43 lines
1.4 KiB
Nim
43 lines
1.4 KiB
Nim
# 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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## Aristo DB -- Obects Retrival Via Traversal Path
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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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"."/[aristo_desc, aristo_hike]
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# ------------------------------------------------------------------------------
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# Public functions
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# ------------------------------------------------------------------------------
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proc fetchPayload*(
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db: AristoDbRef;
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key: LeafTie;
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): Result[PayloadRef,(VertexID,AristoError)] =
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## Cascaded attempt to traverse the `Aristo Trie` and fetch the value of a
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## leaf vertex. This function is complementary to `merge()`.
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##
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let hike = key.hikeUp db
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if hike.error != AristoError(0):
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let vid =
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if hike.legs.len == 0: VertexID(0)
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else: hike.legs[^1].wp.vid
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return err((vid,hike.error))
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ok hike.legs[^1].wp.vtx.lData
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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