gitlab-org--gitlab-foss/lib/gitlab/sql/pattern.rb
Sean McGivern eba5672077 Allow filtering labels by a single character
When we use Gitlab::SQL::Pattern, this typically relates to a trigram
index. As the 'tri' indicates, we need at least three characters to be
able to use that index.

Labels don't have a trigram index, because we never allow you to search
for them globally: it's always in the context of a project or a
group. In that context, it's just as fast to search for a single
character (in general) because there is already a pretty specific index
being used.
2019-03-13 10:54:43 +00:00

75 lines
2.1 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module SQL
module Pattern
extend ActiveSupport::Concern
MIN_CHARS_FOR_PARTIAL_MATCHING = 3
REGEX_QUOTED_WORD = /(?<=\A| )"[^"]+"(?= |\z)/
class_methods do
def fuzzy_search(query, columns)
matches = columns.map { |col| fuzzy_arel_match(col, query) }.compact.reduce(:or)
where(matches)
end
def to_pattern(query)
if partial_matching?(query)
"%#{sanitize_sql_like(query)}%"
else
sanitize_sql_like(query)
end
end
def min_chars_for_partial_matching
MIN_CHARS_FOR_PARTIAL_MATCHING
end
def partial_matching?(query)
query.length >= min_chars_for_partial_matching
end
# column - The column name to search in.
# query - The text to search for.
# lower_exact_match - When set to `true` we'll fall back to using
# `LOWER(column) = query` instead of using `ILIKE`.
def fuzzy_arel_match(column, query, lower_exact_match: false)
query = query.squish
return unless query.present?
words = select_fuzzy_words(query)
if words.any?
words.map { |word| arel_table[column].matches(to_pattern(word)) }.reduce(:and)
else
# No words of at least 3 chars, but we can search for an exact
# case insensitive match with the query as a whole
if lower_exact_match
Arel::Nodes::NamedFunction
.new('LOWER', [arel_table[column]])
.eq(query)
else
arel_table[column].matches(sanitize_sql_like(query))
end
end
end
def select_fuzzy_words(query)
quoted_words = query.scan(REGEX_QUOTED_WORD)
query = quoted_words.reduce(query) { |q, quoted_word| q.sub(quoted_word, '') }
words = query.split
quoted_words.map! { |quoted_word| quoted_word[1..-2] }
words.concat(quoted_words)
words.select { |word| partial_matching?(word) }
end
end
end
end
end