Make patch release 4.1.1 (#555)

* Restore support for Python 3.8

* PyPy compatibility patch

* Load libtreelite.so with symbols visible globally

* Make 4.1.1 release

CMakeLists.txt

@@ -3,7 +3,7 @@ cmake_policy(SET CMP0091 NEW)
 set(CMAKE_FIND_NO_INSTALL_PREFIX TRUE FORCE)
 cmake_minimum_required(VERSION 3.16 FATAL_ERROR)
 
-project(treelite LANGUAGES CXX C VERSION 4.1.0)
+project(treelite LANGUAGES CXX C VERSION 4.1.1)
 
 # Check compiler versions
 # Use latest compilers to ensure that std::filesystem is available

python/pyproject.toml

@@ -7,7 +7,7 @@ build-backend = "packager.pep517"
 
 [project]
 name = "treelite"
-version = "4.1.0"
+version = "4.1.1"
 authors = [
     {name = "Hyunsu Cho", email = "[email protected]"}
 ]

python/treelite/VERSION

@@ -1 +1 @@
-4.1.0
+4.1.1

python/treelite/core.py

@@ -36,7 +36,7 @@ def _load_lib():
         os.add_dll_directory(
             os.path.join(os.path.normpath(sys.base_prefix), "Library", "bin")
         )
-    lib = ctypes.cdll.LoadLibrary(lib_path[0])
+    lib = ctypes.CDLL(lib_path[0], mode=ctypes.RTLD_GLOBAL)
     lib.TreeliteGetLastError.restype = ctypes.c_char_p
     lib.log_callback = _log_callback
     lib.warn_callback = _warn_callback

python/treelite/model.py

@@ -4,6 +4,7 @@
 
 import ctypes
 import pathlib
+import platform
 import warnings
 from typing import Any, List, Optional, Union
 
@@ -419,17 +420,20 @@ class _PyBuffer(ctypes.Structure):  # pylint: disable=R0902,R0903
     )
 
 
-ctypes.pythonapi.PyMemoryView_FromBuffer.argtypes = [ctypes.POINTER(_PyBuffer)]
-ctypes.pythonapi.PyMemoryView_FromBuffer.restype = ctypes.py_object
-ctypes.pythonapi.PyObject_GetBuffer.argtypes = [
-    ctypes.py_object,
-    ctypes.POINTER(_PyBuffer),
-    ctypes.c_int,
-]
-ctypes.pythonapi.PyObject_GetBuffer.restype = ctypes.c_int
+if platform.python_implementation() == "CPython":
+    ctypes.pythonapi.PyMemoryView_FromBuffer.argtypes = [ctypes.POINTER(_PyBuffer)]
+    ctypes.pythonapi.PyMemoryView_FromBuffer.restype = ctypes.py_object
+    ctypes.pythonapi.PyObject_GetBuffer.argtypes = [
+        ctypes.py_object,
+        ctypes.POINTER(_PyBuffer),
+        ctypes.c_int,
+    ]
+    ctypes.pythonapi.PyObject_GetBuffer.restype = ctypes.c_int
 
 
 def _pybuffer2numpy(frame: _TreelitePyBufferFrame) -> np.ndarray:
+    if platform.python_implementation() != "CPython":
+        raise NotImplementedError("_pybuffer2numpy() not supported on PyPy")
     if not frame.buf:
         if frame.format == b"=l":
             dtype = "int32"
@@ -466,6 +470,8 @@ def _pybuffer2numpy(frame: _TreelitePyBufferFrame) -> np.ndarray:
 
 
 def _numpy2pybuffer(array: np.ndarray) -> _TreelitePyBufferFrame:
+    if platform.python_implementation() != "CPython":
+        raise NotImplementedError("_numpy2pybuffer() not supported on PyPy")
     if len(array.shape) != 1:
         raise ValueError("Cannot handle NumPy array that has more than 1 dimension")
     view: memoryview = array.data
@@ -516,6 +522,8 @@ def get_field(self, name: str) -> Union[np.ndarray, str]:
             Value in the field
             (``str`` for a string field, ``np.ndarray`` for other fields)
         """
+        if platform.python_implementation() != "CPython":
+            raise NotImplementedError("get_field() not supported on PyPy")
         obj = _TreelitePyBufferFrame()
         _check_call(
             _LIB.TreeliteGetHeaderField(
@@ -542,6 +550,8 @@ def set_field(self, name: str, value: Union[np.ndarray, str]):
             New value for the field
             (``str`` for a string field, ``np.ndarray`` for other fields)
         """
+        if platform.python_implementation() != "CPython":
+            raise NotImplementedError("set_field() not supported on PyPy")
         if isinstance(value, str):
             value = np.frombuffer(value.encode("utf-8"), dtype="S1")
         _check_call(

python/treelite/model_builder.py

@@ -3,8 +3,7 @@
 import ctypes
 import dataclasses
 import json
-from collections.abc import Sequence
-from typing import Any, Dict, List, Optional, Tuple, Union
+from typing import Any, Dict, List, Optional, Sequence, Tuple, Union
 
 from .core import _LIB, _check_call
 from .model import Model