mirror of https://github.com/XTLS/Xray-core
63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
package drain
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import (
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"io"
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"io/ioutil"
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"github.com/xtls/xray-core/common/dice"
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)
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type BehaviorSeedLimitedDrainer struct {
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DrainSize int
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}
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func NewBehaviorSeedLimitedDrainer(behaviorSeed int64, drainFoundation, maxBaseDrainSize, maxRandDrain int) (Drainer, error) {
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behaviorRand := dice.NewDeterministicDice(behaviorSeed)
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BaseDrainSize := behaviorRand.Roll(maxBaseDrainSize)
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RandDrainMax := behaviorRand.Roll(maxRandDrain) + 1
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RandDrainRolled := dice.Roll(RandDrainMax)
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DrainSize := drainFoundation + BaseDrainSize + RandDrainRolled
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return &BehaviorSeedLimitedDrainer{DrainSize: DrainSize}, nil
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}
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func (d *BehaviorSeedLimitedDrainer) AcknowledgeReceive(size int) {
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d.DrainSize -= size
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}
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func (d *BehaviorSeedLimitedDrainer) Drain(reader io.Reader) error {
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if d.DrainSize > 0 {
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err := drainReadN(reader, d.DrainSize)
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if err == nil {
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return newError("drained connection")
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}
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return newError("unable to drain connection").Base(err)
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}
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return nil
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}
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func drainReadN(reader io.Reader, n int) error {
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_, err := io.CopyN(ioutil.Discard, reader, int64(n))
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return err
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}
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func WithError(drainer Drainer, reader io.Reader, err error) error {
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drainErr := drainer.Drain(reader)
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if drainErr == nil {
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return err
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}
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return newError(drainErr).Base(err)
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}
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type NopDrainer struct{}
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func (n NopDrainer) AcknowledgeReceive(size int) {
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}
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func (n NopDrainer) Drain(reader io.Reader) error {
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return nil
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}
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func NewNopDrainer() Drainer {
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return &NopDrainer{}
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}
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