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

66 lines
2.2 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.
## Kvt DB -- Transaction interface
## ===============================
##
{.push raises: [].}
import
results,
./kvt_tx/[tx_frame, tx_stow],
./kvt_init/memory_only,
./kvt_desc
export tx_frame
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
func to*(tx: KvtTxRef; T: type[KvtDbRef]): T =
## Getter, retrieves the parent database descriptor from argument `tx`
tx.db
func toKvtDbRef*(tx: KvtTxRef): KvtDbRef =
## Same as `.to(KvtDbRef)`
tx.db
# ------------------------------------------------------------------------------
# Public functions: save database
# ------------------------------------------------------------------------------
proc persist*(
db: KvtDbRef; # Database
): Result[void,KvtError] =
## Persistently store data onto backend database. If the system is running
## without a database backend, the function returns immediately with an
## error. The same happens if there is a pending transaction.
##
## The function merges all staged data from the top layer cache onto the
## backend stage area. After that, the top layer cache is cleared.
##
## Finally, the staged data are merged into the physical backend database
## and the staged data area is cleared. Wile performing this last step,
## the recovery journal is updated (if available.)
##
# Register for saving if piggybacked on remote database
if db.backend.kind == BackendRdbTriggered:
? db.txPersistOk()
? db.backend.setWrReqFn db
return err(TxPersistDelayed)
db.txPersist()
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------