nim-codex/codex/merkletree/coders.nim

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## Nim-Codex
## Copyright (c) 2023 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
import pkg/libp2p
import pkg/questionable
import pkg/questionable/results
import ./merkletree
import ../units
import ../errors
const MaxMerkleTreeSize = 100.MiBs.uint
const MaxMerkleProofSize = 1.MiBs.uint
proc encode*(self: MerkleTree): seq[byte] =
var pb = initProtoBuffer(maxSize = MaxMerkleTreeSize)
pb.write(1, self.mcodec.uint64)
pb.write(2, self.digestSize.uint64)
pb.write(3, self.leavesCount.uint64)
pb.write(4, self.nodesBuffer)
pb.finish
pb.buffer
proc decode*(_: type MerkleTree, data: seq[byte]): ?!MerkleTree =
var pb = initProtoBuffer(data, maxSize = MaxMerkleTreeSize)
var mcodecCode: uint64
var digestSize: uint64
var leavesCount: uint64
discard ? pb.getField(1, mcodecCode).mapFailure
discard ? pb.getField(2, digestSize).mapFailure
discard ? pb.getField(3, leavesCount).mapFailure
let mcodec = MultiCodec.codec(cast[int](mcodecCode))
if mcodec == InvalidMultiCodec:
return failure("Invalid MultiCodec code " & $cast[int](mcodec))
var nodesBuffer = newSeq[byte]()
discard ? pb.getField(4, nodesBuffer).mapFailure
let tree = ? MerkleTree.init(mcodec, digestSize, leavesCount, nodesBuffer)
success(tree)
proc encode*(self: MerkleProof): seq[byte] =
var pb = initProtoBuffer(maxSize = MaxMerkleProofSize)
pb.write(1, self.mcodec.uint64)
pb.write(2, self.digestSize.uint64)
pb.write(3, self.index.uint64)
pb.write(4, self.nodesBuffer)
pb.finish
pb.buffer
proc decode*(_: type MerkleProof, data: seq[byte]): ?!MerkleProof =
var pb = initProtoBuffer(data, maxSize = MaxMerkleProofSize)
var mcodecCode: uint64
var digestSize: uint64
var index: uint64
discard ? pb.getField(1, mcodecCode).mapFailure
discard ? pb.getField(2, digestSize).mapFailure
discard ? pb.getField(3, index).mapFailure
let mcodec = MultiCodec.codec(cast[int](mcodecCode))
if mcodec == InvalidMultiCodec:
return failure("Invalid MultiCodec code " & $cast[int](mcodec))
var nodesBuffer = newSeq[byte]()
discard ? pb.getField(4, nodesBuffer).mapFailure
let proof = ? MerkleProof.init(mcodec, digestSize, index, nodesBuffer)
success(proof)