mirror of https://github.com/vacp2p/nim-libp2p.git
67 lines
1.8 KiB
Nim
67 lines
1.8 KiB
Nim
# Nim-LibP2P
|
|
# Copyright (c) 2023 Status Research & Development GmbH
|
|
# Licensed under either of
|
|
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
|
|
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
|
|
# at your option.
|
|
# This file may not be copied, modified, or distributed except according to
|
|
# those terms.
|
|
|
|
{.push raises: [].}
|
|
|
|
import std/[sets, tables]
|
|
import rpc/[messages]
|
|
import results
|
|
|
|
export sets, tables, messages, results
|
|
|
|
type
|
|
CacheEntry* = object
|
|
msgId*: MessageId
|
|
topic*: string
|
|
|
|
MCache* = object of RootObj
|
|
msgs*: Table[MessageId, Message]
|
|
history*: seq[seq[CacheEntry]]
|
|
pos*: int
|
|
windowSize*: Natural
|
|
|
|
func get*(c: MCache, msgId: MessageId): Opt[Message] =
|
|
if msgId in c.msgs:
|
|
try:
|
|
Opt.some(c.msgs[msgId])
|
|
except KeyError:
|
|
raiseAssert "checked"
|
|
else:
|
|
Opt.none(Message)
|
|
|
|
func contains*(c: MCache, msgId: MessageId): bool =
|
|
msgId in c.msgs
|
|
|
|
func put*(c: var MCache, msgId: MessageId, msg: Message) =
|
|
if not c.msgs.hasKeyOrPut(msgId, msg):
|
|
# Only add cache entry if the message was not already in the cache
|
|
c.history[c.pos].add(CacheEntry(msgId: msgId, topic: msg.topic))
|
|
|
|
func window*(c: MCache, topic: string): HashSet[MessageId] =
|
|
let len = min(c.windowSize, c.history.len)
|
|
|
|
for i in 0 ..< len:
|
|
# Work backwards from `pos` in the circular buffer
|
|
for entry in c.history[(c.pos + c.history.len - i) mod c.history.len]:
|
|
if entry.topic == topic:
|
|
result.incl(entry.msgId)
|
|
|
|
func shift*(c: var MCache) =
|
|
# Shift circular buffer to write to a new position, clearing it from past
|
|
# iterations
|
|
c.pos = (c.pos + 1) mod c.history.len
|
|
|
|
for entry in c.history[c.pos]:
|
|
c.msgs.del(entry.msgId)
|
|
|
|
reset(c.history[c.pos])
|
|
|
|
func init*(T: type MCache, window, history: Natural): T =
|
|
T(history: newSeq[seq[CacheEntry]](history), windowSize: window)
|