Index on Tag for name, item id, item type.

graph/loaders/tags.js

@@ -8,7 +8,7 @@ const TagModel = require('../../models/tag');
 /**
  * Gets tags based on their item id's.
  */
-const genTagsByItemID = (_, item_ids) => {
+const getByItemID = (_, item_ids) => {
   return TagsService
     .findByItemIdArray(item_ids)
     .then(util.arrayJoinBy(item_ids, 'item_id'));
@@ -31,7 +31,7 @@ const getItemIdsByItemType = (_, item_type) => {
  */
 module.exports = (context) => ({
   Tags: {
-    getByID: new DataLoader((ids) => genTagsByItemID(context, ids)),
+    getByID: new DataLoader((ids) => getByItemID(context, ids)),
     getByTypes: ({item_type}) => getItemIdsByItemType(context, item_type)
   }
 });

graph/resolvers/comment.js

@@ -6,6 +6,9 @@ const Comment = {
 
     return Comments.get.load(parent_id);
   },
+  tags({id}, _, {loaders: {Tags}}) {
+    return Tags.getByID.load([id]);
+  },
   user({author_id}, _, {loaders: {Users}}) {
     return Users.getByID.load(author_id);
   },
@@ -23,9 +26,9 @@ const Comment = {
   },
   replyCount({id}, {excludeIgnored}, {user, loaders: {Comments}}) {
     if (user && excludeIgnored) {
-      return Comments.countByParentIDPersonalized({id, excludeIgnored});      
+      return Comments.countByParentIDPersonalized({id, excludeIgnored});
     }
-    return Comments.countByParentID.load(id);      
+    return Comments.countByParentID.load(id);
   },
   actions({id}, _, {user, loaders: {Actions}}) {
 

models/tag.js

@@ -62,6 +62,16 @@ const TagSchema = new Schema({
   }
 });
 
+// Add the indixies on the tag on an item.
+TagSchema.index({
+  'item_type': 1,
+  'item_id': 1,
+  'name': 1
+}, {
+  unique: true,
+  background: false
+});
+
 const Tag = mongoose.model('Tag', TagSchema);
 
 module.exports = Tag;

services/tags.js

@@ -28,6 +28,22 @@ module.exports = class TagsService {
     });
   }
 
+  /**
+   * Finds actions in an array of ids.
+   * @param {String} ids array of user identifiers (uuid)
+  */
+  static async findByItemIdArray(item_ids) {
+    let tags = await TagModel.find({
+      'item_id': {$in: item_ids}
+    });
+
+    if (tags === null) {
+      return [];
+    }
+
+    return tags;
+  }
+
   /**
    * Add a tag.
    * @param {string} name the actual tag