Python WAMR API binding: Add malloc/free and register_native (#1989)

language-bindings/python/setup.py

@@ -9,9 +9,10 @@
 # pylint: disable=missing-module-docstring
 
 import pathlib
-from setuptools import setup
+from setuptools import setup, find_packages
 from setuptools.command.develop import develop
 from setuptools.command.install import install
+from setuptools.command.egg_info import egg_info
 from subprocess import check_call
 
 
@@ -19,19 +20,25 @@ def build_library():
     cur_path = pathlib.Path(__file__).parent
     check_call(f"{cur_path}/utils/create_lib.sh".split())
 
+
 class PreDevelopCommand(develop):
-    """Pre-installation for development mode."""
     def run(self):
         build_library()
         develop.run(self)
 
+
 class PreInstallCommand(install):
-    """Pre-installation for installation mode."""
     def run(self):
         build_library()
         install.run(self)
 
 
+class PreEggInfoCommand(egg_info):
+    def run(self):
+        build_library()
+        egg_info.run(self)
+
+
 with open("README.md") as f:
     readme = f.read()
 
@@ -43,6 +50,8 @@ setup(
     version="0.1.0",
     description="A WebAssembly runtime powered by WAMR",
     long_description=readme,
+    packages=find_packages(where="src"),
+    package_dir={"": "src"},
     author="The WAMR Project Developers",
     author_email="hello@bytecodealliance.org",
     url="https://github.com/bytecodealliance/wasm-micro-runtime",
@@ -51,5 +60,6 @@ setup(
     cmdclass={
         'develop': PreDevelopCommand,
         'install': PreInstallCommand,
+        'egg_info': PreEggInfoCommand,
     },
 )

language-bindings/python/src/wamr/wamrapi/wamr.py

@@ -10,7 +10,7 @@ from ctypes import cast
 from ctypes import create_string_buffer
 from ctypes import POINTER
 from ctypes import pointer
-
+from wamr.wamrapi.iwasm import String
 from wamr.wamrapi.iwasm import Alloc_With_Pool
 from wamr.wamrapi.iwasm import RuntimeInitArgs
 from wamr.wamrapi.iwasm import wasm_exec_env_t
@@ -27,10 +27,15 @@ from wamr.wamrapi.iwasm import wasm_runtime_instantiate
 from wamr.wamrapi.iwasm import wasm_runtime_load
 from wamr.wamrapi.iwasm import wasm_runtime_lookup_function
 from wamr.wamrapi.iwasm import wasm_runtime_unload
+from wamr.wamrapi.iwasm import wasm_runtime_module_malloc
+from wamr.wamrapi.iwasm import wasm_runtime_module_free
+from wamr.wamrapi.iwasm import wasm_runtime_register_natives
+from wamr.wamrapi.iwasm import NativeSymbol
 
 
 class Engine:
     def __init__(self):
+        self._native_symbols = dict()
         self.init_args = self._get_init_args()
         wasm_runtime_full_init(pointer(self.init_args))
 
@@ -47,6 +52,21 @@ class Engine:
         init_args.mem_alloc_option.pool.heap_size = heap_size
         return init_args
 
+    def register_natives(self, module_name: str, native_symbols: list[NativeSymbol]) -> None:
+        module_name = String.from_param(module_name)
+        # WAMR does not copy the symbols. We must store them.
+        for native in native_symbols:
+            self._native_symbols[str(native.symbol)] = (module_name, native)
+
+        if not wasm_runtime_register_natives(
+            module_name,
+            cast(
+                (NativeSymbol * len(native_symbols))(*native_symbols),
+                POINTER(NativeSymbol)
+            ),
+            len(native_symbols)
+        ):
+            raise Exception("Error while registering symbols")
 
 class Module:
     __create_key = object()
@@ -87,7 +107,13 @@ class Instance:
         print("deleting Instance")
         wasm_runtime_deinstantiate(self.module_inst)
 
-    def lookup_function(self, name: str):
+    def malloc(self, nbytes: int, native_handler) -> c_uint:
+        return wasm_runtime_module_malloc(self.module_inst, nbytes, native_handler)
+
+    def free(self, wasm_handler) -> None:
+        wasm_runtime_module_free(self.module_inst, wasm_handler)
+
+    def lookup_function(self, name: str) -> wasm_function_inst_t:
         func = wasm_runtime_lookup_function(self.module_inst, name, None)
         if not func:
             raise Exception("Error while looking-up function")

language-bindings/python/wamr-api/README.md

@@ -1,25 +1,29 @@
 # WARM API
 
-## Examples
+## Setup
 
-Copy in `language-bindings/python/wamr/libs` the library `libiwasm` generated from `product-mini/platforms`.
+### Pre-requisites
 
-There is a [simple example](./samples/main.py) to show how to use bindings.
+Install requirements,
 
 ```
-python samples/main.py
+pip install -r requirements.txt
 ```
 
-## Update WAMR API bindings
+### Build native lib and update bindings
 
-Install requirements,
+The following command builds the iwasm library and generates the Python bindings,
 
-```
-pip install -r requirements.txt
+```sh
+bash language-bindings/python/utils/create_lib.sh
 ```
 
-Run the following command,
+This will build and copy libiwasm into the package.
 
-```sh
-ctypesgen ../../../../core/iwasm/include/wasm_export.h -l ../libs/libiwasm.so -o iwasm.py
+## Examples
+
+There is a [simple example](./samples/main.py) to show how to use bindings.
+
+```
+python samples/main.py
 ```