70 lines
2.2 KiB
Python
70 lines
2.2 KiB
Python
|
"""Loads zbar and its dependencies.
|
||
|
|
"""
|
||
|
|
import platform
|
||
|
|
import sys
|
||
|
|
|
||
|
|
from ctypes import cdll
|
||
|
|
from ctypes.util import find_library
|
||
|
|
from pathlib import Path
|
||
|
|
|
||
|
|
__all__ = ['load']
|
||
|
|
|
||
|
|
|
||
|
|
def _windows_fnames():
|
||
|
|
"""For convenience during development and to aid debugging, the DLL names
|
||
|
|
are specific to the bit depth of interpreter.
|
||
|
|
|
||
|
|
This logic has its own function to make testing easier
|
||
|
|
"""
|
||
|
|
# 'libzbar-64.dll' and 'libzbar-32.dll' each have a dependent DLL -
|
||
|
|
# 'libiconv.dll' and 'libiconv-2.dll' respectively.
|
||
|
|
if sys.maxsize > 2**32:
|
||
|
|
# 64-bit
|
||
|
|
fname = 'libzbar-64.dll'
|
||
|
|
dependencies = ['libiconv.dll']
|
||
|
|
else:
|
||
|
|
# 32-bit
|
||
|
|
fname = 'libzbar-32.dll'
|
||
|
|
dependencies = ['libiconv-2.dll']
|
||
|
|
|
||
|
|
return fname, dependencies
|
||
|
|
|
||
|
|
|
||
|
|
def load():
|
||
|
|
"""Loads the libzar shared library and its dependencies.
|
||
|
|
"""
|
||
|
|
if 'Windows' == platform.system():
|
||
|
|
# Possible scenarios here
|
||
|
|
# 1. Run from source, DLLs are in pyzbar directory
|
||
|
|
# cdll.LoadLibrary() imports DLLs in repo root directory
|
||
|
|
# 2. Wheel install into CPython installation
|
||
|
|
# cdll.LoadLibrary() imports DLLs in package directory
|
||
|
|
# 3. Wheel install into virtualenv
|
||
|
|
# cdll.LoadLibrary() imports DLLs in package directory
|
||
|
|
# 4. Frozen
|
||
|
|
# cdll.LoadLibrary() imports DLLs alongside executable
|
||
|
|
fname, dependencies = _windows_fnames()
|
||
|
|
|
||
|
|
def load_objects(directory):
|
||
|
|
# Load dependencies before loading libzbar dll
|
||
|
|
deps = [
|
||
|
|
cdll.LoadLibrary(str(directory.joinpath(dep)))
|
||
|
|
for dep in dependencies
|
||
|
|
]
|
||
|
|
libzbar = cdll.LoadLibrary(str(directory.joinpath(fname)))
|
||
|
|
return deps, libzbar
|
||
|
|
|
||
|
|
try:
|
||
|
|
dependencies, libzbar = load_objects(Path(''))
|
||
|
|
except OSError:
|
||
|
|
dependencies, libzbar = load_objects(Path(__file__).parent)
|
||
|
|
else:
|
||
|
|
# Assume a shared library on the path
|
||
|
|
path = find_library('zbar')
|
||
|
|
if not path:
|
||
|
|
raise ImportError('Unable to find zbar shared library')
|
||
|
|
libzbar = cdll.LoadLibrary(path)
|
||
|
|
dependencies = []
|
||
|
|
|
||
|
|
return libzbar, dependencies
|