1 files changed, 321 insertions, 0 deletions
diff --git a/vendor/github.com/go-logfmt/logfmt/encode.go b/vendor/github.com/go-logfmt/logfmt/encode.go
new file mode 100644
index 0000000..55f1603
--- /dev/null
+++ b/vendor/github.com/go-logfmt/logfmt/encode.go
@@ -0,0 +1,321 @@
+package logfmt
+
+import (
+	"bytes"
+	"encoding"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"unicode/utf8"
+)
+
+// MarshalKeyvals returns the logfmt encoding of keyvals, a variadic sequence
+// of alternating keys and values.
+func MarshalKeyvals(keyvals ...interface{}) ([]byte, error) {
+	buf := &bytes.Buffer{}
+	if err := NewEncoder(buf).EncodeKeyvals(keyvals...); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// An Encoder writes logfmt data to an output stream.
+type Encoder struct {
+	w       io.Writer
+	scratch bytes.Buffer
+	needSep bool
+}
+
+// NewEncoder returns a new encoder that writes to w.
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{
+		w: w,
+	}
+}
+
+var (
+	space   = []byte(" ")
+	equals  = []byte("=")
+	newline = []byte("\n")
+	null    = []byte("null")
+)
+
+// EncodeKeyval writes the logfmt encoding of key and value to the stream. A
+// single space is written before the second and subsequent keys in a record.
+// Nothing is written if a non-nil error is returned.
+func (enc *Encoder) EncodeKeyval(key, value interface{}) error {
+	enc.scratch.Reset()
+	if enc.needSep {
+		if _, err := enc.scratch.Write(space); err != nil {
+			return err
+		}
+	}
+	if err := writeKey(&enc.scratch, key); err != nil {
+		return err
+	}
+	if _, err := enc.scratch.Write(equals); err != nil {
+		return err
+	}
+	if err := writeValue(&enc.scratch, value); err != nil {
+		return err
+	}
+	_, err := enc.w.Write(enc.scratch.Bytes())
+	enc.needSep = true
+	return err
+}
+
+// EncodeKeyvals writes the logfmt encoding of keyvals to the stream. Keyvals
+// is a variadic sequence of alternating keys and values. Keys of unsupported
+// type are skipped along with their corresponding value. Values of
+// unsupported type or that cause a MarshalerError are replaced by their error
+// but do not cause EncodeKeyvals to return an error. If a non-nil error is
+// returned some key/value pairs may not have be written.
+func (enc *Encoder) EncodeKeyvals(keyvals ...interface{}) error {
+	if len(keyvals) == 0 {
+		return nil
+	}
+	if len(keyvals)%2 == 1 {
+		keyvals = append(keyvals, nil)
+	}
+	for i := 0; i < len(keyvals); i += 2 {
+		k, v := keyvals[i], keyvals[i+1]
+		err := enc.EncodeKeyval(k, v)
+		if err == ErrUnsupportedKeyType {
+			continue
+		}
+		if _, ok := err.(*MarshalerError); ok || err == ErrUnsupportedValueType {
+			v = err
+			err = enc.EncodeKeyval(k, v)
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// MarshalerError represents an error encountered while marshaling a value.
+type MarshalerError struct {
+	Type reflect.Type
+	Err  error
+}
+
+func (e *MarshalerError) Error() string {
+	return "error marshaling value of type " + e.Type.String() + ": " + e.Err.Error()
+}
+
+// ErrNilKey is returned by Marshal functions and Encoder methods if a key is
+// a nil interface or pointer value.
+var ErrNilKey = errors.New("nil key")
+
+// ErrInvalidKey is returned by Marshal functions and Encoder methods if a key
+// contains an invalid character.
+var ErrInvalidKey = errors.New("invalid key")
+
+// ErrUnsupportedKeyType is returned by Encoder methods if a key has an
+// unsupported type.
+var ErrUnsupportedKeyType = errors.New("unsupported key type")
+
+// ErrUnsupportedValueType is returned by Encoder methods if a value has an
+// unsupported type.
+var ErrUnsupportedValueType = errors.New("unsupported value type")
+
+func writeKey(w io.Writer, key interface{}) error {
+	if key == nil {
+		return ErrNilKey
+	}
+
+	switch k := key.(type) {
+	case string:
+		return writeStringKey(w, k)
+	case []byte:
+		if k == nil {
+			return ErrNilKey
+		}
+		return writeBytesKey(w, k)
+	case encoding.TextMarshaler:
+		kb, err := safeMarshal(k)
+		if err != nil {
+			return err
+		}
+		if kb == nil {
+			return ErrNilKey
+		}
+		return writeBytesKey(w, kb)
+	case fmt.Stringer:
+		ks, ok := safeString(k)
+		if !ok {
+			return ErrNilKey
+		}
+		return writeStringKey(w, ks)
+	default:
+		rkey := reflect.ValueOf(key)
+		switch rkey.Kind() {
+		case reflect.Array, reflect.Chan, reflect.Func, reflect.Map, reflect.Slice, reflect.Struct:
+			return ErrUnsupportedKeyType
+		case reflect.Ptr:
+			if rkey.IsNil() {
+				return ErrNilKey
+			}
+			return writeKey(w, rkey.Elem().Interface())
+		}
+		return writeStringKey(w, fmt.Sprint(k))
+	}
+}
+
+func invalidKeyRune(r rune) bool {
+	return r <= ' ' || r == '=' || r == '"' || r == utf8.RuneError
+}
+
+func invalidKeyString(key string) bool {
+	return len(key) == 0 || strings.IndexFunc(key, invalidKeyRune) != -1
+}
+
+func invalidKey(key []byte) bool {
+	return len(key) == 0 || bytes.IndexFunc(key, invalidKeyRune) != -1
+}
+
+func writeStringKey(w io.Writer, key string) error {
+	if invalidKeyString(key) {
+		return ErrInvalidKey
+	}
+	_, err := io.WriteString(w, key)
+	return err
+}
+
+func writeBytesKey(w io.Writer, key []byte) error {
+	if invalidKey(key) {
+		return ErrInvalidKey
+	}
+	_, err := w.Write(key)
+	return err
+}
+
+func writeValue(w io.Writer, value interface{}) error {
+	switch v := value.(type) {
+	case nil:
+		return writeBytesValue(w, null)
+	case string:
+		return writeStringValue(w, v, true)
+	case []byte:
+		return writeBytesValue(w, v)
+	case encoding.TextMarshaler:
+		vb, err := safeMarshal(v)
+		if err != nil {
+			return err
+		}
+		if vb == nil {
+			vb = null
+		}
+		return writeBytesValue(w, vb)
+	case error:
+		se, ok := safeError(v)
+		return writeStringValue(w, se, ok)
+	case fmt.Stringer:
+		ss, ok := safeString(v)
+		return writeStringValue(w, ss, ok)
+	default:
+		rvalue := reflect.ValueOf(value)
+		switch rvalue.Kind() {
+		case reflect.Array, reflect.Chan, reflect.Func, reflect.Map, reflect.Slice, reflect.Struct:
+			return ErrUnsupportedValueType
+		case reflect.Ptr:
+			if rvalue.IsNil() {
+				return writeBytesValue(w, null)
+			}
+			return writeValue(w, rvalue.Elem().Interface())
+		}
+		return writeStringValue(w, fmt.Sprint(v), true)
+	}
+}
+
+func needsQuotedValueRune(r rune) bool {
+	return r <= ' ' || r == '=' || r == '"' || r == utf8.RuneError
+}
+
+func writeStringValue(w io.Writer, value string, ok bool) error {
+	var err error
+	if ok && value == "null" {
+		_, err = io.WriteString(w, `"null"`)
+	} else if strings.IndexFunc(value, needsQuotedValueRune) != -1 {
+		_, err = writeQuotedString(w, value)
+	} else {
+		_, err = io.WriteString(w, value)
+	}
+	return err
+}
+
+func writeBytesValue(w io.Writer, value []byte) error {
+	var err error
+	if bytes.IndexFunc(value, needsQuotedValueRune) != -1 {
+		_, err = writeQuotedBytes(w, value)
+	} else {
+		_, err = w.Write(value)
+	}
+	return err
+}
+
+// EndRecord writes a newline character to the stream and resets the encoder
+// to the beginning of a new record.
+func (enc *Encoder) EndRecord() error {
+	_, err := enc.w.Write(newline)
+	if err == nil {
+		enc.needSep = false
+	}
+	return err
+}
+
+// Reset resets the encoder to the beginning of a new record.
+func (enc *Encoder) Reset() {
+	enc.needSep = false
+}
+
+func safeError(err error) (s string, ok bool) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(err); v.Kind() == reflect.Ptr && v.IsNil() {
+				s, ok = "null", false
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s, ok = err.Error(), true
+	return
+}
+
+func safeString(str fmt.Stringer) (s string, ok bool) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(str); v.Kind() == reflect.Ptr && v.IsNil() {
+				s, ok = "null", false
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	s, ok = str.String(), true
+	return
+}
+
+func safeMarshal(tm encoding.TextMarshaler) (b []byte, err error) {
+	defer func() {
+		if panicVal := recover(); panicVal != nil {
+			if v := reflect.ValueOf(tm); v.Kind() == reflect.Ptr && v.IsNil() {
+				b, err = nil, nil
+			} else {
+				panic(panicVal)
+			}
+		}
+	}()
+	b, err = tm.MarshalText()
+	if err != nil {
+		return nil, &MarshalerError{
+			Type: reflect.TypeOf(tm),
+			Err:  err,
+		}
+	}
+	return
+}