| /* |
| * |
| * Copyright 2016, 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/lib/transport/bdp_estimator.h" |
| |
| #include <stdlib.h> |
| |
| #include <grpc/support/log.h> |
| #include <grpc/support/useful.h> |
| |
| void grpc_bdp_estimator_init(grpc_bdp_estimator *estimator) { |
| estimator->num_samples = 0; |
| estimator->first_sample_idx = 0; |
| estimator->sampling = false; |
| } |
| |
| static int compare_samples(const void *a, const void *b) { |
| return GPR_ICMP(*(int64_t *)a, *(int64_t *)b); |
| } |
| |
| bool grpc_bdp_estimator_get_estimate(grpc_bdp_estimator *estimator, |
| int64_t *estimate) { |
| if (estimator->num_samples < GRPC_BDP_MIN_SAMPLES_FOR_ESTIMATE) { |
| return false; |
| } |
| |
| int64_t samples[GRPC_BDP_SAMPLES]; |
| for (uint8_t i = 0; i < estimator->num_samples; i++) { |
| samples[i] = |
| estimator |
| ->samples[(estimator->first_sample_idx + i) % GRPC_BDP_SAMPLES]; |
| } |
| qsort(samples, estimator->num_samples, sizeof(*samples), compare_samples); |
| |
| if (estimator->num_samples & 1) { |
| *estimate = samples[estimator->num_samples / 2]; |
| } else { |
| *estimate = (samples[estimator->num_samples / 2] + |
| samples[estimator->num_samples / 2 + 1]) / |
| 2; |
| } |
| return true; |
| } |
| |
| static int64_t *sampling(grpc_bdp_estimator *estimator) { |
| return &estimator |
| ->samples[(estimator->first_sample_idx + estimator->num_samples) % |
| GRPC_BDP_SAMPLES]; |
| } |
| |
| bool grpc_bdp_estimator_add_incoming_bytes(grpc_bdp_estimator *estimator, |
| int64_t num_bytes) { |
| if (estimator->sampling) { |
| *sampling(estimator) += num_bytes; |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| void grpc_bdp_estimator_start_ping(grpc_bdp_estimator *estimator) { |
| GPR_ASSERT(!estimator->sampling); |
| estimator->sampling = true; |
| if (estimator->num_samples == GRPC_BDP_SAMPLES) { |
| estimator->first_sample_idx++; |
| estimator->num_samples--; |
| } |
| *sampling(estimator) = 0; |
| } |
| |
| void grpc_bdp_estimator_complete_ping(grpc_bdp_estimator *estimator) { |
| GPR_ASSERT(estimator->sampling); |
| estimator->num_samples++; |
| estimator->sampling = false; |
| } |