nimbus-eth1/nimbus/db/aristo/aristo_utils.nim
Jacek Sieka f034af422a
Pre-allocate vids for branches (#2882)
Each branch node may have up to 16 sub-items - currently, these are
given VertexID based when they are first needed leading to a
mostly-random order of vertexid for each subitem.

Here, we pre-allocate all 16 vertex ids such that when a branch subitem
is filled, it already has a vertexid waiting for it. This brings several
important benefits:

* subitems are sorted and "close" in their id sequencing - this means
that when rocksdb stores them, they are likely to end up in the same
data block thus improving read efficiency
* because the ids are consequtive, we can store just the starting id and
a bitmap representing which subitems are in use - this reduces disk
space usage for branches allowing more of them fit into a single disk
read, further improving disk read and caching performance - disk usage
at block 18M is down from 84 to 78gb!
* the in-memory footprint of VertexRef reduced allowing more instances
to fit into caches and less memory to be used overall.

Because of the increased locality of reference, it turns out that we no
longer need to iterate over the entire database to efficiently generate
the hash key database because the normal computation is now faster -
this significantly benefits "live" chain processing as well where each
dirtied key must be accompanied by a read of all branch subitems next to
it - most of the performance benefit in this branch comes from this
locality-of-reference improvement.

On a sample resync, there's already ~20% improvement with later blocks
seeing increasing benefit (because the trie is deeper in later blocks
leading to more benefit from branch read perf improvements)

```
blocks: 18729664, baseline: 190h43m49s, contender: 153h59m0s
Time (total): -36h44m48s, -19.27%
```

Note: clients need to be resynced as the PR changes the on-disk format

R.I.P. little bloom filter - your life in the repo was short but
valuable
2024-12-04 11:42:04 +01:00

90 lines
2.9 KiB
Nim

# nimbus-eth1
# Copyright (c) 2023-2024 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.
## Aristo DB -- Handy Helpers
## ==========================
##
{.push raises: [].}
import
eth/common,
results,
"."/[aristo_desc, aristo_compute]
# ------------------------------------------------------------------------------
# Public functions, converters
# ------------------------------------------------------------------------------
proc toNode*(
vtx: VertexRef; # Vertex to convert
root: VertexID; # Sub-tree root the `vtx` belongs to
db: AristoDbRef; # Database
): Result[NodeRef,seq[VertexID]] =
## Convert argument the vertex `vtx` to a node type. Missing Merkle hash
## keys are searched for on the argument database `db`.
##
## On error, at least the vertex ID of the first missing Merkle hash key is
## returned. If the argument `stopEarly` is set `false`, all missing Merkle
## hash keys are returned.
##
## In the argument `beKeyOk` is set `false`, keys for node links are accepted
## only from the cache layer. This does not affect a link key for a payload
## storage root.
##
case vtx.vType:
of Leaf:
let node = NodeRef(vtx: vtx.dup())
# Need to resolve storage root for account leaf
if vtx.lData.pType == AccountData:
let stoID = vtx.lData.stoID
if stoID.isValid:
let key = db.computeKey((stoID.vid, stoID.vid)).valueOr:
return err(@[stoID.vid])
node.key[0] = key
return ok node
of Branch:
let node = NodeRef(vtx: vtx.dup())
for n, subvid in vtx.pairs():
let key = db.computeKey((root, subvid)).valueOr:
return err(@[subvid])
node.key[n] = key
return ok node
iterator subVids*(vtx: VertexRef): VertexID =
## Returns the list of all sub-vertex IDs for the argument `vtx`.
case vtx.vType:
of Leaf:
if vtx.lData.pType == AccountData:
let stoID = vtx.lData.stoID
if stoID.isValid:
yield stoID.vid
of Branch:
for _, subvid in vtx.pairs():
yield subvid
iterator subVidKeys*(node: NodeRef): (VertexID,HashKey) =
## Simolar to `subVids()` but for nodes
case node.vtx.vType:
of Leaf:
if node.vtx.lData.pType == AccountData:
let stoID = node.vtx.lData.stoID
if stoID.isValid:
yield (stoID.vid, node.key[0])
of Branch:
for n, subvid in node.vtx.pairs():
yield (subvid,node.key[n])
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------