diff --git a/_site/main.js b/_site/main.js new file mode 100644 index 0000000..a5bba93 --- /dev/null +++ b/_site/main.js @@ -0,0 +1,63 @@ +import "xterm"; +import "wasm_exec"; + + +var term = new Terminal(); +term.open(document.getElementById('terminal')); + +function startSession(term) { + let buffer = ""; + let lineBuffer = ""; + + term.writeln('Interactive mode'); + term.write('> '); + + term.onKey((ev, dom) => { + const {key} = ev; + + switch (key) { + case '\r': + // Enter + term.writeln(''); + + let wantContinue = lineBuffer.length > 0; + buffer += lineBuffer; + lineBuffer = ''; + + ucl.eval(buffer, wantContinue); + break; + case '\u007F': + // Backspace + if (lineBuffer.length > 0) { + term.write([0x08, 0x20, 0x08]); + lineBuffer = lineBuffer.slice(0, lineBuffer.length - 1); + } + break; + default: + if (key >= ' ') { + term.write(key); + lineBuffer += key; + } + } + }); + + ucl.onContinue = () => { + buffer += "\n"; + lineBuffer = ''; + term.write(': '); + } + ucl.onNewCommand = () => { + term.write('> '); + buffer = ''; + lineBuffer = ''; + } + ucl.onOutLine = (line) => { term.writeln(line); } + ucl.onError = (err) => { term.writeln('error: ' + err); } +} + +const go = new Go(); +WebAssembly.instantiateStreaming(fetch("/playwasm.wasm"), go.importObject) + .then((result) => { + go.run(result.instance); + startSession(term); + }); \ No newline at end of file diff --git a/_site/playground.html b/_site/playground.html new file mode 100644 index 0000000..011d1e1 --- /dev/null +++ b/_site/playground.html @@ -0,0 +1,21 @@ + + + + + + +

Playground

+ +
+ + + + + \ No newline at end of file diff --git a/_site/wasm_exec.js b/_site/wasm_exec.js new file mode 100644 index 0000000..bc6f210 --- /dev/null +++ b/_site/wasm_exec.js @@ -0,0 +1,561 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +"use strict"; + +(() => { + const enosys = () => { + const err = new Error("not implemented"); + err.code = "ENOSYS"; + return err; + }; + + if (!globalThis.fs) { + let outputBuf = ""; + globalThis.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.substring(0, nl)); + outputBuf = outputBuf.substring(nl + 1); + } + return buf.length; + }, + write(fd, buf, offset, length, position, callback) { + if (offset !== 0 || length !== buf.length || position !== null) { + callback(enosys()); + return; + } + const n = this.writeSync(fd, buf); + callback(null, n); + }, + chmod(path, mode, callback) { callback(enosys()); }, + chown(path, uid, gid, callback) { callback(enosys()); }, + close(fd, callback) { callback(enosys()); }, + fchmod(fd, mode, callback) { callback(enosys()); }, + fchown(fd, uid, gid, callback) { callback(enosys()); }, + fstat(fd, callback) { callback(enosys()); }, + fsync(fd, callback) { callback(null); }, + ftruncate(fd, length, callback) { callback(enosys()); }, + lchown(path, uid, gid, callback) { callback(enosys()); }, + link(path, link, callback) { callback(enosys()); }, + lstat(path, callback) { callback(enosys()); }, + mkdir(path, perm, callback) { callback(enosys()); }, + open(path, flags, mode, callback) { callback(enosys()); }, + read(fd, buffer, offset, length, position, callback) { callback(enosys()); }, + readdir(path, callback) { callback(enosys()); }, + readlink(path, callback) { callback(enosys()); }, + rename(from, to, callback) { callback(enosys()); }, + rmdir(path, callback) { callback(enosys()); }, + stat(path, callback) { callback(enosys()); }, + symlink(path, link, callback) { callback(enosys()); }, + truncate(path, length, callback) { callback(enosys()); }, + unlink(path, callback) { callback(enosys()); }, + utimes(path, atime, mtime, callback) { callback(enosys()); }, + }; + } + + if (!globalThis.process) { + globalThis.process = { + getuid() { return -1; }, + getgid() { return -1; }, + geteuid() { return -1; }, + getegid() { return -1; }, + getgroups() { throw enosys(); }, + pid: -1, + ppid: -1, + umask() { throw enosys(); }, + cwd() { throw enosys(); }, + chdir() { throw enosys(); }, + } + } + + if (!globalThis.crypto) { + throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)"); + } + + if (!globalThis.performance) { + throw new Error("globalThis.performance is not available, polyfill required (performance.now only)"); + } + + if (!globalThis.TextEncoder) { + throw new Error("globalThis.TextEncoder is not available, polyfill required"); + } + + if (!globalThis.TextDecoder) { + throw new Error("globalThis.TextDecoder is not available, polyfill required"); + } + + const encoder = new TextEncoder("utf-8"); + const decoder = new TextDecoder("utf-8"); + + globalThis.Go = class { + constructor() { + this.argv = ["js"]; + this.env = {}; + this.exit = (code) => { + if (code !== 0) { + console.warn("exit code:", code); + } + }; + this._exitPromise = new Promise((resolve) => { + this._resolveExitPromise = resolve; + }); + this._pendingEvent = null; + this._scheduledTimeouts = new Map(); + this._nextCallbackTimeoutID = 1; + + const setInt64 = (addr, v) => { + this.mem.setUint32(addr + 0, v, true); + this.mem.setUint32(addr + 4, Math.floor(v / 4294967296), true); + } + + const setInt32 = (addr, v) => { + this.mem.setUint32(addr + 0, v, true); + } + + const getInt64 = (addr) => { + const low = this.mem.getUint32(addr + 0, true); + const high = this.mem.getInt32(addr + 4, true); + return low + high * 4294967296; + } + + const loadValue = (addr) => { + const f = this.mem.getFloat64(addr, true); + if (f === 0) { + return undefined; + } + if (!isNaN(f)) { + return f; + } + + const id = this.mem.getUint32(addr, true); + return this._values[id]; + } + + const storeValue = (addr, v) => { + const nanHead = 0x7FF80000; + + if (typeof v === "number" && v !== 0) { + if (isNaN(v)) { + this.mem.setUint32(addr + 4, nanHead, true); + this.mem.setUint32(addr, 0, true); + return; + } + this.mem.setFloat64(addr, v, true); + return; + } + + if (v === undefined) { + this.mem.setFloat64(addr, 0, true); + return; + } + + let id = this._ids.get(v); + if (id === undefined) { + id = this._idPool.pop(); + if (id === undefined) { + id = this._values.length; + } + this._values[id] = v; + this._goRefCounts[id] = 0; + this._ids.set(v, id); + } + this._goRefCounts[id]++; + let typeFlag = 0; + switch (typeof v) { + case "object": + if (v !== null) { + typeFlag = 1; + } + break; + case "string": + typeFlag = 2; + break; + case "symbol": + typeFlag = 3; + break; + case "function": + typeFlag = 4; + break; + } + this.mem.setUint32(addr + 4, nanHead | typeFlag, true); + this.mem.setUint32(addr, id, true); + } + + const loadSlice = (addr) => { + const array = getInt64(addr + 0); + const len = getInt64(addr + 8); + return new Uint8Array(this._inst.exports.mem.buffer, array, len); + } + + const loadSliceOfValues = (addr) => { + const array = getInt64(addr + 0); + const len = getInt64(addr + 8); + const a = new Array(len); + for (let i = 0; i < len; i++) { + a[i] = loadValue(array + i * 8); + } + return a; + } + + const loadString = (addr) => { + const saddr = getInt64(addr + 0); + const len = getInt64(addr + 8); + return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len)); + } + + const timeOrigin = Date.now() - performance.now(); + this.importObject = { + _gotest: { + add: (a, b) => a + b, + }, + gojs: { + // Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters) + // may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported + // function. A goroutine can switch to a new stack if the current stack is too small (see morestack function). + // This changes the SP, thus we have to update the SP used by the imported function. + + // func wasmExit(code int32) + "runtime.wasmExit": (sp) => { + sp >>>= 0; + const code = this.mem.getInt32(sp + 8, true); + this.exited = true; + delete this._inst; + delete this._values; + delete this._goRefCounts; + delete this._ids; + delete this._idPool; + this.exit(code); + }, + + // func wasmWrite(fd uintptr, p unsafe.Pointer, n int32) + "runtime.wasmWrite": (sp) => { + sp >>>= 0; + const fd = getInt64(sp + 8); + const p = getInt64(sp + 16); + const n = this.mem.getInt32(sp + 24, true); + fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n)); + }, + + // func resetMemoryDataView() + "runtime.resetMemoryDataView": (sp) => { + sp >>>= 0; + this.mem = new DataView(this._inst.exports.mem.buffer); + }, + + // func nanotime1() int64 + "runtime.nanotime1": (sp) => { + sp >>>= 0; + setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000); + }, + + // func walltime() (sec int64, nsec int32) + "runtime.walltime": (sp) => { + sp >>>= 0; + const msec = (new Date).getTime(); + setInt64(sp + 8, msec / 1000); + this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true); + }, + + // func scheduleTimeoutEvent(delay int64) int32 + "runtime.scheduleTimeoutEvent": (sp) => { + sp >>>= 0; + const id = this._nextCallbackTimeoutID; + this._nextCallbackTimeoutID++; + this._scheduledTimeouts.set(id, setTimeout( + () => { + this._resume(); + while (this._scheduledTimeouts.has(id)) { + // for some reason Go failed to register the timeout event, log and try again + // (temporary workaround for https://github.com/golang/go/issues/28975) + console.warn("scheduleTimeoutEvent: missed timeout event"); + this._resume(); + } + }, + getInt64(sp + 8), + )); + this.mem.setInt32(sp + 16, id, true); + }, + + // func clearTimeoutEvent(id int32) + "runtime.clearTimeoutEvent": (sp) => { + sp >>>= 0; + const id = this.mem.getInt32(sp + 8, true); + clearTimeout(this._scheduledTimeouts.get(id)); + this._scheduledTimeouts.delete(id); + }, + + // func getRandomData(r []byte) + "runtime.getRandomData": (sp) => { + sp >>>= 0; + crypto.getRandomValues(loadSlice(sp + 8)); + }, + + // func finalizeRef(v ref) + "syscall/js.finalizeRef": (sp) => { + sp >>>= 0; + const id = this.mem.getUint32(sp + 8, true); + this._goRefCounts[id]--; + if (this._goRefCounts[id] === 0) { + const v = this._values[id]; + this._values[id] = null; + this._ids.delete(v); + this._idPool.push(id); + } + }, + + // func stringVal(value string) ref + "syscall/js.stringVal": (sp) => { + sp >>>= 0; + storeValue(sp + 24, loadString(sp + 8)); + }, + + // func valueGet(v ref, p string) ref + "syscall/js.valueGet": (sp) => { + sp >>>= 0; + const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16)); + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 32, result); + }, + + // func valueSet(v ref, p string, x ref) + "syscall/js.valueSet": (sp) => { + sp >>>= 0; + Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32)); + }, + + // func valueDelete(v ref, p string) + "syscall/js.valueDelete": (sp) => { + sp >>>= 0; + Reflect.deleteProperty(loadValue(sp + 8), loadString(sp + 16)); + }, + + // func valueIndex(v ref, i int) ref + "syscall/js.valueIndex": (sp) => { + sp >>>= 0; + storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16))); + }, + + // valueSetIndex(v ref, i int, x ref) + "syscall/js.valueSetIndex": (sp) => { + sp >>>= 0; + Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24)); + }, + + // func valueCall(v ref, m string, args []ref) (ref, bool) + "syscall/js.valueCall": (sp) => { + sp >>>= 0; + try { + const v = loadValue(sp + 8); + const m = Reflect.get(v, loadString(sp + 16)); + const args = loadSliceOfValues(sp + 32); + const result = Reflect.apply(m, v, args); + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 56, result); + this.mem.setUint8(sp + 64, 1); + } catch (err) { + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 56, err); + this.mem.setUint8(sp + 64, 0); + } + }, + + // func valueInvoke(v ref, args []ref) (ref, bool) + "syscall/js.valueInvoke": (sp) => { + sp >>>= 0; + try { + const v = loadValue(sp + 8); + const args = loadSliceOfValues(sp + 16); + const result = Reflect.apply(v, undefined, args); + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 40, result); + this.mem.setUint8(sp + 48, 1); + } catch (err) { + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 40, err); + this.mem.setUint8(sp + 48, 0); + } + }, + + // func valueNew(v ref, args []ref) (ref, bool) + "syscall/js.valueNew": (sp) => { + sp >>>= 0; + try { + const v = loadValue(sp + 8); + const args = loadSliceOfValues(sp + 16); + const result = Reflect.construct(v, args); + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 40, result); + this.mem.setUint8(sp + 48, 1); + } catch (err) { + sp = this._inst.exports.getsp() >>> 0; // see comment above + storeValue(sp + 40, err); + this.mem.setUint8(sp + 48, 0); + } + }, + + // func valueLength(v ref) int + "syscall/js.valueLength": (sp) => { + sp >>>= 0; + setInt64(sp + 16, parseInt(loadValue(sp + 8).length)); + }, + + // valuePrepareString(v ref) (ref, int) + "syscall/js.valuePrepareString": (sp) => { + sp >>>= 0; + const str = encoder.encode(String(loadValue(sp + 8))); + storeValue(sp + 16, str); + setInt64(sp + 24, str.length); + }, + + // valueLoadString(v ref, b []byte) + "syscall/js.valueLoadString": (sp) => { + sp >>>= 0; + const str = loadValue(sp + 8); + loadSlice(sp + 16).set(str); + }, + + // func valueInstanceOf(v ref, t ref) bool + "syscall/js.valueInstanceOf": (sp) => { + sp >>>= 0; + this.mem.setUint8(sp + 24, (loadValue(sp + 8) instanceof loadValue(sp + 16)) ? 1 : 0); + }, + + // func copyBytesToGo(dst []byte, src ref) (int, bool) + "syscall/js.copyBytesToGo": (sp) => { + sp >>>= 0; + const dst = loadSlice(sp + 8); + const src = loadValue(sp + 32); + if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) { + this.mem.setUint8(sp + 48, 0); + return; + } + const toCopy = src.subarray(0, dst.length); + dst.set(toCopy); + setInt64(sp + 40, toCopy.length); + this.mem.setUint8(sp + 48, 1); + }, + + // func copyBytesToJS(dst ref, src []byte) (int, bool) + "syscall/js.copyBytesToJS": (sp) => { + sp >>>= 0; + const dst = loadValue(sp + 8); + const src = loadSlice(sp + 16); + if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) { + this.mem.setUint8(sp + 48, 0); + return; + } + const toCopy = src.subarray(0, dst.length); + dst.set(toCopy); + setInt64(sp + 40, toCopy.length); + this.mem.setUint8(sp + 48, 1); + }, + + "debug": (value) => { + console.log(value); + }, + } + }; + } + + async run(instance) { + if (!(instance instanceof WebAssembly.Instance)) { + throw new Error("Go.run: WebAssembly.Instance expected"); + } + this._inst = instance; + this.mem = new DataView(this._inst.exports.mem.buffer); + this._values = [ // JS values that Go currently has references to, indexed by reference id + NaN, + 0, + null, + true, + false, + globalThis, + this, + ]; + this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id + this._ids = new Map([ // mapping from JS values to reference ids + [0, 1], + [null, 2], + [true, 3], + [false, 4], + [globalThis, 5], + [this, 6], + ]); + this._idPool = []; // unused ids that have been garbage collected + this.exited = false; // whether the Go program has exited + + // Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory. + let offset = 4096; + + const strPtr = (str) => { + const ptr = offset; + const bytes = encoder.encode(str + "\0"); + new Uint8Array(this.mem.buffer, offset, bytes.length).set(bytes); + offset += bytes.length; + if (offset % 8 !== 0) { + offset += 8 - (offset % 8); + } + return ptr; + }; + + const argc = this.argv.length; + + const argvPtrs = []; + this.argv.forEach((arg) => { + argvPtrs.push(strPtr(arg)); + }); + argvPtrs.push(0); + + const keys = Object.keys(this.env).sort(); + keys.forEach((key) => { + argvPtrs.push(strPtr(`${key}=${this.env[key]}`)); + }); + argvPtrs.push(0); + + const argv = offset; + argvPtrs.forEach((ptr) => { + this.mem.setUint32(offset, ptr, true); + this.mem.setUint32(offset + 4, 0, true); + offset += 8; + }); + + // The linker guarantees global data starts from at least wasmMinDataAddr. + // Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr. + const wasmMinDataAddr = 4096 + 8192; + if (offset >= wasmMinDataAddr) { + throw new Error("total length of command line and environment variables exceeds limit"); + } + + this._inst.exports.run(argc, argv); + if (this.exited) { + this._resolveExitPromise(); + } + await this._exitPromise; + } + + _resume() { + if (this.exited) { + throw new Error("Go program has already exited"); + } + this._inst.exports.resume(); + if (this.exited) { + this._resolveExitPromise(); + } + } + + _makeFuncWrapper(id) { + const go = this; + return function () { + const event = { id: id, this: this, args: arguments }; + go._pendingEvent = event; + go._resume(); + return event.result; + }; + } + } +})(); diff --git a/cmd/playwasm/jsiter.go b/cmd/playwasm/jsiter.go new file mode 100644 index 0000000..a5730e1 --- /dev/null +++ b/cmd/playwasm/jsiter.go @@ -0,0 +1,73 @@ +//go:build js && wasm + +package main + +import ( + "bytes" + "context" + "errors" + "github.com/alecthomas/participle/v2" + "github.com/lmika/cmdlang-proto/cmdlang" + "strings" + "syscall/js" +) + +func invokeUCLCallback(name string, args ...any) { + if onLine := js.Global().Get("ucl").Get(name); !onLine.IsNull() { + onLine.Invoke(args...) + } +} + +func initJS(ctx context.Context) { + ucl := make(map[string]any) + + inst := cmdlang.New(cmdlang.WithOut(&uclOut{ + lineBuffer: new(bytes.Buffer), + writeLine: func(line string) { + invokeUCLCallback("onOutLine", line) + }, + })) + + ucl["eval"] = js.FuncOf(func(this js.Value, args []js.Value) any { + if len(args) != 2 { + return nil + } + + cmdLine := args[0].String() + if strings.TrimSpace(cmdLine) == "" { + invokeUCLCallback("onNewCommand") + return nil + } + + wantContinue := args[1].Bool() + if err := inst.EvalAndDisplay(ctx, cmdLine); err != nil { + var p participle.Error + if errors.As(err, &p) && wantContinue { + invokeUCLCallback("onContinue") + return nil + } + + invokeUCLCallback("onError", err.Error()) + } + invokeUCLCallback("onNewCommand") + return nil + }) + js.Global().Set("ucl", ucl) +} + +type uclOut struct { + lineBuffer *bytes.Buffer + writeLine func(line string) +} + +func (uo *uclOut) Write(p []byte) (n int, err error) { + for _, b := range p { + if b == '\n' { + uo.writeLine(uo.lineBuffer.String()) + uo.lineBuffer.Reset() + } else { + uo.lineBuffer.WriteByte(b) + } + } + return len(p), nil +} diff --git a/cmd/playwasm/main.go b/cmd/playwasm/main.go new file mode 100644 index 0000000..d0274e7 --- /dev/null +++ b/cmd/playwasm/main.go @@ -0,0 +1,11 @@ +package main + +import ( + "context" +) + +func main() { + initJS(context.Background()) + + <-make(chan struct{}) +}