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Viewing changes to src/core/iomgr/time_averaged_stats.c

  • Committer: Package Import Robot
  • Author(s): Andrew Pollock
  • Date: 2015-05-07 13:28:11 UTC
  • Revision ID: package-import@ubuntu.com-20150507132811-ybm4hfq73tnvvd2e
Tags: upstream-0.10.0
Import upstream version 0.10.0

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src/core/iomgr/time_averaged_stats.c
 
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/*
 
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 *
 
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 * Copyright 2015, Google Inc.
 
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 * All rights reserved.
 
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 *
 
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 * Redistribution and use in source and binary forms, with or without
 
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 * modification, are permitted provided that the following conditions are
 
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 * met:
 
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 *
 
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 *     * Redistributions of source code must retain the above copyright
 
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 * notice, this list of conditions and the following disclaimer.
 
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 *     * Redistributions in binary form must reproduce the above
 
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 * copyright notice, this list of conditions and the following disclaimer
 
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 * in the documentation and/or other materials provided with the
 
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 * distribution.
 
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 *     * Neither the name of Google Inc. nor the names of its
 
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 * contributors may be used to endorse or promote products derived from
 
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 * this software without specific prior written permission.
 
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 *
 
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 
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 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 
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 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 
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 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 
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 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
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 *
 
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 */
 
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#include "src/core/iomgr/time_averaged_stats.h"
 
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void grpc_time_averaged_stats_init(grpc_time_averaged_stats *stats,
 
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                                   double init_avg, double regress_weight,
 
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                                   double persistence_factor) {
 
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  stats->init_avg = init_avg;
 
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  stats->regress_weight = regress_weight;
 
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  stats->persistence_factor = persistence_factor;
 
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  stats->batch_total_value = 0;
 
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  stats->batch_num_samples = 0;
 
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  stats->aggregate_total_weight = 0;
 
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  stats->aggregate_weighted_avg = init_avg;
 
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}
 
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void grpc_time_averaged_stats_add_sample(grpc_time_averaged_stats *stats,
 
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                                         double value) {
 
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  stats->batch_total_value += value;
 
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  ++stats->batch_num_samples;
 
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}
 
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double grpc_time_averaged_stats_update_average(
 
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    grpc_time_averaged_stats *stats) {
 
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  /* Start with the current batch: */
 
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  double weighted_sum = stats->batch_total_value;
 
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  double total_weight = stats->batch_num_samples;
 
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  if (stats->regress_weight > 0) {
 
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    /* Add in the regression towards init_avg_: */
 
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    weighted_sum += stats->regress_weight * stats->init_avg;
 
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    total_weight += stats->regress_weight;
 
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  }
 
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  if (stats->persistence_factor > 0) {
 
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    /* Add in the persistence: */
 
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    const double prev_sample_weight =
 
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        stats->persistence_factor * stats->aggregate_total_weight;
 
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    weighted_sum += prev_sample_weight * stats->aggregate_weighted_avg;
 
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    total_weight += prev_sample_weight;
 
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  }
 
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  stats->aggregate_weighted_avg =
 
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      (total_weight > 0) ? (weighted_sum / total_weight) : stats->init_avg;
 
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  stats->aggregate_total_weight = total_weight;
 
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  stats->batch_num_samples = 0;
 
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  stats->batch_total_value = 0;
 
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  return stats->aggregate_weighted_avg;
 
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}