96 lines
2.8 KiB
Nim
96 lines
2.8 KiB
Nim
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# nimbus-eth1
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# Copyright (c) 2021 Status Research & Development GmbH
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# Licensed under either of
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# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
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# http://www.apache.org/licenses/LICENSE-2.0)
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# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
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# http://opensource.org/licenses/MIT)
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# at your option. This file may not be copied, modified, or distributed
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# except according to those terms.
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## Kvt DB -- Common functions
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## ==========================
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##
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{.push raises: [].}
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import
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eth/common,
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results,
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./kvt_desc/desc_backend,
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./kvt_desc
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# ------------------------------------------------------------------------------
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# Private helpers
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# ------------------------------------------------------------------------------
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proc getBE*(
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db: KvtDbRef; # Database
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key: Blob; # Key of database record
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): Result[Blob,KvtError] =
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## For the argument `key` return the associated value from the backend
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## database if available.
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##
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let be = db.backend
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if not be.isNil:
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return be.getKvpFn key
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err(GetNotFound)
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# ------------------------------------------------------------------------------
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# Public functions, converters
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# ------------------------------------------------------------------------------
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proc put*(
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db: KvtDbRef; # Database
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key: Blob; # Key of database record to store
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data: Blob; # Value of database record to store
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): Result[void,KvtError] =
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## For the argument `key` associated the argument `data` as value (which
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## will be marked in the top layer cache.)
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if key.len == 0:
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return err(KeyInvalid)
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if data.len == 0:
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return err(DataInvalid)
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db.top.tab[key] = data
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ok()
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proc del*(
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db: KvtDbRef; # Database
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key: Blob; # Key of database record to delete
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): Result[void,KvtError] =
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## For the argument `key` delete the associated value (which will be marked
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## in the top layer cache.)
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if key.len == 0:
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return err(KeyInvalid)
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let rc = db.getBE(key)
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if rc.isOk:
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db.top.tab[key] = EmptyBlob
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elif rc.error == GetNotFound:
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db.top.tab.del key
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else:
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return err(rc.error)
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ok()
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# ------------
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proc get*(
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db: KvtDbRef; # Database
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key: Blob; # Key of database record
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): Result[Blob,KvtError] =
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## For the argument `key` return the associated value preferably from the
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## top layer, or the database otherwise.
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##
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if key.len == 0:
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return err(KeyInvalid)
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let data = db.top.tab.getOrVoid key
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if data.isValid:
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return ok(data)
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db.getBE key
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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