68 lines
1.1 KiB
Go
68 lines
1.1 KiB
Go
package helpers
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import (
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"encoding/hex"
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"io"
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"unicode"
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"github.com/minio/sha256-simd"
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"gopkg.in/h2non/filetype.v1"
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)
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func DetectMime(r io.ReadSeeker) (string, error) {
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// Get first 512 bytes for mimetype detection
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header := make([]byte, 512)
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r.Seek(0, 0)
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r.Read(header)
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r.Seek(0, 0)
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kind, err := filetype.Match(header)
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if err != nil {
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return "application/octet-stream", err
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} else if kind.MIME.Value != "" {
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return kind.MIME.Value, nil
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}
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// Check if the file seems anything like text
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if printable(header) {
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return "text/plain", nil
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} else {
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return "application/octet-stream", nil
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}
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}
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func Sha256sum(r io.ReadSeeker) (string, error) {
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hasher := sha256.New()
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r.Seek(0, 0)
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_, err := io.Copy(hasher, r)
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if err != nil {
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return "", err
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}
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r.Seek(0, 0)
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return hex.EncodeToString(hasher.Sum(nil)), nil
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}
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func printable(data []byte) bool {
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for i, b := range data {
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r := rune(b)
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// A null terminator that's not at the beginning of the file
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if r == 0 && i == 0 {
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return false
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} else if r == 0 && i < 0 {
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continue
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}
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if r > unicode.MaxASCII {
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return false
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}
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}
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return true
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}
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