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// Copyright 2018 The Go Authors. All rights reserved. |
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// Use of this source code is governed by a BSD-style |
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// license that can be found in the LICENSE file. |
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(() => { |
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if (typeof global !== "undefined") { |
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// global already exists |
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} else if (typeof window !== "undefined") { |
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window.global = window; |
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} else if (typeof self !== "undefined") { |
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self.global = self; |
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} else { |
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throw new Error("cannot export Go (neither global, window nor self is defined)"); |
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} |
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// Map web browser API and Node.js API to a single common API (preferring web standards over Node.js API). |
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const isNodeJS = global.process && global.process.title === "node"; |
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if (isNodeJS) { |
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global.require = require; |
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global.fs = require("fs"); |
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const nodeCrypto = require("crypto"); |
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global.crypto = { |
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getRandomValues(b) { |
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nodeCrypto.randomFillSync(b); |
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}, |
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}; |
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global.performance = { |
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now() { |
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const [sec, nsec] = process.hrtime(); |
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return sec * 1000 + nsec / 1000000; |
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}, |
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}; |
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const util = require("util"); |
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global.TextEncoder = util.TextEncoder; |
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global.TextDecoder = util.TextDecoder; |
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} else { |
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let outputBuf = ""; |
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global.fs = { |
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constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused |
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writeSync(fd, buf) { |
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outputBuf += decoder.decode(buf); |
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const nl = outputBuf.lastIndexOf("\n"); |
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if (nl != -1) { |
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console.log(outputBuf.substr(0, nl)); |
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outputBuf = outputBuf.substr(nl + 1); |
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} |
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return buf.length; |
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}, |
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write(fd, buf, offset, length, position, callback) { |
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if (offset !== 0 || length !== buf.length || position !== null) { |
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throw new Error("not implemented"); |
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} |
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const n = this.writeSync(fd, buf); |
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callback(null, n); |
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}, |
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open(path, flags, mode, callback) { |
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const err = new Error("not implemented"); |
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err.code = "ENOSYS"; |
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callback(err); |
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}, |
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read(fd, buffer, offset, length, position, callback) { |
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const err = new Error("not implemented"); |
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err.code = "ENOSYS"; |
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callback(err); |
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}, |
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fsync(fd, callback) { |
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callback(null); |
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}, |
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}; |
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} |
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const encoder = new TextEncoder("utf-8"); |
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const decoder = new TextDecoder("utf-8"); |
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global.Go = class { |
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constructor() { |
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this.argv = ["js"]; |
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this.env = {}; |
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this.exit = (code) => { |
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if (code !== 0) { |
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console.warn("exit code:", code); |
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} |
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}; |
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this._exitPromise = new Promise((resolve) => { |
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this._resolveExitPromise = resolve; |
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}); |
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this._pendingEvent = null; |
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this._scheduledTimeouts = new Map(); |
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this._nextCallbackTimeoutID = 1; |
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|
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const mem = () => { |
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// The buffer may change when requesting more memory. |
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return new DataView(this._inst.exports.mem.buffer); |
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} |
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const setInt64 = (addr, v) => { |
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mem().setUint32(addr + 0, v, true); |
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mem().setUint32(addr + 4, Math.floor(v / 4294967296), true); |
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} |
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const getInt64 = (addr) => { |
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const low = mem().getUint32(addr + 0, true); |
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const high = mem().getInt32(addr + 4, true); |
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return low + high * 4294967296; |
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} |
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const loadValue = (addr) => { |
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const f = mem().getFloat64(addr, true); |
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if (f === 0) { |
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return undefined; |
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} |
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if (!isNaN(f)) { |
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return f; |
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} |
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const id = mem().getUint32(addr, true); |
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return this._values[id]; |
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} |
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const storeValue = (addr, v) => { |
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const nanHead = 0x7FF80000; |
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if (typeof v === "number") { |
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if (isNaN(v)) { |
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mem().setUint32(addr + 4, nanHead, true); |
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mem().setUint32(addr, 0, true); |
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return; |
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} |
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if (v === 0) { |
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mem().setUint32(addr + 4, nanHead, true); |
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mem().setUint32(addr, 1, true); |
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return; |
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} |
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mem().setFloat64(addr, v, true); |
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return; |
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} |
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switch (v) { |
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case undefined: |
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mem().setFloat64(addr, 0, true); |
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return; |
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case null: |
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mem().setUint32(addr + 4, nanHead, true); |
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mem().setUint32(addr, 2, true); |
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return; |
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case true: |
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mem().setUint32(addr + 4, nanHead, true); |
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mem().setUint32(addr, 3, true); |
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return; |
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case false: |
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mem().setUint32(addr + 4, nanHead, true); |
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mem().setUint32(addr, 4, true); |
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return; |
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} |
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let ref = this._refs.get(v); |
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if (ref === undefined) { |
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ref = this._values.length; |
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this._values.push(v); |
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this._refs.set(v, ref); |
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} |
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let typeFlag = 0; |
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switch (typeof v) { |
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case "string": |
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typeFlag = 1; |
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break; |
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case "symbol": |
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typeFlag = 2; |
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break; |
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case "function": |
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typeFlag = 3; |
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break; |
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} |
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mem().setUint32(addr + 4, nanHead | typeFlag, true); |
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mem().setUint32(addr, ref, true); |
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} |
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const loadSlice = (addr) => { |
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const array = getInt64(addr + 0); |
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const len = getInt64(addr + 8); |
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return new Uint8Array(this._inst.exports.mem.buffer, array, len); |
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} |
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const loadSliceOfValues = (addr) => { |
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const array = getInt64(addr + 0); |
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const len = getInt64(addr + 8); |
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const a = new Array(len); |
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for (let i = 0; i < len; i++) { |
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a[i] = loadValue(array + i * 8); |
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} |
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return a; |
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} |
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const loadString = (addr) => { |
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const saddr = getInt64(addr + 0); |
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const len = getInt64(addr + 8); |
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return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len)); |
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} |
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const timeOrigin = Date.now() - performance.now(); |
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this.importObject = { |
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go: { |
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// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters) |
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// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported |
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// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function). |
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// This changes the SP, thus we have to update the SP used by the imported function. |
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// func wasmExit(code int32) |
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"runtime.wasmExit": (sp) => { |
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const code = mem().getInt32(sp + 8, true); |
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this.exited = true; |
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delete this._inst; |
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delete this._values; |
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delete this._refs; |
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this.exit(code); |
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}, |
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// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32) |
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"runtime.wasmWrite": (sp) => { |
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const fd = getInt64(sp + 8); |
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const p = getInt64(sp + 16); |
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const n = mem().getInt32(sp + 24, true); |
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fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n)); |
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}, |
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// func nanotime() int64 |
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"runtime.nanotime": (sp) => { |
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setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000); |
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}, |
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// func walltime() (sec int64, nsec int32) |
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"runtime.walltime": (sp) => { |
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const msec = (new Date).getTime(); |
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setInt64(sp + 8, msec / 1000); |
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mem().setInt32(sp + 16, (msec % 1000) * 1000000, true); |
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}, |
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// func scheduleTimeoutEvent(delay int64) int32 |
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"runtime.scheduleTimeoutEvent": (sp) => { |
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const id = this._nextCallbackTimeoutID; |
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this._nextCallbackTimeoutID++; |
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this._scheduledTimeouts.set(id, setTimeout( |
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() => { this._resume(); }, |
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getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early |
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)); |
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mem().setInt32(sp + 16, id, true); |
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}, |
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// func clearTimeoutEvent(id int32) |
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"runtime.clearTimeoutEvent": (sp) => { |
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const id = mem().getInt32(sp + 8, true); |
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clearTimeout(this._scheduledTimeouts.get(id)); |
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this._scheduledTimeouts.delete(id); |
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}, |
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// func getRandomData(r []byte) |
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"runtime.getRandomData": (sp) => { |
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crypto.getRandomValues(loadSlice(sp + 8)); |
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}, |
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// func stringVal(value string) ref |
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"syscall/js.stringVal": (sp) => { |
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storeValue(sp + 24, loadString(sp + 8)); |
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}, |
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// func valueGet(v ref, p string) ref |
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"syscall/js.valueGet": (sp) => { |
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const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16)); |
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sp = this._inst.exports.getsp(); // see comment above |
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storeValue(sp + 32, result); |
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}, |
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// func valueSet(v ref, p string, x ref) |
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"syscall/js.valueSet": (sp) => { |
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Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32)); |
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}, |
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// func valueIndex(v ref, i int) ref |
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"syscall/js.valueIndex": (sp) => { |
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storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16))); |
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}, |
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// valueSetIndex(v ref, i int, x ref) |
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"syscall/js.valueSetIndex": (sp) => { |
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Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24)); |
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}, |
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// func valueCall(v ref, m string, args []ref) (ref, bool) |
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"syscall/js.valueCall": (sp) => { |
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try { |
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const v = loadValue(sp + 8); |
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const m = Reflect.get(v, loadString(sp + 16)); |
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const args = loadSliceOfValues(sp + 32); |
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const result = Reflect.apply(m, v, args); |
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sp = this._inst.exports.getsp(); // see comment above |
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storeValue(sp + 56, result); |
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mem().setUint8(sp + 64, 1); |
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} catch (err) { |
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storeValue(sp + 56, err); |
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mem().setUint8(sp + 64, 0); |
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} |
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}, |
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// func valueInvoke(v ref, args []ref) (ref, bool) |
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"syscall/js.valueInvoke": (sp) => { |
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try { |
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const v = loadValue(sp + 8); |
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const args = loadSliceOfValues(sp + 16); |
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const result = Reflect.apply(v, undefined, args); |
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sp = this._inst.exports.getsp(); // see comment above |
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storeValue(sp + 40, result); |
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mem().setUint8(sp + 48, 1); |
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} catch (err) { |
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storeValue(sp + 40, err); |
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mem().setUint8(sp + 48, 0); |
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} |
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}, |
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// func valueNew(v ref, args []ref) (ref, bool) |
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"syscall/js.valueNew": (sp) => { |
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try { |
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const v = loadValue(sp + 8); |
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const args = loadSliceOfValues(sp + 16); |
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const result = Reflect.construct(v, args); |
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sp = this._inst.exports.getsp(); // see comment above |
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storeValue(sp + 40, result); |
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mem().setUint8(sp + 48, 1); |
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} catch (err) { |
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storeValue(sp + 40, err); |
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mem().setUint8(sp + 48, 0); |
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} |
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}, |
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// func valueLength(v ref) int |
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"syscall/js.valueLength": (sp) => { |
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setInt64(sp + 16, parseInt(loadValue(sp + 8).length)); |
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}, |
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// valuePrepareString(v ref) (ref, int) |
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"syscall/js.valuePrepareString": (sp) => { |
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const str = encoder.encode(String(loadValue(sp + 8))); |
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storeValue(sp + 16, str); |
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setInt64(sp + 24, str.length); |
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}, |
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// valueLoadString(v ref, b []byte) |
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"syscall/js.valueLoadString": (sp) => { |
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const str = loadValue(sp + 8); |
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loadSlice(sp + 16).set(str); |
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}, |
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// func valueInstanceOf(v ref, t ref) bool |
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"syscall/js.valueInstanceOf": (sp) => { |
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mem().setUint8(sp + 24, loadValue(sp + 8) instanceof loadValue(sp + 16)); |
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}, |
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"debug": (value) => { |
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console.log(value); |
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}, |
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} |
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}; |
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} |
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async run(instance) { |
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this._inst = instance; |
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this._values = [ // TODO: garbage collection |
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NaN, |
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0, |
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null, |
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true, |
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false, |
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global, |
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this._inst.exports.mem, |
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this, |
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]; |
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this._refs = new Map(); |
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this.exited = false; |
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const mem = new DataView(this._inst.exports.mem.buffer) |
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// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory. |
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let offset = 4096; |
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const strPtr = (str) => { |
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let ptr = offset; |
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new Uint8Array(mem.buffer, offset, str.length + 1).set(encoder.encode(str + "\0")); |
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offset += str.length + (8 - (str.length % 8)); |
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return ptr; |
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}; |
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const argc = this.argv.length; |
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const argvPtrs = []; |
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this.argv.forEach((arg) => { |
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argvPtrs.push(strPtr(arg)); |
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}); |
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const keys = Object.keys(this.env).sort(); |
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argvPtrs.push(keys.length); |
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keys.forEach((key) => { |
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argvPtrs.push(strPtr(`${key}=${this.env[key]}`)); |
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}); |
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const argv = offset; |
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argvPtrs.forEach((ptr) => { |
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mem.setUint32(offset, ptr, true); |
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mem.setUint32(offset + 4, 0, true); |
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offset += 8; |
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}); |
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this._inst.exports.run(argc, argv); |
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if (this.exited) { |
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this._resolveExitPromise(); |
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} |
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await this._exitPromise; |
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} |
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_resume() { |
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if (this.exited) { |
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throw new Error("Go program has already exited"); |
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} |
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this._inst.exports.resume(); |
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if (this.exited) { |
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this._resolveExitPromise(); |
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} |
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} |
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_makeFuncWrapper(id) { |
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const go = this; |
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return function () { |
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const event = { id: id, this: this, args: arguments }; |
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go._pendingEvent = event; |
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go._resume(); |
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return event.result; |
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}; |
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} |
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} |
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if (isNodeJS) { |
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if (process.argv.length < 3) { |
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process.stderr.write("usage: go_js_wasm_exec [wasm binary] [arguments]\n"); |
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process.exit(1); |
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} |
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const go = new Go(); |
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go.argv = process.argv.slice(2); |
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go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env); |
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go.exit = process.exit; |
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WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => { |
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process.on("exit", (code) => { // Node.js exits if no event handler is pending |
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if (code === 0 && !go.exited) { |
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// deadlock, make Go print error and stack traces |
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go._pendingEvent = { id: 0 }; |
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go._resume(); |
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} |
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}); |
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return go.run(result.instance); |
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}).catch((err) => { |
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throw err; |
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}); |
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} |
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})(); |
