Contents

require 'thread'

module Datadog
  # Trace buffer that stores application traces. The buffer has a maximum size and when
  # the buffer is full, a random trace is discarded. This class is thread-safe and is used
  # automatically by the ``Tracer`` instance when a ``Span`` is finished.
  class TraceBuffer
    def initialize(max_size)
      @max_size = max_size

      @mutex = Mutex.new()
      @traces = []
    end

    # Add a new ``trace`` in the local queue. This method doesn't block the execution
    # even if the buffer is full. In that case, a random trace is discarded.
    def push(trace)
      @mutex.synchronize do
        len = @traces.length
        if len < @max_size || @max_size <= 0
          @traces << trace
        else
          # we should replace a random trace with the new one
          @traces[rand(len)] = trace
        end
      end
    end

    # Return the current number of stored traces.
    def length
      @mutex.synchronize do
        return @traces.length
      end
    end

    # Return if the buffer is empty.
    def empty?
      @mutex.synchronize do
        return @traces.empty?
      end
    end

    # Stored traces are returned and the local buffer is reset.
    def pop
      @mutex.synchronize do
        traces = @traces
        @traces = []
        return traces
      end
    end
  end
end

Version data entries

4 entries across 4 versions & 2 rubygems

Version	Path
fair-ddtrace-0.8.2.a	lib/ddtrace/buffer.rb
ddtrace-0.8.2	lib/ddtrace/buffer.rb
ddtrace-0.8.1	lib/ddtrace/buffer.rb
ddtrace-0.8.0	lib/ddtrace/buffer.rb