debian-mirror-gitlab/lib/gitlab/metrics/methods.rb
2019-02-15 15:39:39 +05:30

131 lines
4.1 KiB
Ruby

# frozen_string_literal: true
# rubocop:disable Style/ClassVars
module Gitlab
module Metrics
module Methods
extend ActiveSupport::Concern
included do
@@_metric_provider_mutex ||= Mutex.new
@@_metrics_provider_cache = {}
end
class_methods do
def reload_metric!(name)
@@_metrics_provider_cache.delete(name)
end
private
def define_metric(type, name, opts = {}, &block)
if respond_to?(name)
raise ArgumentError, "method #{name} already exists"
end
define_singleton_method(name) do
# inlining fetch_metric method to avoid method call overhead when instrumenting hot spots
@@_metrics_provider_cache[name] || init_metric(type, name, opts, &block)
end
end
def fetch_metric(type, name, opts = {}, &block)
@@_metrics_provider_cache[name] || init_metric(type, name, opts, &block)
end
def init_metric(type, name, opts = {}, &block)
options = MetricOptions.new(opts)
options.evaluate(&block)
if disabled_by_feature(options)
synchronized_cache_fill(name) { NullMetric.instance }
else
synchronized_cache_fill(name) { build_metric!(type, name, options) }
end
end
def synchronized_cache_fill(key)
@@_metric_provider_mutex.synchronize do
@@_metrics_provider_cache[key] ||= yield
end
end
def disabled_by_feature(options)
options.with_feature && !::Feature.get(options.with_feature).enabled?
end
def build_metric!(type, name, options)
case type
when :gauge
Gitlab::Metrics.gauge(name, options.docstring, options.base_labels, options.multiprocess_mode)
when :counter
Gitlab::Metrics.counter(name, options.docstring, options.base_labels)
when :histogram
Gitlab::Metrics.histogram(name, options.docstring, options.base_labels, options.buckets)
when :summary
raise NotImplementedError, "summary metrics are not currently supported"
else
raise ArgumentError, "uknown metric type #{type}"
end
end
# Fetch and/or initialize counter metric
# @param [Symbol] name
# @param [Hash] opts
def fetch_counter(name, opts = {}, &block)
fetch_metric(:counter, name, opts, &block)
end
# Fetch and/or initialize gauge metric
# @param [Symbol] name
# @param [Hash] opts
def fetch_gauge(name, opts = {}, &block)
fetch_metric(:gauge, name, opts, &block)
end
# Fetch and/or initialize histogram metric
# @param [Symbol] name
# @param [Hash] opts
def fetch_histogram(name, opts = {}, &block)
fetch_metric(:histogram, name, opts, &block)
end
# Fetch and/or initialize summary metric
# @param [Symbol] name
# @param [Hash] opts
def fetch_summary(name, opts = {}, &block)
fetch_metric(:summary, name, opts, &block)
end
# Define metric accessor method for a Counter
# @param [Symbol] name
# @param [Hash] opts
def define_counter(name, opts = {}, &block)
define_metric(:counter, name, opts, &block)
end
# Define metric accessor method for a Gauge
# @param [Symbol] name
# @param [Hash] opts
def define_gauge(name, opts = {}, &block)
define_metric(:gauge, name, opts, &block)
end
# Define metric accessor method for a Histogram
# @param [Symbol] name
# @param [Hash] opts
def define_histogram(name, opts = {}, &block)
define_metric(:histogram, name, opts, &block)
end
# Define metric accessor method for a Summary
# @param [Symbol] name
# @param [Hash] opts
def define_summary(name, opts = {}, &block)
define_metric(:summary, name, opts, &block)
end
end
end
end
end