forked from Shiloh/githaven
c18d8d6968
Go 1.17 and later use modern `//go:build` constraints, the old `// +build:` constraints should be removed.
63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
// Copyright 2015 The Gogs Authors. All rights reserved.
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// Copyright 2019 The Gitea Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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//go:build !gogit
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package git
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import (
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"crypto/sha1"
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"encoding/hex"
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"hash"
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"strconv"
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)
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// SHA1 a git commit name
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type SHA1 [20]byte
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// String returns a string representation of the SHA
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func (s SHA1) String() string {
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return hex.EncodeToString(s[:])
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}
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// IsZero returns whether this SHA1 is all zeroes
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func (s SHA1) IsZero() bool {
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var empty SHA1
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return s == empty
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}
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// ComputeBlobHash compute the hash for a given blob content
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func ComputeBlobHash(content []byte) SHA1 {
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return ComputeHash(ObjectBlob, content)
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}
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// ComputeHash compute the hash for a given ObjectType and content
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func ComputeHash(t ObjectType, content []byte) SHA1 {
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h := NewHasher(t, int64(len(content)))
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_, _ = h.Write(content)
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return h.Sum()
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}
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// Hasher is a struct that will generate a SHA1
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type Hasher struct {
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hash.Hash
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}
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// NewHasher takes an object type and size and creates a hasher to generate a SHA
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func NewHasher(t ObjectType, size int64) Hasher {
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h := Hasher{sha1.New()}
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_, _ = h.Write(t.Bytes())
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_, _ = h.Write([]byte(" "))
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_, _ = h.Write([]byte(strconv.FormatInt(size, 10)))
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_, _ = h.Write([]byte{0})
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return h
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}
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// Sum generates a SHA1 for the provided hash
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func (h Hasher) Sum() (sha1 SHA1) {
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copy(sha1[:], h.Hash.Sum(nil))
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return
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}
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