// Send implements the client.Sender interface. The store is looked up from the
// store map if specified by the request; otherwise, the command is being
// executed locally, and the replica is determined via lookup through each
// store's LookupRange method. The latter path is taken only by unit tests.
func (ls *LocalSender) Send(ctx context.Context, ba roachpb.BatchRequest) (*roachpb.BatchResponse, *roachpb.Error) {
trace := tracer.FromCtx(ctx)
var store *storage.Store
var err error
// If we aren't given a Replica, then a little bending over
// backwards here. This case applies exclusively to unittests.
if ba.RangeID == 0 || ba.Replica.StoreID == 0 {
var repl *roachpb.ReplicaDescriptor
var rangeID roachpb.RangeID
key, endKey := keys.Range(ba)
rangeID, repl, err = ls.lookupReplica(key, endKey)
if err == nil {
ba.RangeID = rangeID
ba.Replica = *repl
}
}
ctx = log.Add(ctx,
log.RangeID, ba.RangeID)
if err == nil {
store, err = ls.GetStore(ba.Replica.StoreID)
}
var br *roachpb.BatchResponse
if err != nil {
return nil, roachpb.NewError(err)
}
// For calls that read data within a txn, we can avoid uncertainty
// related retries in certain situations. If the node is in
// "CertainNodes", we need not worry about uncertain reads any
// more. Setting MaxTimestamp=Timestamp for the operation
// accomplishes that. See roachpb.Transaction.CertainNodes for details.
if ba.Txn != nil && ba.Txn.CertainNodes.Contains(ba.Replica.NodeID) {
// MaxTimestamp = Timestamp corresponds to no clock uncertainty.
trace.Event("read has no clock uncertainty")
ba.Txn.MaxTimestamp = ba.Txn.Timestamp
}
br, pErr := store.Send(ctx, ba)
if br != nil && br.Error != nil {
panic(roachpb.ErrorUnexpectedlySet(store, br))
}
return br, pErr
}