services/syncbase/vsync/types.vdl

// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package vsync

import (
	"v.io/x/ref/services/syncbase/server/interfaces"
)

// Key prefixes for sync data structures. All these prefixes are prepended with
// util.SyncPrefix.
const (
	logPrefix     = "log"  // log state.
	logDataPrefix = "data" // data log state.
	dbssPrefix    = "dbss" // database sync state.
	dagPrefix     = "dag"  // dag state.
	sgPrefix      = "sg"   // syncgroup state.
)

// syncData represents the persistent state of the sync module.
type syncData struct {
	Id uint64
}

// localGenInfo represents the persistent state corresponding to local generations.
type localGenInfo struct {
	Gen        uint64 // local generation number incremented on every local update.
	CheckptGen uint64 // local generation number advertised to remote peers (used by the responder).
}

// dbSyncState represents the persistent sync state of a Database.
type dbSyncState struct {
	Data     localGenInfo
	Sgs      map[interfaces.GroupId]localGenInfo
	GenVec   interfaces.GenVector // generation vector capturing the locally-known generations of remote peers for data in Database.
	SgGenVec interfaces.GenVector // generation vector capturing the locally-known generations of remote peers for SyncGroups in Database.
}

// localLogRec represents the persistent local state of a log record. Metadata
// is synced across peers, while pos is local-only.
type localLogRec struct {
	Metadata interfaces.LogRecMetadata
	Pos      uint64 // position in the Database log.
}