TimeSync.pbj

/*  Sirikata
 *  TimeSync.pbj
 *
 *  Copyright (c) 2010, Ewen Cheslack-Postava
 *  All rights reserved.
 *
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 *  modification, are permitted provided that the following conditions are
 *  met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
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 *    distribution.
 *  * Neither the name of Sirikata nor the names of its contributors may
 *    be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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 */

"pbj-0.0.3"

package Sirikata.Protocol;

// A simple message for time synchronization. The synchronization is
// performed by the client sending a TimeSync packet containing only a
// sequence number to the server and saving a timestamp locally.  The
// server responds with a TimeSync packet with the same sequence
// number and its local time when it generated the reply.  When the
// client receives the reply, it can compute round-trip time and an
// approximate offset.
//
// Note that the sequence numbers are limited so that a fixed amount
// of space can be used to efficiently track outstanding sync
// packets.  If a loss occurs, the error can be trivially ignored --
// the next sync packet will get another update.
message TimeSync {
    optional uint8 seqno = 1;
    optional time t = 2;
}