From 77c172b823b64ebface655681ab0749b9d2f7081 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ra=C3=BAl=20Benencia?= Date: Fri, 13 Apr 2018 16:30:31 -0700 Subject: First public commit --- vendor/github.com/go-logfmt/logfmt/encode.go | 321 +++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 vendor/github.com/go-logfmt/logfmt/encode.go (limited to 'vendor/github.com/go-logfmt/logfmt/encode.go') 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 +} -- cgit v1.2.3