syncer

type SchemaSyncer interface {
	// Init sets the global schema version path to etcd if it isn't exist,
	// then watch this path, and initializes the self schema version to etcd.
	Init(ctx context.Context) error
	// UpdateSelfVersion updates the current version to the self path on etcd.
	UpdateSelfVersion(ctx context.Context, jobID int64, version int64) error
	// OwnerUpdateGlobalVersion updates the latest version to the global path on etcd until updating is successful or the ctx is done.
	OwnerUpdateGlobalVersion(ctx context.Context, version int64) error
	// GlobalVersionCh gets the chan for watching global version.
	GlobalVersionCh() clientv3.WatchChan
	// WatchGlobalSchemaVer watches the global schema version.
	WatchGlobalSchemaVer(ctx context.Context)
	// Done returns a channel that closes when the syncer is no longer being refreshed.
	Done() <-chan struct{}
	// Restart restarts the syncer when it's on longer being refreshed.
	Restart(ctx context.Context) error
	// OwnerCheckAllVersions checks whether all followers' schema version are equal to
	// the latest schema version. (exclude the isolated TiDB)
	// It returns until all servers' versions are equal to the latest version.
	OwnerCheckAllVersions(ctx context.Context, jobID int64, latestVer int64) error
	// Close ends SchemaSyncer.
	Close()
}

type StateInfo struct {
	State string `json:"state"`
}

type StateSyncer interface {
	// Init sets the global schema version path to etcd if it isn't exist,
	// then watch this path, and initializes the self schema version to etcd.
	Init(ctx context.Context) error
	// UpdateGlobalState updates the latest version to the global path on etcd until updating is successful or the ctx is done.
	UpdateGlobalState(ctx context.Context, stateInfo *StateInfo) error
	// GetGlobalState gets the global state from etcd.
	GetGlobalState(ctx context.Context) (*StateInfo, error)
	// IsUpgradingState returns whether the cluster state is upgrading.
	IsUpgradingState() bool
	WatchChan() clientv3.WatchChan
	Rewatch(ctx context.Context)
}

type Watcher interface {
	// WatchChan returns the chan for watching etcd path.
	WatchChan() clientv3.WatchChan
	// Watch watches the etcd path.
	Watch(ctx context.Context, etcdCli *clientv3.Client, path string)
	// Rewatch rewatches the etcd path.
	Rewatch(ctx context.Context, etcdCli *clientv3.Client, path string)
}