Use pybind11 in ttconv module

thomasjpfan · thomasjpfan · commit 8da08a7bd9f0 · 2023-02-22T22:21:47.000-05:00
diff --git a/setupext.py b/setupext.py
@@ -468,15 +468,15 @@ def get_extensions(self):
             cxx_std=11)
         yield ext
         # ttconv
-        ext = Extension(
+        ext = Pybind11Extension(
             "matplotlib._ttconv", [
                 "src/_ttconv.cpp",
                 "extern/ttconv/pprdrv_tt.cpp",
                 "extern/ttconv/pprdrv_tt2.cpp",
                 "extern/ttconv/ttutil.cpp",
             ],
-            include_dirs=["extern"])
-        add_numpy_flags(ext)
+            include_dirs=["extern"],
+            cxx_std=11)
         yield ext
 
 
diff --git a/src/_ttconv.cpp b/src/_ttconv.cpp
@@ -5,157 +5,79 @@
 
   Python wrapper for TrueType conversion library in ../ttconv.
  */
-#define PY_SSIZE_T_CLEAN
 #include "mplutils.h"
 
-#include <Python.h>
+#include <pybind11/pybind11.h>
 #include "ttconv/pprdrv.h"
-#include "py_exceptions.h"
 #include <vector>
-#include <cassert>
 
 /**
  * An implementation of TTStreamWriter that writes to a Python
  * file-like object.
  */
 class PythonFileWriter : public TTStreamWriter
 {
-    PyObject *_write_method;
+  pybind11::function _write_method;
 
   public:
-    PythonFileWriter()
-    {
-        _write_method = NULL;
-    }
-
-    ~PythonFileWriter()
-    {
-        Py_XDECREF(_write_method);
-    }
-
-    void set(PyObject *write_method)
-    {
-        Py_XDECREF(_write_method);
-        _write_method = write_method;
-        Py_XINCREF(_write_method);
-    }
+    PythonFileWriter(pybind11::object& file_object)
+    : _write_method(file_object.attr("write")) {}
 
     virtual void write(const char *a)
     {
-        PyObject *result = NULL;
-        if (_write_method) {
-            PyObject *decoded = NULL;
-            decoded = PyUnicode_DecodeLatin1(a, strlen(a), "");
-            if (decoded == NULL) {
-                throw py::exception();
-            }
-            result = PyObject_CallFunctionObjArgs(_write_method, decoded, NULL);
-            Py_DECREF(decoded);
-            if (!result) {
-                throw py::exception();
-            }
-            Py_DECREF(result);
+        PyObject* decoded = PyUnicode_DecodeLatin1(a, strlen(a), "");
+        if (decoded == NULL) {
+            throw pybind11::error_already_set();
         }
+        _write_method(pybind11::handle(decoded));
+        Py_DECREF(decoded);
     }
 };
 
-int fileobject_to_PythonFileWriter(PyObject *object, void *address)
+static void convert_ttf_to_ps(
+    const char *filename,
+    pybind11::object &output,
+    int fonttype,
+    pybind11::iterable* glyph_ids)
 {
-    PythonFileWriter *file_writer = (PythonFileWriter *)address;
-
-    PyObject *write_method = PyObject_GetAttrString(object, "write");
-    if (write_method == NULL || !PyCallable_Check(write_method)) {
-        PyErr_SetString(PyExc_TypeError, "Expected a file-like object with a write method.");
-        return 0;
-    }
+    PythonFileWriter output_(output);
 
-    file_writer->set(write_method);
-    Py_DECREF(write_method);
-
-    return 1;
-}
-
-int pyiterable_to_vector_int(PyObject *object, void *address)
-{
-    std::vector<int> *result = (std::vector<int> *)address;
-
-    PyObject *iterator = PyObject_GetIter(object);
-    if (!iterator) {
-        return 0;
-    }
-
-    PyObject *item;
-    while ((item = PyIter_Next(iterator))) {
-        long value = PyLong_AsLong(item);
-        Py_DECREF(item);
-        if (value == -1 && PyErr_Occurred()) {
-            return 0;
+    std::vector<int> glyph_ids_;
+    if (glyph_ids) {
+        for (pybind11::handle glyph_id: *glyph_ids) {
+            glyph_ids_.push_back(glyph_id.cast<int>());
         }
-        result->push_back((int)value);
     }
 
-    Py_DECREF(iterator);
-
-    return 1;
-}
-
-static PyObject *convert_ttf_to_ps(PyObject *self, PyObject *args, PyObject *kwds)
-{
-    const char *filename;
-    PythonFileWriter output;
-    int fonttype;
-    std::vector<int> glyph_ids;
-
-    static const char *kwlist[] = { "filename", "output", "fonttype", "glyph_ids", NULL };
-    if (!PyArg_ParseTupleAndKeywords(args,
-                                     kwds,
-                                     "yO&i|O&:convert_ttf_to_ps",
-                                     (char **)kwlist,
-                                     &filename,
-                                     fileobject_to_PythonFileWriter,
-                                     &output,
-                                     &fonttype,
-                                     pyiterable_to_vector_int,
-                                     &glyph_ids)) {
-        return NULL;
-    }
 
     if (fonttype != 3 && fonttype != 42) {
-        PyErr_SetString(PyExc_ValueError,
-                        "fonttype must be either 3 (raw Postscript) or 42 "
-                        "(embedded Truetype)");
-        return NULL;
+        throw pybind11::value_error(
+            "fonttype must be either 3 (raw Postscript) or 42 (embedded Truetype)");
     }
 
     try
     {
-        insert_ttfont(filename, output, (font_type_enum)fonttype, glyph_ids);
+        insert_ttfont(filename, output_, static_cast<font_type_enum>(fonttype), glyph_ids_);
     }
     catch (TTException &e)
     {
-        PyErr_SetString(PyExc_RuntimeError, e.getMessage());
-        return NULL;
-    }
-    catch (const py::exception &)
-    {
-        return NULL;
+        throw std::runtime_error(e.getMessage());
     }
     catch (...)
     {
-        PyErr_SetString(PyExc_RuntimeError, "Unknown C++ exception");
-        return NULL;
+        throw std::runtime_error("Unknown C++ exception");
     }
-
-    Py_INCREF(Py_None);
-    return Py_None;
 }
 
-static PyMethodDef ttconv_methods[] =
-{
-    {
-        "convert_ttf_to_ps", (PyCFunction)convert_ttf_to_ps, METH_VARARGS | METH_KEYWORDS,
-        "convert_ttf_to_ps(filename, output, fonttype, glyph_ids)\n"
-        "\n"
+PYBIND11_MODULE(_ttconv, m) {
+    m.doc() = "Module to handle converting and subsetting TrueType "
+              "fonts to Postscript Type 3, Postscript Type 42 and "
+              "Pdf Type 3 fonts.";
+    m.def("convert_ttf_to_ps", &convert_ttf_to_ps,
+        pybind11::arg("filename"),
+        pybind11::arg("output"),
+        pybind11::arg("fonttype"),
+        pybind11::arg("glyph_ids") = pybind11::none(),
         "Converts the Truetype font into a Type 3 or Type 42 Postscript font, "
         "optionally subsetting the font to only the desired set of characters.\n"
         "\n"
@@ -169,29 +91,5 @@ static PyMethodDef ttconv_methods[] =
         "subsetting to a Type 3 font.  If glyph_ids is not provided or is None, "
         "then all glyphs will be included.  If any of the glyphs specified are "
         "composite glyphs, then the component glyphs will also be included."
-    },
-    {0, 0, 0, 0}  /* Sentinel */
-};
-
-static const char *module_docstring =
-    "Module to handle converting and subsetting TrueType "
-    "fonts to Postscript Type 3, Postscript Type 42 and "
-    "Pdf Type 3 fonts.";
-
-static PyModuleDef ttconv_module = {
-    PyModuleDef_HEAD_INIT,
-    "ttconv",
-    module_docstring,
-    -1,
-    ttconv_methods,
-};
-
-#pragma GCC visibility push(default)
-
-PyMODINIT_FUNC
-PyInit__ttconv(void)
-{
-    return PyModule_Create(&ttconv_module);
+    );
 }
-
-#pragma GCC visibility pop
