sql/rowflow: refactor monitor name

The monitor names created in `(*rowBasedFlow).setupRouter` now use
`(*mon.Name).WithID` to add the stream ID to the name instead of
allocating a new string.

Release note: None

Author: mgartner

pkg/sql/rowflow/BUILD.bazel

@@ -29,7 +29,6 @@ go_library(
         "//pkg/util/tracing",
         "//pkg/util/tracing/tracingpb",
         "@com_github_cockroachdb_errors//:errors",
-        "@com_github_cockroachdb_redact//:redact",
         "@io_opentelemetry_go_otel//attribute",
     ],
 )

pkg/sql/rowflow/row_based_flow.go

@@ -22,7 +22,6 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/util/log"
 	"github.com/cockroachdb/cockroach/pkg/util/mon"
 	"github.com/cockroachdb/errors"
-	"github.com/cockroachdb/redact"
 )
 
 type rowBasedFlow struct {
@@ -461,9 +460,9 @@ func (f *rowBasedFlow) setupRouter(
 	unlimitedMemMonitors := make([]*mon.BytesMonitor, len(spec.Streams))
 	diskMonitors := make([]*mon.BytesMonitor, len(spec.Streams))
 	for i := range spec.Streams {
-		// TODO(mgartner): Is a StreamID ever greater than math.MaxInt32? If
-		// not, we can use (*mon.Name).WithID() instead of allocating a string.
-		mn := mon.MakeName("router" + redact.SafeString(spec.Streams[i].StreamID.String()))
+		// NB: Stream IDs are indexes into slices, so we'd expect to OOM long
+		// before a stream ID exceeds 2^31.
+		mn := mon.MakeName("router").WithID(int32(spec.Streams[i].StreamID))
 		memoryMonitors[i] = execinfra.NewLimitedMonitor(ctx, f.Mon, &f.FlowCtx, mn.Limited())
 		unlimitedMemMonitors[i] = execinfra.NewMonitor(ctx, f.Mon, mn.Unlimited())
 		diskMonitors[i] = execinfra.NewMonitor(ctx, f.DiskMonitor, mn.Disk())