gitlab-org--gitlab-foss/lib/gitlab/query_limiting/transaction.rb

107 lines
2.9 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module QueryLimiting
class Transaction
THREAD_KEY = :__gitlab_query_counts_transaction
attr_accessor :count
# The name of the action (e.g. `UsersController#show`) that is being
# executed.
attr_accessor :action
# The maximum number of SQL queries that can be executed in a request. For
# the sake of keeping things simple we hardcode this value here, it's not
# supposed to be changed very often anyway.
THRESHOLD = 100
LOG_THRESHOLD = THRESHOLD * 1.5
# Error that is raised whenever exceeding the maximum number of queries.
ThresholdExceededError = Class.new(StandardError)
def self.current
Thread.current[THREAD_KEY]
end
# Starts a new transaction and returns it and the blocks' return value.
#
# Example:
#
# transaction, retval = Transaction.run do
# 10
# end
#
# retval # => 10
def self.run
transaction = new
Thread.current[THREAD_KEY] = transaction
[transaction, yield]
ensure
Thread.current[THREAD_KEY] = nil
end
def initialize
@action = nil
@count = 0
@sql_executed = []
end
# Sends a notification based on the number of executed SQL queries.
def act_upon_results
return unless threshold_exceeded?
error = ThresholdExceededError.new(error_message)
raise(error) if raise_error?
end
def increment(sql = nil)
@count += 1 if enabled? && !ignorable?(sql)
end
GEO_NODES_LOAD = 'SELECT 1 AS one FROM "geo_nodes" LIMIT 1'
LICENSES_LOAD = 'SELECT "licenses".* FROM "licenses" ORDER BY "licenses"."id"'
ATTR_INTROSPECTION = %r/SELECT .*\ba.attname\b.* (FROM|JOIN) pg_attribute a/m.freeze
# queries can be safely ignored if they are amoritized in regular usage
# (i.e. only requested occasionally and otherwise cached).
def ignorable?(sql)
return true if sql&.include?(GEO_NODES_LOAD)
return true if sql&.include?(LICENSES_LOAD)
return true if ATTR_INTROSPECTION =~ sql
false
end
def executed_sql(sql)
return if @count > LOG_THRESHOLD || ignorable?(sql)
@sql_executed << sql
end
def raise_error?
Rails.env.test?
end
def threshold_exceeded?
count > THRESHOLD
end
def error_message
header = 'Too many SQL queries were executed'
header = "#{header} in #{action}" if action
msg = "a maximum of #{THRESHOLD} is allowed but #{count} SQL queries were executed"
log = @sql_executed.each_with_index.map { |sql, i| "#{i}: #{sql}" }.join("\n").presence
ellipsis = '...' if @count > LOG_THRESHOLD
["#{header}: #{msg}", log, ellipsis].compact.join("\n")
end
def enabled?
::Gitlab::QueryLimiting.enabled?
end
end
end
end