digital-vcd-parser/lib/wrapper.js
2020-09-27 02:42:00 -07:00

106 lines
2.3 KiB
JavaScript

'use strict';
function _waitForStart(mod) {
return new Promise((resolve, reject)=>{
mod.addOnPostRun(resolve);
});
}
module.exports = () => {
// let state = 0; // idle
// let total = 0;
// let start = 0;
const c = {};
const wasm = require('../out/vcd.js');
let bindCallback;
const bindCWrap = () => {
const w = wasm.cwrap;
c.execute = w('execute', 'void', ['number', 'number', 'number', 'number', 'number', 'string']);
c.init = w('init', 'number', ['number', 'number', 'number', 'number']);
};
const start = async() => {
await _waitForStart(wasm);
bindCWrap();
bindCallback();
}
// gets a string from a c heap pointer and length
const getString = (name,len) => {
const view = wasm.HEAPU8.subarray(name, name+len);
let string = '';
for (let i = 0; i < len; i++) {
string += String.fromCharCode(view[i]);
}
return string;
}
let boundInfo;
let boundSet;
let boundGet;
let context = -1;
// wasm.addFunction can't be called until after
// start finishes
bindCallback = () => {
boundSet = wasm.addFunction(function(name, len, type, v0, v1) {
let prop = getString(name, len);
switch(type) {
case 0:
boundInfo[prop] = v0;
break;
case 1:
boundInfo[prop] = getString(v0, v1);
break;
default: throw new Error();
}
console.log(`setting ${prop} to ${boundInfo[prop]}`);
// viiiii means returns void, accepts int int int int int
}, 'viiiii');
boundGet = wasm.addFunction(function(name, len) {
let prop = getString(name, len);
return 42;
}, 'iii');
};
return {
start,
c,
log: () => {
console.log(wasm);
},
init: (cb0, cb1, info) => {
boundInfo = info;
context = c.init(0,0,boundSet,boundGet);
},
execute: () => {
c.execute(context,0,0,boundSet,boundGet,"hi");
},
onB: (time, cmd) => {
},
onNotB: (time, cmd) => {
switch(state) {
case 0: if (cmd === 14) { state = 2; } break;
case 1: if (cmd === 14) { state = 3; start = time; } break;
case 2: if (cmd === 15) { state = 0; } break;
case 3: if (cmd === 15) { state = 1; total += (time - start); start = 0; } break;
default: throw new Error();
}
},
time: () => total + start
};
};