[feature + performance] add JSON logging format (#4355)

# Description

Adds JSON logging as an optional alternative log output format. In the process this moves our log formatting itself into a separate subpkg to make it more easily modular, and improves caller name getting with some calling function name caching.

## Checklist

- [x] I/we have read the [GoToSocial contribution guidelines](https://codeberg.org/superseriousbusiness/gotosocial/src/branch/main/CONTRIBUTING.md).
- [x] I/we have discussed the proposed changes already, either in an issue on the repository, or in the Matrix chat.
- [x] I/we have not leveraged AI to create the proposed changes.
- [x] I/we have performed a self-review of added code.
- [x] I/we have written code that is legible and maintainable by others.
- [x] I/we have commented the added code, particularly in hard-to-understand areas.
- [x] I/we have made any necessary changes to documentation.
- [ ] I/we have added tests that cover new code.
- [x] I/we have run tests and they pass locally with the changes.
- [x] I/we have run `go fmt ./...` and `golangci-lint run`.

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4355
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

vendor/codeberg.org/gruf/go-caller/LICENSE

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) gruf
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/codeberg.org/gruf/go-caller/README.md

@@ -0,0 +1,3 @@
+# go-caller
+
+runtime-cached Go calling function names per PC, useful in shaving time from outputting log entries.

vendor/codeberg.org/gruf/go-caller/caller.go

@@ -0,0 +1,136 @@
+package caller
+
+import (
+	"runtime"
+	"strings"
+	"sync/atomic"
+)
+
+var (
+	// callerCache caches PC values to string names.
+	// note this may be a little slower than Caller()
+	// calls on startup, but after all PCs are cached
+	// this should be ~3x faster + less GC overhead.
+	//
+	// see the following benchmark:
+	// goos: linux
+	// goarch: amd64
+	// pkg: codeberg.org/gruf/go-caller
+	// cpu: AMD Ryzen 7 7840U w/ Radeon  780M Graphics
+	// BenchmarkCallerCache
+	// BenchmarkCallerCache-16         16796982                66.19 ns/op           24 B/op          3 allocs/op
+	// BenchmarkNoCallerCache
+	// BenchmarkNoCallerCache-16        5486168               219.9 ns/op           744 B/op          6 allocs/op
+	callerCache atomic.Pointer[map[uintptr]string]
+
+	// stringCache caches strings to minimise string memory use
+	// by ensuring only 1 instance of the same func name string.
+	stringCache atomic.Pointer[map[string]string]
+)
+
+// Clear will empty the global caller PC -> func names cache.
+func Clear() { callerCache.Store(nil); stringCache.Store(nil) }
+
+// Name returns the calling function name for given
+// program counter, formatted to be useful for logging.
+func Name(pc uintptr) string {
+
+	// Get frame iterator for program counter.
+	frames := runtime.CallersFrames([]uintptr{pc})
+	if frames == nil {
+		return "???"
+	}
+
+	// Get func name from frame.
+	frame, _ := frames.Next()
+	name := frame.Function
+	if name == "" {
+		return "???"
+	}
+
+	// Drop all but package and function name, no path.
+	if idx := strings.LastIndex(name, "/"); idx >= 0 {
+		name = name[idx+1:]
+	}
+
+	const params = `[...]`
+
+	// Drop any function generic type parameter markers.
+	if idx := strings.Index(name, params); idx >= 0 {
+		name = name[:idx] + name[idx+len(params):]
+	}
+
+	return name
+}
+
+// Get will return calling func information for given PC value,
+// caching func names by their PC values to reduce calls to Caller().
+func Get(pc uintptr) string {
+	var cache map[uintptr]string
+	for {
+		// Load caller cache map.
+		ptr := callerCache.Load()
+
+		if ptr != nil {
+			// Look for stored name.
+			name, ok := (*ptr)[pc]
+			if ok {
+				return name
+			}
+
+			// Make a clone of existing caller cache map.
+			cache = make(map[uintptr]string, len(*ptr)+1)
+			for key, value := range *ptr {
+				cache[key] = value
+			}
+		} else {
+			// Allocate new caller cache map.
+			cache = make(map[uintptr]string, 1)
+		}
+
+		// Calculate caller
+		// name for PC value.
+		name := Name(pc)
+		name = getString(name)
+
+		// Store in map.
+		cache[pc] = name
+
+		// Attempt to update caller cache map pointer.
+		if callerCache.CompareAndSwap(ptr, &cache) {
+			return name
+		}
+	}
+}
+
+func getString(key string) string {
+	var cache map[string]string
+	for {
+		// Load string cache map.
+		ptr := stringCache.Load()
+
+		if ptr != nil {
+			// Check for existing string.
+			if str, ok := (*ptr)[key]; ok {
+				return str
+			}
+
+			// Make a clone of existing string cache map.
+			cache = make(map[string]string, len(*ptr)+1)
+			for key, value := range *ptr {
+				cache[key] = value
+			}
+		} else {
+			// Allocate new string cache map.
+			cache = make(map[string]string, 1)
+		}
+
+		// Store this str.
+		cache[key] = key
+
+		// Attempt to update string cache map pointer.
+		if stringCache.CompareAndSwap(ptr, &cache) {
+			return key
+		}
+	}
+}

vendor/codeberg.org/gruf/go-kv/v2/field_format.go

@@ -8,8 +8,6 @@ import (
 	"codeberg.org/gruf/go-kv/v2/format"
 )
 
-var formatter format.Formatter
-
 var argsDefault = format.DefaultArgs()
 
 var argsVerbose = func() format.Args {
@@ -29,7 +27,7 @@ func (f Field) AppendFormat(buf *byteutil.Buffer, vbose bool) {
 	}
 	AppendQuoteString(buf, f.K)
 	buf.WriteByte('=')
-	buf.B = formatter.Append(buf.B, f.V, args)
+	buf.B = format.Global.Append(buf.B, f.V, args)
 }
 
 // Value returns the formatted value string of this Field.
@@ -41,6 +39,6 @@ func (f Field) Value(vbose bool) string {
 		args = argsDefault
 	}
 	buf := make([]byte, 0, bufsize/2)
-	buf = formatter.Append(buf, f.V, args)
+	buf = format.Global.Append(buf, f.V, args)
 	return byteutil.B2S(buf)
 }

vendor/codeberg.org/gruf/go-kv/v2/format/abi.go

@@ -1,4 +1,4 @@
-//go:build go1.24 && !go1.25
+//go:build go1.24 && !go1.26
 
 package format
 
@@ -39,26 +39,36 @@ type abi_EmptyInterface struct {
 	Data unsafe.Pointer
 }
 
+// abi_NonEmptyInterface is a copy of the memory layout of abi.NonEmptyInterface{},
+// which is to say also the memory layout of any interface containing method(s).
+//
+// see: go/src/internal/abi/iface.go on 1.25+
+// see: go/src/reflect/value.go on 1.24
+type abi_NonEmptyInterface struct {
+	ITab uintptr
+	Data unsafe.Pointer
+}
+
 // see: go/src/internal/abi/type.go Type.Kind()
 func abi_Type_Kind(t reflect.Type) uint8 {
-	iface := (*reflect_nonEmptyInterface)(unsafe.Pointer(&t))
-	atype := (*abi_Type)(unsafe.Pointer(iface.word))
+	iface := (*abi_NonEmptyInterface)(unsafe.Pointer(&t))
+	atype := (*abi_Type)(unsafe.Pointer(iface.Data))
 	return atype.Kind_ & abi_KindMask
 }
 
 // see: go/src/internal/abi/type.go Type.IfaceIndir()
 func abi_Type_IfaceIndir(t reflect.Type) bool {
-	iface := (*reflect_nonEmptyInterface)(unsafe.Pointer(&t))
-	atype := (*abi_Type)(unsafe.Pointer(iface.word))
+	iface := (*abi_NonEmptyInterface)(unsafe.Pointer(&t))
+	atype := (*abi_Type)(unsafe.Pointer(iface.Data))
 	return atype.Kind_&abi_KindDirectIface == 0
 }
 
-// pack_iface packs a new reflect.nonEmptyInterface{} using shielded itab
-// pointer and data (word) pointer, returning a pointer for caller casting.
+// pack_iface packs a new reflect.nonEmptyInterface{} using shielded
+// itab and data pointer, returning a pointer for caller casting.
 func pack_iface(itab uintptr, word unsafe.Pointer) unsafe.Pointer {
-	return unsafe.Pointer(&reflect_nonEmptyInterface{
-		itab: itab,
-		word: word,
+	return unsafe.Pointer(&abi_NonEmptyInterface{
+		ITab: itab,
+		Data: word,
 	})
 }
 
@@ -68,8 +78,8 @@ func pack_iface(itab uintptr, word unsafe.Pointer) unsafe.Pointer {
 // this is useful for later calls to pack_iface for known type.
 func get_iface_ITab[I any](t reflect.Type) uintptr {
 	s := reflect.New(t).Elem().Interface().(I)
-	i := (*reflect_nonEmptyInterface)(unsafe.Pointer(&s))
-	return i.itab
+	i := (*abi_NonEmptyInterface)(unsafe.Pointer(&s))
+	return i.ITab
 }
 
 // unpack_eface returns the .Data portion of an abi.EmptyInterface{}.
@@ -162,15 +172,6 @@ func reflect_map_elem_flags(elemType reflect.Type) reflect_flag {
 	return reflect_flag(abi_Type_Kind(elemType))
 }
 
-// reflect_nonEmptyInterface is a copy of the memory layout of reflect.nonEmptyInterface,
-// which is also to say the memory layout of any non-empty (i.e. w/ method) interface.
-//
-// see: go/src/reflect/value.go
-type reflect_nonEmptyInterface struct {
-	itab uintptr
-	word unsafe.Pointer
-}
-
 // reflect_Value is a copy of the memory layout of reflect.Value{}.
 //
 // see: go/src/reflect/value.go
@@ -190,7 +191,7 @@ func init() {
 // as the reflect.nonEmptyInterface{}, which itself will be a pointer
 // to the actual abi.Type{} that this reflect.Type{} is wrapping.
 func reflect_type_data(t reflect.Type) unsafe.Pointer {
-	return (*reflect_nonEmptyInterface)(unsafe.Pointer(&t)).word
+	return (*abi_NonEmptyInterface)(unsafe.Pointer(&t)).Data
 }
 
 // build_reflect_value manually builds a reflect.Value{} by setting the internal field members.

vendor/codeberg.org/gruf/go-kv/v2/format/format.go

@@ -8,6 +8,9 @@ import (
 	"unsafe"
 )
 
+// Global formatter instance.
+var Global Formatter
+
 // FormatFunc defines a function capable of formatting
 // the value contained in State{}.P, based on args in
 // State{}.A, storing the result in buffer State{}.B.
@@ -48,7 +51,7 @@ const ringsz = 16
 
 // ptr_ring is a ring buffer of pointers,
 // purposely stored as uintptrs as all we
-// need them for is value comparisons and
+// need them for is integer comparisons and
 // we don't want to hold-up the GC.
 type ptr_ring struct {
 	p [ringsz]uintptr
@@ -296,38 +299,60 @@ func (fmt *Formatter) get(t typenode) (fn FormatFunc) {
 func (fmt *Formatter) getInterfaceType(t typenode) FormatFunc {
 	if t.rtype.NumMethod() == 0 {
 		return func(s *State) {
+			// Unpack empty interface.
 			eface := *(*any)(s.P)
 			s.P = unpack_eface(eface)
+
+			// Get reflected type information.
 			rtype := reflect.TypeOf(eface)
 			if rtype == nil {
 				appendNil(s)
 				return
 			}
+
+			// Check for ptr recursion.
 			if s.ifaces.contains(s.P) {
 				getPointerType(t)(s)
 				return
 			}
+
+			// Store value ptr.
 			s.ifaces.set(s.P)
+
+			// Wrap in our typenode for before load.
 			flags := reflect_iface_elem_flags(rtype)
 			t := new_typenode(rtype, flags)
+
+			// Load + pass to func.
 			fmt.loadOrStore(t)(s)
 		}
 	} else {
 		return func(s *State) {
+			// Unpack interface-with-method ptr.
 			iface := *(*interface{ M() })(s.P)
 			s.P = unpack_eface(iface)
+
+			// Get reflected type information.
 			rtype := reflect.TypeOf(iface)
 			if rtype == nil {
 				appendNil(s)
 				return
 			}
+
+			// Check for ptr recursion.
 			if s.ifaces.contains(s.P) {
 				getPointerType(t)(s)
 				return
 			}
+
+			// Store value ptr.
 			s.ifaces.set(s.P)
+
+			// Wrap in our typenode for before load.
 			flags := reflect_iface_elem_flags(rtype)
 			t := new_typenode(rtype, flags)
+
+			// Load + pass to func.
 			fmt.loadOrStore(t)(s)
 		}
 	}
@@ -360,14 +385,11 @@ func getIntType(t typenode) FormatFunc {
 			switch {
 			case s.A.AsNumber():
 				// fallthrough
-			case s.A.AsQuotedText():
-				s.B = strconv.AppendQuoteRune(s.B, *(*rune)(s.P))
-				return
 			case s.A.AsQuotedASCII():
 				s.B = strconv.AppendQuoteRuneToASCII(s.B, *(*rune)(s.P))
 				return
-			case s.A.AsText():
-				s.B = AppendEscapeRune(s.B, *(*rune)(s.P))
+			case s.A.AsText() || s.A.AsQuotedText():
+				s.B = strconv.AppendQuoteRune(s.B, *(*rune)(s.P))
 				return
 			}
 			appendInt(s, int64(*(*int32)(s.P)))
@@ -388,12 +410,9 @@ func getUintType(t typenode) FormatFunc {
 			switch {
 			case s.A.AsNumber():
 				// fallthrough
-			case s.A.AsQuotedText() || s.A.AsQuotedASCII():
+			case s.A.AsText() || s.A.AsQuotedText() || s.A.AsQuotedASCII():
 				s.B = AppendQuoteByte(s.B, *(*byte)(s.P))
 				return
-			case s.A.AsText():
-				s.B = AppendEscapeByte(s.B, *(*byte)(s.P))
-				return
 			}
 			appendUint(s, uint64(*(*uint8)(s.P)))
 		})
@@ -468,10 +487,17 @@ func with_typestr_ptrs(t typenode, fn FormatFunc) FormatFunc {
 	if fn == nil {
 		panic("nil func")
 	}
+
+	// Check for type wrapping.
 	if !t.needs_typestr() {
 		return fn
 	}
+
+	// Get type string with pointers.
 	typestr := t.typestr_with_ptrs()
+
+	// Wrap format func to include
+	// type information when needed.
 	return func(s *State) {
 		if s.A.WithType() {
 			s.B = append(s.B, "("+typestr+")("...)
@@ -485,7 +511,7 @@ func with_typestr_ptrs(t typenode, fn FormatFunc) FormatFunc {
 
 func appendString(s *State, v string) {
 	switch {
-	case s.A.Logfmt() || s.A.WithType():
+	case s.A.WithType():
 		if len(v) > SingleTermLine || !IsSafeASCII(v) {
 			// Requires quoting AND escaping
 			s.B = strconv.AppendQuote(s.B, v)
@@ -494,8 +520,22 @@ func appendString(s *State, v string) {
 			s.B = append(s.B, '"')
 			s.B = AppendEscape(s.B, v)
 			s.B = append(s.B, '"')
-		} else if s.A.WithType() ||
-			len(v) == 0 || ContainsSpaceOrTab(v) {
+		} else {
+			// All else, needs quotes
+			s.B = append(s.B, '"')
+			s.B = append(s.B, v...)
+			s.B = append(s.B, '"')
+		}
+	case s.A.Logfmt():
+		if len(v) > SingleTermLine || !IsSafeASCII(v) {
+			// Requires quoting AND escaping
+			s.B = strconv.AppendQuote(s.B, v)
+		} else if ContainsDoubleQuote(v) {
+			// Contains double quotes, needs escaping
+			s.B = append(s.B, '"')
+			s.B = AppendEscape(s.B, v)
+			s.B = append(s.B, '"')
+		} else if len(v) == 0 || ContainsSpaceOrTab(v) {
 			// Contains space / empty, needs quotes
 			s.B = append(s.B, '"')
 			s.B = append(s.B, v...)
@@ -515,75 +555,114 @@ func appendString(s *State, v string) {
 
 func appendInt(s *State, v int64) {
 	args := s.A.Int
+
+	// Set argument defaults.
 	if args == zeroArgs.Int {
 		args = defaultArgs.Int
 	}
+
+	// Add any padding.
 	if args.Pad > 0 {
 		const zeros = `00000000000000000000`
 		if args.Pad > len(zeros) {
 			panic("cannot pad > " + zeros)
 		}
+
 		if v == 0 {
 			s.B = append(s.B, zeros[:args.Pad]...)
 			return
 		}
+
+		// Get absolute.
 		abs := abs64(v)
+
+		// Get number of required chars.
 		chars := int(v / int64(args.Base))
 		if v%int64(args.Base) != 0 {
 			chars++
 		}
+
 		if abs != v {
+			// If this is a negative value,
+			// prepend minus ourselves and
+			// set value as the absolute.
 			s.B = append(s.B, '-')
 			v = abs
 		}
-		if n := args.Pad - chars; n > 0 {
-			s.B = append(s.B, zeros[:n]...)
-		}
+
+		// Prepend required zeros.
+		n := args.Pad - chars
+		s.B = append(s.B, zeros[:n]...)
 	}
+
+	// Append value as signed integer w/ args.
 	s.B = strconv.AppendInt(s.B, v, args.Base)
 }
 
 func appendUint(s *State, v uint64) {
 	args := s.A.Int
+
+	// Set argument defaults.
 	if args == zeroArgs.Int {
 		args = defaultArgs.Int
 	}
+
+	// Add any padding.
 	if args.Pad > 0 {
 		const zeros = `00000000000000000000`
 		if args.Pad > len(zeros) {
 			panic("cannot pad > " + zeros)
 		}
+
 		if v == 0 {
 			s.B = append(s.B, zeros[:args.Pad]...)
 			return
 		}
+
+		// Get number of required chars.
 		chars := int(v / uint64(args.Base))
 		if v%uint64(args.Base) != 0 {
 			chars++
 		}
-		if n := args.Pad - chars; n > 0 {
-			s.B = append(s.B, zeros[:n]...)
-		}
+
+		// Prepend required zeros.
+		n := args.Pad - chars
+		s.B = append(s.B, zeros[:n]...)
 	}
+
+	// Append value as unsigned integer w/ args.
 	s.B = strconv.AppendUint(s.B, v, args.Base)
 }
 
 func appendFloat(s *State, v float64, bits int) {
 	args := s.A.Float
+
+	// Set argument defaults.
 	if args == zeroArgs.Float {
 		args = defaultArgs.Float
 	}
-	s.B = strconv.AppendFloat(s.B, float64(v), args.Fmt, args.Prec, bits)
+
+	// Append value as float${bit} w/ args.
+	s.B = strconv.AppendFloat(s.B, float64(v),
+		args.Fmt, args.Prec, bits)
 }
 
 func appendComplex(s *State, r, i float64, bits int) {
 	args := s.A.Complex
+
+	// Set argument defaults.
 	if args == zeroArgs.Complex {
 		args = defaultArgs.Complex
 	}
-	s.B = strconv.AppendFloat(s.B, float64(r), args.Real.Fmt, args.Real.Prec, bits)
+
+	// Append real value as float${bit} w/ args.
+	s.B = strconv.AppendFloat(s.B, float64(r),
+		args.Real.Fmt, args.Real.Prec, bits)
 	s.B = append(s.B, '+')
-	s.B = strconv.AppendFloat(s.B, float64(i), args.Imag.Fmt, args.Imag.Prec, bits)
+
+	// Append imag value as float${bit} w/ args.
+	s.B = strconv.AppendFloat(s.B, float64(i),
+		args.Imag.Fmt, args.Imag.Prec, bits)
 	s.B = append(s.B, 'i')
 }
 

vendor/codeberg.org/gruf/go-kv/v2/format/methods.go

@@ -45,7 +45,7 @@ func getInterfaceStringerType(t typenode) FormatFunc {
 	case true:
 		return with_typestr_ptrs(t, func(s *State) {
 			s.P = *(*unsafe.Pointer)(s.P)
-			if s.P == nil || (*reflect_nonEmptyInterface)(s.P).word == nil {
+			if s.P == nil || (*abi_NonEmptyInterface)(s.P).Data == nil {
 				appendNil(s)
 				return
 			}
@@ -54,7 +54,7 @@ func getInterfaceStringerType(t typenode) FormatFunc {
 		})
 	case false:
 		return with_typestr_ptrs(t, func(s *State) {
-			if s.P == nil || (*reflect_nonEmptyInterface)(s.P).word == nil {
+			if s.P == nil || (*abi_NonEmptyInterface)(s.P).Data == nil {
 				appendNil(s)
 				return
 			}
@@ -102,7 +102,7 @@ func getInterfaceErrorType(t typenode) FormatFunc {
 	case true:
 		return with_typestr_ptrs(t, func(s *State) {
 			s.P = *(*unsafe.Pointer)(s.P)
-			if s.P == nil || (*reflect_nonEmptyInterface)(s.P).word == nil {
+			if s.P == nil || (*abi_NonEmptyInterface)(s.P).Data == nil {
 				appendNil(s)
 				return
 			}
@@ -111,7 +111,7 @@ func getInterfaceErrorType(t typenode) FormatFunc {
 		})
 	case false:
 		return with_typestr_ptrs(t, func(s *State) {
-			if s.P == nil || (*reflect_nonEmptyInterface)(s.P).word == nil {
+			if s.P == nil || (*abi_NonEmptyInterface)(s.P).Data == nil {
 				appendNil(s)
 				return
 			}

vendor/codeberg.org/gruf/go-kv/v2/util.go

@@ -17,8 +17,8 @@ func AppendQuoteString(buf *byteutil.Buffer, str string) {
 		return
 
 	case len(str) == 1:
-		// Append escaped single byte.
-		buf.B = format.AppendEscapeByte(buf.B, str[0])
+		// Append quoted escaped single byte.
+		buf.B = format.AppendQuoteByte(buf.B, str[0])
 		return
 
 	case len(str) > format.SingleTermLine || !format.IsSafeASCII(str):
@@ -62,7 +62,7 @@ func AppendQuoteValue(buf *byteutil.Buffer, str string) {
 		return
 
 	case len(str) == 1:
-		// Append quoted single byte.
+		// Append quoted escaped single byte.
 		buf.B = format.AppendQuoteByte(buf.B, str[0])
 		return
 

vendor/modules.txt

@@ -232,6 +232,9 @@ codeberg.org/gruf/go-byteutil
 codeberg.org/gruf/go-cache/v3
 codeberg.org/gruf/go-cache/v3/simple
 codeberg.org/gruf/go-cache/v3/ttl
+# codeberg.org/gruf/go-caller v0.0.0-20250806133437-db8d0b1f71cf
+## explicit; go 1.24.5
+codeberg.org/gruf/go-caller
 # codeberg.org/gruf/go-debug v1.3.0
 ## explicit; go 1.16
 codeberg.org/gruf/go-debug
@@ -255,7 +258,7 @@ codeberg.org/gruf/go-iotools
 ## explicit; go 1.20
 codeberg.org/gruf/go-kv
 codeberg.org/gruf/go-kv/format
-# codeberg.org/gruf/go-kv/v2 v2.0.3
+# codeberg.org/gruf/go-kv/v2 v2.0.5
 ## explicit; go 1.24
 codeberg.org/gruf/go-kv/v2
 codeberg.org/gruf/go-kv/v2/format