Factor out dll loader so it can be used by both compat and standard library

https://github.com/ahupp/python-magic/issues/232

3 files changed, 43 insertions, 43 deletions

diff --git a/magic/__init__.py b/magic/__init__.py
index f2fd34d..7a75b75 100644
--- a/magic/__init__.py
+++ b/magic/__init__.py
@@ -206,41 +206,8 @@ def from_descriptor(fd, mime=False):
     m = _get_magic_type(mime)
     return m.from_descriptor(fd)
 
-
-libmagic = None
-# Let's try to find magic or magic1
-dll = ctypes.util.find_library('magic') \
-      or ctypes.util.find_library('magic1') \
-      or ctypes.util.find_library('cygmagic-1') \
-      or ctypes.util.find_library('libmagic-1') \
-      or ctypes.util.find_library('msys-magic-1')  # for MSYS2
-
-# necessary because find_library returns None if it doesn't find the library
-if dll:
-    libmagic = ctypes.CDLL(dll)
-
-if not libmagic or not libmagic._name:
-    windows_dlls = ['magic1.dll', 'cygmagic-1.dll', 'libmagic-1.dll', 'msys-magic-1.dll']
-    platform_to_lib = {'darwin': ['/opt/local/lib/libmagic.dylib',
-                                  '/usr/local/lib/libmagic.dylib'] +
-                                 # Assumes there will only be one version installed
-                                 glob.glob('/usr/local/Cellar/libmagic/*/lib/libmagic.dylib'),  # flake8:noqa
-                       'win32': windows_dlls,
-                       'cygwin': windows_dlls,
-                       'linux': ['libmagic.so.1'],
-                       # fallback for some Linuxes (e.g. Alpine) where library search does not work # flake8:noqa
-                       }
-    platform = 'linux' if sys.platform.startswith('linux') else sys.platform
-    for dll in platform_to_lib.get(platform, []):
-        try:
-            libmagic = ctypes.CDLL(dll)
-            break
-        except OSError:
-            pass
-
-if not libmagic or not libmagic._name:
-    # It is better to raise an ImportError since we are importing magic module
-    raise ImportError('failed to find libmagic.  Check your installation')
+from . import loader
+libmagic = loader.load_lib()
 
 magic_t = ctypes.c_void_p
 
diff --git a/magic/compat.py b/magic/compat.py
index 7b39691..e2d71ee 100644
--- a/magic/compat.py
+++ b/magic/compat.py
@@ -12,16 +12,10 @@ from ctypes import *
 from ctypes.util import find_library
 
 
-def _init():
-    """
-    Loads the shared library through ctypes and returns a library
-    L{ctypes.CDLL} instance
-    """
-    return ctypes.cdll.LoadLibrary(find_library('magic'))
-
+from . import loader
 
 _libraries = {}
-_libraries['magic'] = _init()
+_libraries['magic'] = loader.load_lib()
 
 # Flag constants for open and setflags
 MAGIC_NONE = NONE = 0
diff --git a/magic/loader.py b/magic/loader.py
new file mode 100644
index 0000000..6a47d52
--- /dev/null
+++ b/magic/loader.py
@@ -0,0 +1,39 @@
+import ctypes
+import sys
+
+def load_lib():
+  libmagic = None
+  # Let's try to find magic or magic1
+  dll = ctypes.util.find_library('magic') \
+        or ctypes.util.find_library('magic1') \
+        or ctypes.util.find_library('cygmagic-1') \
+        or ctypes.util.find_library('libmagic-1') \
+        or ctypes.util.find_library('msys-magic-1')  # for MSYS2
+
+  # necessary because find_library returns None if it doesn't find the library
+  if dll:
+      libmagic = ctypes.CDLL(dll)
+
+  if not libmagic or not libmagic._name:
+      windows_dlls = ['magic1.dll', 'cygmagic-1.dll', 'libmagic-1.dll', 'msys-magic-1.dll']
+      platform_to_lib = {'darwin': ['/opt/local/lib/libmagic.dylib',
+                                    '/usr/local/lib/libmagic.dylib'] +
+                                  # Assumes there will only be one version installed
+                                  glob.glob('/usr/local/Cellar/libmagic/*/lib/libmagic.dylib'),  # flake8:noqa
+                        'win32': windows_dlls,
+                        'cygwin': windows_dlls,
+                        'linux': ['libmagic.so.1'],
+                        # fallback for some Linuxes (e.g. Alpine) where library search does not work # flake8:noqa
+                        }
+      platform = 'linux' if sys.platform.startswith('linux') else sys.platform
+      for dll in platform_to_lib.get(platform, []):
+          try:
+              libmagic = ctypes.CDLL(dll)
+              break
+          except OSError:
+              pass
+
+  if not libmagic or not libmagic._name:
+      # It is better to raise an ImportError since we are importing magic module
+      raise ImportError('failed to find libmagic.  Check your installation')
+  return libmagic
\ No newline at end of file