157 lines
3.2 KiB
Nim
157 lines
3.2 KiB
Nim
## Nim-Codex
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## Copyright (c) 2021 Status Research & Development GmbH
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## Licensed under either of
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## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
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## * MIT license ([LICENSE-MIT](LICENSE-MIT))
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## at your option.
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## This file may not be copied, modified, or distributed except according to
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## those terms.
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import std/tables
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export tables
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import pkg/upraises
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push: {.upraises: [].}
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import pkg/libp2p
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import pkg/stew/byteutils
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import pkg/questionable
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import pkg/questionable/results
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import ./errors
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template EmptyCid*: untyped =
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var
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emptyCid {.global, threadvar.}:
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array[CIDv0..CIDv1, Table[MultiCodec, Cid]]
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once:
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emptyCid = [
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CIDv0: {
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multiCodec("sha2-256"): Cid
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.init("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n")
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.get()
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}.toTable,
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CIDv1: {
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multiCodec("sha2-256"): Cid
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.init("bafybeihdwdcefgh4dqkjv67uzcmw7ojee6xedzdetojuzjevtenxquvyku")
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.get()
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}.toTable,
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]
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emptyCid
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template EmptyDigests*: untyped =
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var
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emptyDigests {.global, threadvar.}:
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array[CIDv0..CIDv1, Table[MultiCodec, MultiHash]]
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once:
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emptyDigests = [
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CIDv0: {
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multiCodec("sha2-256"): EmptyCid[CIDv0]
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.catch
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.get()[multiCodec("sha2-256")]
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.catch
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.get()
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.mhash
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.get()
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}.toTable,
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CIDv1: {
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multiCodec("sha2-256"): EmptyCid[CIDv0]
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.catch
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.get()[multiCodec("sha2-256")]
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.catch
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.get()
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.mhash
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.get()
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}.toTable,
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]
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emptyDigests
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template EmptyBlock*: untyped =
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var
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emptyBlock {.global, threadvar.}:
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array[CIDv0..CIDv1, Table[MultiCodec, Block]]
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once:
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emptyBlock = [
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CIDv0: {
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multiCodec("sha2-256"): Block(
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cid: EmptyCid[CIDv1][multiCodec("sha2-256")])
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}.toTable,
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CIDv1: {
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multiCodec("sha2-256"): Block(
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cid: EmptyCid[CIDv1][multiCodec("sha2-256")])
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}.toTable,
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]
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emptyBlock
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const
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BlockSize* = 31 * 64 * 4 # block size
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type
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Block* = ref object of RootObj
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cid*: Cid
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data*: seq[byte]
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proc isEmpty*(cid: Cid): bool =
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cid == EmptyCid[cid.cidver]
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.catch
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.get()[cid.mhash.get().mcodec]
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.catch
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.get()
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proc isEmpty*(blk: Block): bool =
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blk.cid.isEmpty
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proc emptyBlock*(cid: Cid): Block =
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EmptyBlock[cid.cidver]
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.catch
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.get()[cid.mhash.get().mcodec]
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.catch
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.get()
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proc `$`*(b: Block): string =
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result &= "cid: " & $b.cid
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result &= "\ndata: " & string.fromBytes(b.data)
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func new*(
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T: type Block,
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data: openArray[byte] = [],
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version = CIDv1,
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mcodec = multiCodec("sha2-256"),
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codec = multiCodec("raw")): ?!T =
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let
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hash = ? MultiHash.digest($mcodec, data).mapFailure
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cid = ? Cid.init(version, codec, hash).mapFailure
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# TODO: If the hash is `>=` to the data,
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# use the Cid as a container!
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Block(
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cid: cid,
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data: @data).success
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func new*(
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T: type Block,
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cid: Cid,
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data: openArray[byte],
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verify: bool = true): ?!T =
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let
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mhash = ? cid.mhash.mapFailure
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b = ? Block.new(
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data = @data,
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version = cid.cidver,
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codec = cid.mcodec,
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mcodec = mhash.mcodec)
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if verify and cid != b.cid:
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return "Cid and content don't match!".failure
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success b
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