Class: Pantheios::Services::MultiplexingLogService

Inherits:

Object

• Object
• Pantheios::Services::MultiplexingLogService

Defined in:

lib/pantheios/services/multiplexing_log_service.rb

Overview

A class that fulfils the Pantheios LogService protocol by multiplexing its responsibilities to a number of (concrete) log service instances

NOTE: The LogService protocol is implemented by a class that provides the instance methods severity_logged?(severity : Object) : boolean and log(severity : Object, t : Time, prefix : String|Array, msg : String)

Instance Method Summary

• #initialize(services, **options) ⇒ MultiplexingLogService constructor

  Initializes the instance with an array of log services, according to the given options.

• #log(sev, t, pref, msg) ⇒ Object
• #requires_prefix? ⇒ Boolean

  Indicates whether any of the services require a prefix and, if so, what it may require.

• #severity_logged?(severity) ⇒ Boolean

  Indicates whether the given severity is to be logged by any of the multiplexed log services.

Constructor Details

#initialize(services, **options) ⇒ MultiplexingLogService

Initializes the instance with an array of log services, according to the given options

Signature

• Parameters:

  • services

    ::Array

    An array of instances that observe the

    Log Service protocol

  • options

    ::Hash

    options

• Options:

  • :level_cache_mode

    ::Symbol

    Specifies the mode of severity

    level caching, and must be one of the following values:

    • :none

      no severity level caching is performed. This is the

      default because it is completely thread-safe, but it is the slowest mode, and users are advised to specify another mode suitable to their use

    • :thread_fixed

      remembers the response of each multiplexed log

      service to each severity level on a thread-specific basis

    • :process_fixed

      remembers the response of each multiplexed

      log service to each severity level and then remembers that for the duration of the lifetime of the instance

  • :unsync_process_lcm

    boolean

    If truey, causes

    :process_fixed :level_cache_mode to NOT be synchronised; the default is for it to be synchronised using an internal Mutex instance

# File 'lib/pantheios/services/multiplexing_log_service.rb', line 103

def initialize services, **options

	@tss_sym	=	self.to_s.to_sym
	@services	=	services.map { |svc| MultiplexingLogService_Internals_::ServiceManagementInfo.new svc }
	@options	=	options.dup
	@mode		=	options[:level_cache_mode]
	@unsync_pf	=	options[:unsync_process_lcm]

	@process_m	=	{}
	@mx			=	Mutex.new unless @unsync_pf
end

Instance Method Details

#log(sev, t, pref, msg) ⇒ Object

# File 'lib/pantheios/services/multiplexing_log_service.rb', line 239

def log sev, t, pref, msg

	tss_m	=	:thread_fixed == @mode ? get_tss_svc_sev_map_ : nil

	@services.each do |smi|

		svc	=	smi.service

		case @mode
		when :process_fixed

			if @unsync_pf

				isl	=	svc_sev_logged_pf_ @process_m, svc, sev
			else

				isl	=	@mx.synchronize { svc_sev_logged_pf_ @process_m, svc, sev }
			end
		when :thread_fixed

			m	=	tss_m

			isl	=	svc_sev_logged_tf_ m, svc, sev
		else # :none

			isl	=	svc.severity_logged? sev
		end


		svc.log sev, t, pref, msg if isl
	end
end

#requires_prefix? ⇒ Boolean

Indicates whether any of the services require a prefix and, if so, what it may require

Return

(false, true, :parts) An indicator what the most needy of the multiplexed services requires

Returns:

• (Boolean)

# File 'lib/pantheios/services/multiplexing_log_service.rb', line 178

def requires_prefix?

	return @requires_prefix unless @requires_prefix.nil?

	requires_prefix = false

	@services.each do |svc|

		if svc.respond_to? :requires_prefix?

			case rp = svc.requires_prefix?
			when nil, false

				;
			when true

				requires_prefix ||= true
			when :parts

				requires_prefix = rp
				break
			else

				warn "unrecognised return from requires_prefix? for service #{svc}: #{rp} (#{rp.class})"
			end
		end
	end

	@requires_prefix = requires_prefix
end

#severity_logged?(severity) ⇒ Boolean

Indicates whether the given severity is to be logged by any of the multiplexed log services

Returns:

• (Boolean)

# File 'lib/pantheios/services/multiplexing_log_service.rb', line 211

def severity_logged? severity

	case @mode
	when :process_fixed

		if @unsync_pf

			sev_logged_pf_ @process_m, severity
		else

			@mx.synchronize { sev_logged_pf_ @process_m, severity }
		end
	when :thread_fixed

		m	=	get_tss_svc_sev_map_

		@services.any? do |smi|

			svc	=	smi.service

			svc_sev_logged_tf_ m, svc, severity
		end
	else # :none

		@services.any? { |smi| smi.service.severity_logged? severity }
	end
end