Add decorate(event) in case of stateful codecs like multiline

[duaraghav8]

The decorate() method wasn't being called in case of stateful codecs before en-queuing the event. This resulted in type, tags and add_field options being ineffective when a user uses them with this plugin.
This PR fixes it

See issue #153

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[zuifanzhuce]

I'm using s3 and multiline, adding "decorate(event)" into s3.rb doesn't fix my issue. However, after adding all those below, the issue is gone.

@codec.flush do |event|
decorate(event)

  event.set("cloudfront_version", metadata[:cloudfront_version]) unless metadata[:cloudfront_version].nil?
  event.set("cloudfront_fields", metadata[:cloudfront_fields]) unless metadata[:cloudfront_fields].nil?

  if @include_object_properties
    event.set("[@metadata][s3]", object.data.to_h)
  else
    event.set("[@metadata][s3]", {})
  end

  event.set("[@metadata][s3][key]", object.key)
      
  queue << event
end

[roeezab]

I'm using s3 and multiline, adding "decorate(event)" into s3.rb doesn't fix my issue. However, after adding all those below, the issue is gone.

@codec.flush do |event|
decorate(event)

  event.set("cloudfront_version", metadata[:cloudfront_version]) unless metadata[:cloudfront_version].nil?
  event.set("cloudfront_fields", metadata[:cloudfront_fields]) unless metadata[:cloudfront_fields].nil?

  if @include_object_properties
    event.set("[@metadata][s3]", object.data.to_h)
  else
    event.set("[@metadata][s3]", {})
  end

  event.set("[@metadata][s3][key]", object.key)
      
  queue << event
end

It worked for me as well. Thanks @duaraghav8 and @zuifanzhuce!

[kaisecheng]

The issue is fixed in 3.8.3