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https://github.com/logos-storage/nim-poseidon2.git
synced 2026-01-03 22:23:07 +00:00
46 lines
1.2 KiB
Nim
46 lines
1.2 KiB
Nim
import std/sequtils
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import constantine/math/arithmetic
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import constantine/math/io/io_fields
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import ./types
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import ./io
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import ./compress
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const KeyNone = F.fromHex("0x0")
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const KeyBottomLayer = F.fromHex("0x1")
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const KeyOdd = F.fromHex("0x2")
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const KeyOddAndBottomLayer = F.fromhex("0x3")
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func merkleRoot(xs: openArray[F], isBottomLayer: static bool) : F =
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let a = low(xs)
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let b = high(xs)
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let m = b-a+1
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if m==1 and not isBottomLayer:
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return xs[a]
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else:
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let halfn : int = m div 2
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let n : int = 2*halfn
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let isOdd : bool = (n != m)
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var ys : seq[F]
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if not isOdd:
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ys = newSeq[F](halfn)
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else:
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ys = newSeq[F](halfn+1)
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for i in 0..<halfn:
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const key = when isBottomLayer: KeyBottomLayer else: KeyNone
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ys[i] = compress( xs[a+2*i], xs[a+2*i+1], key = key )
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if isOdd:
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const key = when isBottomLayer: KeyOddAndBottomLayer else: KeyOdd
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ys[halfn] = compress( xs[n], zero, key = key )
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return merkleRoot(ys, isBottomLayer = false)
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func merkleRoot*(xs: openArray[F]) : F =
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merkleRoot(xs, isBottomLayer = true)
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func merkleRoot*(bytes: openArray[byte]): F =
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merkleRoot(toSeq bytes.elements(F))
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