func (agent *ActionAgent) readTablet(ctx context.Context) (*topo.TabletInfo, error) {
tablet, err := topo.GetTablet(ctx, agent.TopoServer, agent.TabletAlias)
if err != nil {
return nil, err
}
agent.mutex.Lock()
agent._tablet = tablet
agent.mutex.Unlock()
return tablet, nil
}
// Does a topo lookup for a single shard, and returns the tablet record of the master tablet.
func resolveDestinationShardMaster(ctx context.Context, keyspace, shard string, wr *wrangler.Wrangler) (*topo.TabletInfo, error) {
var ti *topo.TabletInfo
shortCtx, cancel := context.WithTimeout(ctx, *remoteActionsTimeout)
si, err := topo.GetShard(shortCtx, wr.TopoServer(), keyspace, shard)
cancel()
if err != nil {
return ti, fmt.Errorf("unable to resolve destination shard %v/%v", keyspace, shard)
}
if si.MasterAlias.IsZero() {
return ti, fmt.Errorf("no master in destination shard %v/%v", keyspace, shard)
}
wr.Logger().Infof("Found target master alias %v in shard %v/%v", si.MasterAlias, keyspace, shard)
shortCtx, cancel = context.WithTimeout(ctx, *remoteActionsTimeout)
ti, err = topo.GetTablet(shortCtx, wr.TopoServer(), si.MasterAlias)
cancel()
if err != nil {
return ti, fmt.Errorf("unable to get master tablet from alias %v in shard %v/%v",
si.MasterAlias, keyspace, shard)
}
return ti, nil
}