mirror of https://github.com/vacp2p/nim-libp2p.git
first pass, use results for Cid module (#480)
* first pass, use results for Cid module * improvements to decode
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Giovanni Petrantoni
GitHub
parent
a990fe95a0
commit
5543f6681f
171
libp2p/cid.nim
171
libp2p/cid.nim
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@ -8,13 +8,18 @@
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## those terms.
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## This module implementes CID (Content IDentifier).
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{.push raises: [Defect].}
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import tables
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import multibase, multicodec, multihash, vbuffer, varint
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import stew/base58
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import stew/[base58, results]
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export results
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type
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CidStatus* {.pure.} = enum
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Error, Success, Incorrect, Overrun
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CidError* {.pure.} = enum
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Error, Incorrect, Unsupported, Overrun
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CidVersion* = enum
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CIDvIncorrect, CIDv0, CIDv1, CIDvReserved
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@ -25,8 +30,6 @@ type
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hpos*: int
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data*: VBuffer
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CidError* = object of CatchableError
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const
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ContentIdsList = [
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multiCodec("raw"),
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@ -66,66 +69,74 @@ proc initCidCodeTable(): Table[int, MultiCodec] {.compileTime.} =
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const
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CodeContentIds = initCidCodeTable()
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proc decode(data: openarray[byte], cid: var Cid): CidStatus =
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if len(data) == 34:
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if data[0] == 0x12'u8 and data[1] == 0x20'u8:
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cid.cidver = CIDv0
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cid.mcodec = multiCodec("dag-pb")
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cid.hpos = 0
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cid.data = initVBuffer(data)
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result = CidStatus.Success
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if cid.cidver == CIDvIncorrect:
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template orError*(exp: untyped, err: untyped): untyped =
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(exp.mapErr do (_: auto) -> auto: err)
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proc decode(data: openarray[byte]): Result[Cid, CidError] =
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if len(data) == 34 and data[0] == 0x12'u8 and data[1] == 0x20'u8:
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ok(Cid(
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cidver: CIDv0,
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mcodec: multiCodec("dag-pb"),
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hpos: 0,
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data: initVBuffer(data)))
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else:
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var version, codec: uint64
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var res, offset: int
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var vb = initVBuffer(data)
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if vb.isEmpty():
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return CidStatus.Incorrect
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res = vb.readVarint(version)
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if res == -1:
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return CidStatus.Incorrect
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offset += res
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if version != 1'u64:
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return CidStatus.Incorrect
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res = vb.readVarint(codec)
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if res == -1:
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return CidStatus.Incorrect
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offset += res
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var mcodec = CodeContentIds.getOrDefault(cast[int](codec),
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InvalidMultiCodec)
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if mcodec == InvalidMultiCodec:
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return CidStatus.Incorrect
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if not MultiHash.validate(vb.buffer.toOpenArray(vb.offset,
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vb.buffer.high)):
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return CidStatus.Incorrect
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vb.finish()
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cid.cidver = CIDv1
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cid.mcodec = mcodec
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cid.hpos = offset
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cid.data = vb
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result = CidStatus.Success
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err(CidError.Incorrect)
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else:
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res = vb.readVarint(version)
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if res == -1:
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err(CidError.Incorrect)
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else:
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offset += res
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if version != 1'u64:
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err(CidError.Incorrect)
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else:
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res = vb.readVarint(codec)
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if res == -1:
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err(CidError.Incorrect)
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else:
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offset += res
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var mcodec = CodeContentIds.getOrDefault(cast[int](codec),
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InvalidMultiCodec)
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if mcodec == InvalidMultiCodec:
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err(CidError.Incorrect)
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else:
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if not MultiHash.validate(vb.buffer.toOpenArray(vb.offset,
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vb.buffer.high)):
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err(CidError.Incorrect)
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else:
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vb.finish()
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ok(Cid(
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cidver: CIDv1,
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mcodec: mcodec,
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hpos: offset,
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data: vb))
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proc decode(data: openarray[char], cid: var Cid): CidStatus =
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proc decode(data: openarray[char]): Result[Cid, CidError] =
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var buffer: seq[byte]
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var plen = 0
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if len(data) < 2:
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return CidStatus.Incorrect
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return err(CidError.Incorrect)
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if len(data) == 46:
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if data[0] == 'Q' and data[1] == 'm':
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buffer = newSeq[byte](BTCBase58.decodedLength(len(data)))
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if BTCBase58.decode(data, buffer, plen) != Base58Status.Success:
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return CidStatus.Incorrect
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return err(CidError.Incorrect)
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buffer.setLen(plen)
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if len(buffer) == 0:
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let length = MultiBase.decodedLength(data[0], len(data))
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if length == -1:
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return CidStatus.Incorrect
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return err(CidError.Incorrect)
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buffer = newSeq[byte](length)
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if MultiBase.decode(data, buffer, plen) != MultiBaseStatus.Success:
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return CidStatus.Incorrect
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return err(CidError.Incorrect)
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buffer.setLen(plen)
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if buffer[0] == 0x12'u8:
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return CidStatus.Incorrect
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result = decode(buffer, cid)
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return err(CidError.Incorrect)
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decode(buffer)
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proc validate*(ctype: typedesc[Cid], data: openarray[byte]): bool =
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## Returns ``true`` is data has valid binary CID representation.
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@ -157,30 +168,30 @@ proc validate*(ctype: typedesc[Cid], data: openarray[byte]): bool =
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return false
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result = true
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proc mhash*(cid: Cid): MultiHash =
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proc mhash*(cid: Cid): Result[MultiHash, CidError] =
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## Returns MultiHash part of CID.
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if cid.cidver notin {CIDv0, CIDv1}:
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raise newException(CidError, "Incorrect CID!")
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result = MultiHash.init(
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cid.data.buffer.toOpenArray(cid.hpos, cid.data.high)).tryGet()
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err(CidError.Incorrect)
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else:
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MultiHash.init(cid.data.buffer.toOpenArray(cid.hpos, cid.data.high)).orError(CidError.Incorrect)
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proc contentType*(cid: Cid): MultiCodec =
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proc contentType*(cid: Cid): Result[MultiCodec, CidError] =
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## Returns content type part of CID
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if cid.cidver notin {CIDv0, CIDv1}:
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raise newException(CidError, "Incorrect CID!")
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result = cid.mcodec
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err(CidError.Incorrect)
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else:
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ok(cid.mcodec)
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proc version*(cid: Cid): CidVersion =
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## Returns CID version
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result = cid.cidver
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proc init*[T: char|byte](ctype: typedesc[Cid], data: openarray[T]): Cid =
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proc init*[T: char|byte](ctype: typedesc[Cid], data: openarray[T]): Result[Cid, CidError] =
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## Create new content identifier using array of bytes or string ``data``.
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if decode(data, result) != CidStatus.Success:
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raise newException(CidError, "Incorrect CID!")
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decode(data)
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proc init*(ctype: typedesc[Cid], version: CidVersion, content: MultiCodec,
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hash: MultiHash): Cid =
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hash: MultiHash): Result[Cid, CidError] =
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## Create new content identifier using content type ``content`` and
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## MultiHash ``hash`` using version ``version``.
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##
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@ -188,33 +199,35 @@ proc init*(ctype: typedesc[Cid], version: CidVersion, content: MultiCodec,
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## Cid.init(CIDv0, multiCodec("dag-pb"), MultiHash.digest("sha2-256", data))
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##
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## All other encodings and hashes are not supported by CIDv0.
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result.cidver = version
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var res: Cid
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res.cidver = version
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if version == CIDv0:
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if content != multiCodec("dag-pb"):
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raise newException(CidError,
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"CIDv0 supports only `dag-pb` content type!")
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result.data = initVBuffer()
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return err(CidError.Unsupported)
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res.data = initVBuffer()
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if hash.mcodec != multiCodec("sha2-256"):
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raise newException(CidError,
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"CIDv0 supports only `sha2-256` hash digest!")
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result.mcodec = content
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result.data.write(hash)
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result.data.finish()
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return err(CidError.Unsupported)
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res.mcodec = content
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res.data.write(hash)
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res.data.finish()
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return ok(res)
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elif version == CIDv1:
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let mcodec = CodeContentIds.getOrDefault(cast[int](content),
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InvalidMultiCodec)
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if mcodec == InvalidMultiCodec:
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raise newException(CidError, "Incorrect content type")
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result.mcodec = mcodec
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result.data = initVBuffer()
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result.data.writeVarint(cast[uint64](1))
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result.data.write(mcodec)
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result.hpos = len(result.data.buffer)
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result.data.write(hash)
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result.data.finish()
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return err(CidError.Incorrect)
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res.mcodec = mcodec
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res.data = initVBuffer()
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res.data.writeVarint(cast[uint64](1))
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res.data.write(mcodec)
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res.hpos = len(res.data.buffer)
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res.data.write(hash)
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res.data.finish()
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return ok(res)
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else:
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raise newException(CidError, "CID version is not supported" & $version)
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return err(CidError.Unsupported)
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proc `==`*(a: Cid, b: Cid): bool =
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## Compares content identifiers ``a`` and ``b``, returns ``true`` if hashes
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@ -258,6 +271,12 @@ proc encode*(mbtype: typedesc[MultiBase], encoding: string,
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proc `$`*(cid: Cid): string =
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## Return official string representation of content identifier ``cid``.
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if cid.cidver == CIDv0:
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result = BTCBase58.encode(cid.data.buffer)
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BTCBase58.encode(cid.data.buffer)
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elif cid.cidver == CIDv1:
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result = Multibase.encode("base58btc", cid.data.buffer).tryGet()
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let res = Multibase.encode("base58btc", cid.data.buffer)
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if res.isOk():
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res.get()
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else:
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""
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else:
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""
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@ -7,29 +7,24 @@ suite "Content identifier CID test suite":
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test "CIDv0 test vector":
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var cid0Text = "QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n"
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var cid0 = Cid.init(cid0Text)
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var cid0 = Cid.init(cid0Text).tryGet()
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check:
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$cid0 == cid0Text
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cid0.version() == CIDv0
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cid0.contentType() == multiCodec("dag-pb")
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cid0.mhash().mcodec == multiCodec("sha2-256")
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var res = 0
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try:
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discard Cid.init("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zIII")
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except CidError:
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res = 1
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check res == 1
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cid0.contentType().tryGet() == multiCodec("dag-pb")
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cid0.mhash().tryGet().mcodec == multiCodec("sha2-256")
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Cid.init("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zIII").isErr()
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test "CIDv1 test vector":
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var cid1Text = "zb2rhhFAEMepUBbGyP1k8tGfz7BSciKXP6GHuUeUsJBaK6cqG"
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var chex = "015512209D8453505BDC6F269678E16B3E56" &
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"C2A2948A41F2C792617CC9611ED363C95B63"
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var cid1 = Cid.init(cid1Text)
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var cid1 = Cid.init(cid1Text).tryGet()
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check:
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$cid1 == cid1Text
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cid1.version() == CIDv1
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cid1.contentType() == multiCodec("raw")
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cid1.mhash().mcodec == multiCodec("sha2-256")
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cid1.contentType().tryGet() == multiCodec("raw")
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cid1.mhash().tryGet().mcodec == multiCodec("sha2-256")
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hex(cid1) == chex
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test "Comparison test":
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@ -38,17 +33,17 @@ suite "Content identifier CID test suite":
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var bmsg = cast[seq[byte]](msg)
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var bmmsg = cast[seq[byte]](mmsg)
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var cid0 = Cid.init(CIDv0, multiCodec("dag-pb"),
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MultiHash.digest("sha2-256", bmsg).get())
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MultiHash.digest("sha2-256", bmsg).get()).tryGet()
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var cid1 = Cid.init(CIDv1, multiCodec("dag-pb"),
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MultiHash.digest("sha2-256", bmsg).get())
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MultiHash.digest("sha2-256", bmsg).get()).tryGet()
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var cid2 = cid1
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var cid3 = cid0
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var cid4 = Cid.init(CIDv1, multiCodec("dag-cbor"),
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MultiHash.digest("sha2-256", bmsg).get())
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MultiHash.digest("sha2-256", bmsg).get()).tryGet()
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var cid5 = Cid.init(CIDv1, multiCodec("dag-pb"),
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MultiHash.digest("sha2-256", bmmsg).get())
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MultiHash.digest("sha2-256", bmmsg).get()).tryGet()
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var cid6 = Cid.init(CIDv1, multiCodec("dag-pb"),
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MultiHash.digest("keccak-256", bmsg).get())
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MultiHash.digest("keccak-256", bmsg).get()).tryGet()
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check:
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cid0 == cid1
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cid1 == cid2
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