81 lines
1.9 KiB
Go
81 lines
1.9 KiB
Go
package nomino
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import (
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"crypto/md5"
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"crypto/sha1"
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"crypto/sha256"
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"errors"
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"fmt"
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"hash"
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"github.com/gosimple/slug"
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)
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// ErrMissingOriginal is the error returned by Slug if there is no filename
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var ErrMissingOriginal = errors.New("missing original filename")
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func getOriginal(c *Config) (string, error) {
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if c.original == "" {
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return "", ErrMissingOriginal
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}
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name := c.original
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c.original = ""
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return name, nil
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}
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// Slug generates a name from the original filename.
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// When this is used, the original filename will be removed from the final filename.
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// If a language is specified, that may affect the resulting slug.
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func Slug(lang ...string) Generator {
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ret := slug.Make
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if len(lang) > 0 {
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ret = func(in string) string {
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return slug.MakeLang(in, lang[0])
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}
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}
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return func(c *Config) (string, error) {
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name, err := getOriginal(c)
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return ret(name), err
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}
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}
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// HashingFunc is a function that generates a hash.Hash
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type HashingFunc func() hash.Hash
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//go:generate stringer -type=HashType -trimprefix=Hash
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// HashType represents a particular hashing algorithm
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type HashType uint8
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const (
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HashMD5 HashType = iota + 1
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HashSHA1
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HashSHA256
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)
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// ErrInvalidHashType is returned by the Hash generator when an invalid HashType is passed
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var ErrInvalidHashType = errors.New("invalid hash type")
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var hashMap = map[HashType]HashingFunc{
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HashMD5: md5.New,
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HashSHA1: sha1.New,
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HashSHA256: sha256.New,
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}
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// Hash generates a name from a hash of the filename.
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// When this is used, the original filename will be removed from the final filename.
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func Hash(t HashType) Generator {
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f, ok := hashMap[t]
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return func(c *Config) (string, error) {
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if !ok {
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return "", fmt.Errorf("%w: %s", ErrInvalidHashType, t)
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}
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name, err := getOriginal(c)
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if err != nil {
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return "", err
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}
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hs := f()
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hs.Write([]byte(name))
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return fmt.Sprintf("%x", hs.Sum(nil)), nil
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}
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}
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