module Async::HTTP::Cache::Body

def self.wrap(message, &block)
	if body = message.body
		# Create a rewindable body wrapping the message body:
		rewindable = ::Protocol::HTTP::Body::Rewindable.new(body)
		
		# Set the message body to the rewindable body:
		message.body = rewindable
		
		# Wrap the message with the callback:
		::Protocol::HTTP::Body::Streamable.wrap(message) do |error|
			if error
				Async.logger.error(self) {error}
			else
				yield message, rewindable.buffered
			end
		end
	else
		yield message, nil
	end
	
	return message
end