Calculate trends in temporary sets to avoid having to manage items that go below the decay threshold while not having any moments where a half-processed set is accessible to end-users
		
			
				
	
	
		
			123 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
| # frozen_string_literal: true
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| 
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| class Trends::Statuses < Trends::Base
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|   PREFIX = 'trending_statuses'
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| 
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|   self.default_options = {
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|     threshold: 5,
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|     review_threshold: 3,
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|     score_halflife: 2.hours.freeze,
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|     decay_threshold: 0.3,
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|   }
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| 
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|   class Query < Trends::Query
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|     def filtered_for!(account)
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|       @account = account
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|       self
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|     end
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| 
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|     def filtered_for(account)
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|       clone.filtered_for!(account)
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|     end
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| 
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|     private
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| 
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|     def apply_scopes(scope)
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|       if @account.nil?
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|         scope
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|       else
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|         scope.not_excluded_by_account(@account).not_domain_blocked_by_account(@account)
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|       end
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|     end
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|   end
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| 
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|   def register(status, at_time = Time.now.utc)
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|     add(status.proper, status.account_id, at_time) if eligible?(status.proper)
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|   end
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| 
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|   def add(status, _account_id, at_time = Time.now.utc)
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|     # We rely on the total reblogs and favourites count, so we
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|     # don't record which account did the what and when here
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| 
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|     record_used_id(status.id, at_time)
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|   end
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| 
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|   def query
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|     Query.new(key_prefix, klass)
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|   end
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| 
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|   def refresh(at_time = Time.now.utc)
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|     statuses = Status.where(id: (recently_used_ids(at_time) + currently_trending_ids(false, -1)).uniq).includes(:account, :media_attachments)
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|     calculate_scores(statuses, at_time)
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|   end
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| 
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|   def request_review
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|     statuses = Status.where(id: currently_trending_ids(false, -1)).includes(:account)
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| 
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|     statuses.filter_map do |status|
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|       next unless would_be_trending?(status.id) && !status.trendable? && status.requires_review_notification?
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| 
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|       status.account.touch(:requested_review_at)
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|       status
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|     end
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|   end
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| 
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|   protected
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| 
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|   def key_prefix
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|     PREFIX
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|   end
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| 
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|   def klass
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|     Status
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|   end
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| 
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|   private
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| 
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|   def eligible?(status)
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|     status.public_visibility? && status.account.discoverable? && !status.account.silenced? && status.spoiler_text.blank? && !status.sensitive? && !status.reply?
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|   end
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| 
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|   def calculate_scores(statuses, at_time)
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|     global_items = []
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|     locale_items = Hash.new { |h, key| h[key] = [] }
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| 
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|     statuses.each do |status|
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|       expected  = 1.0
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|       observed  = (status.reblogs_count + status.favourites_count).to_f
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| 
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|       score = begin
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|         if expected > observed || observed < options[:threshold]
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|           0
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|         else
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|           ((observed - expected)**2) / expected
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|         end
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|       end
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| 
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|       decaying_score = score * (0.5**((at_time.to_f - status.created_at.to_f) / options[:score_halflife].to_f))
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| 
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|       next unless decaying_score >= options[:decay_threshold]
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| 
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|       global_items << { score: decaying_score, item: status }
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|       locale_items[status.language] << { account_id: status.account_id, score: decaying_score, item: status } if valid_locale?(status.language)
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|     end
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| 
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|     replace_items('', global_items)
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| 
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|     Trends.available_locales.each do |locale|
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|       replace_items(":#{locale}", locale_items[locale])
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|     end
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|   end
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| 
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|   def filter_for_allowed_items(items)
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|     # Show only one status per account, pick the one with the highest score
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|     # that's also eligible to trend
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| 
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|     items.group_by { |item| item[:account_id] }.values.filter_map { |account_items| account_items.select { |item| item[:item].trendable? && item[:item].account.discoverable? }.max_by { |item| item[:score] } }
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|   end
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| 
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|   def would_be_trending?(id)
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|     score(id) > score_at_rank(options[:review_threshold] - 1)
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|   end
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| end
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