snmp.rb in logstash-input-snmp-1.2.8

- old
+ new

@@ -159,13 +159,13 @@
       @client_definitions << definition
     end
   end
 
   def run(queue)
-    # for now a naive single threaded poller which sleeps for the given interval between
+    # for now a naive single threaded poller which sleeps off the remaining interval between
     # each run. each run polls all the defined hosts for the get and walk options.
-    while !stop?
+    stoppable_interval_runner.every(@interval, "polling hosts") do
       @client_definitions.each do |definition|
         result = {}
         if !definition[:get].empty?
           begin
             result = result.merge(definition[:client].get(definition[:get], @oid_root_skip, @oid_path_length))
@@ -205,25 +205,30 @@
           event = LogStash::Event.new(result)
           decorate(event)
           queue << event
         end
       end
-
-      Stud.stoppable_sleep(@interval) { stop? }
     end
   end
 
+  def stoppable_interval_runner
+    StoppableIntervalRunner.new(self)
+  end
+
   def close
     @client_definitions.each do |definition|
       begin
         definition[:client].close
       rescue => e
         logger.warn("error closing client on #{definition[:host_address]}, ignoring", :exception => e)
       end
     end
   end
 
+  def stop
+  end
+
   private
 
   OID_REGEX = /^\.?([0-9\.]+)$/
   HOST_REGEX = /^(?<host_protocol>udp|tcp):(?<host_address>.+)\/(?<host_port>\d+)$/i
   VERSION_REGEX =/^1|2c|3$/
@@ -292,7 +297,48 @@
     end
   end
 
   def validate_strip!
     raise(LogStash::ConfigurationError, "you can not specify both oid_root_skip and oid_path_length") if @oid_root_skip > 0 and @oid_path_length > 0
+  end
+
+  ##
+  # The StoppableIntervalRunner is capable of running a block of code at a
+  # repeating interval, while respecting the stop condition of the plugin.
+  class StoppableIntervalRunner
+    ##
+    # @param plugin [#logger,#stop?]
+    def initialize(plugin)
+      @plugin = plugin
+    end
+
+    ##
+    # Runs the provided block repeatedly using the provided interval.
+    # After executing the block, the remainder of the interval if any is slept off
+    # using an interruptible sleep.
+    # If no time remains, a warning is emitted to the logs.
+    #
+    # @param interval_seconds [Integer,Float]
+    # @param desc [String] (default: "operation"): a description to use when logging
+    # @yield
+    def every(interval_seconds, desc="operation", &block)
+      until @plugin.stop?
+        start_time = Time.now
+
+        yield
+
+        duration_seconds = Time.now - start_time
+        if duration_seconds >= interval_seconds
+          @plugin.logger.warn("#{desc} took longer than the configured interval", :interval_seconds => interval_seconds, :duration_seconds => duration_seconds.round(3))
+        else
+          remaining_interval = interval_seconds - duration_seconds
+          sleep(remaining_interval)
+        end
+      end
+    end
+
+    # @api private
+    def sleep(duration)
+      Stud.stoppable_sleep(duration) { @plugin.stop? }
+    end
   end
 end