feat: add wasm build

Add wasm build using a docker container. Expose some api needed only in
wasm.

.dockerignore

@@ -0,0 +1,6 @@
+node_modules
+.github
+bench
+test
+images
+lib

Dockerfile

@@ -0,0 +1,22 @@
+FROM node:14.16.0-buster
+
+ARG UID=1000
+ARG GID=1000
+ARG WASI_SDK_VERSION_MAJOR=12
+ARG WASI_SDK_VERSION_MINOR=0
+
+ENV WASI_ROOT=/home/node/wasi-sdk-12.0
+
+RUN wget https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-${WASI_SDK_VERSION_MAJOR}/wasi-sdk-${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}-linux.tar.gz -P /tmp
+
+RUN tar xvf /tmp/wasi-sdk-${WASI_SDK_VERSION_MAJOR}.${WASI_SDK_VERSION_MINOR}-linux.tar.gz --directory /home/node
+
+RUN mkdir /home/node/llhttp
+
+WORKDIR /home/node/llhttp
+
+COPY . .
+
+RUN npm ci
+
+USER node

README.md

@@ -98,6 +98,10 @@ if (err == HPE_OK) {
 * Python: [pallas/pyllhttp][8]
 * Ruby: [metabahn/llhttp][9]
 
+### Note
+
+The work on the wasm build present here has been modified from what [devsnek](https://github.com/devsnek) started in https://github.com/devsnek/llhttp/tree/wasm.
+
 #### LICENSE
 
 This software is licensed under the MIT License.

build_wasm.js

@@ -0,0 +1,73 @@
+'use strict'
+
+const { mkdirSync, writeFileSync } = require('fs')
+const { execSync } = require('child_process')
+const { join } = require('path')
+const js = require('javascript-stringify')
+const { WASI_ROOT } = process.env
+
+if (process.argv[2] === '--setup') {
+  try {
+    mkdirSync(join(__dirname, 'build'))
+    process.exit(0);
+  } catch (error) {
+    if (error.code !== 'EEXIST') {
+      throw error
+    }
+    process.exit(0);
+  }
+}
+
+if (process.argv[2] === '--docker') {
+  let cmd = 'docker run --rm -it'; 
+  if (process.platform === 'linux') {
+    cmd += ` --user ${process.getuid()}:${process.getegid()}`;
+  }
+  cmd += ` --mount type=bind,source=${__dirname}/build,target=/home/node/llhttp/build llhttp_wasm_builder node build_wasm.js`;
+  execSync(cmd, { stdio: 'inherit' });
+  process.exit(0);
+}
+
+if (!WASI_ROOT) {
+  throw new Error('Please setup the WASI_ROOT env variable.')
+}
+
+const WASM_OUT = join(__dirname, 'build', 'wasm')
+
+try {
+  mkdirSync(WASM_OUT)
+} catch (error) {
+  if (error.code !== 'EEXIST') {
+    throw error
+  }
+}
+
+// Build ts
+execSync('npm run build', { stdio: 'inherit' })
+
+// Build wasm binary
+execSync(`${WASI_ROOT}/bin/clang \
+ --sysroot=${WASI_ROOT}/share/wasi-sysroot \
+ -target wasm32-unknown-wasi \
+ -Ofast \
+ -fno-exceptions \
+ -fvisibility=hidden \
+ -mexec-model=reactor \
+ -Wl,-error-limit=0 \
+ -Wl,-O3 \
+ -Wl,--lto-O3 \
+ -Wl,--strip-all \
+ -Wl,--allow-undefined \
+ -Wl,--export-dynamic \
+ -Wl,--export-table \
+ -Wl,--export=malloc \
+ -Wl,--export=free \
+ ${join(__dirname, 'build', 'c')}/*.c \
+ ${join(__dirname, 'src', 'native')}/*.c \
+ -I${join(__dirname, 'build')} \
+ -o ${join(WASM_OUT, 'llhttp.wasm')}`, { stdio: 'inherit' })
+
+// Build `constants.js` file
+const { constants } = require('.')
+const data = `module.exports = ${js.stringify(constants)}`
+writeFileSync(join(WASM_OUT, 'constants.js'), data, 'utf8')

examples/wasm.js

@@ -0,0 +1,222 @@
+'use strict';
+
+/* global WebAssembly */
+
+const { readFileSync } = require('fs');
+const { resolve } = require('path');
+const constants = require('../build/wasm/constants.js');
+const bin = readFileSync(resolve(__dirname, '../build/wasm/llhttp.wasm'));
+const mod = new WebAssembly.Module(bin);
+
+const REQUEST = constants.TYPE.REQUEST;
+const RESPONSE = constants.TYPE.RESPONSE;
+const kOnMessageBegin = 0;
+const kOnHeaders = 1;
+const kOnHeadersComplete = 2;
+const kOnBody = 3;
+const kOnMessageComplete = 4;
+const kOnExecute = 5;
+
+const kPtr = Symbol('kPrt');
+const kUrl = Symbol('kUrl');
+const kStatusMessage = Symbol('kStatusMessage');
+const kHeadersFields = Symbol('kHeadersFields');
+const kHeadersValues = Symbol('kHeadersValues');
+const kBody = Symbol('kBody');
+const kReset = Symbol('kReset');
+const kCheckErr = Symbol('kCheckErr');
+
+const cstr = (ptr, len) =>
+  Buffer.from(inst.exports.memory.buffer, ptr, len).toString();
+
+const wasm_on_message_begin = p => {
+  const i = instMap.get(p);
+  i[kReset]();
+  return i[kOnMessageBegin]();
+};
+
+const wasm_on_url = (p, at, length) => {
+  instMap.get(p)[kUrl] = cstr(at, length);
+  return 0;
+};
+
+const wasm_on_status = (p, at, length) => {
+  instMap.get(p)[kStatusMessage] = cstr(at, length);
+  return 0;
+};
+
+const wasm_on_header_field = (p, at, length) => {
+  const i= instMap.get(p)
+  i[kHeadersFields].push(cstr(at, length));
+  return 0;
+};
+
+const wasm_on_header_value = (p, at, length) => {
+  const i = instMap.get(p);
+  i[kHeadersValues].push(cstr(at, length));
+  return 0;
+};
+
+const wasm_on_headers_complete = p => {
+  const i = instMap.get(p);
+  const type = inst.exports.llhttp_get_type(p);
+  const versionMajor = inst.exports.llhttp_get_http_major(p);
+  const versionMinor = inst.exports.llhttp_get_http_minor(p);
+  const rawHeaders = [];
+  let method;
+  let url;
+  let statusCode;
+  let statusMessage;
+  const upgrade = inst.exports.llhttp_get_upgrade(p);
+  const shouldKeepAlive = inst.exports.llhttp_should_keep_alive(p);
+
+  for (let c = 0; c < i[kHeadersFields].length; c++) {
+    rawHeaders.push(i[kHeadersFields][c], i[kHeadersValues][c])
+  }
+  i[kOnHeaders](rawHeaders);
+
+  if (type === HTTPParser.REQUEST) {
+    method = constants.METHODS[inst.exports.llhttp_get_method(p)];
+    url = i[kUrl];
+  } else if (type === HTTPParser.RESPONSE) {
+    statusCode = inst.exports.llhttp_get_status_code(p);
+    statusMessage = i[kStatusMessage];
+  }
+  return i[kOnHeadersComplete](versionMajor, versionMinor, rawHeaders, method,
+url, statusCode, statusMessage, upgrade, shouldKeepAlive);
+};
+
+const wasm_on_body = (p, at, length) => {
+  const i = instMap.get(p);
+  const body = Buffer.from(inst.exports.memory.buffer, at, length);
+  return i[kOnBody](body);
+};
+
+const wasm_on_message_complete = (p) => {
+  return instMap.get(p)[kOnMessageComplete]();
+};
+
+const instMap = new Map();
+
+const inst = new WebAssembly.Instance(mod, {
+  env: {
+    wasm_on_message_begin,
+    wasm_on_url,
+    wasm_on_status,
+    wasm_on_header_field,
+    wasm_on_header_value,
+    wasm_on_headers_complete,
+    wasm_on_body,
+    wasm_on_message_complete,
+  },
+});
+
+inst.exports._initialize(); // wasi reactor
+
+class HTTPParser {
+  constructor(type) {
+    this[kPtr] = inst.exports.llhttp_alloc(constants.TYPE[type]);
+    instMap.set(this[kPtr], this);
+
+    this[kUrl] = '';
+    this[kStatusMessage] = null;
+    this[kHeadersFields] = [];
+    this[kHeadersValues] = [];
+    this[kBody] = null;
+  }
+
+  [kReset]() {
+    this[kUrl] = '';
+    this[kStatusMessage] = null;
+    this[kHeadersFields] = [];
+    this[kHeadersValues] = [];
+    this[kBody] = null;
+  }
+
+  [kOnMessageBegin]() {
+    return 0;
+  }
+
+  [kOnHeaders](rawHeaders) {}
+
+  [kOnHeadersComplete](versionMajor, versionMinor, rawHeaders, method,
+    url, statusCode, statusMessage, upgrade, shouldKeepAlive) {
+    return 0;
+  }
+
+  [kOnBody](body) {
+    this[kBody] = body;
+    return 0;
+  }
+
+  [kOnMessageComplete]() {
+    return 0;
+  }
+
+  destroy() {
+    instMap.delete(this[kPtr]);
+    inst.exports.llhttp_free(this[kPtr]);
+  }
+
+  execute(data) {
+    // TODO(devsnek): could probably use static alloc and chunk but i'm lazy
+    const ptr = inst.exports.malloc(data.byteLength);
+    const u8 = new Uint8Array(inst.exports.memory.buffer);
+    u8.set(data, ptr);
+    const ret = inst.exports.llhttp_execute(this[kPtr], ptr, data.length);
+    inst.exports.free(ptr);
+    this[kCheckErr](ret);
+    return ret;
+  }
+
+  [kCheckErr](n) {
+    if (n === constants.ERROR.OK) {
+      return;
+    }
+    const ptr = inst.exports.llhttp_get_error_reason(this[kPtr]);
+    const u8 = new Uint8Array(inst.exports.memory.buffer);
+    const len = u8.indexOf(0, ptr) - ptr;
+    throw new Error(cstr(ptr, len));
+  }
+}
+
+HTTPParser.REQUEST = REQUEST;
+HTTPParser.RESPONSE = RESPONSE;
+HTTPParser.kOnMessageBegin = kOnMessageBegin;
+HTTPParser.kOnHeaders = kOnHeaders;
+HTTPParser.kOnHeadersComplete = kOnHeadersComplete;
+HTTPParser.kOnBody = kOnBody;
+HTTPParser.kOnMessageComplete = kOnMessageComplete;
+HTTPParser.kOnExecute = kOnExecute;
+
+{
+  const p = new HTTPParser(HTTPParser.REQUEST);
+
+  p.execute(Buffer.from(`\
+POST /owo HTTP/1.1\r
+X: Y\r
+Content-Length: 9\r
+\r
+uh, meow?\r
+`));
+
+  console.log(p);
+
+  p.destroy();
+}
+
+{
+  const p = new HTTPParser(HTTPParser.RESPONSE);
+
+  p.execute(Buffer.from(`\
+HTTP/1.1 200 OK\r
+X: Y\r
+Content-Length: 9\r
+\r
+uh, meow?\r
+`));
+
+  console.log(p);
+
+  p.destroy();
+}