nimbus-eth1/nimbus/sync/snap/worker/db/hexary_paths.nim

338 lines
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Nim

# nimbus-eth1
# Copyright (c) 2021 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed
# except according to those terms.
## Find node paths in hexary tries.
{.push raises: [].}
import
std/[sequtils, sets, tables],
eth/[common, trie/nibbles],
stew/[byteutils, interval_set],
"../.."/[constants, range_desc],
"."/[hexary_desc, hexary_nodes_helper]
# ------------------------------------------------------------------------------
# Private debugging helpers
# ------------------------------------------------------------------------------
#proc pp(w: Blob; db: HexaryTreeDbRef): string =
# w.convertTo(RepairKey).pp(db)
# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------
proc to(a: RepairKey; T: type RepairKey): RepairKey =
## Needed for generic function
a
proc convertTo(key: RepairKey; T: type NodeKey): T =
## Might be lossy, check before use
discard result.init(key.ByteArray33[1 .. 32])
proc getNibblesImpl(path: XPath|RPath; start = 0): NibblesSeq =
## Re-build the key path
for n in start ..< path.path.len:
let it = path.path[n]
case it.node.kind:
of Branch:
result = result & @[it.nibble.byte].initNibbleRange.slice(1)
of Extension:
result = result & it.node.ePfx
of Leaf:
result = result & it.node.lPfx
result = result & path.tail
proc getNibblesImpl(path: XPath|RPath; start, maxLen: int): NibblesSeq =
## Variant of `getNibblesImpl()` for partial rebuild
for n in start ..< min(path.path.len, maxLen):
let it = path.path[n]
case it.node.kind:
of Branch:
result = result & @[it.nibble.byte].initNibbleRange.slice(1)
of Extension:
result = result & it.node.ePfx
of Leaf:
result = result & it.node.lPfx
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
proc rootPathExtend(
path: RPath|XPath; # Partially expanded path
db: HexaryTreeDbRef|HexaryGetFn; # Database abstraction
): auto
{.gcsafe, raises: [CatchableError].} =
## For the given path, extend to the longest possible `db` database
## path following the argument `path.tail`.
result = path
when typeof(path) is RPath:
var key = path.root
else:
var key = path.root.to(Blob)
while true:
let rc = key.getNode(db)
if rc.isErr:
break
let node = rc.value
case node.kind:
of Leaf:
if result.tail.len == result.tail.sharedPrefixLen(node.lPfx):
# Bingo, got full path
result.path.add typeof(path.path[0])(key: key, node: node, nibble: -1)
result.tail = EmptyNibbleSeq
return
of Branch:
if result.tail.len == 0:
result.path.add typeof(path.path[0])(key: key, node: node, nibble: -1)
return
let nibble = result.tail[0].int8
if node.bLink[nibble].isZeroLink:
return
result.path.add typeof(path.path[0])(key: key, node: node, nibble: nibble)
result.tail = result.tail.slice(1)
key = node.bLink[nibble]
of Extension:
if result.tail.len == 0:
result.path.add typeof(path.path[0])(key: key, node: node, nibble: -1)
result.tail = EmptyNibbleSeq # clean up internal indexing
return
if node.ePfx.len != result.tail.sharedPrefixLen(node.ePfx):
return
result.path.add typeof(path.path[0])(key: key, node: node, nibble: -1)
result.tail = result.tail.slice(node.ePfx.len)
key = node.eLink
# ------------------------------------------------------------------------------
# Public helpers
# ------------------------------------------------------------------------------
proc getNibbles*(path: XPath|RPath; start = 0): NibblesSeq =
## Re-build the key path
path.getNibblesImpl(start)
proc getNibbles*(path: XPath|RPath; start, maxLen: int): NibblesSeq =
## Variant of `getNibbles()`
path.getNibblesImpl(start, maxLen)
proc getPartialPath*(path: XPath|RPath): Blob =
## Convert to hex encoded partial path as used in `eth` or `snap` protocol
## where full leaf paths of nibble length 64 are encoded as 32 byte `Blob`
## and non-leaf partial paths are *compact encoded* (i.e. per the Ethereum
## wire protocol.)
let
isLeaf = (0 < path.path.len and path.path[^1].node.kind == Leaf)
nibbles = path.getNibbles
if isLeaf and nibbles.len == 64:
nibbles.getBytes
else:
nibbles.hexPrefixEncode(isLeaf)
proc leafData*(path: XPath): Blob =
## Return the leaf data from a successful `XPath` computation (if any.)
if path.tail.len == 0 and 0 < path.path.len:
let node = path.path[^1].node
case node.kind:
of Branch:
return node.bLink[16]
of Leaf:
return node.lData
of Extension:
discard
proc leafData*(path: RPath): Blob =
## Return the leaf data from a successful `RPath` computation (if any.)
if path.tail.len == 0 and 0 < path.path.len:
let node = path.path[^1].node
case node.kind:
of Branch:
return node.bData
of Leaf:
return node.lData
of Extension:
discard
# ------------------------------------------------------------------------------
# Public functions, hexary path constructors
# ------------------------------------------------------------------------------
proc hexaryPath*(
partialPath: NibblesSeq; # partial path to resolve
rootKey: NodeKey|RepairKey; # State root
db: HexaryTreeDbRef; # Database
): RPath
{.gcsafe, raises: [CatchableError]} =
## Compute the longest possible repair tree `db` path matching the `nodeKey`
## nibbles. The `nodeNey` path argument comes before the `db` one for
## supporting a more functional notation.
RPath(root: rootKey.to(RepairKey), tail: partialPath).rootPathExtend(db)
proc hexaryPath*(
nodeKey: NodeKey;
rootKey: NodeKey|RepairKey;
db: HexaryTreeDbRef;
): RPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a node key.
nodeKey.to(NibblesSeq).hexaryPath(rootKey, db)
proc hexaryPath*(
nodeTag: NodeTag;
rootKey: NodeKey|RepairKey;
db: HexaryTreeDbRef;
): RPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a node tag.
nodeTag.to(NodeKey).hexaryPath(rootKey, db)
proc hexaryPath*(
partialPath: Blob;
rootKey: NodeKey|RepairKey;
db: HexaryTreeDbRef;
): RPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a hex encoded partial path.
partialPath.hexPrefixDecode[1].hexaryPath(rootKey, db)
proc hexaryPath*(
partialPath: NibblesSeq; # partial path to resolve
rootKey: NodeKey; # State root
getFn: HexaryGetFn; # Database abstraction
): XPath
{.gcsafe, raises: [CatchableError]} =
## Compute the longest possible path on an arbitrary hexary trie.
XPath(root: rootKey, tail: partialPath).rootPathExtend(getFn)
proc hexaryPath*(
nodeKey: NodeKey;
rootKey: NodeKey;
getFn: HexaryGetFn;
): XPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a node key..
nodeKey.to(NibblesSeq).hexaryPath(rootKey, getFn)
proc hexaryPath*(
nodeTag: NodeTag;
rootKey: NodeKey;
getFn: HexaryGetFn;
): XPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a node tag..
nodeTag.to(NodeKey).hexaryPath(rootKey, getFn)
proc hexaryPath*(
partialPath: Blob;
rootKey: NodeKey;
getFn: HexaryGetFn;
): XPath
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPath` for a hex encoded partial path.
partialPath.hexPrefixDecode[1].hexaryPath(rootKey, getFn)
# ------------------------------------------------------------------------------
# Public helpers, partial paths resolvers
# ------------------------------------------------------------------------------
proc hexaryPathNodeKey*(
partialPath: NibblesSeq; # Hex encoded partial path
rootKey: NodeKey|RepairKey; # State root
db: HexaryTreeDbRef; # Database
missingOk = false; # Also return key for missing node
): Result[NodeKey,void]
{.gcsafe, raises: [CatchableError]} =
## Returns the `NodeKey` equivalent for the argment `partialPath` if this
## node is available in the database. If the argument flag `missingOk` is
## set`true` and the last node addressed by the argument path is missing,
## its key is returned as well.
let steps = partialPath.hexaryPath(rootKey, db)
if 0 < steps.path.len and steps.tail.len == 0:
let top = steps.path[^1]
# If the path was fully exhaused and the node exists for a `Branch` node,
# then the `nibble` is `-1`.
if top.nibble < 0 and top.key.isNodeKey:
return ok(top.key.convertTo(NodeKey))
if missingOk:
let link = top.node.bLink[top.nibble]
if not link.isZero and link.isNodeKey:
return ok(link.convertTo(NodeKey))
err()
proc hexaryPathNodeKey*(
partialPath: Blob; # Hex encoded partial path
rootKey: NodeKey|RepairKey; # State root
db: HexaryTreeDbRef; # Database
missingOk = false; # Also return key for missing node
): Result[NodeKey,void]
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPathNodeKey()` for hex encoded partial path.
partialPath.hexPrefixDecode[1].hexaryPathNodeKey(rootKey, db, missingOk)
proc hexaryPathNodeKey*(
partialPath: NibblesSeq; # Hex encoded partial path
rootKey: NodeKey; # State root
getFn: HexaryGetFn; # Database abstraction
missingOk = false; # Also return key for missing node
): Result[NodeKey,void]
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPathNodeKey()` for persistent database.
let steps = partialPath.hexaryPath(rootKey, getFn)
if 0 < steps.path.len and steps.tail.len == 0:
let top = steps.path[^1]
# If the path was fully exhaused and the node exists for a `Branch` node,
# then the `nibble` is `-1`.
if top.nibble < 0:
return ok(top.key.convertTo(NodeKey))
if missingOk:
let link = top.node.bLink[top.nibble]
if 0 < link.len:
return ok(link.convertTo(NodeKey))
err()
proc hexaryPathNodeKey*(
partialPath: Blob; # Partial database path
rootKey: NodeKey; # State root
getFn: HexaryGetFn; # Database abstraction
missingOk = false; # Also return key for missing node
): Result[NodeKey,void]
{.gcsafe, raises: [CatchableError]} =
## Variant of `hexaryPathNodeKey()` for persistent database and
## hex encoded partial path.
partialPath.hexPrefixDecode[1].hexaryPathNodeKey(rootKey, getFn, missingOk)
proc hexaryPathNodeKeys*(
partialPaths: seq[Blob]; # Partial paths segments
rootKey: NodeKey|RepairKey; # State root
db: HexaryTreeDbRef; # Database
missingOk = false; # Also return key for missing node
): HashSet[NodeKey]
{.gcsafe, raises: [CatchableError]} =
## Convert a list of path segments to a set of node keys
partialPaths.toSeq
.mapIt(it.hexaryPathNodeKey(rootKey, db, missingOk))
.filterIt(it.isOk)
.mapIt(it.value)
.toHashSet
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------