settimestampdelta.cc

COPE the first practical network coding scheme which is developped on click

// -*- mode: c++; c-basic-offset: 4 -*-
/*
 * settimestampdelta.{cc,hh} -- element observes range of timestamps
 * Eddie Kohler
 *
 * Copyright (c) 2003 International Computer Science Institute
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, subject to the conditions
 * listed in the Click LICENSE file. These conditions include: you must
 * preserve this copyright notice, and you cannot mention the copyright
 * holders in advertising related to the Software without their permission.
 * The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
 * notice is a summary of the Click LICENSE file; the license in that file is
 * legally binding.
 */

#include <click/config.h>
#include <click/error.hh>
#include "settimestampdelta.hh"
#include <click/confparse.hh>
#include <click/straccum.hh>
CLICK_DECLS

SetTimestampDelta::SetTimestampDelta()
    : Element(1, 1)
{
}

SetTimestampDelta::~SetTimestampDelta()
{
}

Packet *
SetTimestampDelta::simple_action(Packet *p)
{
    Timestamp& tv = p->timestamp_anno();
    if (tv) {
	if (!_first)
	    _first = tv;
	tv -= _first;
    }
    return p;
}

String
SetTimestampDelta::read_handler(Element *e, void *thunk)
{
    SetTimestampDelta *td = static_cast<SetTimestampDelta *>(e);
    StringAccum sa;
    switch ((intptr_t)thunk) {
      case 0: {
	  StringAccum sa;
	  sa << td->_first << '\n';
	  return sa.take_string();
      }
      default:
	return "<error>\n";
    }
}

int
SetTimestampDelta::write_handler(const String &, Element *e, void *, ErrorHandler *)
{
    SetTimestampDelta *td = static_cast<SetTimestampDelta *>(e);
    td->_first = Timestamp();
    return 0;
}

void
SetTimestampDelta::add_handlers()
{
    add_read_handler("first", read_handler, (void *)0);
    add_write_handler("reset", write_handler, (void *)0);
}

CLICK_ENDDECLS
EXPORT_ELEMENT(SetTimestampDelta)