railties/lib/rails/rack/logger.rb
# frozen_string_literal: true
require "active_support/core_ext/time/conversions"
require "active_support/log_subscriber"
require "rack/body_proxy"
module Rails
module Rack
# Sets log tags, logs the request, calls the app, and flushes the logs.
#
# Log tags (+taggers+) can be an Array containing: methods that the +request+
# object responds to, objects that respond to +to_s+ or Proc objects that accept
# an instance of the +request+ object.
class Logger < ActiveSupport::LogSubscriber
def initialize(app, taggers = nil)
@app = app
@taggers = taggers || []
end
def call(env)
request = ActionDispatch::Request.new(env)
env["rails.rack_logger_tag_count"] = if logger.respond_to?(:push_tags)
logger.push_tags(*compute_tags(request)).size
else
0
end
call_app(request, env)
end
private
def call_app(request, env) # :doc:
logger_tag_pop_count = env["rails.rack_logger_tag_count"]
instrumenter = ActiveSupport::Notifications.instrumenter
handle = instrumenter.build_handle("request.action_dispatch", { request: request })
handle.start
logger.info { started_request_message(request) }
status, headers, body = response = @app.call(env)
body = ::Rack::BodyProxy.new(body) { finish_request_instrumentation(handle, logger_tag_pop_count) }
if response.frozen?
[status, headers, body]
else
response[2] = body
response
end
rescue Exception
finish_request_instrumentation(handle, logger_tag_pop_count)
raise
end
# Started GET "/session/new" for 127.0.0.1 at 2012-09-26 14:51:42 -0700
def started_request_message(request) # :doc:
sprintf('Started %s "%s" for %s at %s',
request.raw_request_method,
request.filtered_path,
request.remote_ip,
Time.now)
end
def compute_tags(request) # :doc:
@taggers.collect do |tag|
case tag
when Proc
tag.call(request)
when Symbol
request.send(tag)
else
tag
end
end
end
def logger
Rails.logger
end
def finish_request_instrumentation(handle, logger_tag_pop_count)
handle.finish
logger.pop_tags(logger_tag_pop_count) if logger.respond_to?(:pop_tags) && logger_tag_pop_count > 0
ActiveSupport::LogSubscriber.flush_all!
end
end
end
end