nim-libp2p/libp2p/protocols/pubsub/timedcache.nim

57 lines
1.6 KiB
Nim

## Nim-LibP2P
## Copyright (c) 2019 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.
import tables, hashes
import chronos, chronicles
logScope:
topic = "TimedCache"
const Timeout* = 10 * 1000 # default timeout in ms
type
ExpireHandler*[V] = proc(val: V) {.gcsafe.}
TimedEntry*[V] = object of RootObj
val: V
handler: ExpireHandler[V]
TimedCache*[V] = ref object of RootObj
cache*: Table[string, TimedEntry[V]]
onExpire*: ExpireHandler[V]
proc newTimedCache*[V](): TimedCache[V] =
new result
result.cache = initTable[string, TimedEntry[V]]()
proc put*[V](t: TimedCache[V],
key: string,
val: V = "",
timeout: uint64 = Timeout,
handler: ExpireHandler[V] = nil) =
trace "adding entry to timed cache", key = key, val = val
t.cache[key] = TimedEntry[V](val: val, handler: handler)
# TODO: addTimer with param Duration is missing from chronos, needs to be added
addTimer(
timeout,
proc (arg: pointer = nil) {.gcsafe.} =
trace "deleting expired entry from timed cache", key = key, val = val
var entry = t.cache[key]
t.cache.del(key)
if not isNil(entry.handler):
entry.handler(entry.val)
)
proc contains*[V](t: TimedCache[V], key: string): bool =
t.cache.contains(key)
proc del*[V](t: TimedCache[V], key: string) =
trace "deleting entry from timed cache", key = key
t.cache.del(key)