ORMap and friends have deltas (#22350)

This commit is contained in:
gosubpl 2017-02-23 01:20:33 +01:00
parent 40b883cda7
commit 1f2ef60174
15 changed files with 4371 additions and 140 deletions

View file

@ -149,6 +149,22 @@ private object ReplicatedDataSerializer {
override def getValue(entry: rd.ORMultiMap.Entry): rd.ORSet = entry.getValue
}
implicit object ORMapDeltaGroupEntry extends ProtoMapEntryWriter[rd.ORMapDeltaGroup.MapEntry, rd.ORMapDeltaGroup.MapEntry.Builder, dm.OtherMessage] with ProtoMapEntryReader[rd.ORMapDeltaGroup.MapEntry, dm.OtherMessage] {
override def setStringKey(builder: rd.ORMapDeltaGroup.MapEntry.Builder, key: String, value: dm.OtherMessage): rd.ORMapDeltaGroup.MapEntry = builder.setStringKey(key).setValue(value).build()
override def setLongKey(builder: rd.ORMapDeltaGroup.MapEntry.Builder, key: Long, value: dm.OtherMessage): rd.ORMapDeltaGroup.MapEntry = builder.setLongKey(key).setValue(value).build()
override def setIntKey(builder: rd.ORMapDeltaGroup.MapEntry.Builder, key: Int, value: dm.OtherMessage): rd.ORMapDeltaGroup.MapEntry = builder.setIntKey(key).setValue(value).build()
override def setOtherKey(builder: rd.ORMapDeltaGroup.MapEntry.Builder, key: dm.OtherMessage, value: dm.OtherMessage): rd.ORMapDeltaGroup.MapEntry = builder.setOtherKey(key).setValue(value).build()
override def hasStringKey(entry: rd.ORMapDeltaGroup.MapEntry): Boolean = entry.hasStringKey
override def getStringKey(entry: rd.ORMapDeltaGroup.MapEntry): String = entry.getStringKey
override def hasIntKey(entry: rd.ORMapDeltaGroup.MapEntry): Boolean = entry.hasIntKey
override def getIntKey(entry: rd.ORMapDeltaGroup.MapEntry): Int = entry.getIntKey
override def hasLongKey(entry: rd.ORMapDeltaGroup.MapEntry): Boolean = entry.hasLongKey
override def getLongKey(entry: rd.ORMapDeltaGroup.MapEntry): Long = entry.getLongKey
override def hasOtherKey(entry: rd.ORMapDeltaGroup.MapEntry): Boolean = entry.hasOtherKey
override def getOtherKey(entry: rd.ORMapDeltaGroup.MapEntry): OtherMessage = entry.getOtherKey
override def getValue(entry: rd.ORMapDeltaGroup.MapEntry): dm.OtherMessage = entry.getValue
}
}
/**
@ -178,6 +194,11 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
private val PNCounterKeyManifest = "g"
private val ORMapManifest = "H"
private val ORMapKeyManifest = "h"
private val ORMapPutManifest = "Ha"
private val ORMapRemoveManifest = "Hr"
private val ORMapRemoveKeyManifest = "Hk"
private val ORMapUpdateManifest = "Hu"
private val ORMapDeltaGroupManifest = "Hg"
private val LWWMapManifest = "I"
private val LWWMapKeyManifest = "i"
private val PNCounterMapManifest = "J"
@ -198,6 +219,11 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
GCounterManifest gcounterFromBinary,
PNCounterManifest pncounterFromBinary,
ORMapManifest ormapFromBinary,
ORMapPutManifest ormapPutFromBinary,
ORMapRemoveManifest ormapRemoveFromBinary,
ORMapRemoveKeyManifest ormapRemoveKeyFromBinary,
ORMapUpdateManifest ormapUpdateFromBinary,
ORMapDeltaGroupManifest ormapDeltaGroupFromBinary,
LWWMapManifest lwwmapFromBinary,
PNCounterMapManifest pncountermapFromBinary,
ORMultiMapManifest multimapFromBinary,
@ -216,57 +242,67 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
ORMultiMapKeyManifest (bytes ORMultiMapKey(keyIdFromBinary(bytes))))
override def manifest(obj: AnyRef): String = obj match {
case _: ORSet[_] ORSetManifest
case _: ORSet.AddDeltaOp[_] ORSetAddManifest
case _: ORSet.RemoveDeltaOp[_] ORSetRemoveManifest
case _: GSet[_] GSetManifest
case _: GCounter GCounterManifest
case _: PNCounter PNCounterManifest
case _: Flag FlagManifest
case _: LWWRegister[_] LWWRegisterManifest
case _: ORMap[_, _] ORMapManifest
case _: LWWMap[_, _] LWWMapManifest
case _: PNCounterMap[_] PNCounterMapManifest
case _: ORMultiMap[_, _] ORMultiMapManifest
case DeletedData DeletedDataManifest
case _: VersionVector VersionVectorManifest
case _: ORSet[_] ORSetManifest
case _: ORSet.AddDeltaOp[_] ORSetAddManifest
case _: ORSet.RemoveDeltaOp[_] ORSetRemoveManifest
case _: GSet[_] GSetManifest
case _: GCounter GCounterManifest
case _: PNCounter PNCounterManifest
case _: Flag FlagManifest
case _: LWWRegister[_] LWWRegisterManifest
case _: ORMap[_, _] ORMapManifest
case _: ORMap.PutDeltaOp[_, _] ORMapPutManifest
case _: ORMap.RemoveDeltaOp[_, _] ORMapRemoveManifest
case _: ORMap.RemoveKeyDeltaOp[_, _] ORMapRemoveKeyManifest
case _: ORMap.UpdateDeltaOp[_, _] ORMapUpdateManifest
case _: LWWMap[_, _] LWWMapManifest
case _: PNCounterMap[_] PNCounterMapManifest
case _: ORMultiMap[_, _] ORMultiMapManifest
case DeletedData DeletedDataManifest
case _: VersionVector VersionVectorManifest
case _: ORSetKey[_] ORSetKeyManifest
case _: GSetKey[_] GSetKeyManifest
case _: GCounterKey GCounterKeyManifest
case _: PNCounterKey PNCounterKeyManifest
case _: FlagKey FlagKeyManifest
case _: LWWRegisterKey[_] LWWRegisterKeyManifest
case _: ORMapKey[_, _] ORMapKeyManifest
case _: LWWMapKey[_, _] LWWMapKeyManifest
case _: PNCounterMapKey[_] PNCounterMapKeyManifest
case _: ORMultiMapKey[_, _] ORMultiMapKeyManifest
case _: ORSetKey[_] ORSetKeyManifest
case _: GSetKey[_] GSetKeyManifest
case _: GCounterKey GCounterKeyManifest
case _: PNCounterKey PNCounterKeyManifest
case _: FlagKey FlagKeyManifest
case _: LWWRegisterKey[_] LWWRegisterKeyManifest
case _: ORMapKey[_, _] ORMapKeyManifest
case _: LWWMapKey[_, _] LWWMapKeyManifest
case _: PNCounterMapKey[_] PNCounterMapKeyManifest
case _: ORMultiMapKey[_, _] ORMultiMapKeyManifest
case _: ORSet.DeltaGroup[_] ORSetDeltaGroupManifest
case _: ORSet.FullStateDeltaOp[_] ORSetFullManifest
case _: ORSet.DeltaGroup[_] ORSetDeltaGroupManifest
case _: ORMap.DeltaGroup[_, _] ORMapDeltaGroupManifest
case _: ORSet.FullStateDeltaOp[_] ORSetFullManifest
case _
throw new IllegalArgumentException(s"Can't serialize object of type ${obj.getClass} in [${getClass.getName}]")
}
def toBinary(obj: AnyRef): Array[Byte] = obj match {
case m: ORSet[_] compress(orsetToProto(m))
case m: ORSet.AddDeltaOp[_] orsetToProto(m.underlying).toByteArray
case m: ORSet.RemoveDeltaOp[_] orsetToProto(m.underlying).toByteArray
case m: GSet[_] gsetToProto(m).toByteArray
case m: GCounter gcounterToProto(m).toByteArray
case m: PNCounter pncounterToProto(m).toByteArray
case m: Flag flagToProto(m).toByteArray
case m: LWWRegister[_] lwwRegisterToProto(m).toByteArray
case m: ORMap[_, _] compress(ormapToProto(m))
case m: LWWMap[_, _] compress(lwwmapToProto(m))
case m: PNCounterMap[_] compress(pncountermapToProto(m))
case m: ORMultiMap[_, _] compress(multimapToProto(m))
case DeletedData dm.Empty.getDefaultInstance.toByteArray
case m: VersionVector versionVectorToProto(m).toByteArray
case Key(id) keyIdToBinary(id)
case m: ORSet.DeltaGroup[_] orsetDeltaGroupToProto(m).toByteArray
case m: ORSet.FullStateDeltaOp[_] orsetToProto(m.underlying).toByteArray
case m: ORSet[_] compress(orsetToProto(m))
case m: ORSet.AddDeltaOp[_] orsetToProto(m.underlying).toByteArray
case m: ORSet.RemoveDeltaOp[_] orsetToProto(m.underlying).toByteArray
case m: GSet[_] gsetToProto(m).toByteArray
case m: GCounter gcounterToProto(m).toByteArray
case m: PNCounter pncounterToProto(m).toByteArray
case m: Flag flagToProto(m).toByteArray
case m: LWWRegister[_] lwwRegisterToProto(m).toByteArray
case m: ORMap[_, _] compress(ormapToProto(m))
case m: ORMap.PutDeltaOp[_, _] ormapPutToProto(m).toByteArray
case m: ORMap.RemoveDeltaOp[_, _] ormapRemoveToProto(m).toByteArray
case m: ORMap.RemoveKeyDeltaOp[_, _] ormapRemoveKeyToProto(m).toByteArray
case m: ORMap.UpdateDeltaOp[_, _] ormapUpdateToProto(m).toByteArray
case m: LWWMap[_, _] compress(lwwmapToProto(m))
case m: PNCounterMap[_] compress(pncountermapToProto(m))
case m: ORMultiMap[_, _] compress(multimapToProto(m))
case DeletedData dm.Empty.getDefaultInstance.toByteArray
case m: VersionVector versionVectorToProto(m).toByteArray
case Key(id) keyIdToBinary(id)
case m: ORSet.DeltaGroup[_] orsetDeltaGroupToProto(m).toByteArray
case m: ORMap.DeltaGroup[_, _] ormapDeltaGroupToProto(m).toByteArray
case m: ORSet.FullStateDeltaOp[_] orsetToProto(m.underlying).toByteArray
case _
throw new IllegalArgumentException(s"Can't serialize object of type ${obj.getClass} in [${getClass.getName}]")
}
@ -512,8 +548,9 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
}
def ormapToProto(ormap: ORMap[_, _]): rd.ORMap = {
val ormapBuilder = rd.ORMap.newBuilder()
val entries: jl.Iterable[rd.ORMap.Entry] = getEntries(ormap.values, rd.ORMap.Entry.newBuilder, otherMessageToProto)
rd.ORMap.newBuilder().setKeys(orsetToProto(ormap.keys)).addAllEntries(entries).build()
ormapBuilder.setKeys(orsetToProto(ormap.keys)).addAllEntries(entries).build()
}
def ormapFromBinary(bytes: Array[Byte]): ORMap[Any, ReplicatedData] =
@ -536,9 +573,144 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
entries)
}
def singleMapEntryFromProto[PEntry <: GeneratedMessage, A <: GeneratedMessage, B <: ReplicatedData](entry: PEntry, valueCreator: A B)(implicit eh: ProtoMapEntryReader[PEntry, A]): Map[Any, B] = {
val elem = if (eh.hasStringKey(entry)) Some(eh.getStringKey(entry) valueCreator(eh.getValue(entry)))
else if (eh.hasIntKey(entry)) Some(eh.getIntKey(entry) valueCreator(eh.getValue(entry)))
else if (eh.hasLongKey(entry)) Some(eh.getLongKey(entry) valueCreator(eh.getValue(entry)))
else if (eh.hasOtherKey(entry)) Some(otherMessageFromProto(eh.getOtherKey(entry)) valueCreator(eh.getValue(entry)))
else None
elem match {
case Some(e) Map(e)
case _ Map.empty[Any, B]
}
}
// wire protocol is always DeltaGroup
private def ormapPutFromBinary(bytes: Array[Byte]): ORMap.PutDeltaOp[Any, ReplicatedData] = {
val group = ormapDeltaGroupFromBinary(bytes)
if (group.ops.size == 1 && group.ops.head.isInstanceOf[ORMap.PutDeltaOp[_, _]])
group.ops.head.asInstanceOf[ORMap.PutDeltaOp[Any, ReplicatedData]]
else
throw new NotSerializableException("Improper ORMap delta put operation size or kind")
}
// wire protocol is always delta group
private def ormapRemoveFromBinary(bytes: Array[Byte]): ORMap.RemoveDeltaOp[Any, ReplicatedData] = {
val group = ormapDeltaGroupFromBinary(bytes)
if (group.ops.size == 1 && group.ops.head.isInstanceOf[ORMap.RemoveDeltaOp[_, _]])
group.ops.head.asInstanceOf[ORMap.RemoveDeltaOp[Any, ReplicatedData]]
else
throw new NotSerializableException("Improper ORMap delta remove operation size or kind")
}
// wire protocol is always delta group
private def ormapRemoveKeyFromBinary(bytes: Array[Byte]): ORMap.RemoveKeyDeltaOp[Any, ReplicatedData] = {
val group = ormapDeltaGroupFromBinary(bytes)
if (group.ops.size == 1 && group.ops.head.isInstanceOf[ORMap.RemoveKeyDeltaOp[_, _]])
group.ops.head.asInstanceOf[ORMap.RemoveKeyDeltaOp[Any, ReplicatedData]]
else
throw new NotSerializableException("Improper ORMap delta remove key operation size or kind")
}
// wire protocol is always delta group
private def ormapUpdateFromBinary(bytes: Array[Byte]): ORMap.UpdateDeltaOp[Any, ReplicatedDelta] = {
val group = ormapDeltaGroupFromBinary(bytes)
if (group.ops.size == 1 && group.ops.head.isInstanceOf[ORMap.UpdateDeltaOp[_, _]])
group.ops.head.asInstanceOf[ORMap.UpdateDeltaOp[Any, ReplicatedDelta]]
else
throw new NotSerializableException("Improper ORMap delta update operation size or kind")
}
// this can be made client-extendable in the same way as Http codes in Spray are
private def zeroTagFromCode(code: Int) = code match {
case ORMap.VanillaORMapTag.value ORMap.VanillaORMapTag
case ORMap.PNCounterMapTag.value ORMap.PNCounterMapTag
case ORMap.ORMultiMapTag.value ORMap.ORMultiMapTag
case ORMap.ORMultiMapWithValueDeltasTag.value ORMap.ORMultiMapWithValueDeltasTag
case ORMap.LWWMapTag.value ORMap.LWWMapTag
case _ throw new IllegalArgumentException("Invalid ZeroTag code")
}
private def ormapDeltaGroupFromBinary(bytes: Array[Byte]): ORMap.DeltaGroup[Any, ReplicatedData] = {
val deltaGroup = rd.ORMapDeltaGroup.parseFrom(bytes)
val ops: Vector[ORMap.DeltaOp] =
deltaGroup.getEntriesList.asScala.map { entry
if (entry.getOperation == rd.ORMapDeltaOp.ORMapPut) {
val map = singleMapEntryFromProto(entry.getEntryData, (v: dm.OtherMessage) otherMessageFromProto(v).asInstanceOf[ReplicatedData])
ORMap.PutDeltaOp(ORSet.AddDeltaOp(orsetFromProto(entry.getUnderlying)), map.head, zeroTagFromCode(entry.getZeroTag))
} else if (entry.getOperation == rd.ORMapDeltaOp.ORMapRemove) {
val map = singleMapEntryFromProto(entry.getEntryData, (v: dm.OtherMessage) otherMessageFromProto(v).asInstanceOf[ReplicatedData])
ORMap.RemoveDeltaOp(ORSet.RemoveDeltaOp(orsetFromProto(entry.getUnderlying)), zeroTagFromCode(entry.getZeroTag))
} else if (entry.getOperation == rd.ORMapDeltaOp.ORMapRemoveKey) {
val map = singleMapEntryFromProto(entry.getEntryData, (v: dm.OtherMessage) otherMessageFromProto(v).asInstanceOf[ReplicatedData])
ORMap.RemoveKeyDeltaOp(ORSet.RemoveDeltaOp(orsetFromProto(entry.getUnderlying)), map.keySet.head, zeroTagFromCode(entry.getZeroTag))
} else if (entry.getOperation == rd.ORMapDeltaOp.ORMapUpdate) {
val map = singleMapEntryFromProto(entry.getEntryData, (v: dm.OtherMessage) otherMessageFromProto(v).asInstanceOf[ReplicatedDelta])
ORMap.UpdateDeltaOp(ORSet.AddDeltaOp(orsetFromProto(entry.getUnderlying)), map, zeroTagFromCode(entry.getZeroTag))
} else
throw new NotSerializableException(s"Unknown ORMap delta operation ${entry.getOperation}")
}(collection.breakOut)
ORMap.DeltaGroup(ops)
}
private def ormapPutToProto(addDelta: ORMap.PutDeltaOp[_, _]): rd.ORMapDeltaGroup = {
ormapDeltaGroupToProto(ORMap.DeltaGroup(scala.collection.immutable.IndexedSeq(addDelta.asInstanceOf[ORMap.DeltaOp])))
}
private def ormapRemoveToProto(addDelta: ORMap.RemoveDeltaOp[_, _]): rd.ORMapDeltaGroup = {
ormapDeltaGroupToProto(ORMap.DeltaGroup(scala.collection.immutable.IndexedSeq(addDelta.asInstanceOf[ORMap.DeltaOp])))
}
private def ormapRemoveKeyToProto(addDelta: ORMap.RemoveKeyDeltaOp[_, _]): rd.ORMapDeltaGroup = {
ormapDeltaGroupToProto(ORMap.DeltaGroup(scala.collection.immutable.IndexedSeq(addDelta.asInstanceOf[ORMap.DeltaOp])))
}
private def ormapUpdateToProto(addDelta: ORMap.UpdateDeltaOp[_, _]): rd.ORMapDeltaGroup = {
ormapDeltaGroupToProto(ORMap.DeltaGroup(scala.collection.immutable.IndexedSeq(addDelta.asInstanceOf[ORMap.DeltaOp])))
}
private def ormapDeltaGroupToProto(deltaGroup: ORMap.DeltaGroup[_, _]): rd.ORMapDeltaGroup = {
def createEntry(opType: rd.ORMapDeltaOp, u: ORSet[_], m: Map[_, _], zt: Int) = {
if (m.size > 1)
throw new IllegalArgumentException("Invalid size of ORMap delta map")
else {
val entryDataBuilder = rd.ORMapDeltaGroup.MapEntry.newBuilder()
m.headOption.map {
case (key: String, value) entryDataBuilder.setStringKey(key).setValue(otherMessageToProto(value))
case (key: Int, value) entryDataBuilder.setIntKey(key).setValue(otherMessageToProto(value))
case (key: Long, value) entryDataBuilder.setLongKey(key).setValue(otherMessageToProto(value))
case (key, value) entryDataBuilder.setOtherKey(otherMessageToProto(key)).setValue(otherMessageToProto(value))
}
val builder = rd.ORMapDeltaGroup.Entry.newBuilder()
.setOperation(opType)
.setUnderlying(orsetToProto(u))
.setZeroTag(zt)
if (m.size > 0)
builder.setEntryData(entryDataBuilder.build())
builder
}
}
val b = rd.ORMapDeltaGroup.newBuilder()
deltaGroup.ops.foreach {
case ORMap.PutDeltaOp(op, pair, zt)
b.addEntries(createEntry(rd.ORMapDeltaOp.ORMapPut, op.asInstanceOf[ORSet.AddDeltaOp[_]].underlying, Map(pair), zt.value))
case ORMap.RemoveDeltaOp(op, zt)
b.addEntries(createEntry(rd.ORMapDeltaOp.ORMapRemove, op.asInstanceOf[ORSet.RemoveDeltaOp[_]].underlying, Map.empty, zt.value))
case ORMap.RemoveKeyDeltaOp(op, k, zt)
b.addEntries(createEntry(rd.ORMapDeltaOp.ORMapRemove, op.asInstanceOf[ORSet.RemoveDeltaOp[_]].underlying, Map(k k), zt.value))
case ORMap.UpdateDeltaOp(op, m, zt)
b.addEntries(createEntry(rd.ORMapDeltaOp.ORMapUpdate, op.asInstanceOf[ORSet.AddDeltaOp[_]].underlying, m, zt.value))
case ORMap.DeltaGroup(u)
throw new IllegalArgumentException("ORMap.DeltaGroup should not be nested")
}
b.build()
}
def lwwmapToProto(lwwmap: LWWMap[_, _]): rd.LWWMap = {
val lwwmapBuilder = rd.LWWMap.newBuilder()
val entries: jl.Iterable[rd.LWWMap.Entry] = getEntries(lwwmap.underlying.entries, rd.LWWMap.Entry.newBuilder, lwwRegisterToProto)
rd.LWWMap.newBuilder().setKeys(orsetToProto(lwwmap.underlying.keys)).addAllEntries(entries).build()
lwwmapBuilder.setKeys(orsetToProto(lwwmap.underlying.keys)).addAllEntries(entries).build()
}
def lwwmapFromBinary(bytes: Array[Byte]): LWWMap[Any, Any] =
@ -548,12 +720,13 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
val entries = mapTypeFromProto(lwwmap.getEntriesList, lwwRegisterFromProto)
new LWWMap(new ORMap(
keys = orsetFromProto(lwwmap.getKeys),
entries))
entries, ORMap.LWWMapTag))
}
def pncountermapToProto(pncountermap: PNCounterMap[_]): rd.PNCounterMap = {
val pncountermapBuilder = rd.PNCounterMap.newBuilder()
val entries: jl.Iterable[rd.PNCounterMap.Entry] = getEntries(pncountermap.underlying.entries, rd.PNCounterMap.Entry.newBuilder, pncounterToProto)
rd.PNCounterMap.newBuilder().setKeys(orsetToProto(pncountermap.underlying.keys)).addAllEntries(entries).build()
pncountermapBuilder.setKeys(orsetToProto(pncountermap.underlying.keys)).addAllEntries(entries).build()
}
def pncountermapFromBinary(bytes: Array[Byte]): PNCounterMap[_] =
@ -563,12 +736,16 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
val entries = mapTypeFromProto(pncountermap.getEntriesList, pncounterFromProto)
new PNCounterMap(new ORMap(
keys = orsetFromProto(pncountermap.getKeys),
entries))
entries, ORMap.PNCounterMapTag))
}
def multimapToProto(multimap: ORMultiMap[_, _]): rd.ORMultiMap = {
val ormultimapBuilder = rd.ORMultiMap.newBuilder()
val entries: jl.Iterable[rd.ORMultiMap.Entry] = getEntries(multimap.underlying.entries, rd.ORMultiMap.Entry.newBuilder, orsetToProto)
rd.ORMultiMap.newBuilder().setKeys(orsetToProto(multimap.underlying.keys)).addAllEntries(entries).build()
ormultimapBuilder.setKeys(orsetToProto(multimap.underlying.keys)).addAllEntries(entries)
if (multimap.withValueDeltas)
ormultimapBuilder.setWithValueDeltas(true)
ormultimapBuilder.build()
}
def multimapFromBinary(bytes: Array[Byte]): ORMultiMap[Any, Any] =
@ -576,9 +753,18 @@ class ReplicatedDataSerializer(val system: ExtendedActorSystem)
def multimapFromProto(multimap: rd.ORMultiMap): ORMultiMap[Any, Any] = {
val entries = mapTypeFromProto(multimap.getEntriesList, orsetFromProto)
new ORMultiMap(new ORMap(
keys = orsetFromProto(multimap.getKeys),
entries))
val withValueDeltas = if (multimap.hasWithValueDeltas)
multimap.getWithValueDeltas
else false
new ORMultiMap(
new ORMap(
keys = orsetFromProto(multimap.getKeys),
entries,
if (withValueDeltas)
ORMap.ORMultiMapWithValueDeltasTag
else
ORMap.ORMultiMapTag),
withValueDeltas)
}
def keyIdToBinary(id: String): Array[Byte] =