Move the codec decode type checks to bytes/bytearray.decode().

Use faster PyUnicode_FromEncodedObject() for bytes/bytearray.decode().

Add new PyCodec_KnownEncoding() API.

Add new PyUnicode_AsDecodedUnicode() and PyUnicode_AsEncodedUnicode() APIs.

Add missing PyUnicode_AsDecodedObject() to unicodeobject.h

Fix punicode codec to also work on memoryviews.

Include/codecs.h

@@ -27,7 +27,7 @@ PyAPI_FUNC(int) PyCodec_Register(
        PyObject *search_function
        );
 
-/* Codec register lookup API.
+/* Codec registry lookup API.
 
    Looks up the given encoding and returns a CodecInfo object with
    function attributes which implement the different aspects of
@@ -49,6 +49,17 @@ PyAPI_FUNC(PyObject *) _PyCodec_Lookup(
        const char *encoding
        );
 
+/* Codec registry encoding check API.
+
+   Returns 1/0 depending on whether there is a registered codec for
+   the given encoding.
+
+*/
+
+PyAPI_FUNC(int) PyCodec_KnownEncoding(
+       const char *encoding
+       );
+
 /* Generic codec based encoding API.
 
    object is passed through the encoder function found for the given

Include/unicodeobject.h

@@ -139,8 +139,11 @@ typedef PY_UNICODE_TYPE Py_UNICODE;
 
 # define PyUnicode_AsASCIIString PyUnicodeUCS2_AsASCIIString
 # define PyUnicode_AsCharmapString PyUnicodeUCS2_AsCharmapString
+# define PyUnicode_AsDecodedObject PyUnicodeUCS2_AsDecodedObject
+# define PyUnicode_AsDecodedUnicode PyUnicodeUCS2_AsDecodedUnicode
 # define PyUnicode_AsEncodedObject PyUnicodeUCS2_AsEncodedObject
 # define PyUnicode_AsEncodedString PyUnicodeUCS2_AsEncodedString
+# define PyUnicode_AsEncodedUnicode PyUnicodeUCS2_AsEncodedUnicode
 # define PyUnicode_AsLatin1String PyUnicodeUCS2_AsLatin1String
 # define PyUnicode_AsRawUnicodeEscapeString PyUnicodeUCS2_AsRawUnicodeEscapeString
 # define PyUnicode_AsUTF32String PyUnicodeUCS2_AsUTF32String
@@ -233,8 +236,11 @@ typedef PY_UNICODE_TYPE Py_UNICODE;
 
 # define PyUnicode_AsASCIIString PyUnicodeUCS4_AsASCIIString
 # define PyUnicode_AsCharmapString PyUnicodeUCS4_AsCharmapString
+# define PyUnicode_AsDecodedObject PyUnicodeUCS4_AsDecodedObject
+# define PyUnicode_AsDecodedUnicode PyUnicodeUCS4_AsDecodedUnicode
 # define PyUnicode_AsEncodedObject PyUnicodeUCS4_AsEncodedObject
 # define PyUnicode_AsEncodedString PyUnicodeUCS4_AsEncodedString
+# define PyUnicode_AsEncodedUnicode PyUnicodeUCS4_AsEncodedUnicode
 # define PyUnicode_AsLatin1String PyUnicodeUCS4_AsLatin1String
 # define PyUnicode_AsRawUnicodeEscapeString PyUnicodeUCS4_AsRawUnicodeEscapeString
 # define PyUnicode_AsUTF32String PyUnicodeUCS4_AsUTF32String
@@ -744,6 +750,24 @@ PyAPI_FUNC(PyObject*) PyUnicode_Decode(
     const char *errors          /* error handling */
     );
 
+/* Decode a Unicode object unicode and return the result as Python
+   object. */
+
+PyAPI_FUNC(PyObject*) PyUnicode_AsDecodedObject(
+    PyObject *unicode,	 	/* Unicode object */
+    const char *encoding,	/* encoding */
+    const char *errors		/* error handling */
+    );
+
+/* Decode a Unicode object unicode and return the result as Unicode
+   object. */
+
+PyAPI_FUNC(PyObject*) PyUnicode_AsDecodedUnicode(
+    PyObject *unicode,	 	/* Unicode object */
+    const char *encoding,	/* encoding */
+    const char *errors		/* error handling */
+    );
+
 /* Encodes a Py_UNICODE buffer of the given size and returns a 
    Python string object. */
 
@@ -772,11 +796,21 @@ PyAPI_FUNC(PyObject*) PyUnicode_AsEncodedString(
     const char *errors		/* error handling */
     );
 
+/* Encodes a Unicode object and returns the result as Unicode
+   object. */
+
+PyAPI_FUNC(PyObject*) PyUnicode_AsEncodedUnicode(
+    PyObject *unicode,	 	/* Unicode object */
+    const char *encoding,	/* encoding */
+    const char *errors		/* error handling */
+    );
+
+/* Build an encoding map. */
+
 PyAPI_FUNC(PyObject*) PyUnicode_BuildEncodingMap(
     PyObject* string            /* 256 character map */
    );
 
-
 /* --- UTF-7 Codecs ------------------------------------------------------- */
 
 PyAPI_FUNC(PyObject*) PyUnicode_DecodeUTF7(

Lib/encodings/punycode.py

@@ -183,6 +183,8 @@ def insertion_sort(base, extended, errors):
 def punycode_decode(text, errors):
     if isinstance(text, str):
         text = text.encode("ascii")
+    if isinstance(text, memoryview):
+        text = bytes(text)
     pos = text.rfind(b"-")
     if pos == -1:
         base = ""

Objects/bytearrayobject.c

@@ -725,7 +725,7 @@ bytes_init(PyByteArrayObject *self, PyObject *args, PyObject *kwds)
                             "string argument without an encoding");
             return -1;
         }
-        encoded = PyCodec_Encode(arg, encoding, errors);
+        encoded = PyUnicode_AsEncodedString(arg, encoding, errors);
         if (encoded == NULL)
             return -1;
         assert(PyBytes_Check(encoded));
@@ -2854,7 +2854,7 @@ bytes_decode(PyObject *self, PyObject *args)
         return NULL;
     if (encoding == NULL)
         encoding = PyUnicode_GetDefaultEncoding();
-    return PyCodec_Decode(self, encoding, errors);
+    return PyUnicode_FromEncodedObject(self, encoding, errors);
 }
 
 PyDoc_STRVAR(alloc_doc,

Objects/bytesobject.c

@@ -2713,7 +2713,7 @@ string_decode(PyObject *self, PyObject *args)
 		return NULL;
 	if (encoding == NULL)
 		encoding = PyUnicode_GetDefaultEncoding();
-	return PyCodec_Decode(self, encoding, errors);
+	return PyUnicode_FromEncodedObject(self, encoding, errors);
 }
 
 
@@ -2899,7 +2899,7 @@ string_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 					"string argument without an encoding");
 			return NULL;
 		}
-		new = PyCodec_Encode(x, encoding, errors);
+		new = PyUnicode_AsEncodedString(x, encoding, errors);
 		if (new == NULL)
 			return NULL;
 		assert(PyBytes_Check(new));

Objects/unicodeobject.c

@@ -1099,14 +1099,18 @@ PyObject *PyUnicode_FromEncodedObject(register PyObject *obj,
 
     /* Coerce object */
     if (PyBytes_Check(obj)) {
-	    s = PyBytes_AS_STRING(obj);
-	    len = PyBytes_GET_SIZE(obj);
-	    }
+        s = PyBytes_AS_STRING(obj);
+        len = PyBytes_GET_SIZE(obj);
+    }
+    else if (PyByteArray_Check(obj)) {
+        s = PyByteArray_AS_STRING(obj);
+        len = PyByteArray_GET_SIZE(obj);
+    }
     else if (PyObject_AsCharBuffer(obj, &s, &len)) {
 	/* Overwrite the error message with something more useful in
 	   case of a TypeError. */
 	if (PyErr_ExceptionMatches(PyExc_TypeError))
-	PyErr_Format(PyExc_TypeError,
+            PyErr_Format(PyExc_TypeError,
 			 "coercing to Unicode: need string or buffer, "
 			 "%.80s found",
 		     Py_TYPE(obj)->tp_name);
@@ -1188,7 +1192,7 @@ PyObject *PyUnicode_Decode(const char *s,
         goto onError;
     if (!PyUnicode_Check(unicode)) {
         PyErr_Format(PyExc_TypeError,
-                     "decoder did not return an unicode object (type=%.400s)",
+                     "decoder did not return a unicode object (type=%.400s)",
                      Py_TYPE(unicode)->tp_name);
         Py_DECREF(unicode);
         goto onError;
@@ -1225,6 +1229,37 @@ PyObject *PyUnicode_AsDecodedObject(PyObject *unicode,
     return NULL;
 }
 
+PyObject *PyUnicode_AsDecodedUnicode(PyObject *unicode,
+                                     const char *encoding,
+                                     const char *errors)
+{
+    PyObject *v;
+
+    if (!PyUnicode_Check(unicode)) {
+        PyErr_BadArgument();
+        goto onError;
+    }
+
+    if (encoding == NULL)
+	encoding = PyUnicode_GetDefaultEncoding();
+
+    /* Decode via the codec registry */
+    v = PyCodec_Decode(unicode, encoding, errors);
+    if (v == NULL)
+        goto onError;
+    if (!PyUnicode_Check(v)) {
+        PyErr_Format(PyExc_TypeError,
+                     "decoder did not return a unicode object (type=%.400s)",
+                     Py_TYPE(v)->tp_name);
+        Py_DECREF(v);
+        goto onError;
+    }
+    return v;
+
+ onError:
+    return NULL;
+}
+
 PyObject *PyUnicode_Encode(const Py_UNICODE *s,
 			   Py_ssize_t size,
 			   const char *encoding,
@@ -1296,7 +1331,54 @@ PyObject *PyUnicode_AsEncodedString(PyObject *unicode,
     v = PyCodec_Encode(unicode, encoding, errors);
     if (v == NULL)
         goto onError;
-    assert(PyBytes_Check(v));
+    if (PyByteArray_Check(v)) {
+        char msg[100];
+        PyOS_snprintf(msg, sizeof(msg),
+                      "encoder %s returned buffer instead of bytes",
+                      encoding);
+        if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0) {
+            v = NULL;
+            goto onError;
+        }
+        v = PyBytes_FromStringAndSize(PyByteArray_AS_STRING(v), Py_SIZE(v));
+    }
+    else if (!PyBytes_Check(v)) {
+        PyErr_Format(PyExc_TypeError,
+                     "encoder did not return a bytes object (type=%.400s)",
+                     Py_TYPE(v)->tp_name);
+        v = NULL;
+    }
+    return v;
+
+ onError:
+    return NULL;
+}
+
+PyObject *PyUnicode_AsEncodedUnicode(PyObject *unicode,
+                                     const char *encoding,
+                                     const char *errors)
+{
+    PyObject *v;
+
+    if (!PyUnicode_Check(unicode)) {
+        PyErr_BadArgument();
+        goto onError;
+    }
+
+    if (encoding == NULL)
+	encoding = PyUnicode_GetDefaultEncoding();
+
+    /* Encode via the codec registry */
+    v = PyCodec_Encode(unicode, encoding, errors);
+    if (v == NULL)
+        goto onError;
+    if (!PyUnicode_Check(v)) {
+        PyErr_Format(PyExc_TypeError,
+                     "encoder did not return an unicode object (type=%.400s)",
+                     Py_TYPE(v)->tp_name);
+        Py_DECREF(v);
+        goto onError;
+    }
     return v;
 
  onError:
@@ -6617,7 +6699,7 @@ unicode_encode(PyUnicodeObject *self, PyObject *args)
 
     if (!PyArg_ParseTuple(args, "|ss:encode", &encoding, &errors))
         return NULL;
-    v = PyUnicode_AsEncodedObject((PyObject *)self, encoding, errors);
+    v = PyUnicode_AsEncodedString((PyObject *)self, encoding, errors);
     if (v == NULL)
         goto onError;
     if (!PyBytes_Check(v)) {

Python/codecs.c

@@ -183,6 +183,23 @@ PyObject *_PyCodec_Lookup(const char *encoding)
     return NULL;
 }
 
+/* Codec registry encoding check API. */
+
+int PyCodec_KnownEncoding(const char *encoding)
+{
+    PyObject *codecs;
+
+    codecs = _PyCodec_Lookup(encoding);
+    if (!codecs) {
+	PyErr_Clear();
+	return 0;
+    }
+    else {
+	Py_DECREF(codecs);
+	return 1;
+    }
+}
+
 static
 PyObject *args_tuple(PyObject *object,
 		     const char *errors)
@@ -344,32 +361,20 @@ PyObject *PyCodec_Encode(PyObject *object,
 			"encoder must return a tuple (object, integer)");
 	goto onError;
     }
-    v = PyTuple_GET_ITEM(result, 0);
-    if (PyByteArray_Check(v)) {
-        char msg[100];
-        PyOS_snprintf(msg, sizeof(msg),
-                      "encoder %s returned buffer instead of bytes",
-                      encoding);
-        if (PyErr_WarnEx(PyExc_RuntimeWarning, msg, 1) < 0) {
-            v = NULL;
-            goto onError;
-        }
-        v = PyBytes_FromStringAndSize(PyByteArray_AS_STRING(v), Py_SIZE(v));
-    }
-    else if (PyBytes_Check(v))
-        Py_INCREF(v);
-    else {
-        PyErr_SetString(PyExc_TypeError,
-                        "encoding must return a tuple(bytes, integer)");
-        v = NULL;
-    }
+    v = PyTuple_GET_ITEM(result,0);
+    Py_INCREF(v);
     /* We don't check or use the second (integer) entry. */
 
+    Py_DECREF(args);
+    Py_DECREF(encoder);
+    Py_DECREF(result);
+    return v;
+
  onError:
     Py_XDECREF(result);
     Py_XDECREF(args);
     Py_XDECREF(encoder);
-    return v;
+    return NULL;
 }
 
 /* Decode an object (usually a Python string) using the given encoding

Python/pythonrun.c

@@ -261,14 +261,10 @@ Py_InitializeEx(int install_sigs)
 
 	codeset = nl_langinfo(CODESET);
 	if (codeset && *codeset) {
-		PyObject *enc = PyCodec_Encoder(codeset);
-		if (enc) {
-			codeset = strdup(codeset);
-			Py_DECREF(enc);
-		} else {
-			codeset = NULL;
-			PyErr_Clear();
-		}
+	    if (PyCodec_KnownEncoding(codeset))
+		codeset = strdup(codeset);
+	    else
+		codeset = NULL;
 	} else
 		codeset = NULL;