132 lines
4.5 KiB
Nim
132 lines
4.5 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.
|
|
|
|
{.push raises: [].}
|
|
|
|
import
|
|
std/[sequtils, sets, tables],
|
|
results,
|
|
./kvt_desc
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public getters/helpers
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func nLayersKeys*(db: KvtDbRef): int =
|
|
## Maximum number of ley/value entries on the cache layers. This is an upper
|
|
## bound for the number of effective key/value mappings held on the cache
|
|
## layers as there might be duplicate entries for the same key on different
|
|
## layers.
|
|
db.stack.mapIt(it.sTab.len).foldl(a + b, db.top.sTab.len)
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions: get function
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func layersLen*(db: KvtDbRef; key: openArray[byte]|seq[byte]): Opt[int] =
|
|
## Returns the size of the value associated with `key`.
|
|
##
|
|
when key isnot seq[byte]:
|
|
let key = @key
|
|
|
|
db.top.sTab.withValue(key, item):
|
|
return Opt.some(item[].len())
|
|
|
|
for w in db.rstack:
|
|
w.sTab.withValue(key, item):
|
|
return Opt.some(item[].len())
|
|
|
|
Opt.none(int)
|
|
|
|
func layersHasKey*(db: KvtDbRef; key: openArray[byte]|seq[byte]): bool =
|
|
## Return `true` if the argument key is cached.
|
|
##
|
|
db.layersLen(key).isSome()
|
|
|
|
func layersGet*(db: KvtDbRef; key: openArray[byte]|seq[byte]): Opt[seq[byte]] =
|
|
## Find an item on the cache layers. An `ok()` result might contain an
|
|
## empty value if it is stored on the cache that way.
|
|
##
|
|
when key isnot seq[byte]:
|
|
let key = @key
|
|
|
|
db.top.sTab.withValue(key, item):
|
|
return Opt.some(item[])
|
|
|
|
for w in db.rstack:
|
|
w.sTab.withValue(key, item):
|
|
return Opt.some(item[])
|
|
|
|
Opt.none(seq[byte])
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions: put function
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func layersPut*(db: KvtDbRef; key: openArray[byte]; data: openArray[byte]) =
|
|
## Store a (potentally empty) value on the top layer
|
|
db.top.sTab[@key] = @data
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public functions
|
|
# ------------------------------------------------------------------------------
|
|
|
|
func layersCc*(db: KvtDbRef; level = high(int)): LayerRef =
|
|
## Provide a collapsed copy of layers up to a particular transaction level.
|
|
## If the `level` argument is too large, the maximum transaction level is
|
|
## returned. For the result layer, the `txUid` value set to `0`.
|
|
let layers = if db.stack.len <= level: db.stack & @[db.top]
|
|
else: db.stack[0 .. level]
|
|
|
|
# Set up initial layer (bottom layer)
|
|
result = LayerRef(sTab: layers[0].sTab)
|
|
|
|
# Consecutively merge other layers on top
|
|
for n in 1 ..< layers.len:
|
|
for (key,val) in layers[n].sTab.pairs:
|
|
result.sTab[key] = val
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# Public iterators
|
|
# ------------------------------------------------------------------------------
|
|
|
|
iterator layersWalk*(
|
|
db: KvtDbRef;
|
|
seen: var HashSet[seq[byte]];
|
|
): tuple[key: seq[byte], data: seq[byte]] =
|
|
## Walk over all key-value pairs on the cache layers. Note that
|
|
## entries are unsorted.
|
|
##
|
|
## The argument `seen` collects a set of all visited vertex IDs including
|
|
## the one with a zero vertex which are othewise skipped by the iterator.
|
|
## The `seen` argument must not be modified while the iterator is active.
|
|
##
|
|
for (key,val) in db.top.sTab.pairs:
|
|
yield (key,val)
|
|
seen.incl key
|
|
|
|
for w in db.rstack:
|
|
for (key,val) in w.sTab.pairs:
|
|
if key notin seen:
|
|
yield (key,val)
|
|
seen.incl key
|
|
|
|
iterator layersWalk*(
|
|
db: KvtDbRef;
|
|
): tuple[key: seq[byte], data: seq[byte]] =
|
|
## Variant of `layersWalk()`.
|
|
var seen: HashSet[seq[byte]]
|
|
for (key,val) in db.layersWalk seen:
|
|
yield (key,val)
|
|
|
|
# ------------------------------------------------------------------------------
|
|
# End
|
|
# ------------------------------------------------------------------------------
|