debian-mirror-gitlab/lib/gitlab/instrumentation/redis_interceptor.rb
2020-06-23 00:09:42 +05:30

86 lines
2.7 KiB
Ruby

# frozen_string_literal: true
require 'redis'
module Gitlab
module Instrumentation
module RedisInterceptor
def call(*args, &block)
start = Time.now
super(*args, &block)
ensure
duration = (Time.now - start)
if ::RequestStore.active?
instrumentation_class.increment_request_count
instrumentation_class.add_duration(duration)
instrumentation_class.add_call_details(duration, args)
end
end
def write(command)
measure_write_size(command) if ::RequestStore.active?
super
end
def read
result = super
measure_read_size(result) if ::RequestStore.active?
result
end
private
def measure_write_size(command)
size = 0
# Mimic what happens in
# https://github.com/redis/redis-rb/blob/f597f21a6b954b685cf939febbc638f6c803e3a7/lib/redis/connection/command_helper.rb#L8.
# This count is an approximation that omits the Redis protocol overhead
# of type prefixes, length prefixes and line endings.
command.each do |x|
size += begin
if x.is_a? Array
x.inject(0) { |sum, y| sum + y.to_s.bytesize }
else
x.to_s.bytesize
end
end
end
instrumentation_class.increment_write_bytes(size)
end
def measure_read_size(result)
# The Connection::Ruby#read class can return one of four types of results from read:
# https://github.com/redis/redis-rb/blob/f597f21a6b954b685cf939febbc638f6c803e3a7/lib/redis/connection/ruby.rb#L406
#
# 1. Error (exception, will not reach this line)
# 2. Status (string)
# 3. Integer (will be converted to string by to_s.bytesize and thrown away)
# 4. "Binary" string (i.e. may contain zero byte)
# 5. Array of binary string
if result.is_a? Array
# Redis can return nested arrays, e.g. from XRANGE or GEOPOS, so we use recursion here.
result.each { |x| measure_read_size(x) }
else
# This count is an approximation that omits the Redis protocol overhead
# of type prefixes, length prefixes and line endings.
instrumentation_class.increment_read_bytes(result.to_s.bytesize)
end
end
# That's required so it knows which GitLab Redis instance
# it's interacting with in order to categorize accordingly.
#
def instrumentation_class
@options[:instrumentation_class] # rubocop:disable Gitlab/ModuleWithInstanceVariables
end
end
end
end
class ::Redis::Client
prepend ::Gitlab::Instrumentation::RedisInterceptor
end