mirror of
https://github.com/logos-storage/nim-datastore.git
synced 2026-02-07 23:33:31 +00:00
92af582d97
This adds tracking of open iterators to leveldbds so that when one attempts to close it, iterators are disposed of first. It also adds automatic disposal if iterators are completely consumed. fixes #82
58 lines
1.4 KiB
Nim
58 lines
1.4 KiB
Nim
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{.push raises: [].}
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import pkg/chronos
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import pkg/questionable
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import pkg/questionable/results
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import ./key
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import ./types
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type
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SortOrder* {.pure.} = enum
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Assending,
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Descending
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Query* = object
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key*: Key # Key to be queried
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value*: bool # Flag to indicate if data should be returned
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limit*: int # Max items to return - not available in all backends
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offset*: int # Offset from which to start querying - not available in all backends
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sort*: SortOrder # Sort order - not available in all backends
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QueryResponse* = tuple[key: ?Key, data: seq[byte]]
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QueryEndedError* = object of DatastoreError
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GetNext* = proc(): Future[?!QueryResponse] {.async: (raises: [CancelledError]), gcsafe, closure.}
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IterDispose* = proc(): Future[?!void] {.async: (raises: [CancelledError]), gcsafe.}
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QueryIter* = ref object
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finished*: bool
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disposed*: bool
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next*: GetNext
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dispose*: IterDispose
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iterator items*(q: QueryIter): Future[?!QueryResponse] =
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while not q.finished:
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yield q.next()
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proc defaultDispose(): Future[?!void] {.gcsafe, async: (raises: [CancelledError]).} =
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return success()
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proc new*(T: type QueryIter, dispose = defaultDispose): T =
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QueryIter(dispose: dispose)
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proc init*(
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T: type Query,
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key: Key,
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value = true,
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sort = SortOrder.Assending,
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offset = 0,
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limit = -1): T =
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T(
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key: key,
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value: value,
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sort: sort,
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offset: offset,
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limit: limit)
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