Port scaled marshal tests to new node interfaces.

Marshal is 25% faster.  Not bad.  (There's also a perf bug in the codec
code which I'm about to fix which will change the speedup to *double*.)

Unmarshal is a bit faster, but not as much improved as marshal.
This is unsurprisingly because we chose not to amortize allocations
as much as we could in map and list creation because the size penalty
seemed too steep to make it a worthy trade.  (This gives us *much*
better numbers to fuel further consideration of that trade, though.)

_rsrch/nodesolution/node/basic/map_test.go

@@ -31,13 +31,19 @@ func BenchmarkMapStrInt_25n_Iteration(b *testing.B) {
 	tests.SpecBenchmarkMapStrInt_25n_Iteration(b, Style__Map{})
 }
 
-func BenchmarkUnmarshalMapStrInt_3n(b *testing.B) {
-	tests.SpecBenchmarkUnmarshalMapStrInt_3n(b, Style__Map{})
+func BenchmarkSpec_Marshal_Map3StrInt(b *testing.B) {
+	tests.BenchmarkSpec_Marshal_Map3StrInt(b, Style__Map{})
+}
+func BenchmarkSpec_Marshal_Map3StrInt_CodecNull(b *testing.B) {
+	tests.BenchmarkSpec_Marshal_Map3StrInt_CodecNull(b, Style__Map{})
+}
+func BenchmarkSpec_Marshal_MapNStrMap3StrInt(b *testing.B) {
+	tests.BenchmarkSpec_Marshal_MapNStrMap3StrInt(b, Style__Map{})
 }
 
-func BenchmarkMarshalMapStrInt_3n(b *testing.B) {
-	tests.SpecBenchmarkMarshalMapStrInt_3n(b, Style__Map{})
+func BenchmarkSpec_Unmarshal_Map3StrInt(b *testing.B) {
+	tests.BenchmarkSpec_Unmarshal_Map3StrInt(b, Style__Map{})
 }
-func BenchmarkMarshalToNullMapStrInt_3n(b *testing.B) {
-	tests.SpecBenchmarkMarshalToNullMapStrInt_3n(b, Style__Map{})
+func BenchmarkSpec_Unmarshal_MapNStrMap3StrInt(b *testing.B) {
+	tests.BenchmarkSpec_Unmarshal_MapNStrMap3StrInt(b, Style__Map{})
 }

_rsrch/nodesolution/node/mixins/tests/marshalBenchmarks.go

@@ -2,6 +2,7 @@ package tests
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 
 	refmtjson "github.com/polydawn/refmt/json"
@@ -10,6 +11,7 @@ import (
 	ipld "github.com/ipld/go-ipld-prime/_rsrch/nodesolution"
 	"github.com/ipld/go-ipld-prime/_rsrch/nodesolution/codec"
 	"github.com/ipld/go-ipld-prime/must"
+	"github.com/ipld/go-ipld-prime/tests/corpus"
 )
 
 // All of the marshalling and unmarshalling benchmark specs use JSON.
@@ -21,7 +23,7 @@ import (
 // - we can make direct comparisons to the standard library json marshalling
 //    and unmarshalling, thus having a back-of-the-envelope baseline to compare.
 
-func SpecBenchmarkMarshalMapStrInt_3n(b *testing.B, ns ipld.NodeStyle) {
+func BenchmarkSpec_Marshal_Map3StrInt(b *testing.B, ns ipld.NodeStyle) {
 	nb := ns.NewBuilder()
 	must.NotError(codec.Unmarshal(nb, refmtjson.NewDecoder(bytes.NewBufferString(`{"whee":1,"woot":2,"waga":3}`))))
 	n := nb.Build()
@@ -37,7 +39,7 @@ func SpecBenchmarkMarshalMapStrInt_3n(b *testing.B, ns ipld.NodeStyle) {
 	}
 }
 
-func SpecBenchmarkMarshalToNullMapStrInt_3n(b *testing.B, ns ipld.NodeStyle) {
+func BenchmarkSpec_Marshal_Map3StrInt_CodecNull(b *testing.B, ns ipld.NodeStyle) {
 	nb := ns.NewBuilder()
 	must.NotError(codec.Unmarshal(nb, refmtjson.NewDecoder(bytes.NewBufferString(`{"whee":1,"woot":2,"waga":3}`))))
 	n := nb.Build()
@@ -59,3 +61,28 @@ type nullTokenSink struct{}
 func (nullTokenSink) Step(_ *tok.Token) (bool, error) {
 	return false, nil
 }
+
+func BenchmarkSpec_Marshal_MapNStrMap3StrInt(b *testing.B, ns ipld.NodeStyle) {
+	for _, n := range []int{0, 1, 2, 4, 8, 16, 32} {
+		b.Run(fmt.Sprintf("n=%d", n), func(b *testing.B) {
+			msg := corpus.MapNStrMap3StrInt(n)
+			node := mustNodeFromJsonString(ns.NewBuilder(), msg)
+			b.ResetTimer()
+
+			var buf bytes.Buffer
+			var err error
+			for i := 0; i < b.N; i++ {
+				buf = bytes.Buffer{}
+				err = codec.Marshal(node, refmtjson.NewEncoder(&buf, refmtjson.EncodeOptions{}))
+			}
+
+			b.StopTimer()
+			if err != nil {
+				b.Fatalf("marshal errored: %s", err)
+			}
+			if buf.String() != msg {
+				b.Fatalf("marshal didn't match corpus")
+			}
+		})
+	}
+}

_rsrch/nodesolution/node/mixins/tests/unmarshalBenchmarks.go

@@ -2,12 +2,14 @@ package tests
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 
 	refmtjson "github.com/polydawn/refmt/json"
 
 	ipld "github.com/ipld/go-ipld-prime/_rsrch/nodesolution"
 	"github.com/ipld/go-ipld-prime/_rsrch/nodesolution/codec"
+	"github.com/ipld/go-ipld-prime/tests/corpus"
 )
 
 // All of the marshalling and unmarshalling benchmark specs use JSON.
@@ -19,7 +21,7 @@ import (
 // - we can make direct comparisons to the standard library json marshalling
 //    and unmarshalling, thus having a back-of-the-envelope baseline to compare.
 
-func SpecBenchmarkUnmarshalMapStrInt_3n(b *testing.B, ns ipld.NodeStyle) {
+func BenchmarkSpec_Unmarshal_Map3StrInt(b *testing.B, ns ipld.NodeStyle) {
 	var err error
 	for i := 0; i < b.N; i++ {
 		nb := ns.NewBuilder()
@@ -30,3 +32,31 @@ func SpecBenchmarkUnmarshalMapStrInt_3n(b *testing.B, ns ipld.NodeStyle) {
 		panic(err)
 	}
 }
+
+func BenchmarkSpec_Unmarshal_MapNStrMap3StrInt(b *testing.B, ns ipld.NodeStyle) {
+	for _, n := range []int{0, 1, 2, 4, 8, 16, 32} {
+		b.Run(fmt.Sprintf("n=%d", n), func(b *testing.B) {
+			msg := corpus.MapNStrMap3StrInt(n)
+			b.ResetTimer()
+
+			var node ipld.Node
+			var err error
+			nb := ns.NewBuilder()
+			for i := 0; i < b.N; i++ {
+				err = codec.Unmarshal(nb, refmtjson.NewDecoder(bytes.NewBufferString(msg)))
+				node = nb.Build()
+				nb.Reset()
+			}
+
+			b.StopTimer()
+			if err != nil {
+				b.Fatalf("unmarshal errored: %s", err)
+			}
+			var buf bytes.Buffer
+			codec.Marshal(node, refmtjson.NewEncoder(&buf, refmtjson.EncodeOptions{}))
+			if buf.String() != msg {
+				b.Fatalf("remarshal didn't match corpus")
+			}
+		})
+	}
+}

_rsrch/nodesolution/node/mixins/tests/util.go

 package tests
 
+import (
+	"bytes"
+
+	refmtjson "github.com/polydawn/refmt/json"
+
+	ipld "github.com/ipld/go-ipld-prime/_rsrch/nodesolution"
+	"github.com/ipld/go-ipld-prime/_rsrch/nodesolution/codec"
+)
+
 // various benchmarks assign their final result here,
 // in order to defuse the possibility of their work being elided.
 var sink interface{}
+
+func mustNodeFromJsonString(nb ipld.NodeBuilder, str string) ipld.Node {
+	err := codec.Unmarshal(nb, refmtjson.NewDecoder(bytes.NewBufferString(str)))
+	if err != nil {
+		panic(err)
+	}
+	return nb.Build()
+}