| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * 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 the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. 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 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; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "src/core/iomgr/time_averaged_stats.h" |
| |
| void grpc_time_averaged_stats_init(grpc_time_averaged_stats* stats, |
| double init_avg, double regress_weight, |
| double persistence_factor) { |
| stats->init_avg = init_avg; |
| stats->regress_weight = regress_weight; |
| stats->persistence_factor = persistence_factor; |
| stats->batch_total_value = 0; |
| stats->batch_num_samples = 0; |
| stats->aggregate_total_weight = 0; |
| stats->aggregate_weighted_avg = init_avg; |
| } |
| |
| void grpc_time_averaged_stats_add_sample(grpc_time_averaged_stats* stats, |
| double value) { |
| stats->batch_total_value += value; |
| ++stats->batch_num_samples; |
| } |
| |
| double grpc_time_averaged_stats_update_average( |
| grpc_time_averaged_stats* stats) { |
| /* Start with the current batch: */ |
| double weighted_sum = stats->batch_total_value; |
| double total_weight = stats->batch_num_samples; |
| if (stats->regress_weight > 0) { |
| /* Add in the regression towards init_avg_: */ |
| weighted_sum += stats->regress_weight * stats->init_avg; |
| total_weight += stats->regress_weight; |
| } |
| if (stats->persistence_factor > 0) { |
| /* Add in the persistence: */ |
| const double prev_sample_weight = |
| stats->persistence_factor * stats->aggregate_total_weight; |
| weighted_sum += prev_sample_weight * stats->aggregate_weighted_avg; |
| total_weight += prev_sample_weight; |
| } |
| stats->aggregate_weighted_avg = |
| (total_weight > 0) ? (weighted_sum / total_weight) : stats->init_avg; |
| stats->aggregate_total_weight = total_weight; |
| stats->batch_num_samples = 0; |
| stats->batch_total_value = 0; |
| return stats->aggregate_weighted_avg; |
| } |