Reduce String() allocations

base32/base32.go

@@ -34,13 +34,17 @@ func EncodeLower(src [16]byte) string {
 	return Encode(src, alphLow)
 }
 
-// Encode encodes the src [16]byte into a base32 string with the given alphabet.
-// The alphabet must be 32 bytes long. If the alphabet is shorter, the function
-// will panic. It's the callers responsiblity to ensure the alphabet is valid.
-//
-// Direct usage is discouraged. Use EncodeUpper or EncodeLower instead.
-func Encode(src [16]byte, alphabet string) string {
-	dst := make([]byte, 26)
+// EncodeLowerTo encodes the src [16]byte into a provided 26-byte buffer using uppercase letters.
+func EncodeUpperTo(dst []byte, src [16]byte) {
+	EncodeTo(dst, src, alphUp)
+}
+
+// EncodeLowerTo encodes the src [16]byte into a provided 26-byte buffer using lowercase letters.
+func EncodeLowerTo(dst []byte, src [16]byte) {
+	EncodeTo(dst, src, alphLow)
+}
+
+func EncodeTo(dst []byte, src [16]byte, alphabet string) {
 	// Optimized unrolled loop ahead.
 
 	// 10 byte timestamp
@@ -72,7 +76,16 @@ func Encode(src [16]byte, alphabet string) string {
 	dst[23] = alphabet[(src[14]&124)>>2]
 	dst[24] = alphabet[((src[14]&3)<<3)|((src[15]&224)>>5)]
 	dst[25] = alphabet[src[15]&31]
+}
 
+// Encode encodes the src [16]byte into a base32 string with the given alphabet.
+// The alphabet must be 32 bytes long. If the alphabet is shorter, the function
+// will panic. It's the callers responsiblity to ensure the alphabet is valid.
+//
+// Direct usage is discouraged. Use EncodeUpper or EncodeLower instead.
+func Encode(src [16]byte, alphabet string) string {
+	dst := make([]byte, 26)
+	EncodeTo(dst, src, alphabet)
 	return string(dst)
 }
 

benchmark/benchmark_test.go

@@ -86,6 +86,7 @@ func BenchmarkFromString(b *testing.B) {
 func benchStringRandom(n int) (string, func(*testing.B)) {
 	ids := makeSortableIDs(n)
 	return fmt.Sprintf("n=%d", n), func(b *testing.B) {
+		b.ResetTimer()
 		b.ReportAllocs()
 		for i := 0; i < b.N; i++ {
 			for idx := range ids {
@@ -99,6 +100,7 @@ func benchStringRandom(n int) (string, func(*testing.B)) {
 func benchStringSortable(n int) (string, func(*testing.B)) {
 	ids := makeSortableIDs(n)
 	return fmt.Sprintf("n=%d", n), func(b *testing.B) {
+		b.ResetTimer()
 		b.ReportAllocs()
 		for i := 0; i < b.N; i++ {
 			for idx := range ids {
@@ -112,6 +114,7 @@ func benchStringSortable(n int) (string, func(*testing.B)) {
 func benchStringJp(n int) (string, func(*testing.B)) {
 	ids := makeJpTypeIDs(n)
 	return fmt.Sprintf("n=%d", n), func(b *testing.B) {
+		b.ResetTimer()
 		b.ReportAllocs()
 		for i := 0; i < b.N; i++ {
 			for idx := range ids {

benchmark/go.mod

@@ -4,12 +4,14 @@ go 1.21.6
 
 toolchain go1.21.7
 
-require github.com/sumup/typeid v0.0.0-20240207125954-757b87eaff3c
+replace github.com/sumup/typeid => ../
+
+require (
+	github.com/sumup/typeid v0.0.0-20240207125954-757b87eaff3c
+	go.jetpack.io/typeid v1.0.0
+)
 
 require (
 	github.com/gofrs/uuid/v5 v5.0.0 // indirect
 	github.com/jackc/pgx/v5 v5.5.3 // indirect
-	go.jetpack.io/typeid v1.0.0 // indirect
-	golang.org/x/crypto v0.18.0 // indirect
-	golang.org/x/sync v0.5.0 // indirect
 )

benchmark/go.sum

@@ -14,16 +14,12 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
-github.com/sumup/typeid v0.0.0-20240207125954-757b87eaff3c h1:jHCDCEs+alb1DCheUJxR7IlXKr6Qn7cFUBVoZrxZoyQ=
-github.com/sumup/typeid v0.0.0-20240207125954-757b87eaff3c/go.mod h1:gMQ6rvv9//+PumvkKu1tAOyXW/u9Pwg1dkbPWhQ62vk=
-go.jetpack.io/typeid v0.1.0 h1:suTmjNR3y2em2gCTG06agFfcACm3+zuxfziMUk5UXnw=
-go.jetpack.io/typeid v0.1.0/go.mod h1:E11ObFkKlvsSTxwwYIm+zpbsRthjIMDy/JGBogs2vSo=
 go.jetpack.io/typeid v1.0.0 h1:8gQ+iYGdyiQ0Pr40ydSB/PzMOIwlXX5DTojp1CBeSPQ=
 go.jetpack.io/typeid v1.0.0/go.mod h1:+UPEaECUgFxgAjFPn5Yf9eO/3ft/3xZ98Eahv9JW/GQ=
 golang.org/x/crypto v0.18.0 h1:PGVlW0xEltQnzFZ55hkuX5+KLyrMYhHld1YHO4AKcdc=
 golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1mg=
-golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
-golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/sync v0.6.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=

generate.go

@@ -2,6 +2,7 @@ package typeid
 
 import (
 	"fmt"
+	"unsafe"
 
 	"github.com/gofrs/uuid/v5"
 )
@@ -11,6 +12,8 @@ import (
 type processor struct {
 	// b32Encode applies a base32 encoding to a UUID.
 	b32Encode func(uuid.UUID) string
+	// b32EncodeTo applies a base32 encoding to a UUID and copies the result into a provided 26-byte buffer.
+	b32EncodeTo func([]byte, uuid.UUID)
 	// b32Decode decode a UUID using the resp. base32 decoding.
 	b32Decode func(string) (uuid.UUID, error)
 	// Generates a new universal unique identifer.
@@ -89,5 +92,11 @@ func toString[P Prefix](suffix uuid.UUID, p *processor) string {
 	if prefix == "" {
 		return p.b32Encode(suffix)
 	}
-	return prefix + "_" + p.b32Encode(suffix)
+
+	buf := make([]byte, len(prefix)+1+suffixStrLen)
+	copy(buf, prefix)
+	copy(buf[len(prefix):], "_")
+	p.b32EncodeTo(buf[len(prefix)+1:], suffix)
+
+	return unsafe.String(unsafe.SliceData(buf), len(buf))
 }

random.go

@@ -16,6 +16,9 @@ var randomIDProc = &processor{
 	b32Encode: func(u uuid.UUID) string {
 		return base32.EncodeUpper([16]byte(u))
 	},
+	b32EncodeTo: func(dst []byte, u uuid.UUID) {
+		base32.EncodeUpperTo(dst, [16]byte(u))
+	},
 	b32Decode: func(s string) (uuid.UUID, error) {
 		decoded, err := base32.DecodeUpper(s)
 		if err != nil {

sortable.go

@@ -16,6 +16,9 @@ var sortableIDProc = &processor{
 	b32Encode: func(u uuid.UUID) string {
 		return base32.EncodeLower([16]byte(u))
 	},
+	b32EncodeTo: func(dst []byte, u uuid.UUID) {
+		base32.EncodeLowerTo(dst, [16]byte(u))
+	},
 	b32Decode: func(s string) (uuid.UUID, error) {
 		decoded, err := base32.DecodeLower(s)
 		if err != nil {