337 lines
8.0 KiB
Go
337 lines
8.0 KiB
Go
// 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 (
|
|
"bytes"
|
|
"context"
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"strconv"
|
|
"time"
|
|
"unicode/utf8"
|
|
|
|
"golang.org/x/exp/slog/internal/buffer"
|
|
)
|
|
|
|
// JSONHandler is a Handler that writes Records to an io.Writer as
|
|
// line-delimited JSON objects.
|
|
type JSONHandler struct {
|
|
*commonHandler
|
|
}
|
|
|
|
// NewJSONHandler creates a JSONHandler that writes to w,
|
|
// using the given options.
|
|
// If opts is nil, the default options are used.
|
|
func NewJSONHandler(w io.Writer, opts *HandlerOptions) *JSONHandler {
|
|
if opts == nil {
|
|
opts = &HandlerOptions{}
|
|
}
|
|
return &JSONHandler{
|
|
&commonHandler{
|
|
json: true,
|
|
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 *JSONHandler) Enabled(_ context.Context, level Level) bool {
|
|
return h.commonHandler.enabled(level)
|
|
}
|
|
|
|
// WithAttrs returns a new JSONHandler whose attributes consists
|
|
// of h's attributes followed by attrs.
|
|
func (h *JSONHandler) WithAttrs(attrs []Attr) Handler {
|
|
return &JSONHandler{commonHandler: h.commonHandler.withAttrs(attrs)}
|
|
}
|
|
|
|
func (h *JSONHandler) WithGroup(name string) Handler {
|
|
return &JSONHandler{commonHandler: h.commonHandler.withGroup(name)}
|
|
}
|
|
|
|
// Handle formats its argument Record as a JSON object on a single line.
|
|
//
|
|
// If the Record's time is zero, the time is omitted.
|
|
// Otherwise, the key is "time"
|
|
// and the value is output as with json.Marshal.
|
|
//
|
|
// 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].
|
|
//
|
|
// Values are formatted as with an [encoding/json.Encoder] with SetEscapeHTML(false),
|
|
// with two exceptions.
|
|
//
|
|
// First, an Attr whose Value is of type error is formatted as a string, by
|
|
// calling its Error method. Only errors in Attrs receive this special treatment,
|
|
// not errors embedded in structs, slices, maps or other data structures that
|
|
// are processed by the encoding/json package.
|
|
//
|
|
// Second, an encoding failure does not cause Handle to return an error.
|
|
// Instead, the error message is formatted as a string.
|
|
//
|
|
// Each call to Handle results in a single serialized call to io.Writer.Write.
|
|
func (h *JSONHandler) Handle(_ context.Context, r Record) error {
|
|
return h.commonHandler.handle(r)
|
|
}
|
|
|
|
// Adapted from time.Time.MarshalJSON to avoid allocation.
|
|
func appendJSONTime(s *handleState, t time.Time) {
|
|
if y := t.Year(); y < 0 || y >= 10000 {
|
|
// RFC 3339 is clear that years are 4 digits exactly.
|
|
// See golang.org/issue/4556#c15 for more discussion.
|
|
s.appendError(errors.New("time.Time year outside of range [0,9999]"))
|
|
}
|
|
s.buf.WriteByte('"')
|
|
*s.buf = t.AppendFormat(*s.buf, time.RFC3339Nano)
|
|
s.buf.WriteByte('"')
|
|
}
|
|
|
|
func appendJSONValue(s *handleState, v Value) error {
|
|
switch v.Kind() {
|
|
case KindString:
|
|
s.appendString(v.str())
|
|
case KindInt64:
|
|
*s.buf = strconv.AppendInt(*s.buf, v.Int64(), 10)
|
|
case KindUint64:
|
|
*s.buf = strconv.AppendUint(*s.buf, v.Uint64(), 10)
|
|
case KindFloat64:
|
|
// json.Marshal is funny about floats; it doesn't
|
|
// always match strconv.AppendFloat. So just call it.
|
|
// That's expensive, but floats are rare.
|
|
if err := appendJSONMarshal(s.buf, v.Float64()); err != nil {
|
|
return err
|
|
}
|
|
case KindBool:
|
|
*s.buf = strconv.AppendBool(*s.buf, v.Bool())
|
|
case KindDuration:
|
|
// Do what json.Marshal does.
|
|
*s.buf = strconv.AppendInt(*s.buf, int64(v.Duration()), 10)
|
|
case KindTime:
|
|
s.appendTime(v.Time())
|
|
case KindAny:
|
|
a := v.Any()
|
|
_, jm := a.(json.Marshaler)
|
|
if err, ok := a.(error); ok && !jm {
|
|
s.appendString(err.Error())
|
|
} else {
|
|
return appendJSONMarshal(s.buf, a)
|
|
}
|
|
default:
|
|
panic(fmt.Sprintf("bad kind: %s", v.Kind()))
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func appendJSONMarshal(buf *buffer.Buffer, v any) error {
|
|
// Use a json.Encoder to avoid escaping HTML.
|
|
var bb bytes.Buffer
|
|
enc := json.NewEncoder(&bb)
|
|
enc.SetEscapeHTML(false)
|
|
if err := enc.Encode(v); err != nil {
|
|
return err
|
|
}
|
|
bs := bb.Bytes()
|
|
buf.Write(bs[:len(bs)-1]) // remove final newline
|
|
return nil
|
|
}
|
|
|
|
// appendEscapedJSONString escapes s for JSON and appends it to buf.
|
|
// It does not surround the string in quotation marks.
|
|
//
|
|
// Modified from encoding/json/encode.go:encodeState.string,
|
|
// with escapeHTML set to false.
|
|
func appendEscapedJSONString(buf []byte, s string) []byte {
|
|
char := func(b byte) { buf = append(buf, b) }
|
|
str := func(s string) { buf = append(buf, s...) }
|
|
|
|
start := 0
|
|
for i := 0; i < len(s); {
|
|
if b := s[i]; b < utf8.RuneSelf {
|
|
if safeSet[b] {
|
|
i++
|
|
continue
|
|
}
|
|
if start < i {
|
|
str(s[start:i])
|
|
}
|
|
char('\\')
|
|
switch b {
|
|
case '\\', '"':
|
|
char(b)
|
|
case '\n':
|
|
char('n')
|
|
case '\r':
|
|
char('r')
|
|
case '\t':
|
|
char('t')
|
|
default:
|
|
// This encodes bytes < 0x20 except for \t, \n and \r.
|
|
str(`u00`)
|
|
char(hex[b>>4])
|
|
char(hex[b&0xF])
|
|
}
|
|
i++
|
|
start = i
|
|
continue
|
|
}
|
|
c, size := utf8.DecodeRuneInString(s[i:])
|
|
if c == utf8.RuneError && size == 1 {
|
|
if start < i {
|
|
str(s[start:i])
|
|
}
|
|
str(`\ufffd`)
|
|
i += size
|
|
start = i
|
|
continue
|
|
}
|
|
// U+2028 is LINE SEPARATOR.
|
|
// U+2029 is PARAGRAPH SEPARATOR.
|
|
// They are both technically valid characters in JSON strings,
|
|
// but don't work in JSONP, which has to be evaluated as JavaScript,
|
|
// and can lead to security holes there. It is valid JSON to
|
|
// escape them, so we do so unconditionally.
|
|
// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
|
|
if c == '\u2028' || c == '\u2029' {
|
|
if start < i {
|
|
str(s[start:i])
|
|
}
|
|
str(`\u202`)
|
|
char(hex[c&0xF])
|
|
i += size
|
|
start = i
|
|
continue
|
|
}
|
|
i += size
|
|
}
|
|
if start < len(s) {
|
|
str(s[start:])
|
|
}
|
|
return buf
|
|
}
|
|
|
|
var hex = "0123456789abcdef"
|
|
|
|
// Copied from encoding/json/tables.go.
|
|
//
|
|
// safeSet holds the value true if the ASCII character with the given array
|
|
// position can be represented inside a JSON string without any further
|
|
// escaping.
|
|
//
|
|
// All values are true except for the ASCII control characters (0-31), the
|
|
// double quote ("), and the backslash character ("\").
|
|
var safeSet = [utf8.RuneSelf]bool{
|
|
' ': true,
|
|
'!': true,
|
|
'"': false,
|
|
'#': true,
|
|
'$': true,
|
|
'%': true,
|
|
'&': true,
|
|
'\'': true,
|
|
'(': true,
|
|
')': true,
|
|
'*': true,
|
|
'+': true,
|
|
',': true,
|
|
'-': true,
|
|
'.': true,
|
|
'/': true,
|
|
'0': true,
|
|
'1': true,
|
|
'2': true,
|
|
'3': true,
|
|
'4': true,
|
|
'5': true,
|
|
'6': true,
|
|
'7': true,
|
|
'8': true,
|
|
'9': true,
|
|
':': true,
|
|
';': true,
|
|
'<': true,
|
|
'=': true,
|
|
'>': true,
|
|
'?': true,
|
|
'@': true,
|
|
'A': true,
|
|
'B': true,
|
|
'C': true,
|
|
'D': true,
|
|
'E': true,
|
|
'F': true,
|
|
'G': true,
|
|
'H': true,
|
|
'I': true,
|
|
'J': true,
|
|
'K': true,
|
|
'L': true,
|
|
'M': true,
|
|
'N': true,
|
|
'O': true,
|
|
'P': true,
|
|
'Q': true,
|
|
'R': true,
|
|
'S': true,
|
|
'T': true,
|
|
'U': true,
|
|
'V': true,
|
|
'W': true,
|
|
'X': true,
|
|
'Y': true,
|
|
'Z': true,
|
|
'[': true,
|
|
'\\': false,
|
|
']': true,
|
|
'^': true,
|
|
'_': true,
|
|
'`': true,
|
|
'a': true,
|
|
'b': true,
|
|
'c': true,
|
|
'd': true,
|
|
'e': true,
|
|
'f': true,
|
|
'g': true,
|
|
'h': true,
|
|
'i': true,
|
|
'j': true,
|
|
'k': true,
|
|
'l': true,
|
|
'm': true,
|
|
'n': true,
|
|
'o': true,
|
|
'p': true,
|
|
'q': true,
|
|
'r': true,
|
|
's': true,
|
|
't': true,
|
|
'u': true,
|
|
'v': true,
|
|
'w': true,
|
|
'x': true,
|
|
'y': true,
|
|
'z': true,
|
|
'{': true,
|
|
'|': true,
|
|
'}': true,
|
|
'~': true,
|
|
'\u007f': true,
|
|
}
|