nimbus-eth1/nimbus/db/aristo/aristo_fetch.nim
Jordan Hrycaj 2c35390bdf
Core db and aristo maintenance update (#2014)
* Aristo: Update error return code

why:
  Failing of `Aristo` function `delete()` might fail because there is
  no such data item on the db. This must return a single error code
  as is done with `fetch()`.

* Ledger: Better error handling

why:
  The `expect()` clauses have been replaced by raising asserts indicating
  the error from the database backend.

   Also, `delete()` failures are legitimate if the item to delete does not
   exist.

* Aristo: Delete function must always leave a label on DB for `hashify()`

why:
  The `hashify()` uses the labels left bu `merge()` and `delete()` to
  compile (and optimise) a scheduler for subsequent hashing.

  Originally, the labels were not used for deleted entries and `delete()`
  still had some edge case where the deletion label was not properly
  handled.

* Aristo: Update `hashify()` scheduler, remove buggy optimisation

why:
  Was left over from version without virtual state roots which did not
  know about account payload leaf vertices referring to storage roots.

* Aristo: Label storage trie account in `delete()` similar to `merge()`

details;
  The `delete()` function applied to a non-static state root (assumed
  to be a storage root) will check the payload of an accounts leaf
  and mark its Merkle keys to be re-checked when runninh `hashify()`

* Aristo: Clean up and re-org recycled vertex IDs in `hashify()`

why:
  Re-organising the recycled vertex IDs list intends to reduce the size of the
  list.

  This list is organised as a LIFO (or stack.) By reorganising it in a way
  so that the least vertex ID numbers are on top, the list will be kept
  smaller as observed on some examples (less than 30%.)

* CoreDb: Accept storage trie deletion requests in non-initialised state

why:
  Due to lazy initialisation, the root vertex ID might not yet exist. So
  the `Aristo` database handlers would reject this call with an error and
  this condition needs to be handled by the API (which realises the lazy
  feature.)

* Cosmetics & code massage, prettify logging

* fix missing import
2024-02-08 16:32:16 +00:00

84 lines
2.6 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 -- Obects Retrival Via Traversal Path
## ===============================================
##
{.push raises: [].}
import
eth/trie/nibbles,
results,
"."/[aristo_desc, aristo_hike]
# ------------------------------------------------------------------------------
# Private functions
# ------------------------------------------------------------------------------
proc fetchPayloadImpl(
rc: Result[Hike,(VertexID,AristoError,Hike)];
): Result[PayloadRef,(VertexID,AristoError)] =
if rc.isErr:
if rc.error[1] in HikeAcceptableStopsNotFound:
return err((rc.error[0], FetchPathNotFound))
return err((rc.error[0], rc.error[1]))
ok rc.value.legs[^1].wp.vtx.lData
proc fetchPayloadImpl(
db: AristoDbRef;
root: VertexID;
path: openArray[byte];
): Result[PayloadRef,(VertexID,AristoError)] =
path.initNibbleRange.hikeUp(root, db).fetchPayloadImpl
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc fetchPayload*(
db: AristoDbRef;
key: LeafTie;
): Result[PayloadRef,(VertexID,AristoError)] =
## Cascaded attempt to traverse the `Aristo Trie` and fetch the value of a
## leaf vertex. This function is complementary to `merge()`.
##
key.hikeUp(db).fetchPayloadImpl
proc fetchPayload*(
db: AristoDbRef;
root: VertexID;
path: openArray[byte];
): Result[PayloadRef,(VertexID,AristoError)] =
## Variant of `fetchPayload()`
##
if path.len == 0:
return err((VertexID(0),LeafKeyInvalid))
db.fetchPayloadImpl(root, path)
proc hasPath*(
db: AristoDbRef; # Database
root: VertexID;
path: openArray[byte]; # Key of database record
): Result[bool,(VertexID,AristoError)] =
## Variant of `fetchPayload()`
##
if path.len == 0:
return err((VertexID(0),LeafKeyInvalid))
let rc = db.fetchPayloadImpl(root, path)
if rc.isOk:
return ok(true)
if rc.error[1] == FetchPathNotFound:
return ok(false)
err(rc.error)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------