mirror of
https://github.com/discourse/discourse.git
synced 2024-11-30 12:46:08 +08:00
30990006a9
This reduces chances of errors where consumers of strings mutate inputs and reduces memory usage of the app. Test suite passes now, but there may be some stuff left, so we will run a few sites on a branch prior to merging
92 lines
2.7 KiB
Ruby
92 lines
2.7 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
# Speeds up #pluck so its about 2.2x faster, importantly makes pluck avoid creation of a slew
|
|
# of AR objects
|
|
#
|
|
#
|
|
class ActiveRecord::Relation
|
|
|
|
# Note: In discourse, the following code is included in lib/sql_builder.rb
|
|
#
|
|
# class RailsDateTimeDecoder < PG::SimpleDecoder
|
|
# def decode(string, tuple=nil, field=nil)
|
|
# if Rails.version >= "4.2.0"
|
|
# @caster ||= ActiveRecord::Type::DateTime.new
|
|
# @caster.type_cast_from_database(string)
|
|
# else
|
|
# ActiveRecord::ConnectionAdapters::Column.string_to_time string
|
|
# end
|
|
# end
|
|
# end
|
|
#
|
|
# class ActiveRecordTypeMap < PG::BasicTypeMapForResults
|
|
# def initialize(connection)
|
|
# super(connection)
|
|
# rm_coder 0, 1114
|
|
# add_coder RailsDateTimeDecoder.new(name: "timestamp", oid: 1114, format: 0)
|
|
# # we don't need deprecations
|
|
# self.default_type_map = PG::TypeMapInRuby.new
|
|
# end
|
|
# end
|
|
#
|
|
# def self.pg_type_map
|
|
# conn = ActiveRecord::Base.connection.raw_connection
|
|
# @typemap ||= ActiveRecordTypeMap.new(conn)
|
|
# end
|
|
|
|
class ::ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
|
|
def select_raw(arel, name = nil, binds = [], &block)
|
|
arel = arel_from_relation(arel)
|
|
sql, binds = to_sql_and_binds(arel, binds)
|
|
execute_and_clear(sql, name, binds, &block)
|
|
end
|
|
end
|
|
|
|
def pluck(*column_names)
|
|
if loaded? && (column_names.map(&:to_s) - @klass.attribute_names - @klass.attribute_aliases.keys).empty?
|
|
return records.pluck(*column_names)
|
|
end
|
|
|
|
if has_include?(column_names.first)
|
|
relation = apply_join_dependency
|
|
relation.pluck(*column_names)
|
|
else
|
|
enforce_raw_sql_whitelist(column_names)
|
|
relation = spawn
|
|
|
|
relation.select_values = column_names.map { |cn|
|
|
@klass.has_attribute?(cn) || @klass.attribute_alias?(cn) ? arel_attribute(cn) : cn
|
|
}
|
|
|
|
klass.connection.select_raw(relation.arel) do |result, _|
|
|
result.type_map = DB.type_map
|
|
result.nfields == 1 ? result.column_values(0) : result.values
|
|
end
|
|
end
|
|
end
|
|
end
|
|
|
|
# require 'benchmark/ips'
|
|
#
|
|
# ENV['RAILS_ENV'] = 'production'
|
|
# require File.expand_path("../../config/environment", __FILE__)
|
|
#
|
|
# Benchmark.ips do |x|
|
|
# x.report("fast_pluck") do
|
|
# Post.where(topic_id: 48464).fast_pluck(:id)
|
|
# end
|
|
#
|
|
# x.report("pluck") do
|
|
# Post.where(topic_id: 48464).pluck(:id)
|
|
# end
|
|
# end
|
|
#
|
|
# % ruby tmp/fast_pluck.rb
|
|
# Calculating -------------------------------------
|
|
# fast_pluck 165.000 i/100ms
|
|
# pluck 80.000 i/100ms
|
|
# -------------------------------------------------
|
|
# fast_pluck 1.720k (± 8.8%) i/s - 8.580k
|
|
# pluck 807.913 (± 4.0%) i/s - 4.080k
|
|
#
|