Vkm::Engine::NetBaseline Class Reference

What one connection is known to hold, so the next snapshot says less. More...

#include <snapshot.h>

Classes
struct	Confirmed
	One component of one entity, as this connection last confirmed it. More...
struct	Pending
	What a written snapshot claimed, held until it is acknowledged. More...

Public Member Functions
const Confirmed *	find (EntityId entity, uint32_t type) const
	What is confirmed for entity's component type, or null.
void	hold (Pending &&pending)
	Hold what a snapshot said until it is confirmed or given up on.
void	confirm (uint16_t sequence)
	Fold the snapshot sequence said into what is confirmed.
void	expire (uint16_t sequence)
	Give up on everything older than sequence by more than the window an acknowledgement can still arrive in.
void	gatherLost (const Scene &scene, std::vector< EntityId > &out) const
	Entities this connection was told about that are no longer alive.
void	clear ()
	Forget every entity and every unconfirmed snapshot.

Detailed Description

What one connection is known to hold, so the next snapshot says less.

A component is sent, whole, when its encoded bits differ from what this connection has confirmed receiving: the delta is on presence, never on values, so every entry decodes from the packet alone and a joiner's first snapshot is the whole world by the same rule.

Confirmed, not sent, or a lost packet would never be resent: what a snapshot said is held until acknowledged. Per connection, since clients lose different packets. Comparing encoded bits lets a settled world go quiet.

Member Function Documentation

find()

const Confirmed * Vkm::Engine::NetBaseline::find	(	EntityId	entity,
		uint32_t	type ) const

What is confirmed for entity's component type, or null.

By entity, not slot: a slot can be reused before the old occupant's record is freed, and the new one would be taken as already held.

Parameters

entity	The occupant asked about.
type	The component's index in the schema.

Returns

The confirmed record, or null when none is held for that occupant.

confirm()

void Vkm::Engine::NetBaseline::confirm

(

uint16_t

sequence

)

Fold the snapshot sequence said into what is confirmed.

A change is folded only when newer than what the slot holds, so a late acknowledgement cannot write stale bytes over fresh.

Parameters

sequence

The acknowledged snapshot; one not held is ignored.

expire()

void Vkm::Engine::NetBaseline::expire

(

uint16_t

sequence

)

Give up on everything older than sequence by more than the window an acknowledgement can still arrive in.

What they said is never confirmed, so the next snapshot says it again.

Parameters

sequence

The snapshot about to be written.

gatherLost()

void Vkm::Engine::NetBaseline::gatherLost	(	const Scene &	scene,
		std::vector< EntityId > &	out ) const

Entities this connection was told about that are no longer alive.

Reported until confirmed, which makes destruction reliable. By entity, not slot: a slot reused between snapshots is alive both times.

Parameters

scene	The world, to ask what is still in it.
out	Filled with the entities, ascending by slot.

clear()

void Vkm::Engine::NetBaseline::clear ( )

inline

Forget every entity and every unconfirmed snapshot.

For a world replaced under a live session: a replacement reuses slot and generation, defeating find's guard.

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The documentation for this class was generated from the following file:

• net/replication/snapshot.h