Documentation
¶
Overview ¶
Package batching implements a socket optimized for increased throughput.
Index ¶
Constants ¶
const ( // ReadSlabMultiple is the minimum slab length accepted by [Conn.ReadBatch], // and is the suggested multiple when passing a larger value. ReadSlabMultiple = 1<<16 - 1 // MinimumReadBatchSize is the minimum number of packets descriptors accepted // by [Conn.ReadBatch]. MinimumReadBatchSize = udpGROCountMax // MaximumWriteBatchSize is the maximum number of buffs accepted by // [Conn.WriteBatchTo]. MaximumWriteBatchSize = 128 )
Variables ¶
This section is empty.
Functions ¶
func TryUpgradeToConn ¶
func TryUpgradeToConn(pconn nettype.PacketConn, network string, rxqOverflowsMetricName string, knobs *controlknobs.Knobs) nettype.PacketConn
TryUpgradeToConn probes the capabilities of the OS and pconn, and upgrades pconn to a Conn if appropriate. If len(rxqOverflowsMetricName) is nonzero, then read ops will propagate the SO_RXQ_OVFL control message counter to a clientmetric with the supplied name. If knobs is non-nil, UDP GSO and/or UDP GRO may be disabled via control-plane node attributes.
Types ¶
type Conn ¶
type Conn interface {
nettype.PacketConn
// ReadFromUDPAddrPort always returns an error, as UDP GRO is incompatible
// with single packet reads. A single datagram may be multiple, coalesced
// datagrams, and this API lacks the ability to pass that context.
//
// TODO: consider detaching Conn from [nettype.PacketConn]
ReadFromUDPAddrPort([]byte) (int, netip.AddrPort, error)
// ReadBatch reads datagrams from [Conn] into slab, and describes them in
// packets. It returns the number of populated packet descriptors. A single
// GRO-coalesced datagram may produce multiple descriptors.
//
// packets must have a length >= [MinimumReadBatchSize]. slab must have a
// length >= [ReadSlabMultiple]. ReadBatch reads only as many datagrams as
// both arguments can accommodate.
ReadBatch(slab []byte, packets []ReceivedPacket) (n int, err error)
// WriteBatchTo writes buffs to addr.
//
// If geneve.VNI.IsSet(), then geneve is encoded into the space preceding
// offset, and offset must equal [packet.GeneveFixedHeaderLength]. If
// !geneve.VNI.IsSet() then the space preceding offset is ignored.
//
// len(buffs) must be <= [MaximumWriteBatchSize].
//
// WriteBatchTo may return a [neterror.ErrUDPGSODisabled] error if UDP GSO
// was disabled as a result of a send error.
WriteBatchTo(buffs [][]byte, addr netip.AddrPort, geneve packet.GeneveHeader, offset int) error
}
Conn is a nettype.PacketConn that provides batched i/o using platform-specific optimizations, e.g. {recv,send}mmsg & UDP GSO/GRO.
Conn does not support single packet reads (see ReadFromUDPAddrPort docs). It is the caller's responsibility to use the appropriate read API where a nettype.PacketConn has been upgraded to support batched i/o.
Conn originated from (and is still used by) magicsock where its API was strongly influenced by wireguard-go/conn.Bind constraints, namely wireguard-go's ownership of packet memory.
type ReceivedPacket ¶ added in v1.104.0
type ReceivedPacket struct {
// Offset is the starting byte offset into the slab supplied to [Conn.ReadBatch].
Offset int
// Size is the size of the packet.
Size int
// Source is the source address that sent the packet.
Source netip.AddrPort
}
ReceivedPacket describes a packet read by Conn.ReadBatch.
Source Files