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gossip.go
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gossip.go
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// Code generated by atomix-go-framework. DO NOT EDIT.
package counter
import (
"context"
"math/rand"
"time"
"github.com/atomix/atomix-go-framework/pkg/atomix/meta"
"github.com/atomix/atomix-go-framework/pkg/atomix/storage/protocol/gossip"
atime "github.com/atomix/atomix-go-framework/pkg/atomix/time"
"github.com/golang/protobuf/proto"
)
const antiEntropyPeriod = time.Second
func newGossipProtocol(serviceID gossip.ServiceId, partition *gossip.Partition, clock atime.Clock, replicas int) (GossipProtocol, error) {
peers, err := gossip.NewPeerGroup(partition, serviceID, clock, replicas)
if err != nil {
return nil, err
}
return &gossipProtocol{
clock: clock,
group: newGossipGroup(peers),
server: newGossipServer(serviceID, partition, clock),
}, nil
}
type GossipProtocol interface {
Clock() atime.Clock
Group() GossipGroup
Server() GossipServer
}
type GossipHandler interface {
Read(ctx context.Context) (*CounterState, error)
Update(ctx context.Context, state *CounterState) error
}
type GossipServer interface {
Register(GossipHandler) error
handler() GossipHandler
}
type GossipClient interface {
Bootstrap(ctx context.Context) (*CounterState, error)
Repair(ctx context.Context, state *CounterState) (*CounterState, error)
Advertise(ctx context.Context, state *CounterState) error
Update(ctx context.Context, state *CounterState) error
}
type GossipGroup interface {
GossipClient
MemberID() GossipMemberID
Members() []GossipMember
Member(GossipMemberID) GossipMember
}
type GossipMemberID gossip.PeerID
func (i GossipMemberID) String() string {
return string(i)
}
type GossipMember interface {
GossipClient
ID() GossipMemberID
Client() *gossip.Peer
}
type gossipProtocol struct {
clock atime.Clock
group GossipGroup
server GossipServer
}
func (p *gossipProtocol) Clock() atime.Clock {
return p.clock
}
func (p *gossipProtocol) Group() GossipGroup {
return p.group
}
func (p *gossipProtocol) Server() GossipServer {
return p.server
}
var _ GossipProtocol = &gossipProtocol{}
func newGossipGroup(group *gossip.PeerGroup) GossipGroup {
peers := group.Peers()
members := make([]GossipMember, 0, len(peers))
memberIDs := make(map[GossipMemberID]GossipMember)
for _, peer := range peers {
member := newGossipMember(peer)
members = append(members, member)
memberIDs[member.ID()] = member
}
return &gossipGroup{
group: group,
members: members,
memberIDs: memberIDs,
}
}
type gossipGroup struct {
group *gossip.PeerGroup
members []GossipMember
memberIDs map[GossipMemberID]GossipMember
}
func (p *gossipGroup) MemberID() GossipMemberID {
return GossipMemberID(p.group.MemberID())
}
func (p *gossipGroup) Members() []GossipMember {
return p.members
}
func (p *gossipGroup) Member(id GossipMemberID) GossipMember {
return p.memberIDs[id]
}
func (p *gossipGroup) Bootstrap(ctx context.Context) (*CounterState, error) {
objects, err := p.group.Read(ctx, "")
if err != nil {
return nil, err
}
state := &CounterState{}
for _, object := range objects {
if meta.FromProto(object.ObjectMeta).After(meta.FromProto(state.ObjectMeta)) {
err = proto.Unmarshal(object.Value, state)
if err != nil {
return nil, err
}
}
}
return state, nil
}
func (p *gossipGroup) Repair(ctx context.Context, state *CounterState) (*CounterState, error) {
objects, err := p.group.Read(ctx, "")
if err != nil {
return nil, err
}
for _, object := range objects {
if meta.FromProto(object.ObjectMeta).After(meta.FromProto(state.ObjectMeta)) {
err = proto.Unmarshal(object.Value, state)
if err != nil {
return nil, err
}
}
}
return state, nil
}
func (p *gossipGroup) Advertise(ctx context.Context, state *CounterState) error {
peers := p.group.Peers()
peer := peers[rand.Intn(len(peers))]
peer.Advertise(ctx, "", meta.FromProto(state.ObjectMeta))
return nil
}
func (p *gossipGroup) Update(ctx context.Context, state *CounterState) error {
bytes, err := proto.Marshal(state)
if err != nil {
return err
}
object := &gossip.Object{
ObjectMeta: state.ObjectMeta,
Value: bytes,
}
p.group.Update(ctx, object)
return nil
}
var _ GossipGroup = &gossipGroup{}
func newGossipServer(serviceID gossip.ServiceId, partition *gossip.Partition, clock atime.Clock) GossipServer {
return &gossipServer{
serviceID: serviceID,
partition: partition,
clock: clock,
}
}
type gossipServer struct {
serviceID gossip.ServiceId
partition *gossip.Partition
clock atime.Clock
gossipHandler GossipHandler
}
func (s *gossipServer) Register(handler GossipHandler) error {
s.gossipHandler = handler
return s.partition.RegisterReplica(newReplica(s.serviceID, s.clock, handler))
}
func (s *gossipServer) handler() GossipHandler {
return s.gossipHandler
}
var _ GossipServer = &gossipServer{}
func newGossipMember(peer *gossip.Peer) GossipMember {
return &gossipMember{
id: GossipMemberID(peer.ID),
peer: peer,
}
}
type gossipMember struct {
id GossipMemberID
peer *gossip.Peer
}
func (p *gossipMember) ID() GossipMemberID {
return p.id
}
func (p *gossipMember) Client() *gossip.Peer {
return p.peer
}
func (p *gossipMember) Bootstrap(ctx context.Context) (*CounterState, error) {
object, err := p.peer.Read(ctx, "")
if err != nil {
return nil, err
}
state := &CounterState{}
err = proto.Unmarshal(object.Value, state)
if err != nil {
return nil, err
}
return state, nil
}
func (p *gossipMember) Repair(ctx context.Context, state *CounterState) (*CounterState, error) {
object, err := p.peer.Read(ctx, "")
if err != nil {
return nil, err
}
if meta.FromProto(object.ObjectMeta).After(meta.FromProto(state.ObjectMeta)) {
err = proto.Unmarshal(object.Value, state)
if err != nil {
return nil, err
}
}
return state, nil
}
func (p *gossipMember) Advertise(ctx context.Context, state *CounterState) error {
p.peer.Advertise(ctx, "", meta.FromProto(state.ObjectMeta))
return nil
}
func (p *gossipMember) Update(ctx context.Context, state *CounterState) error {
bytes, err := proto.Marshal(state)
if err != nil {
return err
}
object := &gossip.Object{
ObjectMeta: state.ObjectMeta,
Value: bytes,
}
p.peer.Update(ctx, object)
return nil
}
var _ GossipMember = &gossipMember{}
func newReplica(serviceID gossip.ServiceId, clock atime.Clock, handler GossipHandler) gossip.Replica {
return &gossipReplica{
serviceID: serviceID,
clock: clock,
handler: handler,
}
}
type gossipReplica struct {
serviceID gossip.ServiceId
clock atime.Clock
handler GossipHandler
}
func (s *gossipReplica) ID() gossip.ServiceId {
return s.serviceID
}
func (s *gossipReplica) Clock() atime.Clock {
return s.clock
}
func (s *gossipReplica) Type() gossip.ServiceType {
return ServiceType
}
func (s *gossipReplica) Update(ctx context.Context, object *gossip.Object) error {
state := &CounterState{}
err := proto.Unmarshal(object.Value, state)
if err != nil {
return err
}
return s.handler.Update(ctx, state)
}
func (s *gossipReplica) Read(ctx context.Context, key string) (*gossip.Object, error) {
state, err := s.handler.Read(ctx)
if err != nil {
return nil, err
} else if state == nil {
return nil, nil
}
bytes, err := proto.Marshal(state)
if err != nil {
return nil, err
}
return &gossip.Object{
ObjectMeta: state.ObjectMeta,
Value: bytes,
}, nil
}
func (s *gossipReplica) ReadAll(ctx context.Context, ch chan<- gossip.Object) error {
errCh := make(chan error)
go func() {
defer close(errCh)
state, err := s.handler.Read(ctx)
if err != nil {
errCh <- err
return
}
bytes, err := proto.Marshal(state)
if err != nil {
errCh <- err
return
}
object := gossip.Object{
ObjectMeta: state.ObjectMeta,
Value: bytes,
}
ch <- object
}()
return <-errCh
}
var _ gossip.Replica = &gossipReplica{}
type GossipEngine interface {
start()
stop()
}
func newGossipEngine(protocol GossipProtocol) GossipEngine {
return &gossipEngine{
protocol: protocol,
}
}
type gossipEngine struct {
protocol GossipProtocol
ticker *time.Ticker
cancel context.CancelFunc
}
func (m *gossipEngine) start() {
ctx, cancel := context.WithCancel(context.Background())
m.cancel = cancel
if err := m.bootstrap(ctx); err != nil {
log.Errorf("Failed to bootstrap service: %v", err)
}
m.runAntiEntropy(ctx)
}
func (m *gossipEngine) bootstrap(ctx context.Context) error {
state, err := m.protocol.Group().Bootstrap(ctx)
if err != nil {
return err
}
if err := m.protocol.Server().handler().Update(ctx, state); err != nil {
return err
}
return nil
}
func (m *gossipEngine) runAntiEntropy(ctx context.Context) {
m.ticker = time.NewTicker(antiEntropyPeriod)
for range m.ticker.C {
if err := m.advertise(ctx); err != nil {
log.Errorf("Anti-entropy protocol failed: %v", err)
}
}
}
func (m *gossipEngine) advertise(ctx context.Context) error {
state, err := m.protocol.Server().handler().Read(context.Background())
if err != nil {
return err
}
if err := m.protocol.Group().Advertise(ctx, state); err != nil {
return err
}
return nil
}
func (m *gossipEngine) stop() {
m.ticker.Stop()
m.cancel()
}