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| author | 2021-08-12 21:03:24 +0200 | |
|---|---|---|
| committer | 2021-08-12 21:03:24 +0200 | |
| commit | 98263a7de64269898a2f81207e38943b5c8e8653 (patch) | |
| tree | 743c90f109a6c5d27832d1dcef2388d939f0f77a /vendor/github.com/buckket/go-blurhash/base83 | |
| parent | Text duplication fix (#137) (diff) | |
| download | gotosocial-98263a7de64269898a2f81207e38943b5c8e8653.tar.xz | |
Grand test fixup (#138)
* start fixing up tests
* fix up tests + automate with drone
* fiddle with linting
* messing about with drone.yml
* some more fiddling
* hmmm
* add cache
* add vendor directory
* verbose
* ci updates
* update some little things
* update sig
Diffstat (limited to 'vendor/github.com/buckket/go-blurhash/base83')
| -rw-r--r-- | vendor/github.com/buckket/go-blurhash/base83/base83.go | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/vendor/github.com/buckket/go-blurhash/base83/base83.go b/vendor/github.com/buckket/go-blurhash/base83/base83.go new file mode 100644 index 000000000..6d1882811 --- /dev/null +++ b/vendor/github.com/buckket/go-blurhash/base83/base83.go @@ -0,0 +1,58 @@ +package base83 + +import ( + "fmt" + "math" + "strings" +) + +const characters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~" + +// An InvalidCharacterError occurs when a characters is found which is not part of the Base83 character set. +type InvalidCharacterError rune + +func (e InvalidCharacterError) Error() string { + return fmt.Sprintf("base83: invalid string (character %q out of range)", rune(e)) +} + +// An InvalidLengthError occurs when a given value cannot be encoded to a string of given length. +type InvalidLengthError int + +func (e InvalidLengthError) Error() string { + return fmt.Sprintf("base83: invalid length (%d)", int(e)) +} + +// Encode will encode the given integer value to a Base83 string with given length. +// If length is too short to encode the given value InvalidLengthError will be returned. +func Encode(value, length int) (string, error) { + divisor := int(math.Pow(83, float64(length))) + if value/divisor != 0 { + return "", InvalidLengthError(length) + } + divisor /= 83 + + var str strings.Builder + str.Grow(length) + for i := 0; i < length; i++ { + if divisor <= 0 { + return "", InvalidLengthError(length) + } + digit := (value / divisor) % 83 + divisor /= 83 + str.WriteRune(rune(characters[digit])) + } + + return str.String(), nil +} + +// Decode will decode the given Base83 string to an integer. +func Decode(str string) (value int, err error) { + for _, r := range str { + idx := strings.IndexRune(characters, r) + if idx == -1 { + return 0, InvalidCharacterError(r) + } + value = value*83 + idx + } + return value, nil +} |
