Module: MetrixWire::Context

Defined in:
lib/metrixwire/context.rb

Overview

Thread/fiber-local "current trace" holder. Every entry point (Rack middleware, ActiveSupport subscribers, DB/HTTP patches) reads the active trace from here so spans attach to the right request. Fiber-local storage (Thread#[]) keeps concurrent requests isolated on threaded servers.

Constant Summary collapse

KEY = 
:__metrixwire_current_trace__

Class Method Summary collapse

Class Method Details

.clear ⇒ Object 



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# File 'lib/metrixwire/context.rb', line 31

def clear
  Thread.current[KEY] = nil
end

.current ⇒ Object 



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# File 'lib/metrixwire/context.rb', line 13

def current
  Thread.current[KEY]
end

.current=(trace) ⇒ Object 



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# File 'lib/metrixwire/context.rb', line 17

def current=(trace)
  Thread.current[KEY] = trace
end

.with(trace) ⇒ Object

Run a block with trace as the active trace, restoring the previous one afterwards. Restores even if the block raises.



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# File 'lib/metrixwire/context.rb', line 23

def with(trace)
  prev = Thread.current[KEY]
  Thread.current[KEY] = trace
  yield
ensure
  Thread.current[KEY] = prev
end