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/*
*
* Copyright 2016 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#ifndef GRPC_CORE_LIB_TRANSPORT_BDP_ESTIMATOR_H
#define GRPC_CORE_LIB_TRANSPORT_BDP_ESTIMATOR_H
#include <grpc/support/port_platform.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdint.h>
#include <grpc/support/log.h>
#include <grpc/support/time.h>
#include "src/core/lib/debug/trace.h"
#include "src/core/lib/iomgr/exec_ctx.h"
extern grpc_tracer_flag grpc_bdp_estimator_trace;
namespace grpc_core {
class BdpEstimator {
public:
explicit BdpEstimator(const char *name);
~BdpEstimator() {}
// Returns true if a reasonable estimate could be obtained
bool EstimateBdp(int64_t *estimate_out) const {
*estimate_out = estimate_;
return true;
}
bool EstimateBandwidth(double *bw_out) const {
*bw_out = bw_est_;
return true;
}
void AddIncomingBytes(int64_t num_bytes) { accumulator_ += num_bytes; }
// Schedule a ping: call in response to receiving a true from
// grpc_bdp_estimator_add_incoming_bytes once a ping has been scheduled by a
// transport (but not necessarily started)
void SchedulePing() {
if (GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
gpr_log(GPR_DEBUG, "bdp[%s]:sched acc=%" PRId64 " est=%" PRId64, name_,
accumulator_, estimate_);
}
GPR_ASSERT(ping_state_ == PingState::UNSCHEDULED);
ping_state_ = PingState::SCHEDULED;
accumulator_ = 0;
}
// Start a ping: call after calling grpc_bdp_estimator_schedule_ping and
// once
// the ping is on the wire
void StartPing() {
if (GRPC_TRACER_ON(grpc_bdp_estimator_trace)) {
gpr_log(GPR_DEBUG, "bdp[%s]:start acc=%" PRId64 " est=%" PRId64, name_,
accumulator_, estimate_);
}
GPR_ASSERT(ping_state_ == PingState::SCHEDULED);
ping_state_ = PingState::STARTED;
accumulator_ = 0;
ping_start_time_ = gpr_now(GPR_CLOCK_MONOTONIC);
}
// Completes a previously started ping, returns when to schedule the next one
grpc_millis CompletePing(grpc_exec_ctx *exec_ctx);
private:
enum class PingState { UNSCHEDULED, SCHEDULED, STARTED };
PingState ping_state_;
int64_t accumulator_;
int64_t estimate_;
// when was the current ping started?
gpr_timespec ping_start_time_;
int inter_ping_delay_;
int stable_estimate_count_;
double bw_est_;
const char *name_;
};
} // namespace grpc_core
#endif /* GRPC_CORE_LIB_TRANSPORT_BDP_ESTIMATOR_H */
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