Make the custom distances call somewhat more accessible (#404)

And make the naming more consistent
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Kim De Mey 2021-10-07 16:03:12 +02:00 committed by GitHub
parent 32ef1b7f4f
commit 5125a438db
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5 changed files with 38 additions and 29 deletions

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@ -67,7 +67,8 @@ proc verifyNodesRecords(enrs: openarray[Record], fromNode: Node, nodesLimit: int
continue continue
# Check if returned node has one of the requested distances. # Check if returned node has one of the requested distances.
if distances.isSome(): if distances.isSome():
if (not distances.get().contains(logDist(n.id, fromNode.id))): # TODO: This is incorrect for custom distances
if (not distances.get().contains(logDistance(n.id, fromNode.id))):
debug "Incorrect distance", debug "Incorrect distance",
record = n.record.toURI, sender = fromNode.record.toURI record = n.record.toURI, sender = fromNode.record.toURI
continue continue

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@ -586,7 +586,7 @@ proc talkreq*(d: Protocol, toNode: Node, protocol, request: seq[byte]):
return err("Talk response message not received in time") return err("Talk response message not received in time")
proc lookupDistances*(target, dest: NodeId): seq[uint16] = proc lookupDistances*(target, dest: NodeId): seq[uint16] =
let td = logDist(target, dest) let td = logDistance(target, dest)
let tdAsInt = int(td) let tdAsInt = int(td)
result.add(td) result.add(td)
var i = 1 var i = 1
@ -658,7 +658,7 @@ proc lookup*(d: Protocol, target: NodeId): Future[seq[Node]] {.async.} =
# If it wasn't seen before, insert node while remaining sorted # If it wasn't seen before, insert node while remaining sorted
closestNodes.insert(n, closestNodes.lowerBound(n, closestNodes.insert(n, closestNodes.lowerBound(n,
proc(x: Node, n: Node): int = proc(x: Node, n: Node): int =
cmp(distanceTo(x.id, target), distanceTo(n.id, target)) cmp(distance(x.id, target), distance(n.id, target))
)) ))
if closestNodes.len > BUCKET_SIZE: if closestNodes.len > BUCKET_SIZE:

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@ -93,20 +93,11 @@ type
NoAddress NoAddress
# xor distance functions # xor distance functions
# func distance*(a, b: NodeId): Uint256 =
func distanceTo*(a, b: NodeId): Uint256 =
## Calculate the distance to a NodeId. ## Calculate the distance to a NodeId.
a xor b a xor b
func idAtDistance*(id: NodeId, dist: uint16): NodeId = func logDistance*(a, b: NodeId): uint16 =
## Calculate the "lowest" `NodeId` for given logarithmic distance.
## A logarithmic distance obviously covers a whole range of distances and thus
## potential `NodeId`s.
# xor the NodeId with 2^(d - 1) or one could say, calculate back the leading
# zeroes and xor those` with the id.
id xor (1.stuint(256) shl (dist.int - 1))
func logDist*(a, b: NodeId): uint16 =
## Calculate the logarithmic distance between two `NodeId`s. ## Calculate the logarithmic distance between two `NodeId`s.
## ##
## According the specification, this is the log base 2 of the distance. But it ## According the specification, this is the log base 2 of the distance. But it
@ -124,7 +115,14 @@ func logDist*(a, b: NodeId): uint16 =
lz += bitops.countLeadingZeroBits(x) lz += bitops.countLeadingZeroBits(x)
break break
return uint16(a.len * 8 - lz) return uint16(a.len * 8 - lz)
#
func idAtDistance*(id: NodeId, dist: uint16): NodeId =
## Calculate the "lowest" `NodeId` for given logarithmic distance.
## A logarithmic distance obviously covers a whole range of distances and thus
## potential `NodeId`s.
# xor the NodeId with 2^(d - 1) or one could say, calculate back the leading
# zeroes and xor those` with the id.
id xor (1.stuint(256) shl (dist.int - 1))
const const
BUCKET_SIZE* = 16 ## Maximum amount of nodes per bucket BUCKET_SIZE* = 16 ## Maximum amount of nodes per bucket
@ -136,8 +134,17 @@ const
DefaultTableIpLimit* = 10'u DefaultTableIpLimit* = 10'u
DefaultTableIpLimits* = TableIpLimits(tableIpLimit: DefaultTableIpLimit, DefaultTableIpLimits* = TableIpLimits(tableIpLimit: DefaultTableIpLimit,
bucketIpLimit: DefaultBucketIpLimit) bucketIpLimit: DefaultBucketIpLimit)
XorDistanceCalculator* = DistanceCalculator(calculateDistance: distanceTo, XorDistanceCalculator* = DistanceCalculator(calculateDistance: distance,
calculateLogDistance: logDist, calculateIdAtDistance: idAtDistance) calculateLogDistance: logDistance, calculateIdAtDistance: idAtDistance)
func distance*(r: RoutingTable, a, b: NodeId): Uint256 =
r.distanceCalculator.calculateDistance(a, b)
func logDistance*(r: RoutingTable, a, b: NodeId): uint16 =
r.distanceCalculator.calculateLogDistance(a, b)
func idAtDistance*(r: RoutingTable, id: NodeId, dist: uint16): NodeId =
r.distanceCalculator.calculateIdAtDistance(id, dist)
proc new(T: type KBucket, istart, iend: NodeId, bucketIpLimit: uint): T = proc new(T: type KBucket, istart, iend: NodeId, bucketIpLimit: uint): T =
KBucket( KBucket(
@ -420,10 +427,10 @@ proc contains*(r: RoutingTable, n: Node): bool = n in r.bucketForNode(n.id)
# Check if the routing table contains node `n`. # Check if the routing table contains node `n`.
proc bucketsByDistanceTo(r: RoutingTable, id: NodeId): seq[KBucket] = proc bucketsByDistanceTo(r: RoutingTable, id: NodeId): seq[KBucket] =
sortedByIt(r.buckets, r.distanceCalculator.calculateDistance(it.midpoint, id)) sortedByIt(r.buckets, r.distance(it.midpoint, id))
proc nodesByDistanceTo(r: RoutingTable, k: KBucket, id: NodeId): seq[Node] = proc nodesByDistanceTo(r: RoutingTable, k: KBucket, id: NodeId): seq[Node] =
sortedByIt(k.nodes, r.distanceCalculator.calculateDistance(it.id, id)) sortedByIt(k.nodes, r.distance(it.id, id))
proc neighbours*(r: RoutingTable, id: NodeId, k: int = BUCKET_SIZE, proc neighbours*(r: RoutingTable, id: NodeId, k: int = BUCKET_SIZE,
seenOnly = false): seq[Node] = seenOnly = false): seq[Node] =
@ -442,17 +449,17 @@ proc neighbours*(r: RoutingTable, id: NodeId, k: int = BUCKET_SIZE,
# TODO: is this sort still needed? Can we get nodes closer from the "next" # TODO: is this sort still needed? Can we get nodes closer from the "next"
# bucket? # bucket?
result = sortedByIt(result, r.distanceCalculator.calculateDistance(it.id, id)) result = sortedByIt(result, r.distance(it.id, id))
if result.len > k: if result.len > k:
result.setLen(k) result.setLen(k)
proc neighboursAtDistance*(r: RoutingTable, distance: uint16, proc neighboursAtDistance*(r: RoutingTable, distance: uint16,
k: int = BUCKET_SIZE, seenOnly = false): seq[Node] = k: int = BUCKET_SIZE, seenOnly = false): seq[Node] =
## Return up to k neighbours at given logarithmic distance. ## Return up to k neighbours at given logarithmic distance.
result = r.neighbours(r.distanceCalculator.calculateIdAtDistance(r.thisNode.id, distance), k, seenOnly) result = r.neighbours(r.idAtDistance(r.thisNode.id, distance), k, seenOnly)
# This is a bit silly, first getting closest nodes then to only keep the ones # This is a bit silly, first getting closest nodes then to only keep the ones
# that are exactly the requested distance. # that are exactly the requested distance.
keepIf(result, proc(n: Node): bool = r.distanceCalculator.calculateLogDistance(n.id, r.thisNode.id) == distance) keepIf(result, proc(n: Node): bool = r.logDistance(n.id, r.thisNode.id) == distance)
proc neighboursAtDistances*(r: RoutingTable, distances: seq[uint16], proc neighboursAtDistances*(r: RoutingTable, distances: seq[uint16],
k: int = BUCKET_SIZE, seenOnly = false): seq[Node] = k: int = BUCKET_SIZE, seenOnly = false): seq[Node] =
@ -461,12 +468,12 @@ proc neighboursAtDistances*(r: RoutingTable, distances: seq[uint16],
# first one prioritize. It might end up not including all the node distances # first one prioritize. It might end up not including all the node distances
# requested. Need to rework the logic here and not use the neighbours call. # requested. Need to rework the logic here and not use the neighbours call.
if distances.len > 0: if distances.len > 0:
result = r.neighbours(r.distanceCalculator.calculateIdAtDistance(r.thisNode.id, distances[0]), k, result = r.neighbours(r.idAtDistance(r.thisNode.id, distances[0]), k,
seenOnly) seenOnly)
# This is a bit silly, first getting closest nodes then to only keep the ones # This is a bit silly, first getting closest nodes then to only keep the ones
# that are exactly the requested distances. # that are exactly the requested distances.
keepIf(result, proc(n: Node): bool = keepIf(result, proc(n: Node): bool =
distances.contains(r.distanceCalculator.calculateLogDistance(n.id, r.thisNode.id))) distances.contains(r.logDistance(n.id, r.thisNode.id)))
proc len*(r: RoutingTable): int = proc len*(r: RoutingTable): int =
for b in r.buckets: result += b.len for b in r.buckets: result += b.len

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@ -54,7 +54,7 @@ proc nodeAndPrivKeyAtDistance*(n: Node, rng: var BrHmacDrbgContext, d: uint32,
while true: while true:
let pk = PrivateKey.random(rng) let pk = PrivateKey.random(rng)
let node = generateNode(pk, ip = ip) let node = generateNode(pk, ip = ip)
if logDist(n.id, node.id) == d: if logDistance(n.id, node.id) == d:
return (node, pk) return (node, pk)
proc nodeAtDistance*(n: Node, rng: var BrHmacDrbgContext, d: uint32, proc nodeAtDistance*(n: Node, rng: var BrHmacDrbgContext, d: uint32,

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@ -62,6 +62,7 @@ procSuite "Discovery v5 Tests":
const const
targetId = "0x0000" targetId = "0x0000"
testValues = [ testValues = [
("0x0000", 0'u16),
("0x0001", 1'u16), ("0x0001", 1'u16),
("0x0002", 2'u16), ("0x0002", 2'u16),
("0x0003", 2'u16), ("0x0003", 2'u16),
@ -78,7 +79,7 @@ procSuite "Discovery v5 Tests":
] ]
for (id, d) in testValues: for (id, d) in testValues:
check logDist(parse(targetId, UInt256, 16), parse(id, UInt256, 16)) == d check logDistance(parse(targetId, UInt256, 16), parse(id, UInt256, 16)) == d
test "Distance check with keys": test "Distance check with keys":
const const
@ -96,7 +97,7 @@ procSuite "Discovery v5 Tests":
for (key, d) in testValues: for (key, d) in testValues:
let id = toNodeId(PrivateKey.fromHex(key)[].toPublicKey()) let id = toNodeId(PrivateKey.fromHex(key)[].toPublicKey())
check logDist(targetId, id) == d check logDistance(targetId, id) == d
test "Distance to id check": test "Distance to id check":
const const
@ -211,7 +212,7 @@ procSuite "Discovery v5 Tests":
let let
neighbours = mainNode.neighbours(mainNode.localNode.id) neighbours = mainNode.neighbours(mainNode.localNode.id)
closest = neighbours[0] closest = neighbours[0]
closestDistance = logDist(closest.id, mainNode.localNode.id) closestDistance = logDistance(closest.id, mainNode.localNode.id)
debug "Closest neighbour", closestDistance, id=closest.id.toHex() debug "Closest neighbour", closestDistance, id=closest.id.toHex()
@ -471,7 +472,7 @@ procSuite "Discovery v5 Tests":
some(port), some(port))[] some(port), some(port))[]
fromNode = newNode(fromNoderecord)[] fromNode = newNode(fromNoderecord)[]
pk = PrivateKey.random(rng[]) pk = PrivateKey.random(rng[])
targetDistance = @[logDist(fromNode.id, pk.toPublicKey().toNodeId())] targetDistance = @[logDistance(fromNode.id, pk.toPublicKey().toNodeId())]
limit = 16 limit = 16
block: # Duplicates block: # Duplicates