Add new upload limit system (fix #4234).

app/logical/upload_limit.rb

@@ -0,0 +1,99 @@
+class UploadLimit
+  extend Memoist
+
+  INITIAL_POINTS = 1000
+  MAXIMUM_POINTS = 10000
+
+  attr_reader :user
+
+  def initialize(user)
+    @user = user
+  end
+
+  def limited?
+    used_upload_slots >= upload_slots
+  end
+
+  def used_upload_slots
+    pending = user.posts.pending
+    early_deleted = user.posts.deleted.where("created_at >= ?", 3.days.ago)
+
+    pending.or(early_deleted).count
+  end
+
+  def upload_slots
+    upload_level + 5
+  end
+
+  def upload_level
+    UploadLimit.points_to_level(user.upload_points)
+  end
+
+  def approvals_on_current_level
+    (user.upload_points - UploadLimit.level_to_points(upload_level)) / 10
+  end
+
+  def approvals_for_next_level
+    UploadLimit.points_for_next_level(upload_level) / 10
+  end
+
+  def update_limit!(post, incremental: true)
+    return if user.can_upload_free?
+
+    user.with_lock do
+      if incremental
+        user.upload_points += UploadLimit.upload_value(user.upload_points, post.is_deleted)
+        user.save!
+      else
+        user.update!(upload_points: UploadLimit.points_for_user(user))
+      end
+    end
+  end
+
+  def self.points_for_user(user)
+    points = INITIAL_POINTS
+
+    uploads = user.posts.where(is_pending: false).order(id: :asc).pluck(:is_deleted)
+    uploads.each do |is_deleted|
+      points += upload_value(points, is_deleted)
+      points = points.clamp(0, MAXIMUM_POINTS)
+
+      #warn "slots: %2d, points: %3d, value: %2d" % [UploadLimit.points_to_level(points) + 5, points, UploadLimit.upload_value(level, is_deleted)]
+    end
+
+    points
+  end
+
+  def self.upload_value(current_points, is_deleted)
+    if is_deleted
+      level = points_to_level(current_points)
+      -1 * (points_for_next_level(level) / 3.0).round.to_i
+    else
+      10
+    end
+  end
+
+  def self.points_for_next_level(level)
+    100 + 20 * [level - 10, 0].max
+  end
+
+  def self.points_to_level(points)
+    level = 0
+
+    loop do
+      points -= points_for_next_level(level)
+      break if points < 0
+      level += 1
+    end
+
+    level
+  end
+
+  def self.level_to_points(level)
+    (1..level).map do |n|
+      points_for_next_level(n - 1)
+    end.sum
+  end
+
+  memoize :used_upload_slots
+end

app/models/post.rb

@@ -1279,6 +1279,9 @@ class Post < ApplicationRecord
         # XXX This must happen *after* the `is_deleted` flag is set to true (issue #3419).
         give_favorites_to_parent(options) if options[:move_favorites]
 
+        is_automatic = (reason == "Unapproved in three days")
+        uploader.new_upload_limit.update_limit!(self, incremental: is_automatic)
+
         unless options[:without_mod_action]
           ModAction.log("deleted post ##{id}, reason: #{reason}", :post_delete)
         end

app/models/post_approval.rb

@@ -26,10 +26,13 @@ class PostApproval < ApplicationRecord
   end
 
   def approve_post
-    ModAction.log("undeleted post ##{post_id}", :post_undelete) if post.is_deleted
+    is_undeletion = post.is_deleted
 
     post.flags.each(&:resolve!)
     post.update(approver: user, is_flagged: false, is_pending: false, is_deleted: false)
+    ModAction.log("undeleted post ##{post_id}", :post_undelete) if is_undeletion
+
+    post.uploader.new_upload_limit.update_limit!(post, incremental: !is_undeletion)
   end
 
   def self.search(params)

app/models/user.rb

@@ -468,6 +468,10 @@ class User < ApplicationRecord
       (is_moderator? && flag.not_uploaded_by?(id)) || flag.creator_id == id
     end
 
+    def new_upload_limit
+      @new_upload_limit ||= UploadLimit.new(self)
+    end
+
     def upload_limit
       [max_upload_limit - used_upload_slots, 0].max
     end

app/views/users/_statistics.html.erb

@@ -66,6 +66,15 @@
         <td><%= presenter.upload_limit(self) %> (<%= link_to_wiki "help", "about:upload_limits" %>)</td>
       </tr>
 
+      <tr>
+        <th>New Upload Limit</th>
+        <td>
+          <%= link_to user.new_upload_limit.used_upload_slots, posts_path(tags: "user:#{user.name} status:pending") %>
+          /
+          <%= tag.abbr user.new_upload_limit.upload_slots, title: "Next level: #{user.new_upload_limit.approvals_on_current_level} / #{user.new_upload_limit.approvals_for_next_level} approvals" %>
+        </td>
+      </tr>
+
       <tr>
         <th>Uploads</th>
         <td>