1 files changed, 93 insertions, 0 deletions
diff --git a/c/file_emulator.h b/c/file_emulator.h
new file mode 100644
index 0000000..82a34c0
--- /dev/null
+++ b/c/file_emulator.h
@@ -0,0 +1,93 @@
+
+/* Emulation of PyFile_Check() and PyFile_AsFile() for Python 3. */
+
+static PyObject *PyIOBase_TypeObj;
+
+static int init_file_emulator(void)
+{
+    if (PyIOBase_TypeObj == NULL) {
+        PyObject *io = PyImport_ImportModule("_io");
+        if (io == NULL)
+            return -1;
+        PyIOBase_TypeObj = PyObject_GetAttrString(io, "_IOBase");
+        if (PyIOBase_TypeObj == NULL)
+            return -1;
+    }
+    return 0;
+}
+
+
+#define PyFile_Check(p)  PyObject_IsInstance(p, PyIOBase_TypeObj)
+
+
+static void _close_file_capsule(PyObject *ob_capsule)
+{
+    FILE *f = (FILE *)PyCapsule_GetPointer(ob_capsule, "FILE");
+    if (f != NULL)
+        fclose(f);
+}
+
+
+static FILE *PyFile_AsFile(PyObject *ob_file)
+{
+    PyObject *ob, *ob_capsule = NULL, *ob_mode = NULL;
+    FILE *f;
+    int fd;
+    const char *mode;
+
+    ob = PyObject_CallMethod(ob_file, "flush", NULL);
+    if (ob == NULL)
+        goto fail;
+    Py_DECREF(ob);
+
+    ob_capsule = PyObject_GetAttrString(ob_file, "__cffi_FILE");
+    if (ob_capsule == NULL) {
+        PyErr_Clear();
+
+        fd = PyObject_AsFileDescriptor(ob_file);
+        if (fd < 0)
+            goto fail;
+
+        ob_mode = PyObject_GetAttrString(ob_file, "mode");
+        if (ob_mode == NULL)
+            goto fail;
+        mode = PyText_AsUTF8(ob_mode);
+        if (mode == NULL)
+            goto fail;
+
+        fd = dup(fd);
+        if (fd < 0) {
+            PyErr_SetFromErrno(PyExc_OSError);
+            goto fail;
+        }
+
+        f = fdopen(fd, mode);
+        if (f == NULL) {
+            close(fd);
+            PyErr_SetFromErrno(PyExc_OSError);
+            goto fail;
+        }
+        setbuf(f, NULL);    /* non-buffered */
+        Py_DECREF(ob_mode);
+        ob_mode = NULL;
+
+        ob_capsule = PyCapsule_New(f, "FILE", _close_file_capsule);
+        if (ob_capsule == NULL) {
+            fclose(f);
+            goto fail;
+        }
+
+        if (PyObject_SetAttrString(ob_file, "__cffi_FILE", ob_capsule) < 0)
+            goto fail;
+    }
+    else {
+        f = PyCapsule_GetPointer(ob_capsule, "FILE");
+    }
+    Py_DECREF(ob_capsule);   /* assumes still at least one reference */
+    return f;
+
+ fail:
+    Py_XDECREF(ob_mode);
+    Py_XDECREF(ob_capsule);
+    return NULL;
+}