mirror of https://github.com/aptly-dev/aptly
78 lines
1.5 KiB
Go
78 lines
1.5 KiB
Go
package utils
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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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"fmt"
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"hash"
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"io"
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"os"
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)
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// ChecksumInfo represents checksums for a single file
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type ChecksumInfo struct {
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Size int64
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MD5 string
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SHA1 string
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SHA256 string
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}
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// ChecksumsForFile generates size, MD5, SHA1 & SHA256 checksums for given file
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func ChecksumsForFile(path string) (ChecksumInfo, error) {
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file, err := os.Open(path)
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if err != nil {
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return ChecksumInfo{}, err
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}
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defer file.Close()
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w := NewChecksumWriter()
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_, err = io.Copy(w, file)
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if err != nil {
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return ChecksumInfo{}, err
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}
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return w.Sum(), nil
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}
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// ChecksumWriter is a writer that does checksum calculation on the fly passing data
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// to real writer
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type ChecksumWriter struct {
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w io.Writer
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sum ChecksumInfo
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hashes []hash.Hash
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}
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// Interface check
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var (
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_ io.Writer = &ChecksumWriter{}
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)
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// NewChecksumWriter creates checksum calculator for given writer w
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func NewChecksumWriter() *ChecksumWriter {
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return &ChecksumWriter{
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hashes: []hash.Hash{md5.New(), sha1.New(), sha256.New()},
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}
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}
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// Write implememnts pass-through writing with checksum calculation on the fly
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func (c *ChecksumWriter) Write(p []byte) (n int, err error) {
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c.sum.Size += int64(len(p))
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for _, h := range c.hashes {
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h.Write(p)
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}
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return len(p), nil
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}
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// Sum returns caculated ChecksumInfo
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func (c *ChecksumWriter) Sum() ChecksumInfo {
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c.sum.MD5 = fmt.Sprintf("%x", c.hashes[0].Sum(nil))
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c.sum.SHA1 = fmt.Sprintf("%x", c.hashes[1].Sum(nil))
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c.sum.SHA256 = fmt.Sprintf("%x", c.hashes[2].Sum(nil))
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return c.sum
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}
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