Files
livekit/pkg/sfu/ccutils/probe_regulator.go
Raja Subramanian 94488d434d TWCC probing (#3234)
* WIP

* WIP

* WIP

* make it compile

* typo

* clean up

* fmt

* fixes
2024-12-06 00:13:36 +05:30

107 lines
3.3 KiB
Go

// Copyright 2023 LiveKit, Inc.
//
// 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.
package ccutils
import (
"time"
"github.com/livekit/protocol/logger"
"github.com/livekit/protocol/utils/mono"
)
// ------------------------------------------------
type ProbeRegulatorConfig struct {
BaseInterval time.Duration `yaml:"base_interval,omitempty"`
BackoffFactor float64 `yaml:"backoff_factor,omitempty"`
MaxInterval time.Duration `yaml:"max_interval,omitempty"`
MinDuration time.Duration `yaml:"min_duration,omitempty"`
MaxDuration time.Duration `yaml:"max_duration,omitempty"`
DurationIncreaseFactor float64 `yaml:"duration_increase_factor,omitempty"`
}
var (
DefaultProbeRegulatorConfig = ProbeRegulatorConfig{
BaseInterval: 3 * time.Second,
BackoffFactor: 1.5,
MaxInterval: 2 * time.Minute,
MinDuration: 200 * time.Millisecond,
MaxDuration: 20 * time.Second,
DurationIncreaseFactor: 1.5,
}
)
// ---------------------------------------------------------------------------
type ProbeRegulatorParams struct {
Config ProbeRegulatorConfig
Logger logger.Logger
}
type ProbeRegulator struct {
params ProbeRegulatorParams
probeInterval time.Duration
probeDuration time.Duration
nextProbeEarliestAt time.Time
}
func NewProbeRegulator(params ProbeRegulatorParams) *ProbeRegulator {
return &ProbeRegulator{
params: params,
probeInterval: params.Config.BaseInterval,
probeDuration: params.Config.MinDuration,
nextProbeEarliestAt: mono.Now(),
}
}
func (p *ProbeRegulator) CanProbe() bool {
return mono.Now().After(p.nextProbeEarliestAt)
}
func (p *ProbeRegulator) ProbeDuration() time.Duration {
return p.probeDuration
}
func (p *ProbeRegulator) ProbeSignal(probeSignal ProbeSignal, baseTime time.Time) {
if probeSignal == ProbeSignalCongesting {
// wait longer till next probe
p.probeInterval = time.Duration(p.probeInterval.Seconds()*p.params.Config.BackoffFactor) * time.Second
if p.probeInterval > p.params.Config.MaxInterval {
p.probeInterval = p.params.Config.MaxInterval
}
// revert back to starting with shortest probe
p.probeDuration = p.params.Config.MinDuration
} else {
// probe can be started again after minimal interval as previous congestion signal indicated congestion clearing
p.probeInterval = p.params.Config.BaseInterval
// can do longer probe after a good probe
p.probeDuration = time.Duration(float64(p.probeDuration.Milliseconds())*p.params.Config.DurationIncreaseFactor) * time.Millisecond
if p.probeDuration > p.params.Config.MaxDuration {
p.probeDuration = p.params.Config.MaxDuration
}
}
if baseTime.IsZero() {
p.nextProbeEarliestAt = mono.Now().Add(p.probeInterval)
} else {
p.nextProbeEarliestAt = baseTime.Add(p.probeInterval)
}
}