From 40766bea4ccf1781095f38b93ed3009798f50777 Mon Sep 17 00:00:00 2001
From: AJ ONeal <aj@therootcompany.com>
Date: Sun, 26 Nov 2023 09:47:40 +0000
Subject: [PATCH] feat: cold-boot caching w/ lazy warm stale refreshes

---
 _webi/builds-cacher.js | 52 ++++++++++++++++++++++++++++++++----------
 _webi/lint-builds.js   | 31 +++++++++++++++++++++----
 2 files changed, 66 insertions(+), 17 deletions(-)

diff --git a/_webi/builds-cacher.js b/_webi/builds-cacher.js
index df5fd93..8948b8f 100644
--- a/_webi/builds-cacher.js
+++ b/_webi/builds-cacher.js
@@ -71,23 +71,25 @@ async function readFirstBytes(path) {
 }
 
 let promises = {};
-async function getLatestBuilds(Releases, cacheDir, name) {
+async function getLatestBuilds(Releases, cacheDir, name, date) {
   let id = `${cacheDir}/${name}`;
   if (!promises[id]) {
     promises[id] = Promise.resolve();
   }
 
   promises[id] = promises[id].then(async function () {
-    return await getLatestBuildsInner(Releases, cacheDir, name);
+    return await getLatestBuildsInner(Releases, cacheDir, name, date);
   });
 
   return await promises[id];
 }
 
-async function getLatestBuildsInner(Releases, cacheDir, name) {
+async function getLatestBuildsInner(Releases, cacheDir, name, date) {
   let data = await Releases.latest(request);
 
-  let date = new Date();
+  if (!date) {
+    date = new Date();
+  }
   let isoDate = date.toISOString();
   let yearMonth = isoDate.slice(0, 7);
 
@@ -121,6 +123,8 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
   bc.unknownTerms = {};
   bc._triplets = {};
   bc._downloadTriplets = {};
+  bc._caches = {};
+  bc._staleAge = 15 * 60 * 1000;
 
   for (let term of TERMS_META) {
     delete bc.orphanTerms[term];
@@ -216,9 +220,18 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
 
   // Typically a package is organized by release (ex: go has 1.20, 1.21, etc),
   // but we will organize by the build (ex: go1.20-darwin-arm64.tar.gz, etc).
-  bc.getBuilds = async function ({ name, date }) {
+  bc.getBuilds = async function ({ Releases, name, date }) {
     let cacheDir = caches;
     let installerDir = installers;
+
+    if (!Releases) {
+      Releases = require(`${installerDir}/${name}/releases.js`);
+    }
+    // TODO update all releases files with object export
+    if (!Releases.latest) {
+      Releases.latest = Releases;
+    }
+
     if (!date) {
       date = new Date();
     }
@@ -237,6 +250,22 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
 
     // let age = now - seconds;
 
+    let data = bc._caches[name];
+    let now = date.valueOf();
+    if (data) {
+      process.nextTick(async function () {
+        let age = now - data.updated;
+        if (age < bc._staleAge) {
+          return;
+        }
+        data = await getLatestBuilds(Releases, cacheDir, name);
+        let updated = date.valueOf();
+        Object.assign(data, { name, updated });
+        bc._caches[name] = data;
+      });
+      return data;
+    }
+
     let json = await Fs.readFile(dataFile, 'ascii').catch(async function (err) {
       if (err.code !== 'ENOENT') {
         throw err;
@@ -245,7 +274,6 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
       return null;
     });
 
-    let data;
     try {
       data = JSON.parse(json);
     } catch (e) {
@@ -254,14 +282,11 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
     }
 
     if (!data) {
-      let Releases = require(`${installerDir}/${name}/releases.js`);
-      // TODO update all releases files with object export
-      if (!Releases.latest) {
-        Releases.latest = Releases;
-      }
       data = await getLatestBuilds(Releases, cacheDir, name);
     }
-    Object.assign(data, { name });
+    let updated = date.valueOf();
+    Object.assign(data, { name, updated });
+    bc._caches[name] = data;
 
     for (let build of data.releases) {
       if (LEGACY_OS_MAP[build.os]) {
@@ -292,7 +317,10 @@ BuildsCacher.create = function ({ ALL_TERMS, installers, caches }) {
     }
 
     let name = bc._staleNames.pop();
+    let Releases = require(`${installers}/${name}/releases.js`);
+    //data = await getLatestBuilds(Releases, cacheDir, name);
     void (await bc.getBuilds({
+      Releases: Releases,
       name: name,
       date: new Date(),
     }));
diff --git a/_webi/lint-builds.js b/_webi/lint-builds.js
index 9a8d703..c20bcf6 100644
--- a/_webi/lint-builds.js
+++ b/_webi/lint-builds.js
@@ -77,12 +77,12 @@ function showDirs(dirs) {
   }
 }
 
-async function main() {
-  let bc = BuildsCacher.create({
-    caches: CACHE_DIR,
-    installers: INSTALLERS_DIR,
-  });
+let bc = BuildsCacher.create({
+  caches: CACHE_DIR,
+  installers: INSTALLERS_DIR,
+});
 
+async function main() {
   // let names = ['{NAME}-win32.exe'];
   // for (let name of names) {
   //   console.log(name);
@@ -125,7 +125,9 @@ async function main() {
     }
 
     console.info(`    ${name}`);
+    let Releases = require(`${INSTALLERS_DIR}/${name}/releases.js`);
     let pkg = await bc.getBuilds({
+      Releases: Releases,
       name: name,
       date: new Date(),
     });
@@ -221,8 +223,27 @@ async function main() {
 }
 
 if (module === require.main) {
+  let times = [];
+  let now = Date.now();
   main()
+    .then(async function () {
+      let then = Date.now();
+      let delta = then - now;
+      times.push(delta);
+      now = then;
+      await main();
+      then = Date.now();
+      delta = then - now;
+      times.push(delta);
+    })
     .then(function () {
+      console.info('');
+      console.info('Run times');
+      for (let delta of times) {
+        let s = delta / 1000;
+        console.info(`    ${s}`);
+      }
+
       function forceExit() {
         console.warn(`warn: dangling event loop reference`);
         process.exit(0);