39 lines
801 B
Go
39 lines
801 B
Go
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package erasureencode
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import (
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"fmt"
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)
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func merkleSha256(inputHashes [][]byte) []byte {
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CHILD_NUM := 2
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hashesLen := len(inputHashes)
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if hashesLen == 0 {
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panic(fmt.Errorf("input must be at least one hash"))
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}
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hashLen := len(inputHashes[0])
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hashes := make([][]byte, hashesLen)
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copy(hashes, inputHashes)
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for true {
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for i := 0; i < hashesLen; i += CHILD_NUM {
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hashData := make([]byte, hashLen*CHILD_NUM)
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for j := 0; j < CHILD_NUM && i+j < hashesLen; j++ {
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copy(hashData[j*hashLen:], hashes[i+j])
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}
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hashes[i/CHILD_NUM] = sha256sum(hashData)
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}
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newLen := hashesLen / CHILD_NUM
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if hashesLen%CHILD_NUM > 0 {
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newLen += 1
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}
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hashes = hashes[0:newLen]
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hashesLen = newLen
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if hashesLen == 1 {
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return hashes[0]
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}
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}
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panic(fmt.Errorf("unexpected code path"))
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}
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