lib/exception_notifier/modules/error_grouping.rb
# frozen_string_literal: true
require 'active_support'
require 'active_support/core_ext/numeric/time'
require 'active_support/concern'
module ExceptionNotifier
module ErrorGrouping
extend ActiveSupport::Concern
included do
mattr_accessor :error_grouping
self.error_grouping = false
mattr_accessor :error_grouping_period
self.error_grouping_period = 5.minutes
mattr_accessor :notification_trigger
mattr_accessor :error_grouping_cache
end
module ClassMethods
# Fallback to the memory store while the specified cache store doesn't work
#
def fallback_cache_store
@fallback_cache_store ||= ActiveSupport::Cache::MemoryStore.new
end
def error_count(error_key)
count =
begin
error_grouping_cache.read(error_key)
rescue StandardError => e
log_cache_error(error_grouping_cache, e, :read)
fallback_cache_store.read(error_key)
end
count&.to_i
end
def save_error_count(error_key, count)
error_grouping_cache.write(error_key, count, expires_in: error_grouping_period)
rescue StandardError => e
log_cache_error(error_grouping_cache, e, :write)
fallback_cache_store.write(error_key, count, expires_in: error_grouping_period)
end
def group_error!(exception, options)
message_based_key = "exception:#{Zlib.crc32("#{exception.class.name}\nmessage:#{exception.message}")}"
accumulated_errors_count = 1
if (count = error_count(message_based_key))
accumulated_errors_count = count + 1
save_error_count(message_based_key, accumulated_errors_count)
else
backtrace_based_key =
"exception:#{Zlib.crc32("#{exception.class.name}\npath:#{exception.backtrace.try(:first)}")}"
if (count = error_grouping_cache.read(backtrace_based_key))
accumulated_errors_count = count + 1
save_error_count(backtrace_based_key, accumulated_errors_count)
else
save_error_count(backtrace_based_key, accumulated_errors_count)
save_error_count(message_based_key, accumulated_errors_count)
end
end
options[:accumulated_errors_count] = accumulated_errors_count
end
def send_notification?(exception, count)
if notification_trigger.respond_to?(:call)
notification_trigger.call(exception, count)
else
factor = Math.log2(count)
factor.to_i == factor
end
end
private
def log_cache_error(cache, exception, action)
"#{cache.inspect} failed to #{action}, reason: #{exception.message}. Falling back to memory cache store."
end
end
end
end