Run cbor gen in parallel (#710)

Run cbor gen in parallel for faster generation.

gen/main.go

@@ -9,48 +9,45 @@ import (
 	"github.com/filecoin-project/go-f3/cmd/f3/msgdump"
 	"github.com/filecoin-project/go-f3/gpbft"
 	gen "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/sync/errgroup"
 )
 
 //go:generate go run .
 
 func main() {
-	err := gen.WriteTupleEncodersToFile("../gpbft/cbor_gen.go", "gpbft",
-		gpbft.TipSet{},
-		gpbft.GMessage{},
-		gpbft.SupplementalData{},
-		gpbft.Payload{},
-		gpbft.Justification{},
-		gpbft.PowerEntry{},
-		gpbft.PowerEntries{},
-	)
-	if err != nil {
-		fmt.Println(err)
-		os.Exit(1)
-	}
-
-	err = gen.WriteTupleEncodersToFile("../certs/cbor_gen.go", "certs",
-		certs.PowerTableDelta{},
-		certs.PowerTableDiff{},
-		certs.FinalityCertificate{},
-	)
-	if err != nil {
-		fmt.Println(err)
-		os.Exit(1)
-	}
-	err = gen.WriteTupleEncodersToFile("../certexchange/cbor_gen.go", "certexchange",
-		certexchange.Request{},
-		certexchange.ResponseHeader{},
-	)
-	if err != nil {
-		fmt.Println(err)
-		os.Exit(1)
-	}
-	err = gen.WriteTupleEncodersToFile("../cmd/f3/msgdump/cbor_gen.go", "msgdump",
-		msgdump.GMessageEnvelope{},
-		msgdump.GMessageEnvelopeDeffered{},
-	)
-	if err != nil {
-		fmt.Println(err)
+	var eg errgroup.Group
+	eg.Go(func() error {
+		return gen.WriteTupleEncodersToFile("../gpbft/cbor_gen.go", "gpbft",
+			gpbft.TipSet{},
+			gpbft.GMessage{},
+			gpbft.SupplementalData{},
+			gpbft.Payload{},
+			gpbft.Justification{},
+			gpbft.PowerEntry{},
+			gpbft.PowerEntries{},
+		)
+	})
+	eg.Go(func() error {
+		return gen.WriteTupleEncodersToFile("../certs/cbor_gen.go", "certs",
+			certs.PowerTableDelta{},
+			certs.PowerTableDiff{},
+			certs.FinalityCertificate{},
+		)
+	})
+	eg.Go(func() error {
+		return gen.WriteTupleEncodersToFile("../certexchange/cbor_gen.go", "certexchange",
+			certexchange.Request{},
+			certexchange.ResponseHeader{},
+		)
+	})
+	eg.Go(func() error {
+		return gen.WriteTupleEncodersToFile("../cmd/f3/msgdump/cbor_gen.go", "msgdump",
+			msgdump.GMessageEnvelope{},
+			msgdump.GMessageEnvelopeDeffered{},
+		)
+	})
+	if err := eg.Wait(); err != nil {
+		fmt.Printf("Failed to complete cborg_gen: %v\n", err)
 		os.Exit(1)
 	}
 }