Source Code for Module mvpa.clfs.libsmlrc.ctypes_helper

 1  # emacs: -*- mode: python; py-indent-offset: 4; indent-tabs-mode: nil -*- 
 2  # vi: set ft=python sts=4 ts=4 sw=4 et: 
 3  ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ## 
 4  # 
 5  #   See COPYING file distributed along with the PyMVPA package for the 
 6  #   copyright and license terms. 
 7  # 
 8  ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ### ## 
 9  """Helpers for wrapping C libraries with ctypes.""" 
10   
11  import numpy as N 
12  import ctypes as C 
13   
14  # define an array type to help with wrapping 
15  c_darray = N.ctypeslib.ndpointer(dtype=N.float64, flags='aligned,contiguous') 
16  c_larray = N.ctypeslib.ndpointer(dtype=N.int64, flags='aligned,contiguous') 
17  c_farray = N.ctypeslib.ndpointer(dtype=N.float32, flags='aligned,contiguous') 
18  c_iarray = N.ctypeslib.ndpointer(dtype=N.int32, flags='aligned,contiguous') 
19   
20 -def extend_args(*args): 
21      """Turn ndarray arguments into dims and arrays.""" 
22      arglist = [] 
23      for arg in args: 
24          if isinstance(arg, N.ndarray): 
25              # add the dimensions 
26              arglist.extend(arg.shape) 
27   
28          # just append the arg 
29          arglist.append(arg) 
30   
31      return arglist 
32   
33  ############################################################# 
34  # I'm not sure the rest is helpful, but I'll keep it for now. 
35  ############################################################# 
36   
37  # incomplete type conversion 
38  typemap = { 
39      N.float64: C.c_double, 
40      N.float32: C.c_float, 
41      N.int64: C.c_int64, 
42      N.int32: C.c_int32} 
43   
44 -def process_args(*args): 
45      """Turn ndarray arguments into dims and array pointers for calling 
46      a ctypes-wrapped function.""" 
47      arglist = [] 
48      for arg in args: 
49          if isinstance(arg, N.ndarray): 
50              # add the dimensions 
51              arglist.extend(arg.shape) 
52   
53              # add the pointer to the ndarray 
54              arglist.append(arg.ctypes.data_as( 
55                  C.POINTER(typemap[arg.dtype.type]))) 
56          else: 
57              # just append the arg 
58              arglist.append(arg) 
59   
60      return arglist 
61   
62 -def get_argtypes(*args): 
63      argtypes = [] 
64      for arg in args: 
65          if isinstance(arg, N.ndarray): 
66              # add the dimensions 
67              argtypes.extend([C.c_int]*len(arg.shape)) 
68   
69              # add the pointer to the ndarray 
70              argtypes.append(N.ctypeslib.ndpointer(dtype=arg.dtype)) 
71          else: 
72              # try and figure out the type 
73              argtypes.append(arg) 
74      return argtypes 
75