FTerrainReplica

Applies the authority's records to one world in the log's one total order: sculpt commands and patches through an FSculptReplayer, FeatureOps through FTerrainWorld::ApplyFeatureOps, and checks each Checkpoint against the world's SyncHash, the replayer's digest and the next feature id.

Declaration

class FTerrainReplica

Header: #include "Native/Net/NetReplica.h"
Module: PublicDependencyModuleNames.Add("OrreryTerrainCore"); in your module’s Build.cs.
Stability: Experimental: supported, may change in a minor version, with a changelog line.
Thread: Game thread only, like every FTerrainWorld write.

Description

Sculpt and feature records share the one order because the keep-out guard reads the stack (FSculptReplayer, "Same hash"). A BrushMask record adds its mask to the world's FBrushMaskRegistry in its place in the order, or for the hash-only form finds it held; a step naming a mask the registry lacks faults (UnknownMask).

Before each record it sets FTerrainWorld::SetRecordSeq, so the ground journal's entries carry the authority's position. Consecutive brush steps go to the world as one run and publish once; the run's publish carries the position of its last applied step, also when a step that answers Pending cut it short. A step that answers Pending holds the queue until the ground has loaded (pump the world and call Pump again).

The first fault stops it: Pump applies nothing more. A checkpoint fault is repaired at its position (Repair) or, when only the digest disagreed, resynced; a dropped step or a refused FeatureOps record is not repairable and the shell rejoins, as it does after two repairs in a row (RepairsInARow). A late joiner continues the authority's open strokes (ResumeStrokes). Reset is not handled here.

Tier 1. Game thread only, like every FTerrainWorld write. The world must outlive the replica.

Functions

FTerrainReplica (2 overloads)
operator=
Enqueue
Queue the next record of the log, decoded and copied: its Seq must be NextSeq.
Pump
Apply queued records in order until the queue is empty, a sculpt step answers Pending, a fault, or MaxRecords were consumed.
ResumeStrokes
Continue the authority's open strokes at the join position (FJoinHead::Strokes, several authors' at once): the world opens a stroke for each, with its author, steps, reach and tiles, and the replayer expects each one's next step.
Repair
Apply the authority's Repair record for the checkpoint that faulted: set its tiles exactly, replace the stack with its own, then hold the world to the checkpoint's SyncHash, adopt its next feature id and take its digest.
Resync
Clear a checkpoint fault whose SyncHash matches (BuildRepairRequest found nothing to repair): only the digest disagreed, so the replica takes the checkpoint's digest and next feature id.
NextSeq
The Seq the next Enqueue must carry.
AppliedSeq
The newest record applied or checked; NextSeq - 1 once the queue has drained.
Queued
Records waiting, the held one included.
Waiting
A sculpt step answered Pending, or the resumed stroke waits for its codes: pump the world's loads and pages, then Pump again.
SculptDigest
The replayer's FSculptReplayer::Digest.
Fault
None while it follows.
FaultSeq
The record that faulted (for a dropped sculpt step, the last of its run); 0 with no fault.
LastFeatureOps
The last ApplyFeatureOps answer.
LastCheck
Checks
Checkpoints compared.
FaultCheckpoint
The checkpoint that faulted (with Fault Checkpoint): what Repair holds the world to.
RepairsInARow
Repairs since the last checkpoint that matched: two mean the replica cannot keep up, so the shell rejoins.