Don't require wrapping libraw calls in a handler

libraw/__init__.py

@@ -1,12 +0,0 @@
-import libraw.bindings
-
-libraw = libraw.bindings.libraw
-"""
-A handle to the LibRaw binary installed on the end users machine.
-
-This should always be imported first by anything that wants to use `libraw`:
-
-.. sourcecode:: python
-
-    from libraw import libraw
-"""

libraw/bindings.py

@@ -2,21 +2,97 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 The :class:`libraw.bindings` module handles linking against the LibRaw binary.
-It does not provide an API.
 """
 
 from ctypes import *  # noqa
 from ctypes import util
 
+from libraw import errors
+from libraw.errors import c_error
 from libraw.structs import libraw_data_t, libraw_processed_image_t
 
-# TODO: This is necessary because Travis CI is still using Ubuntu 12.04
-try:
-    # TODO: This will do bad things if the API version isn't 10
-    libraw = cdll.LoadLibrary(util.find_library('raw'))    # pragma: no cover
-    libraw.libraw_init.restype = POINTER(libraw_data_t)    # pragma: no cover
-    libraw.libraw_dcraw_make_mem_image.restype = POINTER(  # pragme: no cover
-        libraw_processed_image_t                           # pragma: no cover
-    )                                                      # pragma: no cover
-except:                                                    # pragma: no cover
-    libraw = cdll.LoadLibrary('')                          # pragma: no cover
+
+class LibRaw(CDLL):
+
+    """
+    A :class:`ctypes.CDLL` that links against `libraw.so` (or the equivalent on
+    your platform).
+    """
+
+    def __init__(self):  # pragma: no cover
+        libraw = util.find_library('raw')
+        try:
+            if libraw is not None:
+                super(LibRaw, self).__init__(libraw)
+            else:
+                raise ImportError
+        except (ImportError, AttributeError, OSError, IOError):
+            raise ImportError('Cannot find LibRaw on your system!')
+
+        # Define return types
+
+        self.libraw_init.restype = POINTER(libraw_data_t)
+        self.libraw_version.restype = c_char_p
+        self.libraw_strprogress.restype = c_char_p
+        self.libraw_versionNumber.restype = c_int
+        self.libraw_cameraCount.restype = c_int
+        self.libraw_cameraList.restype = POINTER(
+            c_char_p * self.libraw_cameraCount()
+        )
+        self.libraw_unpack_function_name.restype = c_char_p
+        self.libraw_subtract_black.restype = POINTER(libraw_data_t)
+        self.libraw_open_file.restype = c_error
+        self.libraw_open_file_ex.restype = c_error
+        self.libraw_open_buffer.restype = c_error
+        self.libraw_unpack.restype = c_error
+        self.libraw_unpack_thumb.restype = c_error
+        self.libraw_adjust_sizes_info_only.restype = c_error
+        self.libraw_dcraw_ppm_tiff_writer.restype = c_error
+        self.libraw_dcraw_thumb_writer.restype = c_error
+        self.libraw_dcraw_process.restype = c_error
+        self.libraw_dcraw_make_mem_image.restype = POINTER(
+            libraw_processed_image_t)
+        self.libraw_dcraw_make_mem_thumb.restype = POINTER(
+            libraw_processed_image_t)
+        self.libraw_raw2image.restype = c_error
+        self.libraw_get_decoder_info.restype = c_error
+        self.libraw_COLOR.restype = c_error
+        try:
+            self.libraw_open_wfile.restype = c_error
+            self.libraw_open_wfile_ex.restype = c_error
+        except AttributeError:
+            pass
+
+    @property
+    def version_number(self):
+        """
+        A numeric representation of the version of LibRaw which we have linked
+        against in ``(Major, Minor, Patch)`` form. eg. ::
+
+            (0, 16, 1)
+
+        :returns: The version number
+        :rtype: :class:`3 tuple`
+        """
+        v = self.libraw_versionNumber()
+        return ((v >> 16) & 0x0000ff, (v >> 8) & 0x0000ff, v & 0x0000ff)
+
+    @property
+    def version(self):
+        """
+        A string representation of the version of LibRaw which we have linked
+        against. eg. ::
+
+            "0.16.1-Release"
+
+        :returns: The version
+        :rtype: :class:`basestring`
+        """
+        return self.libraw_version().decode('utf-8')
+
+    def __getitem__(self, name):
+        func = super(LibRaw, self).__getitem__(name)
+
+        func.errcheck = errors.check_call
+
+        return func

libraw/errors.py

@@ -2,6 +2,17 @@
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 """
 
+from ctypes import c_int
+
+
+class c_error(c_int):
+
+    """
+    An error type for LibRaw (since LibRaw errors are ints and you can't
+    distinguish between functions that return an error and functions that
+    return an int that doesn't code for an error).
+    """
+
 
 class UnspecifiedError(Exception):
 
@@ -90,15 +101,18 @@ class BadCrop(Exception):
     """
 
 
-def check_call(exit_code):
+def check_call(exit_code, func, arguments):
     """
     Throws a Python error which corresponds to the given LibRaw exit code.
 
     :param exit_code: the exit code returned by a LibRaw function
     :type exit_code: :class:`int`
+    :returns: Returns :param:`exit_code` or throws an error from
+              :class:`libraw.errors`
+    :rtype: :class:`type(exit_code)`
     """
 
-    if exit_code is not 0:
+    if func.restype is c_error and exit_code.value != 0:
         raise {
             -1: UnspecifiedError,
             -2: FileUnsupported,
@@ -112,4 +126,6 @@ def check_call(exit_code):
             -100009: IOError,
             -100010: CancelledByCallback,
             -100011: BadCrop
-        }[exit_code]
+        }[exit_code.value]
+
+    return exit_code

rawkit/raw.py

@@ -4,11 +4,9 @@
 
 import ctypes
 
-from libraw import libraw
-from libraw import errors as e
-
-
 from rawkit.errors import NoFileSpecified, InvalidFileType
+from libraw.bindings import LibRaw
+
 from rawkit.metadata import Metadata
 from rawkit.options import Options
 
@@ -40,10 +38,9 @@ def __init__(self, filename=None):
         """Initializes a new Raw object."""
         if filename is None:
             raise NoFileSpecified()
-        self.data = libraw.libraw_init(0)
-        e.check_call(
-            libraw.libraw_open_file(self.data, filename.encode('ascii'))
-        )
+        self.libraw = LibRaw()
+        self.data = self.libraw.libraw_init(0)
+        self.libraw.libraw_open_file(self.data, filename.encode('ascii'))
 
         self.options = Options()
 
@@ -60,24 +57,24 @@ def __exit__(self, exc_type, exc_value, traceback):
 
     def close(self):
         """Free the underlying raw representation."""
-        e.check_call(libraw.libraw_close(self.data))
+        self.libraw.libraw_close(self.data)
 
     def unpack(self):
         """Unpack the raw data."""
         if not self.image_unpacked:
-            e.check_call(libraw.libraw_unpack(self.data))
+            self.libraw.libraw_unpack(self.data)
             self.image_unpacked = True
 
     def unpack_thumb(self):
         """Unpack the thumbnail data."""
         if not self.thumb_unpacked:
-            e.check_call(libraw.libraw_unpack_thumb(self.data))
+            self.libraw.libraw_unpack_thumb(self.data)
             self.thumb_unpacked = True
 
     def process(self):
         """Process the raw data based on self.options"""
         self.options._map_to_libraw_params(self.data.contents.params)
-        e.check_call(libraw.libraw_dcraw_process(self.data))
+        self.libraw.libraw_dcraw_process(self.data)
 
     def save(self, filename=None, filetype='ppm'):
         """
@@ -99,8 +96,8 @@ def save(self, filename=None, filetype='ppm'):
         self.unpack()
         self.process()
 
-        e.check_call(libraw.libraw_dcraw_ppm_tiff_writer(
-            self.data, filename.encode('ascii')))
+        self.libraw.libraw_dcraw_ppm_tiff_writer(
+            self.data, filename.encode('ascii'))
 
     def save_thumb(self, filename=None):
         """
@@ -111,8 +108,8 @@ def save_thumb(self, filename=None):
         """
         self.unpack_thumb()
 
-        e.check_call(libraw.libraw_dcraw_thumb_writer(
-            self.data, filename.encode('ascii')))
+        self.libraw.libraw_dcraw_thumb_writer(
+            self.data, filename.encode('ascii'))
 
     def to_buffer(self):
         """
@@ -124,13 +121,13 @@ def to_buffer(self):
         self.unpack()
         self.process()
 
-        processed_image = libraw.libraw_dcraw_make_mem_image(self.data)
+        processed_image = self.libraw.libraw_dcraw_make_mem_image(self.data)
         data_pointer = ctypes.cast(
             processed_image.contents.data,
             ctypes.POINTER(ctypes.c_byte * processed_image.contents.data_size)
         )
         data = bytearray(data_pointer.contents)
-        e.check_call(libraw.libraw_dcraw_clear_mem(processed_image))
+        self.libraw.libraw_dcraw_clear_mem(processed_image)
 
         return data
 
@@ -143,13 +140,13 @@ def thumbnail_to_buffer(self):
         """
         self.unpack_thumb()
 
-        processed_image = libraw.libraw_dcraw_make_mem_thumb(self.data)
+        processed_image = self.libraw.libraw_dcraw_make_mem_thumb(self.data)
         data_pointer = ctypes.cast(
             processed_image.contents.data,
             ctypes.POINTER(ctypes.c_byte * processed_image.contents.data_size)
         )
         data = bytearray(data_pointer.contents)
-        e.check_call(libraw.libraw_dcraw_clear_mem(processed_image))
+        self.libraw.libraw_dcraw_clear_mem(processed_image)
 
         return data
 

rawkit/util.py

@@ -1,7 +1,7 @@
 import ctypes
 import os
 
-from libraw import libraw
+from libraw.bindings import LibRaw
 
 
 def discover(path):
@@ -11,6 +11,7 @@ def discover(path):
     :type path: :class:`str`
     """
     file_list = []
+    libraw = LibRaw()
     raw = libraw.libraw_init(0)
 
     for root, _, files in os.walk(path):
@@ -32,6 +33,9 @@ def camera_list():
     :returns: A list of supported cameras
     :rtype: :class:`str tuple`
     """
+
+    libraw = LibRaw()
+    print(libraw)
     libraw.libraw_cameraList.restype = ctypes.POINTER(
         ctypes.c_char_p * libraw.libraw_cameraCount()
     )