function = getattr(library, name)
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argument_types, return_type, error_checker = signature
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if len(signature) == 2:
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argument_types, return_type = signature
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argument_types, return_type, error_checker = signature
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function.argtypes = argument_types
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function.restype = return_type
added
removed
synaptiks/_bindings/util.py
