mastodon/app/models/glitch/keyword_mute.rb
David Yip 37d495eeeb
keyword mute: Store keywords as a list
This has a couple of advantages over the regex approach:

- Keywords are individually addressable, which makes it easier to gather
  statistics (#363)
- Keywords can be individually applied to different feeds, e.g. skipping
  mentions (#454)

It *does* end up creating many more Regexp objects.  I'm not yet sure if
the difference is significant.
2018-06-03 18:12:55 -05:00

107 lines
2.4 KiB
Ruby

# frozen_string_literal: true
# == Schema Information
#
# Table name: glitch_keyword_mutes
#
# id :integer not null, primary key
# account_id :integer not null
# keyword :string not null
# whole_word :boolean default(TRUE), not null
# created_at :datetime not null
# updated_at :datetime not null
#
class Glitch::KeywordMute < ApplicationRecord
belongs_to :account, required: true
validates_presence_of :keyword
after_commit :invalidate_cached_matchers
def self.text_matcher_for(account_id)
TextMatcher.new(account_id)
end
def self.tag_matcher_for(account_id)
TagMatcher.new(account_id)
end
private
def invalidate_cached_matchers
Rails.cache.delete(TextMatcher.cache_key(account_id))
Rails.cache.delete(TagMatcher.cache_key(account_id))
end
class CachedKeywordMute
attr_reader :keyword
attr_reader :whole_word
def initialize(keyword, whole_word)
@keyword = keyword
@whole_word = whole_word
end
def boundary_regex_for_keyword
sb = keyword =~ /\A[[:word:]]/ ? '\b' : ''
eb = keyword =~ /[[:word:]]\Z/ ? '\b' : ''
/(?mix:#{sb}#{Regexp.escape(keyword)}#{eb})/
end
def matches?(str)
str =~ (whole_word ? boundary_regex_for_keyword : /#{keyword}/i)
end
end
class Matcher
attr_reader :account_id
attr_reader :words
def initialize(account_id)
@account_id = account_id
@words = Rails.cache.fetch(self.class.cache_key(account_id)) { fetch_keywords }
end
protected
def fetch_keywords
Glitch::KeywordMute.where(account_id: account_id).pluck(:whole_word, :keyword).map do |whole_word, keyword|
CachedKeywordMute.new(transform_keyword(keyword), whole_word)
end
end
def transform_keyword(keyword)
keyword
end
end
class TextMatcher < Matcher
def self.cache_key(account_id)
format('keyword_mutes:regex:text:%s', account_id)
end
def matches?(str)
words.any? { |w| w.matches?(str) }
end
end
class TagMatcher < Matcher
def self.cache_key(account_id)
format('keyword_mutes:regex:tag:%s', account_id)
end
def matches?(tags)
tags.pluck(:name).any? do |n|
words.any? { |w| w.matches?(n) }
end
end
protected
def transform_keyword(kw)
Tag::HASHTAG_RE =~ kw ? $1 : kw
end
end
end