49 lines
890 B
Go
49 lines
890 B
Go
package mpt
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// lcp returns longest common prefix of a and b.
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// Note: it does no allocations.
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func lcp(a, b []byte) []byte {
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if len(a) < len(b) {
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return lcp(b, a)
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}
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var i int
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for i = 0; i < len(b); i++ {
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if a[i] != b[i] {
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break
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}
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}
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return a[:i]
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}
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func lcpMany(kv []keyValue) []byte {
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if len(kv) == 1 {
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return kv[0].key
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}
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p := lcp(kv[0].key, kv[1].key)
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if len(p) == 0 {
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return p
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}
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for i := range kv[2:] {
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p = lcp(p, kv[2+i].key)
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}
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return p
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}
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// copySlice is a helper for copying slice if needed.
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func copySlice(a []byte) []byte {
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b := make([]byte, len(a))
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copy(b, a)
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return b
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}
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// toNibbles mangles path by splitting every byte into 2 containing low- and high- 4-byte part.
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func toNibbles(path []byte) []byte {
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result := make([]byte, len(path)*2)
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for i := range path {
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result[i*2] = path[i] >> 4
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result[i*2+1] = path[i] & 0x0F
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}
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return result
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}
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