nim-codex/dagger/blocktype.nim

68 lines
1.4 KiB
Nim

## Nim-Dagger
## Copyright (c) 2021 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/upraises
push: {.upraises: [].}
import pkg/libp2p
import pkg/stew/byteutils
import pkg/questionable
import pkg/questionable/results
import ./errors
const
BlockSize* = 4096 # file chunk read size
type
Block* = ref object of RootObj
cid*: Cid
data*: seq[byte]
proc `$`*(b: Block): string =
result &= "cid: " & $b.cid
result &= "\ndata: " & string.fromBytes(b.data)
func new*(
T: type Block,
data: openArray[byte] = [],
version = CIDv1,
mcodec = multiCodec("sha2-256"),
codec = multiCodec("raw")): ?!T =
let
hash = ? MultiHash.digest($mcodec, data).mapFailure
cid = ? Cid.init(version, codec, hash).mapFailure
# TODO: If the hash is `>=` to the data,
# use the Cid as a container!
Block(
cid: cid,
data: @data).success
func new*(
T: type Block,
cid: Cid,
data: openArray[byte],
verify: bool = true): ?!T =
let
mhash = ? cid.mhash.mapFailure
b = ? Block.new(
data = @data,
version = cid.cidver,
codec = cid.mcodec,
mcodec = mhash.mcodec)
if verify and cid != b.cid:
return "Cid's don't match!".failure
success b