nimbus-eth1/nimbus/db/kvt/kvt_utils.nim

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2.8 KiB
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.
## Kvt DB -- Common functions
## ==========================
##
{.push raises: [].}
import
eth/common,
results,
./kvt_desc/desc_backend,
./kvt_desc
# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------
proc getBE*(
db: KvtDbRef; # Database
key: openArray[byte]; # Key of database record
): Result[Blob,KvtError] =
## For the argument `key` return the associated value from the backend
## database if available.
##
let be = db.backend
if not be.isNil:
return be.getKvpFn key
err(GetNotFound)
# ------------------------------------------------------------------------------
# Public functions, converters
# ------------------------------------------------------------------------------
proc put*(
db: KvtDbRef; # Database
key: openArray[byte]; # Key of database record to store
data: openArray[byte]; # Value of database record to store
): Result[void,KvtError] =
## For the argument `key` associated the argument `data` as value (which
## will be marked in the top layer cache.)
if key.len == 0:
return err(KeyInvalid)
if data.len == 0:
return err(DataInvalid)
db.top.tab[@key] = @data
ok()
proc del*(
db: KvtDbRef; # Database
key: openArray[byte]; # Key of database record to delete
): Result[void,KvtError] =
## For the argument `key` delete the associated value (which will be marked
## in the top layer cache.)
if key.len == 0:
return err(KeyInvalid)
let rc = db.getBE(key)
if rc.isOk:
db.top.tab[@key] = EmptyBlob
elif rc.error == GetNotFound:
db.top.tab.del @key
else:
return err(rc.error)
ok()
# ------------
proc get*(
db: KvtDbRef; # Database
key: openArray[byte]; # Key of database record
): Result[Blob,KvtError] =
## For the argument `key` return the associated value preferably from the
## top layer, or the database otherwise.
##
if key.len == 0:
return err(KeyInvalid)
let data = db.top.tab.getOrVoid @key
if data.isValid:
return ok(data)
db.getBE key
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------