diff options
Diffstat (limited to 'lib/gitlab/metrics/methods.rb')
-rw-r--r-- | lib/gitlab/metrics/methods.rb | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/methods.rb b/lib/gitlab/metrics/methods.rb new file mode 100644 index 00000000000..cd7c1e507f7 --- /dev/null +++ b/lib/gitlab/metrics/methods.rb @@ -0,0 +1,129 @@ +# 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 |