Call Must(En|De)code instead of (En|De)code to save time

Encode/Decode returns an error code, which we are generally not
checking for sub-objects because we never expect it to fail.  In the
new version of codegen Encode() sets up a panic handler and calls
MustEncode(), and the panic handler has a performance cost.  So just
call MustEncode() and if for some reason the encoding does fail we
will see it as a panic.

We still call Encode/Decode at top level and check the return code.

report/controls.go

@@ -91,7 +91,7 @@ type wireNodeControls struct {
 
 // CodecEncodeSelf implements codec.Selfer
 func (nc *NodeControls) CodecEncodeSelf(encoder *codec.Encoder) {
-	encoder.Encode(wireNodeControls{
+	encoder.MustEncode(wireNodeControls{
 		Timestamp: renderTime(nc.Timestamp),
 		Controls:  nc.Controls,
 	})

report/counters.go

@@ -110,7 +110,7 @@ func (c Counters) fromIntermediate(in map[string]int) Counters {
 func (c *Counters) CodecEncodeSelf(encoder *codec.Encoder) {
 	mapWrite(c.psMap, encoder, func(encoder *codec.Encoder, val interface{}) {
 		i := val.(int)
-		encoder.Encode(i)
+		encoder.MustEncode(i)
 	})
 }
 
@@ -119,7 +119,7 @@ func (c *Counters) CodecDecodeSelf(decoder *codec.Decoder) {
 	out := mapRead(decoder, func(isNil bool) interface{} {
 		var value int
 		if !isNil {
-			decoder.Decode(&value)
+			decoder.MustDecode(&value)
 		}
 		return value
 	})

report/latest_map_internal_test.go

@@ -164,7 +164,7 @@ func BenchmarkLatestMapDecode(b *testing.B) {
 
 	for i := 0; i < b.N; i++ {
 		var map1 StringLatestMap
-		codec.NewDecoderBytes(buf.Bytes(), &codec.MsgpackHandle{}).Decode(&map1)
+		codec.NewDecoderBytes(buf.Bytes(), &codec.MsgpackHandle{}).MustDecode(&map1)
 	}
 }
 

report/metric_row.go

@@ -70,7 +70,7 @@ type wiredMetricRow struct {
 // rendering, then adds some row-specific fields.
 func (m *MetricRow) CodecEncodeSelf(encoder *codec.Encoder) {
 	in := m.Metric.ToIntermediate()
-	encoder.Encode(wiredMetricRow{
+	encoder.MustEncode(wiredMetricRow{
 		ID:         m.ID,
 		Label:      m.Label,
 		Format:     m.Format,
@@ -90,7 +90,7 @@ func (m *MetricRow) CodecEncodeSelf(encoder *codec.Encoder) {
 // CodecDecodeSelf implements codec.Selfer
 func (m *MetricRow) CodecDecodeSelf(decoder *codec.Decoder) {
 	var in wiredMetricRow
-	decoder.Decode(&in)
+	decoder.MustDecode(&in)
 	w := WireMetrics{
 		Samples: in.Samples,
 		Min:     in.Min,

report/metrics.go

@@ -272,7 +272,7 @@ func (m WireMetrics) FromIntermediate() Metric {
 // CodecEncodeSelf implements codec.Selfer
 func (m *Metric) CodecEncodeSelf(encoder *codec.Encoder) {
 	in := m.ToIntermediate()
-	encoder.Encode(in)
+	encoder.MustEncode(in)
 }
 
 // CodecDecodeSelf implements codec.Selfer

report/metrics_test.go

@@ -165,9 +165,7 @@ func TestMetricMarshalling(t *testing.T) {
 
 		decoder := codec.NewDecoder(buf, h)
 		var have report.Metric
-		if err := decoder.Decode(&have); err != nil {
-			t.Fatal(err)
-		}
+		decoder.MustDecode(&have)
 
 		if !reflect.DeepEqual(want, have) {
 			t.Error(test.Diff(want, have))
@@ -178,9 +176,7 @@ func TestMetricMarshalling(t *testing.T) {
 		var wire struct {
 			Samples []report.Sample `json:"samples"`
 		}
-		if err := decoder.Decode(&wire); err != nil {
-			t.Error(err)
-		}
+		decoder.MustDecode(&wire)
 		if !reflect.DeepEqual(wantSamples, wire.Samples) {
 			t.Error(test.Diff(wantSamples, wire.Samples))
 		}

report/node_set.go

@@ -133,18 +133,16 @@ func (n NodeSet) fromIntermediate(nodes []Node) NodeSet {
 // CodecEncodeSelf implements codec.Selfer
 func (n *NodeSet) CodecEncodeSelf(encoder *codec.Encoder) {
 	if n.psMap != nil {
-		encoder.Encode(n.toIntermediate())
+		encoder.MustEncode(n.toIntermediate())
 	} else {
-		encoder.Encode(nil)
+		encoder.MustEncode(nil)
 	}
 }
 
 // CodecDecodeSelf implements codec.Selfer
 func (n *NodeSet) CodecDecodeSelf(decoder *codec.Decoder) {
 	in := []Node{}
-	if err := decoder.Decode(&in); err != nil {
-		return
-	}
+	decoder.MustDecode(&in)
 	*n = NodeSet{}.fromIntermediate(in)
 }
 

report/sets.go

@@ -114,7 +114,7 @@ func (s Sets) DeepEqual(t Sets) bool {
 // CodecEncodeSelf implements codec.Selfer
 func (s *Sets) CodecEncodeSelf(encoder *codec.Encoder) {
 	mapWrite(s.psMap, encoder, func(encoder *codec.Encoder, val interface{}) {
-		encoder.Encode(val.(StringSet))
+		encoder.MustEncode(val.(StringSet))
 	})
 }
 
@@ -123,7 +123,7 @@ func (s *Sets) CodecDecodeSelf(decoder *codec.Decoder) {
 	out := mapRead(decoder, func(isNil bool) interface{} {
 		var value StringSet
 		if !isNil {
-			decoder.Decode(&value)
+			decoder.MustDecode(&value)
 		}
 		return value
 	})