buyer_k_saap.py

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# configuring PYTHONPATH (By default, this will add the src and lib directory for each of your dependencies to your PYTHONPATH)
import roslib; roslib.load_manifest('k-saap_pkg')

# import client library
import rospy

# import messages
import auction_msgs.msg

# import services
import auction_srvs.srv

import auction_common

# import auxiliar libraries
import random
import math

# "global" variables (to be referred as global under def fun(something))
winner_id = 'none'
winner_cost = 0


#####################################################################################
## Buyer Service Callback
#####################################################################################
def handle_auction_server_callback(auction_req):

    # update number of messages in parameter server
    if rospy.has_param('/num_messages'):
        num_messages = rospy.get_param('/num_messages')
        num_messages += 2
        rospy.set_param('/num_messages', num_messages)


    # Graph parameters
    graph_parameters = eval(rospy.get_param("graph_info"))
    N = int(graph_parameters[0])
    l = int(graph_parameters[1])
    d = int(graph_parameters[2])
    r = math.sqrt((d*l*l)/(math.pi*(N-1)))

    print N, l, d, r

    
    # Calculate k (number of hop)
    node_position = eval(rospy.get_param('~position'))
    auctioneer_position = eval(auction_req._connection_header['auctioneer_position'])

    x = float(node_position[0])-float(auctioneer_position[0])
    y = float(node_position[1])-float(auctioneer_position[1])
    z = float(node_position[2])-float(auctioneer_position[2])
    distance_from_node_to_auctioneer = math.sqrt(x*x+y*y+z*z)
    k = int(distance_from_node_to_auctioneer/r)

    print distance_from_node_to_auctioneer, k

    
    # Create a bid messsage to put an offer for the item in auction_req!    
    bid_response = auction_msgs.msg.Bid()
    bid_response.header.frame_id = 'base_link' # to be rechecked
    bid_response.header.stamp = rospy.Time.now()
    bid_response.buyer_id = rospy.get_name()          
        
    if auction_req.auction_data.metrics == "distance":
        # to be given by the cost to go to position of the ocurring event
        # the cost for the metrics==distance is calculated using the euclidean
        # distance between the parameter position of the node and the task_position
        # given in the auction_req
        node_position = eval(rospy.get_param('~position'))
        x = float(node_position[0])-auction_req.auction_data.task_location.x
        y = float(node_position[1])-auction_req.auction_data.task_location.y
        z = float(node_position[2])-auction_req.auction_data.task_location.z
        bid_response.cost_distance = float(math.sqrt(x*x+y*y+z*z))
    else:
        rospy.loginfo("Metrics unkown")
        bid_response.cost_distance = 999999;


    print auction_req.auction_data.subject


    # Check if node is in the k-hops required range
    if k < int(auction_req.auction_data.subject):

        # Relay information to neighbour nodes!
        neighbour_nodes_relay_list = auction_common.create_neighbour_nodes_list(auction_req)
        print neighbour_nodes_relay_list
           
        if neighbour_nodes_relay_list:              

            # Prepare auction information
            if auction_req.auction_data.command == 'join_auction':
                role = 'be_buyer'
            else:
                role = 'none'
            auction_req.sending_node = rospy.get_name()

            # updated nodes_collected
            if rospy.has_param('/nodes_collected'):
                auction_req.nodes_collected = rospy.get_param('/nodes_collected')+','+rospy.get_name()
                rospy.set_param('/nodes_collected',auction_req.nodes_collected)
            else:
                auction_req.nodes_collected = rospy.get_param('~neighbour_nodes_list')
                

            for node in neighbour_nodes_relay_list:                  

                # compose service name
                service_path = node+'/auction_server'

                rospy.wait_for_service(service_path)
                neighbour_node_auction_server = rospy.ServiceProxy(service_path, auction_srvs.srv.AuctionService, headers={ 'auctioneer_position': auctioneer_position})

                try:
                    neighbour_node_bid_response = neighbour_node_auction_server(auction_req)

                    # log bid information from the neighbour node (debug)
                    # rospy.loginfo(neighbour_node_bid_response)
                
                except rospy.ServiceException, e:
                    rospy.loginfo("Service call failed: %s",e)


                if neighbour_node_bid_response.bid_data.cost_distance < bid_response.cost_distance:
                    bid_response.buyer_id= neighbour_node_bid_response.bid_data.buyer_id
                    bid_response.cost_distance= neighbour_node_bid_response.bid_data.cost_distance
                             
              
    # return best bid
    return {'response_info': 'valid'+rospy.get_name(), 'bid_data': bid_response}
## End handle_buyer_server_callback