Support building with MSVC

Fixes #7

### Motivation

The Python client cannot be built with MSVC.

### Modifications

Add `vcpkg.json` to download the Boost.Python dependency. Then fix some
CMake errors:
1. Boost.Python cannot be found on Windows. The component of Boost
   cannot be `python3`. It should be a specific version like
   `python310`.
2. Link to `pulsarWithDeps.lib` for MSVC and modify the compilation
   option from `/MD` to `/MT` when `LINK_STATIC` is `ON`.
3. When `LINK_STATIC` is `OFF` (by default), remove the suffix of the
   name because CMake will find the correct suffixes on different
   platforms.
4. Add the Python3 library to the target on Windows, otherwise the
   symbols cannot be found.

Since Python on Windows can only recognize `*.pyd` suffix of a C
extension, change the `CMAKE_SHARED_LIBRARY_SUFFIX` and use
`_pulsar.pyd` in `setup.py` on Windows.

Add README to tell users how to build Python client on Windows.

### TODO

Add a GitHub Actions workflow to verify the Windows build.

Author: BewareMyPower

.github/workflows/ci-pr-validation.yaml

@@ -67,6 +67,7 @@ jobs:
 
   linux-wheel:
     name: Wheel ${{matrix.image.name}} - Py ${{matrix.python.version}} - ${{matrix.cpu.platform}}
+    needs: unit-tests
     runs-on: ubuntu-22.04
     timeout-minutes: 300
 
@@ -118,6 +119,7 @@ jobs:
 
   mac-wheels:
     name: Wheel MacOS Universal2 - Py ${{matrix.py.version}}
+    needs: unit-tests
     runs-on: macos-12
     timeout-minutes: 300
 

.gitignore

@@ -13,4 +13,7 @@ __pycache__
 .pulsar-mac-wheels-cache
 .DS_Store
 wheelhouse
-.pulsar-mac-build
+.pulsar-mac-build
+vcpkg_installed/
+*.pyd
+*.lib

CMakeLists.txt

@@ -21,6 +21,11 @@ project (pulsar-client-python)
 cmake_minimum_required(VERSION 3.18)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake_modules")
 
+if (VCPKG_TRIPLET)
+    message(STATUS "Use vcpkg, triplet is ${VCPKG_TRIPLET}")
+    set(CMAKE_PREFIX_PATH "${CMAKE_SOURCE_DIR}/vcpkg_installed/${VCPKG_TRIPLET}" ${CMAKE_PREFIX_PATH})
+    message(STATUS "Use CMAKE_PREFIX_PATH: ${CMAKE_PREFIX_PATH}")
+endif ()
 option(LINK_STATIC "Link against static libraries" OFF)
 MESSAGE(STATUS "LINK_STATIC:  " ${LINK_STATIC})
 
@@ -29,10 +34,22 @@ set(THREADS_PREFER_PTHREAD_FLAG TRUE)
 find_package(Threads REQUIRED)
 MESSAGE(STATUS "Threads library: " ${CMAKE_THREAD_LIBS_INIT})
 
+if (MSVC)
+    add_compile_options(/wd4819)
+endif ()
+
 if (LINK_STATIC)
-    find_library(PULSAR_LIBRARY NAMES libpulsar.a)
+    if (MSVC)
+        find_library(PULSAR_LIBRARY NAMES pulsarWithDeps.lib)
+        string(REGEX REPLACE "/MD" "/MT" CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
+        string(REGEX REPLACE "/MD" "/MT" CMAKE_CXX_FLAGS_RELEASE ${CMAKE_CXX_FLAGS_RELEASE})
+        string(REGEX REPLACE "/MD" "/MT" CMAKE_CXX_FLAGS_RELWITHDEBINFO ${CMAKE_CXX_FLAGS_RELWITHDEBINFO})
+    else ()
+        find_library(PULSAR_LIBRARY NAMES libpulsar.a)
+    endif ()
+    add_definitions("-DPULSAR_STATIC")
 else()
-    find_library(PULSAR_LIBRARY NAMES libpulsar.so  libpulsar.dylib)
+    find_library(PULSAR_LIBRARY NAMES pulsar libpulsar)
 endif()
 message(STATUS "PULSAR_LIBRARY: ${PULSAR_LIBRARY}")
 
@@ -44,10 +61,29 @@ SET(CMAKE_CXX_STANDARD 11)
 find_package (Python3 REQUIRED COMPONENTS Development.Module)
 MESSAGE(STATUS "PYTHON: " ${Python3_VERSION} " - " ${Python3_INCLUDE_DIRS})
 
+find_package(Boost REQUIRED ${Boost_INCLUDE_DIRS})
+message(STATUS "Boost_INCLUDE_DIRS: ${Boost_INCLUDE_DIRS}")
+
 SET(Boost_USE_STATIC_LIBS   ${LINK_STATIC})
-find_package(Boost REQUIRED COMPONENTS python3)
-MESSAGE(STATUS "Boost Python3: " ${Boost_PYTHON3_LIBRARY})
-MESSAGE(STATUS "Boost_INCLUDE_DIRS: ${Boost_INCLUDE_DIRS}")
+
+set(BOOST_PYTHON_NAME_LIST python3 python310 python39 python38 python37)
+foreach (BOOST_PYTHON_NAME IN LISTS BOOST_PYTHON_NAME_LIST)
+    find_package(Boost QUIET COMPONENTS ${BOOST_PYTHON_NAME})
+    if (${Boost_FOUND})
+        set(BOOST_PYTHON_NAME_FOUND ${BOOST_PYTHON_NAME})
+        message(STATUS "Found Boost COMPONENTS " ${BOOST_PYTHON_NAME_FOUND})
+        break ()
+    endif ()
+endforeach ()
+if (NOT BOOST_PYTHON_NAME_FOUND)
+    message(FATAL_ERROR "Could not find Boost Python library")
+endif ()
+find_package(Boost REQUIRED COMPONENTS ${BOOST_PYTHON_NAME_FOUND})
+set(Boost_PYTHON3_LIBRARIES
+    ${Boost_PYTHON3_LIBRARY}
+    ${Boost_PYTHON310_LIBRARY}
+    )
+MESSAGE(STATUS "Boost Python3: " ${Boost_PYTHON3_LIBRARIES})
 
 ########################################################################################################################
 
@@ -68,8 +104,11 @@ ADD_LIBRARY(_pulsar SHARED src/pulsar.cc
                            src/utils.cc
         )
 
-SET(CMAKE_SHARED_LIBRARY_PREFIX )
-SET(CMAKE_SHARED_LIBRARY_SUFFIX .so)
+if (MSVC)
+    set(CMAKE_SHARED_LIBRARY_SUFFIX .pyd)
+else ()
+    set(CMAKE_SHARED_LIBRARY_SUFFIX .so)
+endif ()
 
 if (NOT APPLE AND NOT MSVC)
     SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS_PYTHON}")
@@ -80,12 +119,17 @@ if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
 endif()
 
 # Try all possible boost-python variable namings
-set(PYTHON_WRAPPER_LIBS ${PULSAR_LIBRARY}
-                        ${Boost_PYTHON3_LIBRARY})
+set(PYTHON_WRAPPER_LIBS
+    ${PULSAR_LIBRARY}
+    ${Boost_PYTHON3_LIBRARIES})
+if (MSVC)
+    message(STATUS "Python3_LIBRARIES: " ${Python3_LIBRARIES})
+    set(PYTHON_WRAPPER_LIBS ${PYTHON_WRAPPER_LIBS} ${Python3_LIBRARIES})
+endif ()
 
 message(STATUS "All libraries: ${PYTHON_WRAPPER_LIBS}")
 
-if (LINK_STATIC)
+if (LINK_STATIC AND NOT MSVC)
     set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
 
     # We need to include all the static libs individually because we cannot easily create a universal2 libpulsar.a
@@ -128,6 +172,7 @@ if (LINK_STATIC)
 else()
     target_link_libraries(_pulsar ${PYTHON_WRAPPER_LIBS})
 endif ()
+install(TARGETS _pulsar DESTINATION ${CMAKE_SOURCE_DIR})
 
 find_package(ClangTools)
 set(BUILD_SUPPORT_DIR "${CMAKE_SOURCE_DIR}/build-support")

README.md

@@ -31,20 +31,48 @@
 
 ## Install the Python wheel
 
+### Windows (with Vcpkg)
+
+First, install the dependencies via [Vcpkg](https://github.com/microsoft/vcpkg).
+
+```PowerShell
+vcpkg install --feature-flags=manifests --triplet x64-windows
+```
+
+> NOTE: For Windows 32-bit library, change `x64-windows` to `x86-windows`, see [here](https://github.com/microsoft/vcpkg/tree/master/triplets) for all available triplets.
+
+Then, build and install the Python wheel.
+
+```PowerShell
+# Assuming the Pulsar C++ client has been installed under the `PULSAR_CPP` directory.
+cmake -B build -DVCPKG_TRIPLET=x64-windows -DCMAKE_PREFIX_PATH="$env:PULSAR_CPP" -DLINK_STATIC=ON
+cmake --build build --config Release
+cmake --install build
+py setup.py bdist_wheel
+py -m pip install ./dist/pulsar_client-*.whl
+```
+
+Since the Python client links to Boost.Python dynamically, you have to copy the dll (e.g. `boost_python310-vc142-mt-x64-1_80.dll`) into the system path (the `PATH` environment variable). If the `-DLINK_STATIC=ON` option is not specified, you have to copy the `pulsar.dll` into the system path as well.
+
+### Linux or macOS
+
+Assuming the Pulsar C++ client and Boost.Python have been installed under the system path.
+
 ```bash
 cmake -B build
 cmake --build build -j8
-cp build/_pulsar.so .
+cmake --install build
 ./setup.py bdist_wheel
 pip3 install dist/pulsar_client-*.whl --force-reinstall
-rm _pulsar.so
 ```
 
 > **NOTE**
 >
 > 1. Here a separate `build` directory is created to store all CMake temporary files. However, the `setup.py` requires the `_pulsar.so` is under the project directory.
 > 2. Add the `--force-reinstall` option to overwrite the existing Python wheel in case your system has already installed a wheel before.
 
+## Running examples
+
 You can run `python3 -c 'import pulsar'` to see whether the wheel has been installed successfully. If it failed, check whether dependencies (e.g. `libpulsar.so`) are in the system path. If not, make sure the dependencies are in `LD_LIBRARY_PATH` (on Linux) or `DYLD_LIBRARY_PATH` (on macOS).
 
 Then you can run examples as a simple end-to-end test.

setup.py

@@ -21,6 +21,7 @@
 from setuptools import setup
 from distutils.core import Extension
 from os import environ, path
+import platform
 
 from distutils.command import build_ext
 
@@ -58,7 +59,13 @@ def build_extension(self, ext):
         except OSError as e:
             if e.errno != 17:  # already exists
                 raise
-        shutil.copyfile('_pulsar.so', self.get_ext_fullpath(ext.name))
+        if 'Windows' in platform.platform():
+            shutil.copyfile('_pulsar.pyd', self.get_ext_fullpath(ext.name))
+        else:
+            try:
+                shutil.copyfile('_pulsar.so', self.get_ext_fullpath(ext.name))
+            except FileNotFoundError:
+                shutil.copyfile('lib_pulsar.so', self.get_ext_fullpath(ext.name))
 
 
 # Core Client dependencies

vcpkg.json

@@ -0,0 +1,8 @@
+{
+  "name": "pulsar-python",
+  "version": "3.0.0",
+  "description": "Pulsar Python SDK",
+  "dependencies": [
+    "boost-python"
+  ]
+}