diff --git a/src/examples/wasm/wasm.go b/src/examples/wasm/wasm.go
index 846fa749..c697e89e 100644
--- a/src/examples/wasm/wasm.go
+++ b/src/examples/wasm/wasm.go
@@ -1,5 +1,10 @@
package main
+import (
+ "strconv"
+ "syscall/js"
+)
+
func main() {
}
@@ -7,3 +12,14 @@ func main() {
func add(a, b int) int {
return a + b
}
+
+//go:export update
+func update() {
+ document := js.Global().Get("document")
+ a_str := document.Call("getElementById", "a").Get("value").String()
+ b_str := document.Call("getElementById", "b").Get("value").String()
+ a, _ := strconv.Atoi(a_str)
+ b, _ := strconv.Atoi(b_str)
+ result := a + b
+ document.Call("getElementById", "result").Set("value", result)
+}
diff --git a/src/examples/wasm/wasm.html b/src/examples/wasm/wasm.html
index d2e1bc15..f8c45b40 100644
--- a/src/examples/wasm/wasm.html
+++ b/src/examples/wasm/wasm.html
@@ -5,7 +5,8 @@
Go WebAssembly
-
+
+
WebAssembly
diff --git a/src/examples/wasm/wasm.js b/src/examples/wasm/wasm.js
index 6b0aef7e..2d2f091b 100644
--- a/src/examples/wasm/wasm.js
+++ b/src/examples/wasm/wasm.js
@@ -3,51 +3,19 @@
const WASM_URL = '../../../wasm.wasm';
var wasm;
-var logLine = [];
-var memory8;
-
-var importObject = {
- env: {
- io_get_stdout: function() {
- return 1;
- },
- resource_write: function(fd, ptr, len) {
- if (fd == 1) {
- for (let i=0; i {
+ // Map web browser API and Node.js API to a single common API (preferring web standards over Node.js API).
+ const isNodeJS = typeof process !== "undefined";
+ if (isNodeJS) {
+ global.require = require;
+ global.fs = require("fs");
+
+ const nodeCrypto = require("crypto");
+ global.crypto = {
+ getRandomValues(b) {
+ nodeCrypto.randomFillSync(b);
+ },
+ };
+
+ global.performance = {
+ now() {
+ const [sec, nsec] = process.hrtime();
+ return sec * 1000 + nsec / 1000000;
+ },
+ };
+
+ const util = require("util");
+ global.TextEncoder = util.TextEncoder;
+ global.TextDecoder = util.TextDecoder;
+ } else {
+ if (typeof window !== "undefined") {
+ window.global = window;
+ } else if (typeof self !== "undefined") {
+ self.global = self;
+ } else {
+ throw new Error("cannot export Go (neither window nor self is defined)");
+ }
+
+ let outputBuf = "";
+ global.fs = {
+ constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
+ writeSync(fd, buf) {
+ outputBuf += decoder.decode(buf);
+ const nl = outputBuf.lastIndexOf("\n");
+ if (nl != -1) {
+ console.log(outputBuf.substr(0, nl));
+ outputBuf = outputBuf.substr(nl + 1);
+ }
+ return buf.length;
+ },
+ write(fd, buf, offset, length, position, callback) {
+ if (offset !== 0 || length !== buf.length || position !== null) {
+ throw new Error("not implemented");
+ }
+ const n = this.writeSync(fd, buf);
+ callback(null, n);
+ },
+ open(path, flags, mode, callback) {
+ const err = new Error("not implemented");
+ err.code = "ENOSYS";
+ callback(err);
+ },
+ fsync(fd, callback) {
+ callback(null);
+ },
+ };
+ }
+
+ const encoder = new TextEncoder("utf-8");
+ const decoder = new TextDecoder("utf-8");
+ var logLine = [];
+
+ global.Go = class {
+ constructor() {
+ this.argv = ["js"];
+ this.env = {};
+ this.exit = (code) => {
+ if (code !== 0) {
+ console.warn("exit code:", code);
+ }
+ };
+ this._callbackTimeouts = new Map();
+ this._nextCallbackTimeoutID = 1;
+
+ const mem = () => {
+ // The buffer may change when requesting more memory.
+ return new DataView(this._inst.exports.memory.buffer);
+ }
+
+ const setInt64 = (addr, v) => {
+ mem().setUint32(addr + 0, v, true);
+ mem().setUint32(addr + 4, Math.floor(v / 4294967296), true);
+ }
+
+ const getInt64 = (addr) => {
+ const low = mem().getUint32(addr + 0, true);
+ const high = mem().getInt32(addr + 4, true);
+ return low + high * 4294967296;
+ }
+
+ const loadValue = (addr) => {
+ const f = mem().getFloat64(addr, true);
+ if (f === 0) {
+ return undefined;
+ }
+ if (!isNaN(f)) {
+ return f;
+ }
+
+ const id = mem().getUint32(addr, true);
+ return this._values[id];
+ }
+
+ const storeValue = (addr, v) => {
+ const nanHead = 0x7FF80000;
+
+ if (typeof v === "number") {
+ if (isNaN(v)) {
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 0, true);
+ return;
+ }
+ if (v === 0) {
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 1, true);
+ return;
+ }
+ mem().setFloat64(addr, v, true);
+ return;
+ }
+
+ switch (v) {
+ case undefined:
+ mem().setFloat64(addr, 0, true);
+ return;
+ case null:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 2, true);
+ return;
+ case true:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 3, true);
+ return;
+ case false:
+ mem().setUint32(addr + 4, nanHead, true);
+ mem().setUint32(addr, 4, true);
+ return;
+ }
+
+ let ref = this._refs.get(v);
+ if (ref === undefined) {
+ ref = this._values.length;
+ this._values.push(v);
+ this._refs.set(v, ref);
+ }
+ let typeFlag = 0;
+ switch (typeof v) {
+ case "string":
+ typeFlag = 1;
+ break;
+ case "symbol":
+ typeFlag = 2;
+ break;
+ case "function":
+ typeFlag = 3;
+ break;
+ }
+ mem().setUint32(addr + 4, nanHead | typeFlag, true);
+ mem().setUint32(addr, ref, true);
+ }
+
+ const loadSlice = (array, len, cap) => {
+ return new Uint8Array(this._inst.exports.memory.buffer, array, len);
+ }
+
+ const loadSliceOfValues = (array, len, cap) => {
+ const a = new Array(len);
+ for (let i = 0; i < len; i++) {
+ a[i] = loadValue(array + i * 8);
+ }
+ return a;
+ }
+
+ const loadString = (ptr, len) => {
+ return decoder.decode(new DataView(this._inst.exports.memory.buffer, ptr, len));
+ }
+
+ const timeOrigin = Date.now() - performance.now();
+ this.importObject = {
+ env: {
+ io_get_stdout: function() {
+ return 1;
+ },
+
+ resource_write: function(fd, ptr, len) {
+ if (fd == 1) {
+ for (let i=0; i {
+ const s = loadString(value_ptr, value_len);
+ storeValue(ret_ptr, s);
+ },
+
+ // func valueGet(v ref, p string) ref
+ "syscall/js.valueGet": (retval, v_addr, p_ptr, p_len) => {
+ let prop = loadString(p_ptr, p_len);
+ let value = loadValue(v_addr);
+ let result = Reflect.get(value, prop);
+ storeValue(retval, result);
+ },
+
+ // func valueSet(v ref, p string, x ref)
+ "syscall/js.valueSet": (v_addr, p_ptr, p_len, x_addr) => {
+ const v = loadValue(v_addr);
+ const p = loadString(p_ptr, p_len);
+ const x = loadValue(x_addr);
+ Reflect.set(v, p, x);
+ },
+
+ // func valueIndex(v ref, i int) ref
+ //"syscall/js.valueIndex": (sp) => {
+ // storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
+ //},
+
+ // valueSetIndex(v ref, i int, x ref)
+ //"syscall/js.valueSetIndex": (sp) => {
+ // Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
+ //},
+
+ // func valueCall(v ref, m string, args []ref) (ref, bool)
+ "syscall/js.valueCall": (ret_addr, v_addr, m_ptr, m_len, args_ptr, args_len, args_cap) => {
+ const v = loadValue(v_addr);
+ const name = loadString(m_ptr, m_len);
+ const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+ try {
+ const m = Reflect.get(v, name);
+ storeValue(ret_addr, Reflect.apply(m, v, args));
+ mem().setUint8(ret_addr + 8, 1);
+ } catch (err) {
+ storeValue(ret_addr, err);
+ mem().setUint8(ret_addr + 8, 0);
+ }
+ },
+
+ // func valueInvoke(v ref, args []ref) (ref, bool)
+ //"syscall/js.valueInvoke": (sp) => {
+ // try {
+ // const v = loadValue(sp + 8);
+ // const args = loadSliceOfValues(sp + 16);
+ // storeValue(sp + 40, Reflect.apply(v, undefined, args));
+ // mem().setUint8(sp + 48, 1);
+ // } catch (err) {
+ // storeValue(sp + 40, err);
+ // mem().setUint8(sp + 48, 0);
+ // }
+ //},
+
+ // func valueNew(v ref, args []ref) (ref, bool)
+ "syscall/js.valueNew": (ret_addr, v_addr, args_ptr, args_len, args_cap) => {
+ const v = loadValue(v_addr);
+ const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+ try {
+ storeValue(ret_addr, Reflect.construct(v, args));
+ mem().setUint8(ret_addr + 8, 1);
+ } catch (err) {
+ storeValue(ret_addr, err);
+ mem().setUint8(ret_addr+ 8, 0);
+ }
+ },
+
+ // func valueLength(v ref) int
+ //"syscall/js.valueLength": (sp) => {
+ // setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
+ //},
+
+ // valuePrepareString(v ref) (ref, int)
+ "syscall/js.valuePrepareString": (ret_addr, v_addr) => {
+ const s = String(loadValue(v_addr));
+ const str = encoder.encode(s);
+ storeValue(ret_addr, str);
+ setInt64(ret_addr + 8, str.length);
+ },
+
+ // valueLoadString(v ref, b []byte)
+ "syscall/js.valueLoadString": (v_addr, slice_ptr, slice_len, slice_cap) => {
+ const str = loadValue(v_addr);
+ loadSlice(slice_ptr, slice_len, slice_cap).set(str);
+ },
+
+ // func valueInstanceOf(v ref, t ref) bool
+ //"syscall/js.valueInstanceOf": (sp) => {
+ // mem().setUint8(sp + 24, loadValue(sp + 8) instanceof loadValue(sp + 16));
+ //},
+ }
+ };
+ }
+
+ async run(instance) {
+ this._inst = instance;
+ this._values = [ // TODO: garbage collection
+ NaN,
+ 0,
+ null,
+ true,
+ false,
+ global,
+ this._inst.exports.mem,
+ this,
+ ];
+ this._refs = new Map();
+ this._callbackShutdown = false;
+ this.exited = false;
+
+ const mem = new DataView(this._inst.exports.memory.buffer)
+
+ // Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
+ let offset = 4096;
+
+ const strPtr = (str) => {
+ let ptr = offset;
+ new Uint8Array(mem.buffer, offset, str.length + 1).set(encoder.encode(str + "\0"));
+ offset += str.length + (8 - (str.length % 8));
+ return ptr;
+ };
+
+ const argc = this.argv.length;
+
+ const argvPtrs = [];
+ this.argv.forEach((arg) => {
+ argvPtrs.push(strPtr(arg));
+ });
+
+ const keys = Object.keys(this.env).sort();
+ argvPtrs.push(keys.length);
+ keys.forEach((key) => {
+ argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
+ });
+
+ const argv = offset;
+ argvPtrs.forEach((ptr) => {
+ mem.setUint32(offset, ptr, true);
+ mem.setUint32(offset + 4, 0, true);
+ offset += 8;
+ });
+
+ while (true) {
+ const callbackPromise = new Promise((resolve) => {
+ this._resolveCallbackPromise = () => {
+ if (this.exited) {
+ throw new Error("bad callback: Go program has already exited");
+ }
+ setTimeout(resolve, 0); // make sure it is asynchronous
+ };
+ });
+ this._inst.exports.cwa_main(argc, argv);
+ if (this.exited) {
+ break;
+ }
+ await callbackPromise;
+ }
+ }
+
+ static _makeCallbackHelper(id, pendingCallbacks, go) {
+ return function () {
+ pendingCallbacks.push({ id: id, args: arguments });
+ go._resolveCallbackPromise();
+ };
+ }
+
+ static _makeEventCallbackHelper(preventDefault, stopPropagation, stopImmediatePropagation, fn) {
+ return function (event) {
+ if (preventDefault) {
+ event.preventDefault();
+ }
+ if (stopPropagation) {
+ event.stopPropagation();
+ }
+ if (stopImmediatePropagation) {
+ event.stopImmediatePropagation();
+ }
+ fn(event);
+ };
+ }
+ }
+
+ if (isNodeJS) {
+ if (process.argv.length < 3) {
+ process.stderr.write("usage: go_js_wasm_exec [wasm binary] [arguments]\n");
+ process.exit(1);
+ }
+
+ const go = new Go();
+ go.argv = process.argv.slice(2);
+ go.env = process.env;
+ go.exit = process.exit;
+ WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+ process.on("exit", (code) => { // Node.js exits if no callback is pending
+ if (code === 0 && !go.exited) {
+ // deadlock, make Go print error and stack traces
+ go._callbackShutdown = true;
+ go._inst.exports.run();
+ }
+ });
+ return go.run(result.instance);
+ }).catch((err) => {
+ throw err;
+ });
+ }
+})();