107 lines
3.3 KiB
Nim
107 lines
3.3 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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## Read vertex record on the layered Aristo DB delta architecture
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## ==============================================================
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{.push raises: [].}
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import
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std/tables,
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stew/results,
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"."/aristo_desc
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type
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VidVtxPair* = object
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vid*: VertexID ## Table lookup vertex ID (if any)
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vtx*: VertexRef ## Reference to vertex
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# ------------------------------------------------------------------------------
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# Public functions
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# ------------------------------------------------------------------------------
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proc getVtxBackend*(
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db: AristoDbRef;
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vid: VertexID;
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): Result[VertexRef,AristoError] =
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## Get the vertex from the `backened` layer if available.
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let be = db.backend
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if not be.isNil:
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return be.getVtxFn vid
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err(GetVtxNotFound)
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proc getKeyBackend*(
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db: AristoDbRef;
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vid: VertexID;
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): Result[HashKey,AristoError] =
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## Get the merkle hash/key from the backend
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let be = db.backend
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if not be.isNil:
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return be.getKeyFn vid
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err(GetKeyNotFound)
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# ------------------
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proc getLeaf*(
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db: AristoDbRef;
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lty: LeafTie;
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): Result[VidVtxPair,AristoError] =
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## Get the vertex from the top layer by the `Patricia Trie` path. This
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## function does not search on the `backend` layer.
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let vid = db.top.lTab.getOrVoid lty
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if not vid.isValid:
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return err(GetLeafNotFound)
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let vtx = db.top.sTab.getOrVoid vid
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if not vtx.isValid:
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return err(GetVtxNotFound)
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ok VidVtxPair(vid: vid, vtx: vtx)
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proc getLeafVtx*(db: AristoDbRef; lty: LeafTie): VertexRef =
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## Variant of `getLeaf()` returning `nil` on error (while ignoring the
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## detailed error type information.)
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##
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let rc = db.getLeaf lty
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if rc.isOk:
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return rc.value.vtx
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# ------------------
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proc getVtx*(db: AristoDbRef; vid: VertexID): VertexRef =
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## Cascaded attempt to fetch a vertex from the top layer or the backend.
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## The function returns `nil` on error or failure.
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##
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if db.top.sTab.hasKey vid:
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# If the vertex is to be deleted on the backend, a `VertexRef(nil)` entry
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# is kept in the local table in which case it is OK to return this value.
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return db.top.sTab.getOrVoid vid
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let rc = db.getVtxBackend vid
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if rc.isOk:
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return rc.value
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VertexRef(nil)
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proc getKey*(db: AristoDbRef; vid: VertexID): HashKey =
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## Cascaded attempt to fetch a Merkle hash from the top layer or the backend.
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## The function returns `VOID_HASH_KEY` on error or failure.
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##
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if db.top.kMap.hasKey vid:
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# If the key is to be deleted on the backend, a `VOID_HASH_LABEL` entry
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# is kept on the local table in which case it is OK to return this value.
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return db.top.kMap.getOrVoid(vid).key
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let rc = db.getKeyBackend vid
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if rc.isOk:
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return rc.value
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VOID_HASH_KEY
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# ------------------------------------------------------------------------------
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# End
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# ------------------------------------------------------------------------------
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