Ignore library cached metadata when queueing

The use of the channel library as a cache for metadata to avoid
re-requesting metadata for known media is an optimization that dates
back to 1.0.  However, it doesn't have any TTL, is prone to bugs, and is
of dubious value.

This commit ignores the results of the library check when queueing a new
video, opting to always re-request the metadata.  This fixes a few bugs:

  * Google Drive metadata being lost when storing in library
  * Streamable metadata being lost when storing in library
  * Videos in the channel library that are now unavailable on their
    source website being queueable and then failing to play (e.g. deleted
    YouTube videos).

In its place, a small fail-open check is left behind to emit metric
counters on how many queues would have been cache-hits, to provide
insight into whether a proper caching solution (i.e. one not tacked on
top of the library) would be worth pursuing or not.  This will be
removed eventually.

package.json

@@ -2,7 +2,7 @@
   "author": "Calvin Montgomery",
   "name": "CyTube",
   "description": "Online media synchronizer and chat",
-  "version": "3.39.6",
+  "version": "3.40.0",
   "repository": {
     "url": "http://github.com/calzoneman/sync"
   },

src/channel/playlist.js

@@ -8,6 +8,7 @@ var Flags = require("../flags");
 var db = require("../database");
 var CustomEmbedFilter = require("../customembed").filter;
 var XSS = require("../xss");
+import counters from '../counters';
 
 const LOGGER = require('@calzoneman/jsli')('playlist');
 
@@ -328,6 +329,10 @@ PlaylistModule.prototype.handleQueue = function (user, data) {
 
     var id = data.id;
     var type = data.type;
+    if (type === "lib") {
+        LOGGER.warn("Outdated client: IP %s emitting queue with type=lib",
+                user.realip);
+    }
 
     if (data.pos !== "next" && data.pos !== "end") {
         return;
@@ -450,36 +455,25 @@ PlaylistModule.prototype.queueStandard = function (user, data) {
 
     const self = this;
     this.channel.refCounter.ref("PlaylistModule::queueStandard");
+    counters.add("playlist:queue:count", 1);
     this.semaphore.queue(function (lock) {
         var lib = self.channel.modules.library;
         if (lib && self.channel.is(Flags.C_REGISTERED) && !util.isLive(data.type)) {
+            // TODO: remove this check entirely once metrics are collected.
             lib.getItem(data.id, function (err, item) {
                 if (err && err !== "Item not in library") {
-                    error(err+"");
-                    self.channel.refCounter.unref("PlaylistModule::queueStandard");
-                    return lock.release();
-                }
-
-                // YouTube livestreams transition to becoming regular videos,
-                // breaking the cached duration of 0.
-                // In the future, the media cache should be decoupled from
-                // the library and this will no longer be an issue, but for now
-                // treat 0-length yt library entries as non-existent.
-                if (item !== null && item.type === "yt" && item.seconds === 0) {
-                    data.type = "yt"; // Kludge -- library queue has type: "lib"
-                    item = null;
-                }
-
-                if (item !== null) {
-                    /* Don't re-cache data we got from the library */
-                    data.shouldAddToLibrary = false;
-                    self._addItem(item, data, user, function () {
-                        lock.release();
-                        self.channel.refCounter.unref("PlaylistModule::queueStandard");
-                    });
+                    LOGGER.error("Failed to query for library item: %s", String(err));
+                } else if (err === "Item not in library") {
+                    counters.add("playlist:queue:library:miss", 1);
                 } else {
-                    handleLookup();
+                    // temp hack until all clients are updated.
+                    // previously, library search results would queue with
+                    // type "lib"; this has now been changed.
+                    data.type = item.type;
+                    counters.add("playlist:queue:library:hit", 1);
                 }
+
+                handleLookup();
             });
         } else {
             handleLookup();

src/database/channels.js

@@ -431,7 +431,8 @@ module.exports = {
             bitrate: media.meta.bitrate,
             codec: media.meta.codec,
             scuri: media.meta.scuri,
-            embed: media.meta.embed
+            embed: media.meta.embed,
+            direct: media.meta.direct
         });
 
         db.query("INSERT INTO `channel_libraries` " +

www/js/callbacks.js

@@ -879,7 +879,7 @@ Callbacks = {
             generator: function (item, page, index) {
                 var li = makeSearchEntry(item, false);
                 if(hasPermission("playlistadd") || hasPermission("deletefromchannellib")) {
-                    addLibraryButtons(li, item.id, data.source);
+                    addLibraryButtons(li, item, data.source);
                 }
                 $(li).appendTo($("#library"));
             },

www/js/util.js

@@ -1084,12 +1084,13 @@ function clearSearchResults() {
     }
 }
 
-function addLibraryButtons(li, id, source) {
+function addLibraryButtons(li, item, source) {
     var btns = $("<div/>").addClass("btn-group")
         .addClass("pull-left")
         .prependTo(li);
 
-    var type = (source === "library") ? "lib" : source;
+    var id = item.id;
+    var type = item.type;
 
     if(hasPermission("playlistadd")) {
         if(hasPermission("playlistnext")) {