Merge pull request #3521 from mdboom/erfa/remove-cython

Use Python/C API instead of Cython for ERFA wrappers

astropy/_erfa/core.c.templ

@@ -0,0 +1,136 @@
+/* -*- mode: c -*- */
+
+/* Licensed under a 3-clause BSD style license - see LICENSE.rst */
+
+/* "core.c" is auto-generated by erfa_generator.py from the template
+   "core.c.templ". Do *not* edit "core.c" directly, instead edit
+   "core.c.templ" and run erfa_generator.py from the source directory to
+   update it. */
+
+
+#include "Python.h"
+#include "numpy/arrayobject.h"
+#include "erfa.h"
+
+
+#if PY_MAJOR_VERSION >= 3
+#define PY3K 1
+#else
+#define PY3K 0
+#endif
+
+
+typedef struct {
+    PyObject_HEAD
+    NpyIter *iter;
+} _NpyIterObject;
+
+
+#define MODULE_DOCSTRING \
+    "This module contains the C part of the ERFA python wrappers.\n" \
+    "This implements only the inner iterator loops, while the heavy lifting\n" \
+    "happens in Python in core.py\n\n" \
+    "For more about the module and how to use it, see the ``core.py``\n" \
+    "docstrings."
+
+
+{%- for func in funcs %}
+
+static PyObject *Py_{{ func.pyname }}(PyObject *self, PyObject *args, PyObject *kwds)
+{
+    {%- for arg in func.args_by_inout('in|inout|out|ret|stat') %}
+    {{ arg.ctype_ptr }} _{{ arg.name }};
+    {%- endfor %}
+    {%- if func.args_by_inout('stat')|length > 0 %}
+    int stat_ok = 1;
+    {%- endif %}
+    NpyIter *it = ((_NpyIterObject *)args)->iter;
+    char **dataptrarray = NpyIter_GetDataPtrArray(it);
+    NpyIter_IterNextFunc *iternext = NpyIter_GetIterNext(it, NULL);
+
+    do {
+        {%- for arg in func.args_by_inout('in|inout|out') %}
+        _{{ arg.name }} = (({{ arg.ctype }} *)(dataptrarray[{{ func.args.index(arg) }}])){%- if arg.ctype_ptr[-1] != '*' %}[0]{%- endif %};
+        {%- endfor %}
+
+        {{ func.args_by_inout('ret|stat')|map(attribute='name')|surround('_', ' = ')|join }}{{func.name}}({{ func.args_by_inout('in|inout|out')|map(attribute='name')|prefix('_')|join(', ') }});
+
+        {%- for arg in func.args_by_inout('ret|stat') %}
+        *(({{ arg.ctype_ptr }} *)(dataptrarray[{{ func.args.index(arg) }}])) = _{{ arg.name }};
+        {%- endfor %}
+
+        {%- for arg in func.args_by_inout('stat') %}
+        if (_{{ arg.name }}) {
+            stat_ok = 0;
+        }
+        {%- endfor %}
+    } while (iternext(it));
+
+    {%- if func.args_by_inout('stat')|length > 0 %}
+    if (stat_ok) {
+        Py_RETURN_TRUE;
+    } else {
+        Py_RETURN_FALSE;
+    }
+    {%- else %}
+    Py_RETURN_NONE;
+    {%- endif %}
+}
+
+{%- endfor %}
+
+static PyMethodDef module_functions[] = {
+    {%- for func in funcs %}
+    { "_" "{{ func.pyname }}", (PyCFunction)Py_{{ func.pyname }}, METH_O, NULL },
+    {%- endfor %}
+    { NULL }
+};
+
+struct module_state
+{
+    int _dummy;
+};
+
+#if PY3K
+
+static struct PyModuleDef moduledef = {
+    PyModuleDef_HEAD_INIT,
+    "_core",
+    MODULE_DOCSTRING,
+    sizeof(struct module_state),
+    module_functions,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+#define INITERROR return NULL
+
+PyMODINIT_FUNC PyInit__core(void)
+
+#else
+#define INITERROR return
+
+PyMODINIT_FUNC init_core(void)
+#endif
+
+{
+    PyObject *m;
+
+#if PY3K
+    m = PyModule_Create(&moduledef);
+#else
+    m = Py_InitModule3("_core", module_functions, MODULE_DOCSTRING);
+#endif
+
+    if (m == NULL) {
+        INITERROR;
+    }
+
+    import_array();
+
+#if PY3K
+    return m;
+#endif
+}

astropy/_erfa/core.py.templ

@@ -6,8 +6,8 @@
 # update it.
 
 """
-This module uses Cython to wrap the ERFA library in numpy-vectorized
-equivalents.
+This module uses the Python/C API to wrap the ERFA library in
+numpy-vectorized equivalents.
 
 ..warning::
     This is currently *not* part of the public Astropy API, and may change in
@@ -25,11 +25,12 @@ want to give ten matricies (i.e., the ERFA input type is double[3][3]),
 you would pass in a (10, 3, 3) numpy array.  If the output of the ERFA
 function is scalar, you'll get back a length-10 1D array.
 
-Note that the Cython part of these functions are implemented in a separate
-module (compiled as ``_core``), derived from the ``core.pyx`` file.  Splitting
-the wrappers into separate pure-python and Cython portions dramatically reduces
-compilation time without notably impacting performance. (See issue [#3063] on the
-github repository for more about this.)
+Note that the C part of these functions are implemented in a separate
+module (compiled as ``_core``), derived from the ``core.c`` file.
+Splitting the wrappers into separate pure-python and C portions
+dramatically reduces compilation time without notably impacting
+performance. (See issue [#3063] on the github repository for more
+about this.)
 """
 from __future__ import absolute_import, division, print_function
 

astropy/_erfa/erfa_generator.py

@@ -1,7 +1,7 @@
 # Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 This module's main purpose is to act as a script to create new versions
-of erfa.pyx when ERFA is updated (or this generator is enhanced).
+of erfa.c when ERFA is updated (or this generator is enhanced).
 
 `Jinja2 <http://jinja.pocoo.org/>`_ must be installed for this
 module/script to function.
@@ -364,7 +364,7 @@ def surround(a_list, pre, post):
     env.filters['postfix'] = postfix
     env.filters['surround'] = surround
 
-    erfa_pyx_in = env.get_template('core.pyx.templ')
+    erfa_c_in = env.get_template('core.c.templ')
     erfa_py_in = env.get_template('core.py.templ')
 
     #Extract all the ERFA function names from erfa.h
@@ -378,7 +378,7 @@ def surround(a_list, pre, post):
     with open(erfahfn, "r") as f:
         erfa_h = f.read()
 
-    funcs = []
+    funcs = {}
     section_subsection_functions = re.findall('/\* (\w*)/(\w*) \*/\n(.*?)\n\n',
                                               erfa_h, flags=re.DOTALL|re.MULTILINE)
     for section, subsection, functions in section_subsection_functions:
@@ -389,7 +389,7 @@ def surround(a_list, pre, post):
                 print_("{0}.{1}.{2}...".format(section, subsection, name))
                 if multifilserc:
                     # easy because it just looks in the file itself
-                    funcs.append(Function(name, srcdir))
+                    funcs[name] = Function(name, srcdir)
                 else:
                     # Have to tell it to look for a declaration matching
                     # the start of the header declaration, otherwise it
@@ -403,14 +403,16 @@ def surround(a_list, pre, post):
                             # argument names and line-breaking or
                             # whitespace
                             match_line = line[:-1].split('(')[0]
-                            funcs.append(Function(name, srcdir, match_line))
+                            funcs[name] = Function(name, srcdir, match_line)
                             break
                     else:
                         raise ValueError("A name for a C file wasn't "
                                          "found in the string that "
                                          "spawned it.  This should be "
                                          "impossible!")
 
+    funcs = list(funcs.values())
+
     #Extract all the ERFA constants from erfam.h
     erfamhfn = os.path.join(srcdir, 'erfam.h')
     with open(erfamhfn, 'r') as f:
@@ -424,20 +426,20 @@ def surround(a_list, pre, post):
                 constants.append(Constant(name, value, doc))
 
     print_("Rendering template")
-    erfa_pyx = erfa_pyx_in.render(funcs=funcs)
+    erfa_c = erfa_c_in.render(funcs=funcs)
     erfa_py = erfa_py_in.render(funcs=funcs, constants=constants)
 
     if outfn is not None:
-        outfnx = outfn + "x"
-        print_("Saving to", outfn, 'and', outfnx)
+        outfn_c = os.path.splitext(outfn)[0] + ".c"
+        print_("Saving to", outfn, 'and', outfn_c)
         with open(outfn, "w") as f:
             f.write(erfa_py)
-        with open(outfnx, "w") as f:
-            f.write(erfa_pyx)
+        with open(outfn_c, "w") as f:
+            f.write(erfa_c)
 
     print_("Done!")
 
-    return erfa_pyx, erfa_py, funcs
+    return erfa_c, erfa_py, funcs
 
 DEFAULT_ERFA_LOC = os.path.join(os.path.split(__file__)[0],
                                 '../../cextern/erfa')
@@ -455,11 +457,11 @@ def surround(a_list, pre, post):
                          'erfa: "{0}"'.format(DEFAULT_ERFA_LOC))
     ap.add_argument('-o', '--output', default='core.py',
                     help='The output filename.  This is the name for only the '
-                         'pure-python output, the Cython part will have the '
-                         'same name but with an "x" appended.')
+                         'pure-python output, the C part will have the '
+                         'same name but with a ".c" extension.')
     ap.add_argument('-t', '--template-loc',
                     default=DEFAULT_TEMPLATE_LOC,
-                    help='the location where the "erfa.pyx.templ" '
+                    help='the location where the "core.c.templ" '
                          'template can be found.')
     ap.add_argument('-q', '--quiet', action='store_false', dest='verbose',
                     help='Suppress output normally printed to stdout.')

astropy/_erfa/setup_package.py

@@ -16,9 +16,9 @@
 
 SRC_FILES = glob.glob(os.path.join(ERFA_SRC, '*'))
 SRC_FILES += [os.path.join(ERFAPKGDIR, filename)
-              for filename in ['core.py.templ', 'core.pyx.templ', 'erfa_generator.py']]
+              for filename in ['core.py.templ', 'core.c.templ', 'erfa_generator.py']]
 
-GEN_FILES = [os.path.join(ERFAPKGDIR, 'core.py'), os.path.join(ERFAPKGDIR, 'core.pyx')]
+GEN_FILES = [os.path.join(ERFAPKGDIR, 'core.py'), os.path.join(ERFAPKGDIR, 'core.c')]
 
 def pre_build_py_hook(cmd_obj):
     preprocess_source()
@@ -35,7 +35,7 @@ def pre_sdist_hook(cmd_obj):
 def preprocess_source():
     # Generating the ERFA wrappers should only be done if needed. This also
     # ensures that it is not done for any release tarball since those will
-    # include core.py and core.pyx.
+    # include core.py and core.c.
     if all(os.path.exists(filename) for filename in GEN_FILES):
 
         # Determine modification times
@@ -65,7 +65,7 @@ def preprocess_source():
             import jinja2
         except:
             log.warn("WARNING: jinja2 could not be imported, so the existing "
-                     "ERFA core.py and core.pyx files will be used")
+                     "ERFA core.py and core.c files will be used")
             return
 
     name = 'erfa_generator'
@@ -86,7 +86,7 @@ def preprocess_source():
 
 
 def get_extensions():
-    sources = [os.path.join(ERFAPKGDIR, "core.pyx")]
+    sources = [os.path.join(ERFAPKGDIR, "core.c")]
     include_dirs = ['numpy']
     libraries = []
 
@@ -118,4 +118,4 @@ def requires_2to3():
 
 
 def get_package_data():
-    return {'astropy._erfa': ['core.py.templ', 'core.pyx.templ']}
+    return {'astropy._erfa': ['core.py.templ', 'core.c.templ']}