nex-go/stream_settings.go

70 lines
4.1 KiB
Go

package nex
import (
"github.com/PretendoNetwork/nex-go/compression"
"github.com/PretendoNetwork/nex-go/encryption"
)
// StreamSettings is an implementation of rdv::StreamSettings.
// StreamSettings holds the state and settings for a PRUDP virtual connection stream.
// Each virtual connection is composed of a virtual port and stream type.
// In the original library this would be tied to a rdv::Stream class, but here it is not.
// The original library has more settings which are not present here as their use is unknown.
// Not all values are used at this time, and only exist to future-proof for a later time.
type StreamSettings struct {
ExtraRestransmitTimeoutTrigger uint32 // * Unused. The number of times a packet can be retransmitted before ExtraRetransmitTimeoutMultiplier is used
MaxPacketRetransmissions uint32 // * The number of times a packet can be retransmitted before the timeout time is checked
KeepAliveTimeout uint32 // * Unused. Presumably the time a packet can be alive for without acknowledgement? Milliseconds?
ChecksumBase uint32 // * Unused. The base value for PRUDPv0 checksum calculations
FaultDetectionEnabled bool // * Unused. Presumably used to detect PIA faults?
InitialRTT uint32 // * Unused. The connections initial RTT
EncryptionAlgorithm encryption.Algorithm // * The encryption algorithm used for packet payloads
ExtraRetransmitTimeoutMultiplier float32 // * Unused. Used as part of the RTO calculations when retransmitting a packet. Only used if ExtraRestransmitTimeoutTrigger has been reached
WindowSize uint32 // * Unused. The max number of (reliable?) packets allowed in a SlidingWindow
CompressionAlgorithm compression.Algorithm // * The compression algorithm used for packet payloads
RTTRetransmit uint32 // * Unused. Unknown use
RetransmitTimeoutMultiplier float32 // * Unused. Used as part of the RTO calculations when retransmitting a packet. Only used if ExtraRestransmitTimeoutTrigger has not been reached
MaxSilenceTime uint32 // * Unused. Presumably the time a connection can go without any packets from the other side? Milliseconds?
}
// Copy returns a new copy of the settings
func (ss *StreamSettings) Copy() *StreamSettings {
copied := NewStreamSettings()
copied.ExtraRestransmitTimeoutTrigger = ss.ExtraRestransmitTimeoutTrigger
copied.MaxPacketRetransmissions = ss.MaxPacketRetransmissions
copied.KeepAliveTimeout = ss.KeepAliveTimeout
copied.ChecksumBase = ss.ChecksumBase
copied.FaultDetectionEnabled = ss.FaultDetectionEnabled
copied.InitialRTT = ss.InitialRTT
copied.EncryptionAlgorithm = ss.EncryptionAlgorithm.Copy()
copied.ExtraRetransmitTimeoutMultiplier = ss.ExtraRetransmitTimeoutMultiplier
copied.WindowSize = ss.WindowSize
copied.CompressionAlgorithm = ss.CompressionAlgorithm.Copy()
copied.RTTRetransmit = ss.RTTRetransmit
copied.RetransmitTimeoutMultiplier = ss.RetransmitTimeoutMultiplier
copied.MaxSilenceTime = ss.MaxSilenceTime
return copied
}
// NewStreamSettings returns a new instance of StreamSettings with default params
func NewStreamSettings() *StreamSettings {
// * Default values based on WATCH_DOGS. Not all values are used currently, and only
// * exist to mimic what is seen in that game. Many are planned for future use.
return &StreamSettings{
ExtraRestransmitTimeoutTrigger: 0x32,
MaxPacketRetransmissions: 0x14,
KeepAliveTimeout: 1000,
ChecksumBase: 0,
FaultDetectionEnabled: true,
InitialRTT: 0xFA,
EncryptionAlgorithm: encryption.NewRC4Encryption(),
ExtraRetransmitTimeoutMultiplier: 1.0,
WindowSize: 8,
CompressionAlgorithm: compression.NewDummyCompression(),
RTTRetransmit: 0x32,
RetransmitTimeoutMultiplier: 1.25,
MaxSilenceTime: 5000,
}
}