Add support for hex-encoded of byte slice (#42)

array.go

@@ -64,6 +64,12 @@ func (a *Array) Bytes(val []byte) *Array {
 	return a
 }
 
+// Hex append the val as a hex string to the array.
+func (a *Array) Hex(val []byte) *Array {
+	a.buf = json.AppendHex(append(a.buf, ','), val)
+	return a
+}
+
 // Err append the err as a string to the array.
 func (a *Array) Err(err error) *Array {
 	a.buf = json.AppendError(append(a.buf, ','), err)

array_test.go

@@ -21,9 +21,11 @@ func TestArray(t *testing.T) {
 		Float32(11).
 		Float64(12).
 		Str("a").
+		Bytes([]byte("b")).
+		Hex([]byte{0x1f}).
 		Time(time.Time{}).
 		Dur(0)
-	want := `[true,1,2,3,4,5,6,7,8,9,10,11,12,"a","0001-01-01T00:00:00Z",0]`
+	want := `[true,1,2,3,4,5,6,7,8,9,10,11,12,"a","b","1f","0001-01-01T00:00:00Z",0]`
 	if got := string(a.write([]byte{})); got != want {
 		t.Errorf("Array.write()\ngot:  %s\nwant: %s", got, want)
 	}

context.go

@@ -79,6 +79,12 @@ func (c Context) Bytes(key string, val []byte) Context {
 	return c
 }
 
+// Hex adds the field key with val as a hex string to the logger context.
+func (c Context) Hex(key string, val []byte) Context {
+	c.l.context = json.AppendHex(json.AppendKey(c.l.context, key), val)
+	return c
+}
+
 // RawJSON adds already encoded JSON to context.
 //
 // No sanity check is performed on b; it must not contain carriage returns and

event.go

@@ -219,6 +219,15 @@ func (e *Event) Bytes(key string, val []byte) *Event {
 	return e
 }
 
+// Hex adds the field key with val as a hex string to the *Event context.
+func (e *Event) Hex(key string, val []byte) *Event {
+	if e == nil {
+		return e
+	}
+	e.buf = json.AppendHex(json.AppendKey(e.buf, key), val)
+	return e
+}
+
 // RawJSON adds already encoded JSON to the log line under key.
 //
 // No sanity check is performed on b; it must not contain carriage returns and

internal/json/base.go

@@ -1,5 +1,6 @@
 package json
 
+// AppendKey appends a new key to the output JSON.
 func AppendKey(dst []byte, key string) []byte {
 	if len(dst) > 1 {
 		dst = append(dst, ',')
@@ -8,13 +9,17 @@ func AppendKey(dst []byte, key string) []byte {
 	return append(dst, ':')
 }
 
+// AppendError encodes the error string to json and appends
+// the encoded string to the input byte slice.
 func AppendError(dst []byte, err error) []byte {
 	if err == nil {
 		return append(dst, `null`...)
 	}
 	return AppendString(dst, err.Error())
 }
 
+// AppendErrors encodes the error strings to json and
+// appends the encoded string list to the input byte slice.
 func AppendErrors(dst []byte, errs []error) []byte {
 	if len(errs) == 0 {
 		return append(dst, '[', ']')

internal/json/string.go

@@ -4,6 +4,8 @@ import "unicode/utf8"
 
 const hex = "0123456789abcdef"
 
+// AppendStrings encodes the input strings to json and
+// appends the encoded string list to the input byte slice.
 func AppendStrings(dst []byte, vals []string) []byte {
 	if len(vals) == 0 {
 		return append(dst, '[', ']')
@@ -123,6 +125,19 @@ func AppendBytes(dst, s []byte) []byte {
 	return append(dst, '"')
 }
 
+// AppendHex encodes the input bytes to a hex string and appends
+// the encoded string to the input byte slice.
+//
+// The operation loops though each byte and encodes it as hex using
+// the hex lookup table.
+func AppendHex(dst, s []byte) []byte {
+	dst = append(dst, '"')
+	for _, v := range s {
+		dst = append(dst, hex[v>>4], hex[v&0x0f])
+	}
+	return append(dst, '"')
+}
+
 // appendBytesComplex is a mirror of the appendStringComplex
 // with []byte arg
 func appendBytesComplex(dst, s []byte, i int) []byte {

internal/json/string_test.go

@@ -53,7 +53,18 @@ var encodeStringTests = []struct {
 	{"emoji \u2764\ufe0f!", `"emoji ❤️!"`},
 }
 
-func TestappendString(t *testing.T) {
+var encodeHexTests = []struct {
+	in  byte
+	out string
+}{
+	{0x00, `"00"`},
+	{0x0f, `"0f"`},
+	{0x10, `"10"`},
+	{0xf0, `"f0"`},
+	{0xff, `"ff"`},
+}
+
+func TestAppendString(t *testing.T) {
 	for _, tt := range encodeStringTests {
 		b := AppendString([]byte{}, tt.in)
 		if got, want := string(b), tt.out; got != want {
@@ -62,7 +73,7 @@ func TestappendString(t *testing.T) {
 	}
 }
 
-func TestappendBytes(t *testing.T) {
+func TestAppendBytes(t *testing.T) {
 	for _, tt := range encodeStringTests {
 		b := AppendBytes([]byte{}, []byte(tt.in))
 		if got, want := string(b), tt.out; got != want {
@@ -71,6 +82,15 @@ func TestappendBytes(t *testing.T) {
 	}
 }
 
+func TestAppendHex(t *testing.T) {
+	for _, tt := range encodeHexTests {
+		b := AppendHex([]byte{}, []byte{tt.in})
+		if got, want := string(b), tt.out; got != want {
+			t.Errorf("appendHex(%x) = %s, want %s", tt.in, got, want)
+		}
+	}
+}
+
 func TestStringBytes(t *testing.T) {
 	t.Parallel()
 	// Test that encodeState.stringBytes and encodeState.string use the same encoding.
@@ -108,7 +128,7 @@ func TestStringBytes(t *testing.T) {
 	}
 }
 
-func BenchmarkappendString(b *testing.B) {
+func BenchmarkAppendString(b *testing.B) {
 	tests := map[string]string{
 		"NoEncoding":       `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
 		"EncodingFirst":    `"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
@@ -128,7 +148,7 @@ func BenchmarkappendString(b *testing.B) {
 	}
 }
 
-func BenchmarkappendBytes(b *testing.B) {
+func BenchmarkAppendBytes(b *testing.B) {
 	tests := map[string]string{
 		"NoEncoding":       `aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,
 		"EncodingFirst":    `"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa`,

internal/json/time.go

@@ -5,13 +5,17 @@ import (
 	"time"
 )
 
+// AppendTime formats the input time with the given format
+// and appends the encoded string to the input byte slice.
 func AppendTime(dst []byte, t time.Time, format string) []byte {
 	if format == "" {
 		return AppendInt64(dst, t.Unix())
 	}
 	return append(t.AppendFormat(append(dst, '"'), format), '"')
 }
 
+// AppendTimes converts the input times with the given format
+// and appends the encoded string list to the input byte slice.
 func AppendTimes(dst []byte, vals []time.Time, format string) []byte {
 	if format == "" {
 		return appendUnixTimes(dst, vals)
@@ -45,13 +49,17 @@ func appendUnixTimes(dst []byte, vals []time.Time) []byte {
 	return dst
 }
 
+// AppendDuration formats the input duration with the given unit & format
+// and appends the encoded string to the input byte slice.
 func AppendDuration(dst []byte, d time.Duration, unit time.Duration, useInt bool) []byte {
 	if useInt {
 		return strconv.AppendInt(dst, int64(d/unit), 10)
 	}
 	return AppendFloat64(dst, float64(d)/float64(unit))
 }
 
+// AppendDurations formats the input durations with the given unit & format
+// and appends the encoded string list to the input byte slice.
 func AppendDurations(dst []byte, vals []time.Duration, unit time.Duration, useInt bool) []byte {
 	if len(vals) == 0 {
 		return append(dst, '[', ']')