// A Record holds information about a log event.
// Copies of a Record share state.
// Do not modify a Record after handing out a copy to it.
+// Call [NewRecord] to create a new Record.
// Use [Record.Clone] to create a copy with no shared state.
type Record struct {
// The time at which the output method (Log, Info, etc.) was called.
back []Attr
}
-// NewRecord creates a Record from the given arguments.
+// NewRecord creates a [Record] from the given arguments.
// Use [Record.AddAttrs] to add attributes to the Record.
//
// NewRecord is intended for logging APIs that want to support a [Handler] as
return r
}
-// NumAttrs returns the number of attributes in the Record.
+// NumAttrs returns the number of attributes in the [Record].
func (r Record) NumAttrs() int {
return r.nFront + len(r.back)
}
-// Attrs calls f on each Attr in the Record.
+// Attrs calls f on each Attr in the [Record].
// Iteration stops if f returns false.
func (r Record) Attrs(f func(Attr) bool) {
for i := 0; i < r.nFront; i++ {
}
}
-// AddAttrs appends the given Attrs to the Record's list of Attrs.
+// AddAttrs appends the given Attrs to the [Record]'s list of Attrs.
+// It omits empty groups.
func (r *Record) AddAttrs(attrs ...Attr) {
- n := copy(r.front[r.nFront:], attrs)
- r.nFront += n
+ var i int
+ for i = 0; i < len(attrs) && r.nFront < len(r.front); i++ {
+ a := attrs[i]
+ if a.Value.isEmptyGroup() {
+ continue
+ }
+ r.front[r.nFront] = a
+ r.nFront++
+ }
// Check if a copy was modified by slicing past the end
// and seeing if the Attr there is non-zero.
if cap(r.back) > len(r.back) {
end := r.back[:len(r.back)+1][len(r.back)]
if !end.isEmpty() {
- panic("copies of a slog.Record were both modified")
+ // Don't panic; copy and muddle through.
+ r.back = slices.Clip(r.back)
+ r.back = append(r.back, String("!BUG", "AddAttrs unsafely called on copy of Record made without using Record.Clone"))
+ }
+ }
+ ne := countEmptyGroups(attrs[i:])
+ r.back = slices.Grow(r.back, len(attrs[i:])-ne)
+ for _, a := range attrs[i:] {
+ if !a.Value.isEmptyGroup() {
+ r.back = append(r.back, a)
}
}
- r.back = append(r.back, attrs[n:]...)
}
// Add converts the args to Attrs as described in [Logger.Log],
-// then appends the Attrs to the Record's list of Attrs.
+// then appends the Attrs to the [Record]'s list of Attrs.
+// It omits empty groups.
func (r *Record) Add(args ...any) {
var a Attr
for len(args) > 0 {
a, args = argsToAttr(args)
+ if a.Value.isEmptyGroup() {
+ continue
+ }
if r.nFront < len(r.front) {
r.front[r.nFront] = a
r.nFront++
} else {
if r.back == nil {
- r.back = make([]Attr, 0, countAttrs(args))
+ r.back = make([]Attr, 0, countAttrs(args)+1)
}
r.back = append(r.back, a)
}
}
-
}
// countAttrs returns the number of Attrs that would be created from args.
// Function is the package path-qualified function name containing the
// source line. If non-empty, this string uniquely identifies a single
// function in the program. This may be the empty string if not known.
- Function string
+ Function string `json:"function"`
// File and Line are the file name and line number (1-based) of the source
// line. These may be the empty string and zero, respectively, if not known.
- File string
- Line int
+ File string `json:"file"`
+ Line int `json:"line"`
}
-// attrs returns the non-zero fields of s as a slice of attrs.
+// group returns the non-zero fields of s as a slice of attrs.
// It is similar to a LogValue method, but we don't want Source
// to implement LogValuer because it would be resolved before
// the ReplaceAttr function was called.