class Jaeger::Tracer
Attributes
@return [ScopeManager] the current ScopeManager
, which may be a no-op
but may not be nil.
Public Class Methods
# File lib/jaeger/tracer.rb, line 5 def initialize(reporter:, sampler:, injectors:, extractors:) @reporter = reporter @sampler = sampler @injectors = injectors @extractors = extractors @scope_manager = ScopeManager.new end
Public Instance Methods
@return [Span, nil] the active span. This is a shorthand for
`scope_manager.active.span`, and nil will be returned if Scope#active is nil.
# File lib/jaeger/tracer.rb, line 20 def active_span scope = scope_manager.active scope.span if scope end
Extract a SpanContext
in the given format from the given carrier.
@param format [OpenTracing::FORMAT_TEXT_MAP, OpenTracing::FORMAT_BINARY, OpenTracing::FORMAT_RACK] @param carrier [Carrier] A carrier object of the type dictated by the specified `format` @return [SpanContext] the extracted SpanContext
or nil if none could be found
# File lib/jaeger/tracer.rb, line 157 def extract(format, carrier) @extractors .fetch(format) .lazy .map { |extractor| extractor.extract(carrier) } .reject(&:nil?) .first end
Inject a SpanContext
into the given carrier
@param span_context [SpanContext] @param format [OpenTracing::FORMAT_TEXT_MAP, OpenTracing::FORMAT_BINARY, OpenTracing::FORMAT_RACK] @param carrier [Carrier] A carrier object of the type dictated by the specified `format`
# File lib/jaeger/tracer.rb, line 146 def inject(span_context, format, carrier) @injectors.fetch(format).each do |injector| injector.inject(span_context, carrier) end end
Creates a newly started and activated Scope
If the Tracer's ScopeManager#active
is not nil, no explicit references are provided, and `ignore_active_scope` is false, then an inferred References#CHILD_OF reference is created to the ScopeManager#active
's SpanContext
when start_active is invoked.
@param operation_name [String] The operation name for the Span
@param child_of [SpanContext, Span] SpanContext
that acts as a parent to
the newly-started Span. If a Span instance is provided, its context is automatically substituted. See [Reference] for more information. If specified, the `references` parameter must be omitted.
@param references [Array<Reference>] An array of reference
objects that identify one or more parent SpanContexts.
@param start_time [Time] When the Span
started, if not now @param tags [Hash] Tags to assign to the Span
at start time @param ignore_active_scope [Boolean] whether to create an implicit
References#CHILD_OF reference to the ScopeManager#active.
@param finish_on_close [Boolean] whether span should automatically be
finished when Scope#close is called
@yield [Scope] If an optional block is passed to start_active_span
it
will yield the newly-started Scope. If `finish_on_close` is true then the Span will be finished automatically after the block is executed.
@return [Scope, Object] If passed an optional block, start_active_span
returns the block's return value, otherwise it returns the newly-started and activated Scope
# File lib/jaeger/tracer.rb, line 112 def start_active_span(operation_name, child_of: nil, references: nil, start_time: Time.now, tags: {}, ignore_active_scope: false, finish_on_close: true, **) span = start_span( operation_name, child_of: child_of, references: references, start_time: start_time, tags: tags, ignore_active_scope: ignore_active_scope ) scope = @scope_manager.activate(span, finish_on_close: finish_on_close) if block_given? begin yield scope ensure scope.close end else scope end end
Starts a new span.
This is similar to start_active_span
, but the returned Span
will not be registered via the ScopeManager
.
@param operation_name [String] The operation name for the Span
@param child_of [SpanContext, Span] SpanContext
that acts as a parent to
the newly-started Span. If a Span instance is provided, its context is automatically substituted. See [Reference] for more information. If specified, the `references` parameter must be omitted.
@param references [Array<Reference>] An array of reference
objects that identify one or more parent SpanContexts.
@param start_time [Time] When the Span
started, if not now @param tags [Hash] Tags to assign to the Span
at start time @param ignore_active_scope [Boolean] whether to create an implicit
References#CHILD_OF reference to the ScopeManager#active.
@yield [Span] If passed an optional block, start_span
will yield the
newly-created span to the block. The span will be finished automatically after the block is executed.
@return [Span, Object] If passed an optional block, start_span
will return
the block's return value, otherwise it returns the newly-started Span instance, which has not been automatically registered via the ScopeManager
# File lib/jaeger/tracer.rb, line 51 def start_span(operation_name, child_of: nil, references: nil, start_time: Time.now, tags: {}, ignore_active_scope: false, **) context, sampler_tags = prepare_span_context( operation_name: operation_name, child_of: child_of, references: references, ignore_active_scope: ignore_active_scope ) span = Span.new( context, operation_name, @reporter, start_time: start_time, references: references, tags: tags.merge(sampler_tags) ) if block_given? begin yield(span) ensure span.finish end else span end end
Private Instance Methods
# File lib/jaeger/tracer.rb, line 206 def context_from_active_scope(ignore_active_scope) return if ignore_active_scope active_scope = @scope_manager.active active_scope.span.context if active_scope end
# File lib/jaeger/tracer.rb, line 191 def context_from_child_of(child_of) return nil unless child_of child_of.respond_to?(:context) ? child_of.context : child_of end
# File lib/jaeger/tracer.rb, line 196 def context_from_references(references) return nil if !references || references.none? # Prefer CHILD_OF reference if present ref = references.detect do |reference| reference.type == OpenTracing::Reference::CHILD_OF end (ref || references[0]).context end
# File lib/jaeger/tracer.rb, line 168 def prepare_span_context(operation_name:, child_of:, references:, ignore_active_scope:) context = context_from_child_of(child_of) || context_from_references(references) || context_from_active_scope(ignore_active_scope) if context [SpanContext.create_from_parent_context(context), {}] else trace_id = TraceId.generate is_sampled, tags = @sampler.sample( trace_id: trace_id, operation_name: operation_name ) span_context = SpanContext.new( trace_id: trace_id, span_id: trace_id, flags: is_sampled ? SpanContext::Flags::SAMPLED : SpanContext::Flags::NONE ) [span_context, tags] end end