Fix encoding for float64 and generate conversion for Timestamp

- fixes encoding/decoding of float64 - uses little endian (contrary to all other types)
- generates helper methods for vpe_types.Timestamp type
- adds usage code to simple-client and binapi-types examples

Change-Id: I2e83eee0629eb67964049406c50c7ee0a692ccaf
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

3 files changed, 69 insertions, 7 deletions

diff --git a/binapigen/gen_helpers.go b/binapigen/gen_helpers.go
index 5eafc76..944bfe2 100644
--- a/binapigen/gen_helpers.go
+++ b/binapigen/gen_helpers.go
@@ -22,6 +22,7 @@ func init() {
 const (
 	fmtPkg     = GoImportPath("fmt")
 	netPkg     = GoImportPath("net")
+	timePkg    = GoImportPath("time")
 	stringsPkg = GoImportPath("strings")
 )
 
@@ -185,13 +186,6 @@ func genIPPrefixConversion(g *GenFile, structName string, ipv int) {
 	g.P("func (x ", structName, ") String() string {")
 	g.P("	ip := x.Address.String()")
 	g.P("	return ip + \"/\" + ", strconvPkg.Ident("Itoa"), "(int(x.Len))")
-	/*if ipv == 4 {
-	  	g.P("	mask := ", netPkg.Ident("CIDRMask"), "(int(x.Len), 32)")
-	  } else {
-	  	g.P("	mask := ", netPkg.Ident("CIDRMask"), "(int(x.Len), 128)")
-	  }
-	  g.P("	ipnet := &", netPkg.Ident("IPNet"), "{IP: x.Address.ToIP(), Mask: mask}")
-	  g.P("	return ipnet.String()")*/
 	g.P("}")
 
 	// MarshalText method
@@ -346,3 +340,42 @@ func genMacAddressConversion(g *GenFile, structName string) {
 	g.P("}")
 	g.P()
 }
+
+func genTimestampConversion(g *GenFile, structName string) {
+	// NewTimestamp method
+	g.P("func New", structName, "(t ", timePkg.Ident("Time"), ") ", structName, " {")
+	g.P("	sec := int64(t.Unix())")
+	g.P("	nsec := int32(t.Nanosecond())")
+	g.P("	ns := float64(sec) + float64(nsec / 1e9)")
+	g.P("	return ", structName, "(ns)")
+	g.P("}")
+
+	// ToTime method
+	g.P("func (x ", structName, ") ToTime() ", timePkg.Ident("Time"), " {")
+	g.P("	ns := int64(x * 1e9)")
+	g.P("	sec := ns / 1e9")
+	g.P("	nsec := ns % 1e9")
+	g.P("	return ", timePkg.Ident("Unix"), "(sec, nsec)")
+	g.P("}")
+
+	// String method
+	g.P("func (x ", structName, ") String() string {")
+	g.P("	return x.ToTime().String()")
+	g.P("}")
+
+	// MarshalText method
+	g.P("func (x *", structName, ") MarshalText() ([]byte, error) {")
+	g.P("	return []byte(x.ToTime().Format(", timePkg.Ident("RFC3339Nano"), ")), nil")
+	g.P("}")
+
+	// UnmarshalText method
+	g.P("func (x *", structName, ") UnmarshalText(text []byte) error {")
+	g.P("	t, err := ", timePkg.Ident("Parse"), "(", timePkg.Ident("RFC3339Nano"), ", string(text))")
+	g.P("	if err != nil {")
+	g.P("		return err")
+	g.P("	}")
+	g.P("	*x = New", structName, "(t)")
+	g.P("	return nil")
+	g.P("}")
+	g.P()
+}
diff --git a/binapigen/gen_helpers_test.go b/binapigen/gen_helpers_test.go
index 371fd6c..075dd8e 100644
--- a/binapigen/gen_helpers_test.go
+++ b/binapigen/gen_helpers_test.go
@@ -17,11 +17,13 @@ package binapigen
 import (
 	"strings"
 	"testing"
+	"time"
 
 	. "github.com/onsi/gomega"
 
 	"git.fd.io/govpp.git/binapi/ethernet_types"
 	"git.fd.io/govpp.git/binapi/ip_types"
+	"git.fd.io/govpp.git/binapi/vpe_types"
 )
 
 func TestGeneratedParseAddress(t *testing.T) {
@@ -154,3 +156,28 @@ func TestGeneratedParseMACError(t *testing.T) {
 	_, err := ethernet_types.ParseMacAddress("malformed_mac")
 	Expect(err).Should(HaveOccurred())
 }
+
+func TestGeneratedParseTimestamp(t *testing.T) {
+	RegisterTestingT(t)
+
+	var data = []struct {
+		input  time.Time
+		result vpe_types.Timestamp
+	}{
+		{time.Unix(0, 0), vpe_types.Timestamp(0)},
+		{time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC),
+			vpe_types.Timestamp(9.466848e+08)},
+	}
+
+	for _, entry := range data {
+		t.Run(entry.input.String(), func(t *testing.T) {
+			ts := vpe_types.NewTimestamp(entry.input)
+			Expect(ts).To(Equal(entry.result))
+
+			Expect(entry.input.Equal(ts.ToTime())).To(BeTrue())
+
+			originTime := ts.String()
+			Expect(originTime).To(Equal(entry.input.Local().String()))
+		})
+	}
+}
diff --git a/binapigen/generate.go b/binapigen/generate.go
index 834c989..bf6df81 100644
--- a/binapigen/generate.go
+++ b/binapigen/generate.go
@@ -246,6 +246,8 @@ func genAlias(g *GenFile, alias *Alias) {
 		genAddressWithPrefixConversion(g, alias.GoName)
 	case "mac_address":
 		genMacAddressConversion(g, alias.GoName)
+	case "timestamp":
+		genTimestampConversion(g, alias.GoName)
 	}
 }