codegen

Documentation

Index

• Constants
• func ClientGoMain(appPath string) (string, error)
• func ServerGoMain(appPath string) (string, error)

Constants

const GlobalCSS = `
body {
	padding-top: 5rem;
  }
  .starter-template {
	padding: 3rem 1.5rem;
	text-align: center;
  }
`

GlobalCSS returns the global CSS code

const IndexHTML = `` /* 1503-byte string literal not displayed */

IndexHTML returns the HTML for the initial index page that serves the wasm "shell"

const Makefile = `` /* 162-byte string literal not displayed */

Makefile returns the Makefile code for the new app

TODO: this won't be necessary after https://github.com/factorapp/factor/issues/11

const NavComponentGo = `package components

import (
	"github.com/gowasm/vecty"
)

type Nav struct {
	vecty.Core
	MyProp      string ` + "`" + "vecty:" + `"Prop"` + "`" + `
	CurrentPath string
}
`

NavComponentGo returns the Go code for the Nav component

TODO: make this flexible to generate arbitrary components see https://github.com/factorapp/factor/issues/24

const NavComponentHTML = `` /* 1417-byte string literal not displayed */

NavComponentHTML returns the HTML code for the Nav component

const RoutesGo = `` /* 320-byte string literal not displayed */

RoutesGo returns the Go code for the index route

const RoutesHTML = `` /* 333-byte string literal not displayed */

RoutesHTML returns the HTML code for the index route

const TodoClient = `` /* 304-byte string literal not displayed */

RoutesHTML returns the HTML code for the index route

const WasmJS = `// 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.

(() => {
	// 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 {
		window.global = window;

		let outputBuf = "";
		global.fs = {
			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1, O_NONBLOCK: -1, O_SYNC: -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;
			},
			openSync(path, flags, mode) {
				const err = new Error("not implemented");
				err.code = "ENOSYS";
				throw err;
			},
		};
	}

	const encoder = new TextEncoder("utf-8");
	const decoder = new TextDecoder("utf-8");

	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.mem.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 (!isNaN(f)) {
					return f;
				}

				const id = mem().getUint32(addr, true);
				return this._values[id];
			}

			const storeValue = (addr, v) => {
				if (typeof v === "number") {
					if (isNaN(v)) {
						mem().setUint32(addr + 4, 0x7FF80000, true); // NaN
						mem().setUint32(addr, 0, true);
						return;
					}
					mem().setFloat64(addr, v, true);
					return;
				}

				mem().setUint32(addr + 4, 0x7FF80000, true); // NaN

				switch (v) {
					case undefined:
						mem().setUint32(addr, 1, true);
						return;
					case null:
						mem().setUint32(addr, 2, true);
						return;
					case true:
						mem().setUint32(addr, 3, true);
						return;
					case false:
						mem().setUint32(addr, 4, true);
						return;
				}

				if (typeof v === "string") {
					let ref = this._stringRefs.get(v);
					if (ref === undefined) {
						ref = this._values.length;
						this._values.push(v);
						this._stringRefs.set(v, ref);
					}
					mem().setUint32(addr, ref, true);
					return;
				}

				if (typeof v === "symbol") {
					let ref = this._symbolRefs.get(v);
					if (ref === undefined) {
						ref = this._values.length;
						this._values.push(v);
						this._symbolRefs.set(v, ref);
					}
					mem().setUint32(addr, ref, true);
					return;
				}

				let ref = v[this._refProp];
				if (ref === undefined) {
					ref = this._values.length;
					this._values.push(v);
					v[this._refProp] = ref;
				}
				mem().setUint32(addr, ref, 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 = {
				go: {
					// func wasmExit(code int32)
					"runtime.wasmExit": (sp) => {
						this.exited = true;
						this.exit(mem().getInt32(sp + 8, true));
					},

					// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
					"runtime.wasmWrite": (sp) => {
						const fd = getInt64(sp + 8);
						const p = getInt64(sp + 16);
						const n = mem().getInt32(sp + 24, true);
						fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n));
					},

					// func nanotime() int64
					"runtime.nanotime": (sp) => {
						setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
					},

					// func walltime() (sec int64, nsec int32)
					"runtime.walltime": (sp) => {
						const msec = (new Date).getTime();
						setInt64(sp + 8, msec / 1000);
						mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
					},

					// func scheduleCallback(delay int64) int32
					"runtime.scheduleCallback": (sp) => {
						const id = this._nextCallbackTimeoutID;
						this._nextCallbackTimeoutID++;
						this._callbackTimeouts.set(id, setTimeout(
							() => { this._resolveCallbackPromise(); },
							getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
						));
						mem().setInt32(sp + 16, id, true);
					},

					// func clearScheduledCallback(id int32)
					"runtime.clearScheduledCallback": (sp) => {
						const id = mem().getInt32(sp + 8, true);
						clearTimeout(this._callbackTimeouts.get(id));
						this._callbackTimeouts.delete(id);
					},

					// func getRandomData(r []byte)
					"runtime.getRandomData": (sp) => {
						crypto.getRandomValues(loadSlice(sp + 8));
					},

					// func stringVal(value string) ref
					"syscall/js.stringVal": (sp) => {
						storeValue(sp + 24, loadString(sp + 8));
					},

					// func valueGet(v ref, p string) ref
					"syscall/js.valueGet": (sp) => {
						storeValue(sp + 32, Reflect.get(loadValue(sp + 8), loadString(sp + 16)));
					},

					// func valueSet(v ref, p string, x ref)
					"syscall/js.valueSet": (sp) => {
						Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
					},

					// 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": (sp) => {
						try {
							const v = loadValue(sp + 8);
							const m = Reflect.get(v, loadString(sp + 16));
							const args = loadSliceOfValues(sp + 32);
							storeValue(sp + 56, Reflect.apply(m, v, args));
							mem().setUint8(sp + 64, 1);
						} catch (err) {
							storeValue(sp + 56, err);
							mem().setUint8(sp + 64, 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": (sp) => {
						try {
							const v = loadValue(sp + 8);
							const args = loadSliceOfValues(sp + 16);
							storeValue(sp + 40, Reflect.construct(v, args));
							mem().setUint8(sp + 48, 1);
						} catch (err) {
							storeValue(sp + 40, err);
							mem().setUint8(sp + 48, 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": (sp) => {
						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) => {
						const str = loadValue(sp + 8);
						loadSlice(sp + 16).set(str);
					},

					// func valueInstanceOf(v ref, t ref) bool
					"syscall/js.valueInstanceOf": (sp) => {
						mem().setUint8(sp + 24, loadValue(sp + 8) instanceof loadValue(sp + 16));
					},

					"debug": (value) => {
						console.log(value);
					},
				}
			};
		}

		async run(instance) {
			this._inst = instance;
			this._values = [ // TODO: garbage collection
				NaN,
				undefined,
				null,
				true,
				false,
				global,
				this._inst.exports.mem,
				() => { // resolveCallbackPromise
					if (this.exited) {
						throw new Error("bad callback: Go program has already exited");
					}
					setTimeout(this._resolveCallbackPromise, 0); // make sure it is asynchronous
				},
			];
			this._stringRefs = new Map();
			this._symbolRefs = new Map();
			this._refProp = Symbol();
			this.exited = false;

			const mem = new DataView(this._inst.exports.mem.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 = resolve;
				});
				this._inst.exports.run(argc, argv);
				if (this.exited) {
					break;
				}
				await callbackPromise;
			}
		}
	}

	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", () => { // Node.js exits if no callback is pending
				if (!go.exited) {
					console.error("error: all goroutines asleep and no JavaScript callback pending - deadlock!");
					process.exit(1);
				}
			});
			return go.run(result.instance);
		}).catch((err) => {
			console.error(err);
			go.exited = true;
			process.exit(1);
		});
	}
})();
`

WasmJS returns the javascript to execute the wasm binary

Functions

func ClientGoMain

func ClientGoMain(appPath string) (string, error)

ClientGoMain returns the Go code for the main function for the wasm app

func ServerGoMain

func ServerGoMain(appPath string) (string, error)

ServerGoMain returns the main.go for the server