2025-02-05 15:59:48 +01:00

95 lines
2.1 KiB
Nim

import pkg/chronos
import pkg/chronicles
import pkg/metrics
import pkg/datastore
import pkg/datastore/typedds
import pkg/stew/byteutils
import pkg/stew/endians2
import pkg/questionable
import pkg/questionable/results
import std/os
import std/times
import std/options
import std/tables
import std/strutils
logScope:
topics = "list"
type
OnUpdateMetric = proc(value: int64): void {.gcsafe, raises:[].}
Entry* = object
id*: string # will be node ID
value*: string
List* = ref object
name: string
store: TypedDatastore
items: seq[Entry]
onMetric: OnUpdateMetric
proc `$`*(entry: Entry): string =
entry.id & ":" & entry.value
proc encode(s: Entry): seq[byte] =
(s.id & ";" & s.value).toBytes()
proc decode(T: type Entry, bytes: seq[byte]): ?!T =
let s = string.fromBytes(bytes)
if s.len == 0:
return success(Entry(id: "", value: ""))
let tokens = s.split(";")
if tokens.len != 2:
return failure("expected 2 tokens")
success(Entry(
id: tokens[0],
value: tokens[1]
))
proc saveItem(this: List, item: Entry): Future[?!void] {.async.} =
without itemKey =? Key.init(this.name / item.id), err:
return failure(err)
? await this.store.put(itemKey, item)
return success()
proc load*(this: List): Future[?!void] {.async.}=
without queryKey =? Key.init(this.name), err:
return failure(err)
without iter =? (await query[Entry](this.store, Query.init(queryKey))), err:
return failure(err)
while not iter.finished:
without item =? (await iter.next()), err:
return failure(err)
without value =? item.value, err:
return failure(err)
if value.id.len > 0:
this.items.add(value)
info "Loaded list", name = this.name, items = this.items.len
return success()
proc new*(
_: type List,
name: string,
store: TypedDatastore,
onMetric: OnUpdateMetric
): List =
List(
name: name,
store: store,
items: newSeq[Entry](),
onMetric: onMetric
)
proc add*(this: List, item: Entry): Future[?!void] {.async.} =
this.items.add(item)
this.onMetric(this.items.len.int64)
if err =? (await this.saveItem(item)).errorOption:
return failure(err)
return success()