Drop Python 2 support from _cmsgpack (#376)

.travis.yml

@@ -6,7 +6,6 @@ python:
   # Available Python (PyPy) can be listed by:
   #
   #   $ aws s3 ls s3://travis-python-archives/binaries/ubuntu/16.04/x86_64/
-  - "2.7"
   - "3.4"
   - "3.5"
   - "3.6"
@@ -41,7 +40,14 @@ matrix:
         - pip install -e .
       script:
         - pytest -v test
-
+    - name: "Python 2 (fallback)"
+      python: "2.7"
+      install:
+        - pip install -U pip
+        - pip install -U pytest
+        - pip install .
+      script:
+        - pytest -v test
 
 install:
   - pip install -U pip

README.rst

@@ -76,10 +76,18 @@ Install
 
    $ pip install msgpack
 
-PyPy
-^^^^
+Pure Python implementation
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The extension module in msgpack (``msgpack._cmsgpack``) does not support
+Python 2 and PyPy.
+
+But msgpack provides a pure Python implementation (``msgpack.fallback``)
+for PyPy and Python 2.
+
+Since the [pip](https://pip.pypa.io/) uses the pure Python implementation,
+Python 2 support will not be dropped in foreseeable feature.
 
-msgpack provides a pure Python implementation.  PyPy can use this.
 
 Windows
 ^^^^^^^
@@ -88,12 +96,6 @@ When you can't use a binary distribution, you need to install Visual Studio
 or Windows SDK on Windows.
 Without extension, using pure Python implementation on CPython runs slowly.
 
-For Python 2.7, `Microsoft Visual C++ Compiler for Python 2.7 <https://www.microsoft.com/en-us/download/details.aspx?id=44266>`_
-is recommended solution.
-
-For Python 3.5, `Microsoft Visual Studio 2015 <https://www.visualstudio.com/en-us/products/vs-2015-product-editions.aspx>`_
-Community Edition or Express Edition can be used to build extension module.
-
 
 How to use
 ----------

docker/shared.env

@@ -3,6 +3,4 @@ PYTHON_VERSIONS=(
     cp37-cp37m
     cp36-cp36m
     cp35-cp35m
-    cp27-cp27m
-    cp27-cp27mu
 )

msgpack/__init__.py

@@ -2,6 +2,8 @@
 from ._version import version
 from .exceptions import *
 
+import os
+import sys
 from collections import namedtuple
 
 
@@ -17,8 +19,7 @@ class ExtType(namedtuple('ExtType', 'code data')):
         return super(ExtType, cls).__new__(cls, code, data)
 
 
-import os
-if os.environ.get('MSGPACK_PUREPYTHON'):
+if os.environ.get('MSGPACK_PUREPYTHON') or sys.version_info[0] == 2:
     from .fallback import Packer, unpackb, Unpacker
 else:
     try:

msgpack/_packer.pyx

@@ -130,10 +130,7 @@ cdef class Packer(object):
 
         self._bencoding = encoding
         if encoding is None:
-            if PY_MAJOR_VERSION < 3:
             self.encoding = 'utf-8'
-            else:
-                self.encoding = NULL
         else:
             self.encoding = self._bencoding
 

msgpack/buff_converter.h

@@ -1,28 +1,8 @@
 #include "Python.h"
 
 /* cython does not support this preprocessor check => write it in raw C */
-#if PY_MAJOR_VERSION == 2
-static PyObject *
-buff_to_buff(char *buff, Py_ssize_t size)
-{
-    return PyBuffer_FromMemory(buff, size);
-}
-
-#elif (PY_MAJOR_VERSION == 3) && (PY_MINOR_VERSION >= 3)
 static PyObject *
 buff_to_buff(char *buff, Py_ssize_t size)
 {
     return PyMemoryView_FromMemory(buff, size, PyBUF_READ);
 }
-#else
-static PyObject *
-buff_to_buff(char *buff, Py_ssize_t size)
-{
-    Py_buffer pybuf;
-    if (PyBuffer_FillInfo(&pybuf, NULL, buff, size, 1, PyBUF_FULL_RO) == -1) {
-        return NULL;
-    }
-
-    return PyMemoryView_FromBuffer(&pybuf);
-}
-#endif

msgpack/fallback.py

@@ -5,13 +5,12 @@ import struct
 import warnings
 
 
-if sys.version_info[0] == 2:
-    PY2 = True
+PY2 = sys.version_info[0] == 2
+if PY2:
     int_types = (int, long)
     def dict_iteritems(d):
         return d.iteritems()
 else:
-    PY2 = False
     int_types = int
     unicode = str
     xrange = range

msgpack/unpack.h

@@ -273,11 +273,7 @@ static inline int unpack_callback_ext(unpack_user* u, const char* base, const ch
         return -1;
     }
     // length also includes the typecode, so the actual data is length-1
-#if PY_MAJOR_VERSION == 2
-    py = PyObject_CallFunction(u->ext_hook, "(is#)", (int)typecode, pos, (Py_ssize_t)length-1);
-#else
     py = PyObject_CallFunction(u->ext_hook, "(iy#)", (int)typecode, pos, (Py_ssize_t)length-1);
-#endif
     if (!py)
         return -1;
     *o = py;

setup.py

@@ -9,6 +9,11 @@ from setuptools import setup, Extension
 
 from distutils.command.build_ext import build_ext
 
+
+PYPY = hasattr(sys, "pypy_version_info")
+PY2 = sys.version_info[0] == 2
+
+
 # for building transitional package.
 TRANSITIONAL = False
 
@@ -64,14 +69,11 @@ version_str = '.'.join(str(x) for x in version[:3])
 if len(version) > 3 and version[3] != 'final':
     version_str += version[3]
 
-# take care of extension modules.
-if have_cython:
+# Cython is required for sdist
 class Sdist(sdist):
     def __init__(self, *args, **kwargs):
         cythonize('msgpack/_cmsgpack.pyx')
         sdist.__init__(self, *args, **kwargs)
-else:
-    Sdist = sdist
 
 libraries = []
 if sys.platform == 'win32':
@@ -83,7 +85,7 @@ else:
     macros = [('__LITTLE_ENDIAN__', '1')]
 
 ext_modules = []
-if not hasattr(sys, 'pypy_version_info'):
+if not PYPY and not PY2:
     ext_modules.append(Extension('msgpack._cmsgpack',
                                  sources=['msgpack/_cmsgpack.cpp'],
                                  libraries=libraries,