add process code

Author: wangding

04-process/07-byte-to-size.js

@@ -0,0 +1,29 @@
+#!/usr/bin/env node
+
+const unit = ['', 'K', 'M', 'G', 'T', 'P'];
+
+function bytesToSize(input, precision = 3) {
+  const index = Math.floor(Math.log(input) / Math.log(1024));
+  return (input / Math.pow(1024, index)).toFixed(precision) + ' ' + unit[index] + 'B';
+}
+
+function mem() {
+  const m = process.memoryUsage();
+  console.log(bytesToSize(m.rss));
+  console.log(bytesToSize(m.heapTotal));
+  console.log(bytesToSize(m.heapUsed));
+  console.log(bytesToSize(m.external));
+  console.log(bytesToSize(m.arrayBuffers));
+  console.log();
+}
+
+mem();
+/*
+const fs = require('fs');
+fs.readFile('../09-stream/big.file', (err, data) =>{
+  mem();
+  fs.writeFile('./tmp.data', data, ()=>{
+    console.log('ok');
+  });
+});
+*/