nim-rocksdb/rocksdb/backup.nim

106 lines
3.3 KiB
Nim

# Nim-RocksDB
# Copyright 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)
# * GPL license, version 2.0, ([LICENSE-GPLv2](LICENSE-GPLv2) or https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html)
#
# at your option. This file may not be copied, modified, or distributed except according to those terms.
## A `BackupEngineRef` is used to create and manage backups against a RocksDB database.
{.push raises: [].}
import
./lib/librocksdb, ./internal/utils, ./options/backupopts, ./rocksdb, ./rocksresult
export backupopts, rocksdb, rocksresult
type
BackupEnginePtr* = ptr rocksdb_backup_engine_t
EnvPtr = ptr rocksdb_env_t
BackupEngineRef* = ref object
cPtr: BackupEnginePtr
env: EnvPtr
path: string
backupOpts: BackupEngineOptionsRef
proc openBackupEngine*(
path: string, backupOpts = defaultBackupEngineOptions(path, autoClose = true)
): RocksDBResult[BackupEngineRef] =
## Create a new backup engine. The `path` parameter is the path of the backup
## directory. Note that the same directory should not be used for both backups
## and the database itself.
##
## If no `backupOpts` are provided, the default options will be used. These
## default backup options will be closed when the backup engine is closed.
## If `backupOpts` are provided, they will need to be closed manually.
let env = rocksdb_create_default_env()
var errors: cstring
let backupEnginePtr = rocksdb_backup_engine_open_opts(
backupOpts.cPtr, env, cast[cstringArray](errors.addr)
)
bailOnErrorsWithCleanup(errors):
autoCloseNonNil(backupOpts)
rocksdb_env_destroy(env)
let engine =
BackupEngineRef(cPtr: backupEnginePtr, path: path, backupOpts: backupOpts)
ok(engine)
proc isClosed*(backupEngine: BackupEngineRef): bool {.inline.} =
## Returns `true` if the `BackupEngineRef` has been closed.
backupEngine.cPtr.isNil()
proc createNewBackup*(
backupEngine: BackupEngineRef, db: RocksDbRef
): RocksDBResult[void] =
## Create a new backup of the database.
doAssert not backupEngine.isClosed()
doAssert not db.isClosed()
var errors: cstring
rocksdb_backup_engine_create_new_backup(
backupEngine.cPtr, db.cPtr, cast[cstringArray](errors.addr)
)
bailOnErrors(errors)
ok()
proc restoreDbFromLatestBackup*(
backupEngine: BackupEngineRef, dbDir: string, walDir = dbDir, keepLogFiles = false
): RocksDBResult[void] =
## Restore the database from the latest backup.
doAssert not backupEngine.isClosed()
let restoreOptions = rocksdb_restore_options_create()
rocksdb_restore_options_set_keep_log_files(restoreOptions, keepLogFiles.cint)
var errors: cstring
rocksdb_backup_engine_restore_db_from_latest_backup(
backupEngine.cPtr,
dbDir.cstring,
walDir.cstring,
restoreOptions,
cast[cstringArray](errors.addr),
)
bailOnErrors(errors)
rocksdb_restore_options_destroy(restoreOptions)
ok()
proc close*(backupEngine: BackupEngineRef) =
## Close the `BackupEngineRef`.
if not backupEngine.isClosed():
rocksdb_backup_engine_close(backupEngine.cPtr)
backupEngine.cPtr = nil
if not backupEngine.env.isNil():
rocksdb_env_destroy(backupEngine.env)
backupEngine.env = nil
autoCloseNonNil(backupEngine.backupOpts)