// $Id: stats.cpp 5188 2012-08-30 00:31:31Z dub $

/*
 Copyright (c) 2007-2012, Trustees of The Leland Stanford Junior University
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
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 list of conditions and the following disclaimer in the documentation and/or
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 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*stats.cpp
 *
 *class stores statistics gnerated by the trafficmanager such as the latency
 *hope count of the the flits
 *
 *reset option resets the min and max alues of this statistiscs
 */

#include "booksim.hpp"
#include <iostream>
#include <sstream>
#include <limits>
#include <cmath>
#include <cstdio>

#include "stats.hpp"

Stats::Stats( Module *parent, const string &name,
	      double bin_size, int num_bins ) :
  Module( parent, name ), _num_bins( num_bins ), _bin_size( bin_size )
{
  Clear();
}

void Stats::Clear( )
{
  _num_samples = 0;
  _sample_sum  = 0.0;
  _sample_squared_sum = 0.0;

  _hist.assign(_num_bins, 0);

  _min = numeric_limits<double>::quiet_NaN();
  _max = -numeric_limits<double>::quiet_NaN();
  
  //  _reset = true;
}

double Stats::Average( ) const
{
  return _sample_sum / (double)_num_samples;
}

double Stats::Variance( ) const
{
  return (_sample_squared_sum * (double)_num_samples - _sample_sum * _sample_sum) / ((double)_num_samples * (double)_num_samples);
}

double Stats::Min( ) const
{
  return _min;
}

double Stats::Max( ) const
{
  return _max;
}

double Stats::Sum( ) const
{
  return _sample_sum;
}

double Stats::SquaredSum( ) const
{
  return _sample_squared_sum;
}

int Stats::NumSamples( ) const
{
  return _num_samples;
}

void Stats::AddSample( double val )
{
  ++_num_samples;
  _sample_sum += val;

  // NOTE: the negation ensures that NaN values are handled correctly!
  _max = !(val <= _max) ? val : _max;
  _min = !(val >= _min) ? val : _min;

  //double clamp between 0 and num_bins-1
  int b = (int)fmax(floor( val / _bin_size ), 0.0);
  b = (b >= _num_bins) ? (_num_bins - 1) : b;

  _hist[b]++;
}

void Stats::Display( ostream & os ) const
{
  os << *this << endl;
}

ostream & operator<<(ostream & os, const Stats & s) {
  vector<int> const & v = s._hist;
  os << "[ ";
  for(size_t i = 0; i < v.size(); ++i) {
    os << v[i] << " ";
  }
  os << "]";
  return os;
}