81 lines
1.4 KiB
Go
81 lines
1.4 KiB
Go
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package metainfo
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import (
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"crypto/sha1"
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"encoding"
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"encoding/hex"
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"fmt"
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)
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const HashSize = 20
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// 20-byte SHA1 hash used for info and pieces.
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type Hash [HashSize]byte
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var _ fmt.Formatter = (*Hash)(nil)
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func (h Hash) Format(f fmt.State, c rune) {
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// TODO: I can't figure out a nice way to just override the 'x' rune, since it's meaningless
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// with the "default" 'v', or .String() already returning the hex.
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f.Write([]byte(h.HexString()))
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}
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func (h Hash) Bytes() []byte {
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return h[:]
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}
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func (h Hash) AsString() string {
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return string(h[:])
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}
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func (h Hash) String() string {
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return h.HexString()
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}
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func (h Hash) HexString() string {
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return fmt.Sprintf("%x", h[:])
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}
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func (h *Hash) FromHexString(s string) (err error) {
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if len(s) != 2*HashSize {
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err = fmt.Errorf("hash hex string has bad length: %d", len(s))
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return
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}
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n, err := hex.Decode(h[:], []byte(s))
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if err != nil {
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return
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}
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if n != HashSize {
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panic(n)
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}
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return
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}
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var (
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_ encoding.TextUnmarshaler = (*Hash)(nil)
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_ encoding.TextMarshaler = Hash{}
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)
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func (h *Hash) UnmarshalText(b []byte) error {
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return h.FromHexString(string(b))
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}
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func (h Hash) MarshalText() (text []byte, err error) {
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return []byte(h.HexString()), nil
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}
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func NewHashFromHex(s string) (h Hash) {
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err := h.FromHexString(s)
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if err != nil {
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panic(err)
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}
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return
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}
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func HashBytes(b []byte) (ret Hash) {
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hasher := sha1.New()
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hasher.Write(b)
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copy(ret[:], hasher.Sum(nil))
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return
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}
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