Methods

Constants

EXPLAINED_SQLS = /\A\s*(\/\*.*\*\/)?\s*(with|select|update|delete|insert)\b/i
IGNORED_PAYLOADS = %w(SCHEMA EXPLAIN)
 

SCHEMA queries cannot be EXPLAINed, also we do not want to run EXPLAIN on our own EXPLAINs no 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.
MUTEX = Mutex.new

Class Public methods

ensure_subscribed()

📝 Source code 
# File activerecord/lib/active_record/explain_registry.rb, line 16
def ensure_subscribed
  return if @subscribed
  MUTEX.synchronize do
    return if @subscribed

    ActiveSupport::Notifications.subscribe("sql.active_record", new)
    @subscribed = true
  end
end
🔎 See on GitHub

Instance Public methods

finish(name, id, payload)

📝 Source code 
# File activerecord/lib/active_record/explain_registry.rb, line 31
def finish(name, id, payload)
  if ExplainRegistry.collect? && !ignore_payload?(payload)
    ExplainRegistry.queries << payload.values_at(:sql, :binds)
  end
end
🔎 See on GitHub

ignore_payload?(payload)

📝 Source code 
# File activerecord/lib/active_record/explain_registry.rb, line 48
def ignore_payload?(payload)
  payload[:exception] ||
    payload[:cached] ||
    IGNORED_PAYLOADS.include?(payload[:name]) ||
    !payload[:sql].match?(EXPLAINED_SQLS)
end
🔎 See on GitHub

silenced?(_name)

📝 Source code 
# File activerecord/lib/active_record/explain_registry.rb, line 37
def silenced?(_name)
  !ExplainRegistry.collect?
end
🔎 See on GitHub

start(name, id, payload)

📝 Source code 
# File activerecord/lib/active_record/explain_registry.rb, line 27
def start(name, id, payload)
  # unused
end
🔎 See on GitHub