merge files from the blockchain infra repo (#59)

code/protocol_demos/short-polling/index.js

@@ -0,0 +1,24 @@
+const app = require("express")();
+const jobs = {}
+
+app.post("/submit", (req, res) =>  {
+    const jobId = `job:${Date.now()}`
+    jobs[jobId] = 0;
+    updateJob(jobId,0); 
+    res.end("\n\n" + jobId + "\n\n");
+})
+
+app.get("/checkstatus", (req, res) => {
+    console.log(jobs[req.query.jobId])
+    res.end("\n\nJobStatus: " + jobs[req.query.jobId] + "%\n\n")
+
+} )
+
+app.listen(8080, () => console.log("listening on 8080"));
+
+function updateJob(jobId, prg) {
+    jobs[jobId] = prg;
+    console.log(`updated ${jobId} to ${prg}`)
+    if (prg == 100) return;
+    this.setTimeout(()=> updateJob(jobId, prg + 10), 3000)
+}