mirrors/kitty
1
0
Fork 0
mirror of https://github.com/kovidgoyal/kitty synced 2026-07-14 04:24:52 +02:00
Code Issues Packages Projects Releases Wiki Activity

Do not build decode table for base85 until it is actually needed

Browse Source 
Also make the tests actual tests
This commit is contained in:
Kovid Goyal
2023-09-04 21:32:25 +05:30
parent 0107d1cb89
commit 541c0cdde4
2 changed files with 75 additions and 66 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
tools/utils/base85/base85.go
View File

@@ -10,10 +10,11 @@ import (
"errors"
"io"
"strconv"
"sync"
)
// 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~
var b2c_table = [85]byte{
var encode = [85]byte{
// 0 1 2 3 4 5 6 7 8 9 A B C D E F
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, //0
0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, //1
@@ -23,22 +24,35 @@ var b2c_table = [85]byte{
0x60, 0x7B, 0x7C, 0x7D, 0x7E,
}
var encode [85]byte
var decode [256]byte
func init() {
copy(encode[:], b2c_table[:])
for i := 0; i < len(decode); i++ {
decode[i] = 0xFF
var decoder_array = sync.OnceValue(func() [256]byte {
var decode = [256]byte{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
}
for i := 0; i < len(encode); i++ {
decode[encode[i]] = byte(i)
}
}
return decode
})
// encodeChunk encodes 4 byte-chunk to 5 byte
// if chunk size is less then 4, then it is padded before convertion.
// return written bytes or error
// if chunk size is less then 4, then it is padded before encoding.
// return written bytes
func encodeChunk(dst, src []byte) int {
if len(src) == 0 {
return 0
@@ -78,7 +92,7 @@ var decode_base = [5]uint32{85 * 85 * 85 * 85, 85 * 85 * 85, 85 * 85, 85, 1}
// decodeChunk decodes 5 byte-chunk to 4 byte
// if chunk size is less then 5, then it is padded before convertion.
// return written bytes and error input index
func decodeChunk(dst, src []byte) (int, int) {
func decodeChunk(decode *[256]byte, dst, src []byte) (int, int) {
if len(src) == 0 {
return 0, 0
}
@@ -150,16 +164,17 @@ func DecodeString(src string) ([]byte, error) {
func Decode(dst, src []byte) (int, error) {
f := 0
t := 0
decode := decoder_array()
for len(src) > 0 {
if len(src) < 5 {
w, err := decodeChunk(dst, src)
w, err := decodeChunk(&decode, dst, src)
if err > 0 {
return t, CorruptInputError(f + err)
}
return t + w, nil
}
_, err := decodeChunk(dst[:4], src[:5])
_, err := decodeChunk(&decode, dst[:4], src[:5])
if err > 0 {
return t, CorruptInputError(f + err)
} else {

98
tools/utils/base85/base85_test.go
View File

@@ -1,60 +1,54 @@
package base85
import (
"testing"
"fmt"
"testing"
"github.com/google/go-cmp/cmp"
)
func TestChunked (t *testing.T) {
a := []byte("M")
fmt.Printf("a %#v\n", a)
b := make([]byte, EncodedLen(len(a)))
encodeChunk(b, a)
fmt.Printf("b %#v\n", b)
c := make([]byte, DecodedLen(len(b)))
decodeChunk(c, b)
fmt.Printf("c %#v\n", c)
var _ = fmt.Print
a = []byte("Ma")
fmt.Printf("a %#v\n", a)
b = make([]byte, EncodedLen(len(a)))
encodeChunk(b, a)
fmt.Printf("b %#v\n", b)
c = make([]byte, DecodedLen(len(b)))
decodeChunk(c, b)
fmt.Printf("c %#v\n", c)
a = []byte("Man")
fmt.Printf("a %#v\n", a)
b = make([]byte, EncodedLen(len(a)))
encodeChunk(b, a)
fmt.Printf("b %#v\n", b)
c = make([]byte, DecodedLen(len(b)))
decodeChunk(c, b)
fmt.Printf("c %#v\n", c)
a = []byte("Man ")
fmt.Printf("a %#v\n", a)
b = make([]byte, EncodedLen(len(a)))
encodeChunk(b, a)
fmt.Printf("b %#v\n", b)
c = make([]byte, DecodedLen(len(b)))
decodeChunk(c, b)
fmt.Printf("c %#v\n", c)
a = []byte("Manual")
fmt.Printf("a %#v\n", a)
b = make([]byte, EncodedLen(len(a)))
n := Encode(b, a)
fmt.Printf("b %#v %d\n", b, n)
c = make([]byte, DecodedLen(len(b)))
n, _ = Decode(c, b)
fmt.Printf("c %#v %d\n", c, n)
a = []byte("Manual")
fmt.Printf("a %s\n", a)
sb := EncodeToString(a) + "\""
fmt.Printf("b %#v\n", sb)
sc, err := DecodeString(sb)
fmt.Printf("c %s %s\n", sc, err)
type pair struct {
src, encoded string
}
func TestBase85(t *testing.T) {
dst, dst2 := [8]byte{}, [8]byte{}
decode := decoder_array()
var el int
for _, x := range []string{"M", "Ma", "Man", "Man "} {
a := []byte(x)
if el = encodeChunk(dst[:], a); el != EncodedLen(len(a)) {
t.Fatalf("Encoded len for %#v wrong: %d != %d", x, el, EncodedLen(len(a)))
}
encoded := dst[:el]
dl, bad_idx := decodeChunk(&decode, dst2[:], encoded)
if bad_idx != 0 {
t.Fatalf("Decode for %#v returned bad data at: %d (%#v)", x, bad_idx, encoded)
}
if dl != DecodedLen(len(encoded)) {
t.Fatalf("Decoded len for %#v wrong: %d != %d", x, dl, DecodedLen(len(a)))
}
decoded := string(dst2[:dl])
if diff := cmp.Diff(x, decoded); diff != "" {
t.Fatalf("Roundtrip failed for %#v: %s", x, diff)
}
}
for _, p := range []pair{
{"M", "O#"},
{"Manual", "O<`_zVQc"},
} {
q := EncodeToString([]byte(p.src))
if diff := cmp.Diff(p.encoded, q); diff != "" {
t.Fatalf("Incorrect encoding of: %#v\n%s", p.src, diff)
}
sc, err := DecodeString(q)
if err != nil {
t.Fatalf("Failed to decode %#v with error: %s", p.src, err)
}
if diff := cmp.Diff(p.src, string(sc)); diff != "" {
t.Fatalf("Failed to roundtrip %#v\n%s", p.src, diff)
}
}
}