File: explain_subscriber.rb

package info (click to toggle)
rails 2%3A4.2.7.1-1%2Bdeb9u2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 23,416 kB
  • sloc: ruby: 186,673; yacc: 45; sql: 43; sh: 14; makefile: 12
file content (29 lines) | stat: -rw-r--r-- 1,027 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
require 'active_support/notifications'
require 'active_record/explain_registry'

module ActiveRecord
  class ExplainSubscriber # :nodoc:
    def start(name, id, payload)
      # unused
    end

    def finish(name, id, payload)
      if ExplainRegistry.collect? && !ignore_payload?(payload)
        ExplainRegistry.queries << payload.values_at(:sql, :binds)
      end
    end

    # SCHEMA queries cannot be EXPLAINed, also we do not want to run EXPLAIN on
    # our own EXPLAINs now matter how loopingly beautiful that would be.
    #
    # On the other hand, we want to monitor the performance of our real database
    # queries, not the performance of the access to the query cache.
    IGNORED_PAYLOADS = %w(SCHEMA EXPLAIN CACHE)
    EXPLAINED_SQLS = /\A\s*(with|select|update|delete|insert)\b/i
    def ignore_payload?(payload)
      payload[:exception] || IGNORED_PAYLOADS.include?(payload[:name]) || payload[:sql] !~ EXPLAINED_SQLS
    end

    ActiveSupport::Notifications.subscribe("sql.active_record", new)
  end
end