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hash.go
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hash.go
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package crc32
import "hash"
// crc32 hash
type Hash32 interface {
hash.Hash
Sum32() uint32
}
// 大小
const Size = 4
type digest struct {
sum uint32
table *Table
}
// Write
func (this *digest) Write(data []byte) (int, error) {
this.sum = this.table.Update(this.sum, data)
return len(data), nil
}
// Sum
func (this *digest) Sum(b []byte) []byte {
s := this.Sum32()
return append(b, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
}
// Reset
func (this *digest) Reset() {
this.sum = this.table.params.Init
}
// Size
func (this *digest) Size() int {
return Size
}
// BlockSize
func (this *digest) BlockSize() int {
return 1
}
// Sum32
func (this *digest) Sum32() uint32 {
return this.table.Complete(this.sum)
}
// 构造函数
func NewHash(table *Table) Hash32 {
h := &digest{
table: table,
}
h.Reset()
return h
}