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Python

""":mod:`wand.api` --- Low-level interfaces
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. versionchanged:: 0.1.10
Changed to throw :exc:`~exceptions.ImportError` instead of
:exc:`~exceptions.AttributeError` when the shared library fails to load.
"""
import ctypes
import ctypes.util
import itertools
import os
import os.path
import platform
import sys
import traceback
# Forward import for backwards compatibility.
from .cdefs.structures import (AffineMatrix, MagickPixelPacket, PixelInfo,
PointInfo)
if platform.system() == "Windows":
try:
import winreg
except ImportError:
import _winreg as winreg
__all__ = ('AffineMatrix', 'MagickPixelPacket', 'library', 'libc', 'libmagick',
'load_library', 'PixelInfo', 'PointInfo')
def library_paths():
"""Iterates for library paths to try loading. The result paths are not
guaranteed that they exist.
:returns: a pair of libwand and libmagick paths. they can be the same.
path can be ``None`` as well
:rtype: :class:`tuple`
"""
libwand = None
libmagick = None
versions = '', '-7', '-7.Q8', '-7.Q16', '-6', '-Q16', '-Q8', '-6.Q16'
options = '', 'HDRI', 'HDRI-2'
system = platform.system()
magick_home = os.environ.get('MAGICK_HOME')
magick_suffix = os.environ.get('WAND_MAGICK_LIBRARY_SUFFIX')
if system == 'Windows':
# ImageMagick installers normally install coder and filter DLLs in
# subfolders, we need to add those folders to PATH, otherwise loading
# the DLL later will fail.
try:
with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE,
r"SOFTWARE\ImageMagick\Current") as reg_key:
libPath = winreg.QueryValueEx(reg_key, "LibPath")
coderPath = winreg.QueryValueEx(reg_key, "CoderModulesPath")
filterPath = winreg.QueryValueEx(reg_key, "FilterModulesPath")
magick_home = libPath[0]
os.environ['PATH'] += str((';' + libPath[0] + ";" +
coderPath[0] + ";" + filterPath[0]))
except OSError:
# otherwise use MAGICK_HOME, and we assume the coder and
# filter DLLs are in the same directory
pass
def magick_path(path):
return os.path.join(magick_home, *path)
combinations = itertools.product(versions, options)
suffixes = list()
if magick_suffix:
suffixes = str(magick_suffix).split(';')
# We need to convert the ``combinations`` generator to a list so we can
# iterate over it twice.
suffixes.extend(list(version + option for version, option in combinations))
if magick_home:
# exhaustively search for libraries in magick_home before calling
# find_library.
for suffix in suffixes:
# On Windows, the API is split between two libs. On other
# platforms, it's all contained in one.
if system == 'Windows':
libwand = 'CORE_RL_wand_{0}.dll'.format(suffix),
libmagick = 'CORE_RL_magick_{0}.dll'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
libwand = 'CORE_RL_MagickWand_{0}.dll'.format(suffix),
libmagick = 'CORE_RL_MagickCore_{0}.dll'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
libwand = 'libMagickWand{0}.dll'.format(suffix),
libmagick = 'libMagickCore{0}.dll'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
elif system == 'Darwin':
libwand = 'lib', 'libMagickWand{0}.dylib'.format(suffix),
yield magick_path(libwand), magick_path(libwand)
else:
libwand = 'lib', 'libMagickWand{0}.so'.format(suffix),
libmagick = 'lib', 'libMagickCore{0}.so'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
libwand = 'lib', 'libMagickWand{0}.so.9'.format(suffix),
libmagick = 'lib', 'libMagickCore{0}.so.9'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
libwand = 'lib', 'libMagickWand{0}.so.6'.format(suffix),
libmagick = 'lib', 'libMagickCore{0}.so.6'.format(suffix),
yield magick_path(libwand), magick_path(libmagick)
for suffix in suffixes:
if system == 'Windows':
libwand = ctypes.util.find_library('CORE_RL_wand_' + suffix)
libmagick = ctypes.util.find_library('CORE_RL_magick_' + suffix)
yield libwand, libmagick
libwand = ctypes.util.find_library('CORE_RL_MagickWand_' + suffix)
libmagick = ctypes.util.find_library(
'CORE_RL_MagickCore_' + suffix
)
yield libwand, libmagick
libwand = ctypes.util.find_library('libMagickWand' + suffix)
libmagick = ctypes.util.find_library('libMagickCore' + suffix)
yield libwand, libmagick
else:
libmagick = ctypes.util.find_library('MagickCore' + suffix)
libwand = ctypes.util.find_library('MagickWand' + suffix)
if libmagick is not None:
yield libwand, libmagick
yield libwand, libwand
def load_library():
"""Loads the MagickWand library.
:returns: the MagickWand library and the ImageMagick library
:rtype: :class:`ctypes.CDLL`
"""
tried_paths = []
for libwand_path, libmagick_path in library_paths():
if libwand_path is None or libmagick_path is None:
continue
try:
tried_paths.append(libwand_path)
libwand = ctypes.CDLL(str(libwand_path))
if libwand_path == libmagick_path:
libmagick = libwand
else:
tried_paths.append(libmagick_path)
libmagick = ctypes.CDLL(str(libmagick_path))
except (IOError, OSError):
continue
return libwand, libmagick
raise IOError('cannot find library; tried paths: ' + repr(tried_paths))
try:
# Preserve the module itself even if it fails to import
sys.modules['wand._api'] = sys.modules['wand.api']
except KeyError:
# Loading the module locally or a non-standard setting
pass
try:
libraries = load_library()
except (OSError, IOError):
msg = 'https://docs.wand-py.org/en/latest/guide/install.html'
if sys.platform.startswith(('dragonfly', 'freebsd')):
msg = 'pkg install'
elif sys.platform == 'win32':
msg += '#install-imagemagick-on-windows'
elif sys.platform == 'darwin':
mac_pkgmgrs = {'brew': 'brew install freetype imagemagick',
'port': 'port install imagemagick'}
for pkgmgr in mac_pkgmgrs:
with os.popen('which ' + pkgmgr) as f:
if f.read().strip():
msg = mac_pkgmgrs[pkgmgr]
break
else:
msg += '#install-imagemagick-on-mac'
elif hasattr(platform, 'linux_distribution'):
distname, _, __ = platform.linux_distribution()
distname = (distname or '').lower()
if distname in ('debian', 'ubuntu'):
msg = 'apt-get install libmagickwand-dev'
elif distname in ('fedora', 'centos', 'redhat'):
msg = 'yum install ImageMagick-devel'
raise ImportError('MagickWand shared library not found.\n'
'You probably had not installed ImageMagick library.\n'
'Try to install:\n ' + msg)
#: (:class:`ctypes.CDLL`) The MagickWand library.
library = libraries[0]
#: (:class:`ctypes.CDLL`) The ImageMagick library. It is the same with
#: :data:`library` on platforms other than Windows.
#:
#: .. versionadded:: 0.1.10
libmagick = libraries[1]
try:
from wand.cdefs import (core, drawing_wand, magick_image, magick_property,
magick_wand, pixel_iterator, pixel_wand)
core.load(libmagick)
# Let's get the magick-version number to pass to load methods.
IM_VERSION = ctypes.c_size_t()
libmagick.GetMagickVersion(ctypes.byref(IM_VERSION))
# Query Quantum Depth (i.e. Q8, Q16, ... etc).
IM_QUANTUM_DEPTH = ctypes.c_size_t()
libmagick.GetMagickQuantumDepth(ctypes.byref(IM_QUANTUM_DEPTH))
# Does the library support HDRI?
IM_HDRI = 'HDRI' in str(libmagick.GetMagickFeatures())
core.load_with_version(libmagick, IM_VERSION.value)
magick_wand.load(library, IM_VERSION.value)
magick_property.load(library, IM_VERSION.value)
magick_image.load(library, IM_VERSION.value)
pixel_iterator.load(library, IM_VERSION.value)
pixel_wand.load(library, IM_VERSION.value, IM_QUANTUM_DEPTH.value, IM_HDRI)
drawing_wand.load(library, IM_VERSION.value)
del IM_HDRI, IM_QUANTUM_DEPTH, IM_VERSION
except AttributeError:
raise ImportError('MagickWand shared library not found or incompatible\n'
'Original exception was raised in:\n' +
traceback.format_exc())
#: (:class:`ctypes.CDLL`) The C standard library.
libc = None
if platform.system() == 'Windows':
msvcrt = ctypes.util.find_msvcrt()
# workaround -- the newest visual studio DLL is named differently:
if not msvcrt and '1900' in platform.python_compiler():
msvcrt = 'vcruntime140.dll'
if msvcrt:
libc = ctypes.CDLL(msvcrt)
else:
libc_path = ctypes.util.find_library('c')
if libc_path:
libc = ctypes.cdll.LoadLibrary(libc_path)
else:
# Attempt to guess popular versions of libc
libc_paths = ('libc.so.6', 'libc.so', 'libc.a', 'libc.dylib',
'/usr/lib/libc.dylib')
for libc_path in libc_paths:
try:
libc = ctypes.cdll.LoadLibrary(libc_path)
break
except (IOError, OSError):
continue
if libc:
libc.fdopen.argtypes = [ctypes.c_int, ctypes.c_char_p]
libc.fdopen.restype = ctypes.c_void_p
libc.fflush.argtypes = [ctypes.c_void_p]