chore: vendor

vendor/golang.org/x/exp/slog/text_handler.go

@@ -0,0 +1,161 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package slog
+
+import (
+	"context"
+	"encoding"
+	"fmt"
+	"io"
+	"reflect"
+	"strconv"
+	"unicode"
+	"unicode/utf8"
+)
+
+// TextHandler is a Handler that writes Records to an io.Writer as a
+// sequence of key=value pairs separated by spaces and followed by a newline.
+type TextHandler struct {
+	*commonHandler
+}
+
+// NewTextHandler creates a TextHandler that writes to w,
+// using the given options.
+// If opts is nil, the default options are used.
+func NewTextHandler(w io.Writer, opts *HandlerOptions) *TextHandler {
+	if opts == nil {
+		opts = &HandlerOptions{}
+	}
+	return &TextHandler{
+		&commonHandler{
+			json: false,
+			w:    w,
+			opts: *opts,
+		},
+	}
+}
+
+// Enabled reports whether the handler handles records at the given level.
+// The handler ignores records whose level is lower.
+func (h *TextHandler) Enabled(_ context.Context, level Level) bool {
+	return h.commonHandler.enabled(level)
+}
+
+// WithAttrs returns a new TextHandler whose attributes consists
+// of h's attributes followed by attrs.
+func (h *TextHandler) WithAttrs(attrs []Attr) Handler {
+	return &TextHandler{commonHandler: h.commonHandler.withAttrs(attrs)}
+}
+
+func (h *TextHandler) WithGroup(name string) Handler {
+	return &TextHandler{commonHandler: h.commonHandler.withGroup(name)}
+}
+
+// Handle formats its argument Record as a single line of space-separated
+// key=value items.
+//
+// If the Record's time is zero, the time is omitted.
+// Otherwise, the key is "time"
+// and the value is output in RFC3339 format with millisecond precision.
+//
+// If the Record's level is zero, the level is omitted.
+// Otherwise, the key is "level"
+// and the value of [Level.String] is output.
+//
+// If the AddSource option is set and source information is available,
+// the key is "source" and the value is output as FILE:LINE.
+//
+// The message's key is "msg".
+//
+// To modify these or other attributes, or remove them from the output, use
+// [HandlerOptions.ReplaceAttr].
+//
+// If a value implements [encoding.TextMarshaler], the result of MarshalText is
+// written. Otherwise, the result of fmt.Sprint is written.
+//
+// Keys and values are quoted with [strconv.Quote] if they contain Unicode space
+// characters, non-printing characters, '"' or '='.
+//
+// Keys inside groups consist of components (keys or group names) separated by
+// dots. No further escaping is performed.
+// Thus there is no way to determine from the key "a.b.c" whether there
+// are two groups "a" and "b" and a key "c", or a single group "a.b" and a key "c",
+// or single group "a" and a key "b.c".
+// If it is necessary to reconstruct the group structure of a key
+// even in the presence of dots inside components, use
+// [HandlerOptions.ReplaceAttr] to encode that information in the key.
+//
+// Each call to Handle results in a single serialized call to
+// io.Writer.Write.
+func (h *TextHandler) Handle(_ context.Context, r Record) error {
+	return h.commonHandler.handle(r)
+}
+
+func appendTextValue(s *handleState, v Value) error {
+	switch v.Kind() {
+	case KindString:
+		s.appendString(v.str())
+	case KindTime:
+		s.appendTime(v.time())
+	case KindAny:
+		if tm, ok := v.any.(encoding.TextMarshaler); ok {
+			data, err := tm.MarshalText()
+			if err != nil {
+				return err
+			}
+			// TODO: avoid the conversion to string.
+			s.appendString(string(data))
+			return nil
+		}
+		if bs, ok := byteSlice(v.any); ok {
+			// As of Go 1.19, this only allocates for strings longer than 32 bytes.
+			s.buf.WriteString(strconv.Quote(string(bs)))
+			return nil
+		}
+		s.appendString(fmt.Sprintf("%+v", v.Any()))
+	default:
+		*s.buf = v.append(*s.buf)
+	}
+	return nil
+}
+
+// byteSlice returns its argument as a []byte if the argument's
+// underlying type is []byte, along with a second return value of true.
+// Otherwise it returns nil, false.
+func byteSlice(a any) ([]byte, bool) {
+	if bs, ok := a.([]byte); ok {
+		return bs, true
+	}
+	// Like Printf's %s, we allow both the slice type and the byte element type to be named.
+	t := reflect.TypeOf(a)
+	if t != nil && t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Uint8 {
+		return reflect.ValueOf(a).Bytes(), true
+	}
+	return nil, false
+}
+
+func needsQuoting(s string) bool {
+	if len(s) == 0 {
+		return true
+	}
+	for i := 0; i < len(s); {
+		b := s[i]
+		if b < utf8.RuneSelf {
+			// Quote anything except a backslash that would need quoting in a
+			// JSON string, as well as space and '='
+			if b != '\\' && (b == ' ' || b == '=' || !safeSet[b]) {
+				return true
+			}
+			i++
+			continue
+		}
+		r, size := utf8.DecodeRuneInString(s[i:])
+		if r == utf8.RuneError || unicode.IsSpace(r) || !unicode.IsPrint(r) {
+			return true
+		}
+		i += size
+	}
+	return false
+}