Cache currency data in a file for better reliability

.gitignore

@@ -7,3 +7,4 @@
 **/__sapper__
 **/.rpt2_cache
 **/build
+/web/data

web/package.json

@@ -42,7 +42,8 @@
     "elementtree": "^0.1.7",
     "express": "^4.17.1",
     "node-fetch": "^2.6.1",
-    "sirv": "^1.0.0"
+    "sirv": "^1.0.0",
+    "atomically": "1.7.0"
   },
   "browserslist": [
     "last 3 chrome versions",

web/src/routes/data/currency.json.ts → web/src/currency.ts

@@ -1,7 +1,8 @@
-import cached from "./_cached";
 import { Def } from "util/defs";
 import fetch from "node-fetch";
 import { parse } from "elementtree";
+import { writeFile } from "atomically";
+import { mkdir } from "fs/promises";
 
 async function btc() {
   interface Format {
@@ -104,10 +105,17 @@ async function ecb() {
   return defs;
 }
 
-export const get = cached(3600 * 1000, async () => {
-  const [btcDefs, ecbDefs] = await Promise.all([btc(), ecb()]);
+const DATA_DIR = process.env.DATA_DIR || "data";
+export const currencyPath = `${DATA_DIR}/currency.json`;
 
+export async function updateCurrency() {
+  const [btcDefs, ecbDefs] = await Promise.all([btc(), ecb()]);
   const defs: Def[] = [...btcDefs, ...ecbDefs];
 
-  return defs;
-});
+  await mkdir(DATA_DIR, { recursive: true });
+
+  await writeFile(currencyPath, JSON.stringify(defs, undefined, "\t"), {
+    encoding: "utf8",
+  });
+  console.log("Successfully updated file.");
+}

web/src/server.js

@@ -4,23 +4,43 @@ import sirv from "sirv";
 import express from "express";
 import compression from "compression";
 import * as sapper from "@sapper/server";
+import { updateCurrency, currencyPath } from "./currency.ts";
+import { existsSync } from "fs";
 
 const { PORT, NODE_ENV } = process.env;
 const dev = NODE_ENV === "development";
 
-express()
-  .use(
-    compression({ threshold: 0 }),
-    sirv("static", { dev }),
-    sapper.middleware()
-  )
-  .listen(PORT, (err) => {
-    if (err) console.log("error", err);
-  });
+async function batchJob() {
+  await updateCurrency();
+  process.exit(0);
+}
+
+async function main() {
+  if (!existsSync(currencyPath)) {
+    await updateCurrency();
+  }
+
+  express()
+    .use("data", sirv(".", { dev }))
+    .use(
+      compression({ threshold: 0 }),
+      sirv("static", { dev }),
+      sapper.middleware()
+    )
+    .listen(PORT, (err) => {
+      if (err) console.log("error", err);
+    });
 
-async function loadRink() {
-  let rink = await wasm();
-  Rink.setRink(rink);
+  async function loadRink() {
+    let rink = await wasm();
+    Rink.setRink(rink);
+  }
+
+  loadRink();
 }
 
-loadRink();
+if (process.argv[2] == "batch-job") {
+  batchJob();
+} else {
+  main();
+}