本项目是学习WebAssembly过程中做的example，本意是通过学习目前主流的wasm runtime，发现各家的优劣
选择的标准有
- 最少支持Wasm MVP
- 支持Wasi
- host env 支持golang或者nodejs
本项目包含了
- wasmtime
- wasmedge
- nodejs
- browser
WebAssembly front
- rust
- c
- Assemblyscript
本项目需要你对WebAssembly与WASI有基本的了解
为了比较尺度一致，所以想通过不同的frontend和不同的backend去实现相同的功能
本例子包含的webassembly知识点
- import host funtion
- moudle _start function
- export func to host runtime
- host runtime write wasm module momory
- host runtime传递字符串给wasm module
- wasm module 通过wasi32 调用系统接口
本例子包括以下过程
- import一个host function，
- export 一个wasm func 给到host runtime，让host runtime 调用这个export-function
- export-function里面会调用import的host function传递一个memory address给到host runtime，host runtime写一个字符串到memory
- webassembly 从momory里面读取字符串，并且打印到标准输出
- host runtime重定向标准输出到某个文件，然后打印文件里面的信息
Table of Contents generated with DocToc
- exmaple 说明
- Rust to WebAssembly module and embedded to wasmtime-go
- Rust to WebAssembly module and embedded to nodejs
- Rust to WebAssembly module and embedded to wasmedge-go
- Rust to WebAssembly module and embedded to browser
- C to webassembly module and embedded to wasmtime-go
- C to webassembly module and embedded to nodejs
- C to WebAssembly module and embedded to wasmedge-go
- C to webassembly module and embedded to browser
- Assemblyscript to WebAssembly module and embedded to node
安装cargo-wasi
cargo install cargo-wasi
build to wasm
cd rust-wasm
cargo wasi build
安装wabt
https://github.com/WebAssembly/wabt
wasm to wat
这不不是必须的，只是为了看wasm 文本格式，默认情况runtime是加载.wasm
wasm2wat target/wasm32-wasi/debug/hello_world.wasm -o target/wasm32-wasi/debug/hello_world.wat --generate-names
run
cp target/wasm32-wasi/debug/hello_world.wat ../wasmtime-go/hello.wat
cd wasmtime-go
go run main.go
结果输出
param is :1060192
Hello World,i am rust, get content from from wasmtime-go
拷贝wasm到node
cp ../rust-wasm/target/wasm32-wasi/debug/hello_world.wasm ./hello.wasm
node --experimental-wasi-unstable-preview1 hello.js
输出结果
param is:1067776
Hello World,i am rust, get content from nodejs
安装wasmedge
curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash
启动wasmedge-docker,注意wasmedge-go目前还不支持Mac Arm
docker pull wasmedge/appdev_aarch64:0.9.1
docker run -v $(pwd):/app -it wasmedge/appdev_aarch64:0.9.1
//把你本机的本项目映射到docker app目录下
run
cd wasmedge-go
cp cp ../rust-wasm/target/wasm32-wasi/debug/hello_world.wasm ./
go mod tidy
go run main.go hello_world.wasm
输出结果
param is :1061184
Hello World,i am rust, get content from wasmedge-go
安装web-pack
cargo install wasm-pack
初始化项目
cargo new --lib hello-wasm
build and push
wasm-pack build --scope mynpmusername
cd pkg
npm publish --access=public (注意此处需要先登录npm)
在web引入rust npm 包
创建package.json
{
"scripts": {
"serve": "webpack-dev-server"
},
"dependencies": {
"@mynpmusername/hello-wasm": "^0.1.0"
},
"devDependencies": {
"webpack": "^4.25.1",
"webpack-cli": "^3.1.2",
"webpack-dev-server": "^3.1.10"
}
}
创建 webpack.config.js
const path = require('path');
module.exports = {
entry: "./index.js",
output: {
path: path.resolve(__dirname, "dist"),
filename: "index.js",
},
mode: "development"
};
创建一个index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>hello-wasm example</title>
</head>
<body>
<script src="./index.js"></script>
</body>
</html>
从HTML文件中引用index.js
const js = import("./node_modules/@yournpmusername/hello-wasm/hello_wasm.js");
js.then(js => {
js.greet("WebAssembly");
});
run
npm install
npm run serve
浏览器输入访问 http://localhost:8080
安装llvm
brew install llvm ;export PATH=/usr/local/opt/llvm/bin:$PATH
llc --version
看是否支持wasi,输出以下信息表示支持
...
wasm32 - WebAssembly 32-bit
wasm64 - WebAssembly 64-bit
...
安装wasi-libc
git clone https://github.com/CraneStation/wasi-libc.git
cd wasi-libc
make install INSTALL_DIR=/tmp/wasi-libc
生成libclang_rt.builtins-wasm32.a
https://github.com/WebAssembly/wasi-sdk
按照上面的方法编译wasi-sdk，拷贝wasm32静态包到llvm目录下
cp lib/clang/13.0.0/lib/wasi/libclang_rt.builtins-wasm32.a /usr/local/Cellar/llvm/9.0.0/lib/clang/9.0.0/lib/wasi/libclang_rt.builtins-wasm32.a
//在mac下wasi-sdk默认放在/opt/wasi-opt/ 下面，其他wasm runtime在使用到wasi 的时候会默认去这个目录下去找
编译生成wasm
https://wasdk.github.io/WasmFiddle/,你可以直接在上面的网站上把你的c代码编译成wasm，检查你的语法已成查看你的wat，但是上面的网站不支持wasi
clang --target=wasm32-unknown-wasi --sysroot /tmp/wasi-libc -nostartfiles -Wl,--no-entry -Wl,--export-all -o hello.wasm hello.c
wasm2wat hello.wasm -o hello.wat --generate-names
cp hello.wat ../wasmtime-go
run
cd wasm-go
go run main.go
输出结果
param is :69216
Hello World,i am c,i get content from wasmtime-go
run
cp ../c-wasm/hello.wasm ./
node --experimental-wasi-unstable-preview1 hello.js
输出结果
param is:69216
Hello World,i am c,i get content nodejs
run
cd wasmedge-go
cp cp ../c-wasm/hello.wasm ./
go run main.go hello.wasm
输出结果
param is :69216
Hello World,i am c,i get content wasmedge-go
安装Emscripten SDK
git clone https://github.com/juj/emsdk.git
cd emsdk
# 在 Linux 或者 Mac OS X 上
./emsdk install --build=Release sdk-incoming-64bit binaryen-master-64bit
./emsdk activate --global --build=Release sdk-incoming-64bit binaryen-master-64bit
# 如果在你的macos上获得以下错误
Error: No tool or SDK found by name 'sdk-incoming-64bit'
# 请执行
./emsdk install latest
# 按照提示配置环境变量即可
./emsdk activate latest
用emcc编译
# 注意emsdk的目录
cp ~/emsdk/emscripten/1.38.15/src/shell_minimal.html html_template
emcc -o hello.html hello.c -O3 -s WASM=1 -s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall']" --shell-file html_template/shell_minimal.html
run
python -m SimpleHTTPServer
浏览器输入localhost:8000
run
npm install
npm run asbuild
npm test
输出结果
param is:26000
Hello world,i am ASSEMBLYSCRIPT,i get content from :javascript
i am javascript ,i get print_hello function result from assemblyscript: ASSEMBLY,SCRIPT