Queue for tag downloads

package-lock.json

@@ -7,8 +7,9 @@
     "": {
       "name": "bc-explorer",
       "version": "1.0.0",
-      "license": "ISC",
+      "license": "AGPL-3.0-only",
       "dependencies": {
+        "@chriscdn/promise-semaphore": "^2.0.10",
         "@cloudrac3r/pug": "^4.0.4",
         "@iconify-json/iconoir": "^1.2.7",
         "@iconify/utils": "^2.3.0",
@@ -85,6 +86,12 @@
         "node": ">=6.9.0"
       }
     },
+    "node_modules/@chriscdn/promise-semaphore": {
+      "version": "2.0.10",
+      "resolved": "https://registry.npmjs.org/@chriscdn/promise-semaphore/-/promise-semaphore-2.0.10.tgz",
+      "integrity": "sha512-NagoHAZEYISDYYprsHe+x2BEcD6GKhTpEreI8BM1qgtHOtCS3lbwRvvTQxzAxU8JVSmw7ep/ROLv3Ng/MPcMHg==",
+      "license": "MIT"
+    },
     "node_modules/@cloudrac3r/pug": {
       "version": "4.0.4",
       "resolved": "https://registry.npmjs.org/@cloudrac3r/pug/-/pug-4.0.4.tgz",

package.json

@@ -8,8 +8,9 @@
   },
   "keywords": [],
   "author": "",
-  "license": "ISC",
+  "license": "AGPL-3.0-only",
   "dependencies": {
+    "@chriscdn/promise-semaphore": "^2.0.10",
     "@cloudrac3r/pug": "^4.0.4",
     "@iconify-json/iconoir": "^1.2.7",
     "@iconify/utils": "^2.3.0",

pug/home.pug

@@ -6,6 +6,7 @@ html
     title BC Explorer
     link(rel="icon" href="/favicon.png")
     link(rel="stylesheet" type="text/css" href="/static/stacks.css")
+    link(rel="stylesheet" type="text/css" href="/static/style.css")
     script(src="/static/htmx.js")
     meta(name="htmx-config" content='{"requestClass":"is-loading"}')
   body.themed.theme-system.overflow-y-scroll
@@ -30,3 +31,17 @@ html
           input.s-input.wmx3#username(name="account" placeholder="Enter your Bandcamp username here")
         button.s-btn.s-btn__filled.my16#submit-username Load collection
         #results.d-flex
+
+      .s-prose.mt32
+        main
+          h2 About BC Explorer
+          p Explore your Bandcamp collection online!
+          p You can easily search your whole collection and play it streaming rather than downloading every mp3 to your computer and using a media player.
+          aside: p.fs-fine (you should download every mp3, though, because the Bandcamp TOS says they can take away your online access at any time)
+
+        footer.mt32.d-flex.fw-wrap.gx8.ai-center
+          a(href="https://cadence.moe") Created by Cadence
+          .s-award-bling.s-award-bling__silver.ml4
+          a(href="https://gitdab.com/cadence/bc-explorer") BC Explorer source code
+          .s-award-bling.s-award-bling__silver.ml4
+          span Not affiliated with Bandcamp.

pug/includes/tag-status.pug

@@ -1,6 +1,15 @@
 if downloader.total > 0 || downloader.outcome
   #tag-download
-    if !downloader.running && !downloader.outcome
+    if downloader.queuePosition > 0
+      .s-notice.p16(role="status" hx-target="#tag-download" hx-select="#tag-download" hx-get=`/api/tag-download?account=${account}` hx-trigger="every 30s" hx-indicator="null")
+        .d-flex.gx16.ai-center
+          != icons.get("cloud-download")
+          .fl-grow1 Waiting to download...
+        p.mt12.mb0 #{downloader.queuePosition} people are ahead of you in the queue.
+        p.mt12.mb0 You can keep using BC Explorer and this will process in the background.
+        title#title(hx-swap-oob="true") In queue | Tags | BC Explorer
+
+    else if !downloader.running && !downloader.outcome
       form.s-notice.s-notice__info.d-flex.ai-center.p8.gx16.pl16(role="status" hx-target="#tag-download" hx-select="#tag-download" hx-post="/api/tag-download")
         != icons.get("info-circle")
         div Tag data needs to be downloaded. This will take a while.
@@ -28,7 +37,7 @@ if downloader.total > 0 || downloader.outcome
         != icons.get("cloud-check")
         .fl-grow1 Tags downloaded.
         - downloader.resolve()
-        a.s-btn.s-btn__outlined(href=and({arrange: "tag"}) hx-boost="true") Refresh
+        a.s-btn.s-btn__outlined(href=and({arrange: "tag", shape: "grid"})) Refresh
 
     else
       .s-notice.s-notice__danger.p8.gx16.pl16.d-flex.ai-center

routes/load-collection.js

@@ -82,7 +82,7 @@ async function loadCollection(inputUsername) {
 
 	// load full tracks/tags immediately if there's not too many
 	const downloader = loadTags.downloadManager.check(account)
-	if (downloader.total <= 5) loadTags.downloadManager.start(account)
+	if (downloader.total > 0 && downloader.total <= 20 && loadTags.downloadManager.queue === 0) loadTags.downloadManager.start(account)
 
 	return {
 		storedItemCount,

routes/load-tags.js

@@ -2,6 +2,8 @@
 
 const domino = require("domino")
 const {getValidatedQuery, readValidatedBody, defineEventHandler} = require("h3")
+/** @type {import("@chriscdn/promise-semaphore")["default"]} */ // @ts-ignore
+const Semaphore = require("@chriscdn/promise-semaphore")
 
 const {sync, db, router} = require("../passthrough")
 
@@ -22,6 +24,7 @@ class TagDownloader extends sync.reloadClassMethods(() => TagDownloader) {
 		this.untaggedItems = []
 		this.total = this.untaggedItems.length
 		this.running = false
+		this.queuePosition = 0
 		this.outcome = null
 		this.check()
 	}
@@ -32,8 +35,14 @@ class TagDownloader extends sync.reloadClassMethods(() => TagDownloader) {
 		this.total = this.untaggedItems.length
 	}
 
+	_setQueued(queuePosition) {
+		if (this.running) return
+		this.queuePosition = queuePosition
+	}
+
 	async _start() {
 		if (this.running) return
+		this.queuePosition = 0
 		this.running = true
 		this.outcome = null
 		this.processed = 0
@@ -79,7 +88,7 @@ class TagDownloader extends sync.reloadClassMethods(() => TagDownloader) {
 			}
 			this.outcome = "Success"
 		} catch (e) {
-			console.error(e)
+			console.error(`error downloading tags for ${this.account} - ${e}`)
 			this.outcome = e.toString()
 		} finally {
 			this.running = false
@@ -94,6 +103,8 @@ class TagDownloader extends sync.reloadClassMethods(() => TagDownloader) {
 const downloadManager = new class {
 	/** @type {Map<string, TagDownloader>} */
 	inProgressTagDownloads = sync.remember(() => new Map())
+	semaphore = sync.remember(() => new Semaphore(1))
+	queue = 0
 
 	/** @param {string} account */
 	check(account) {
@@ -109,14 +120,21 @@ const downloadManager = new class {
 	/** @param {string} account */
 	start(account) {
 		const downloader = this.check(account)
-		downloader._start()
+		downloader._setQueued(++this.queue)
+		console.log(`requested tag download for ${account} - ${this.queue} in queue`)
+		this.semaphore.request(() => downloader._start()).finally(() => {
+			this.queue--
+			for (const otherDownloader of this.inProgressTagDownloads.values()) {
+				otherDownloader.queuePosition--
+			}
+		})
 		return downloader
 	}
 
 	/** @param {string} account */
 	resolve(account) {
 		const downloader = this.check(account)
-		if (!downloader.running) {
+		if (!downloader.running && downloader.queuePosition <= 0) {
 			this.inProgressTagDownloads.delete(account)
 		}
 	}