From e6f23c313ee98261a1b49992dc898b89e491df40 Mon Sep 17 00:00:00 2001 From: Dag Sverre Seljebotn Date: Sun, 19 Apr 2009 23:03:09 +0200 Subject: [PATCH] Format strings from numpy.pxd: Added endian/packing information --- Cython/Includes/numpy.pxd | 64 ++++++++++++++++++++++++++++++--------- 1 file changed, 49 insertions(+), 15 deletions(-) diff --git a/Cython/Includes/numpy.pxd b/Cython/Includes/numpy.pxd index d351a3c0..3565ec89 100644 --- a/Cython/Includes/numpy.pxd +++ b/Cython/Includes/numpy.pxd @@ -1,3 +1,16 @@ +# NumPy static imports for Cython +# +# This also defines backwards-compatability buffer acquisition +# code for use in Python 2.x (or Python <= 2.5 when NumPy starts +# implementing PEP-3118 directly). + + +# Because of laziness, the format string of the buffer is statically +# allocated. Increase the size if this is not enough, or submit a +# patch to do this properly. + +DEF _buffer_format_string_len = 255 + cimport python_buffer as pybuf cimport stdlib @@ -29,6 +42,8 @@ cdef extern from "numpy/arrayobject.h": ctypedef class numpy.dtype [object PyArray_Descr]: cdef int type_num + cdef int itemsize "elsize" + cdef char byteorder cdef object fields cdef object names @@ -89,17 +104,11 @@ cdef extern from "numpy/arrayobject.h": cdef char* f = NULL cdef dtype descr = self.descr cdef list stack + cdef int offset + cdef char byteorder = 0 cdef bint hasfields = PyDataType_HASFIELDS(descr) - # Ugly hack warning: - # Cython currently will not support helper functions in - # pxd files -- so we must keep our own, manual stack! - # In addition, avoid allocation of the stack in the common - # case that we are dealing with a single non-nested datatype... - # (this would look much prettier if we could use utility - # functions). - if not hasfields and not copy_shape: # do not call releasebuffer info.obj = None @@ -131,8 +140,11 @@ cdef extern from "numpy/arrayobject.h": info.format = f return else: - info.format = stdlib.malloc(255) # static size - f = _util_dtypestring(descr, info.format, info.format + 255) + info.format = stdlib.malloc(_buffer_format_string_len) + offset = 0 + f = _util_dtypestring(descr, info.format, + info.format + _buffer_format_string_len, + &offset, &byteorder) f[0] = 0 # Terminate format string def __releasebuffer__(ndarray self, Py_buffer* info): @@ -245,14 +257,36 @@ ctypedef npy_cdouble cdouble_t ctypedef npy_clongdouble clongdouble_t -cdef inline char* _util_dtypestring(dtype descr, char* f, char* end) except NULL: +cdef inline char* _util_dtypestring(dtype descr, char* f, char* end, int* offset, char* byteorder) except NULL: # Recursive utility function used in __getbuffer__ to get format # string. The new location in the format string is returned. cdef dtype child + cdef int delta_offset cdef tuple i + cdef char new_byteorder for i in descr.fields.itervalues(): child = i[0] + new_offset = i[1] + + if (end - f) - (new_offset - offset[0]) < 15: # this should leave room for "T{" and "}" as well + raise RuntimeError("Format string allocated too short, see comment in numpy.pxd") + + new_byteorder = child.byteorder + if new_byteorder == '|': new_byteorder = '=' + if byteorder[0] != new_byteorder: + f[0] = new_byteorder + f += 1 + byteorder[0] = new_byteorder + + # Output padding bytes + while offset[0] < new_offset: + f[0] = 120 # "x"; pad byte + f += 1 + offset[0] += 1 + + offset[0] += child.itemsize + if not PyDataType_HASFIELDS(child): t = child.type_num if end - f < 15: # this should leave room for "T{" and "}" as well @@ -272,9 +306,9 @@ cdef inline char* _util_dtypestring(dtype descr, char* f, char* end) except NULL elif t == NPY_FLOAT: f[0] = 102 #"f" elif t == NPY_DOUBLE: f[0] = 100 #"d" elif t == NPY_LONGDOUBLE: f[0] = 103 #"g" - elif t == NPY_CFLOAT: f[0] = 90; f[1] = 102; f += 1 - elif t == NPY_CDOUBLE: f[0] = 90; f[1] = 100; f += 1 - elif t == NPY_CLONGDOUBLE: f[0] = 90; f[1] = 103; f += 1 + elif t == NPY_CFLOAT: f[0] = 90; f[1] = 102; f += 1 # Zf + elif t == NPY_CDOUBLE: f[0] = 90; f[1] = 100; f += 1 # Zd + elif t == NPY_CLONGDOUBLE: f[0] = 90; f[1] = 103; f += 1 # Zg elif t == NPY_OBJECT: f[0] = 79 #"O" else: raise ValueError("unknown dtype code in numpy.pxd (%d)" % t) @@ -283,7 +317,7 @@ cdef inline char* _util_dtypestring(dtype descr, char* f, char* end) except NULL f[0] = 84 #"T" f[1] = 123 #"{" f += 2 - f = _util_dtypestring(child, f, end) + f = _util_dtypestring(child, f, end, offset, byteorder) f[0] = 125 #"}" f += 1 return f -- 2.26.2