coursier.internal.InMemoryCachingFetcher.scala Maven / Gradle / Ivy
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package coursier.internal
import java.util.concurrent.ConcurrentHashMap
import coursier.core.{Artifact, Repository}
import coursier.util.{EitherT, Sync}
/** For benchmarking purposes */
final class InMemoryCachingFetcher[F[_]](underlying: Repository.Fetch[F])(implicit S: Sync[F]) {
@volatile private var onlyCache0 = false
private val cache = new ConcurrentHashMap[Artifact, Either[String, String]]
private val byUrl = new ConcurrentHashMap[String, Either[String, String]]
def onlyCache(): Unit = {
onlyCache0 = true
}
def fromCache(url: String): String =
Option(byUrl.get(url)) match {
case None =>
throw new NoSuchElementException(url)
case Some(Left(err)) =>
sys.error(s"$url is errored: $err")
case Some(Right(s)) => s
}
def fetcher: Repository.Fetch[F] =
artifact =>
EitherT {
Option(cache.get(artifact)) match {
case None =>
if (onlyCache0)
S.fromAttempt(Left(new NoSuchElementException(s"Artifact $artifact")))
else
S.map(underlying(artifact).run) { res =>
val res0 = Option(cache.putIfAbsent(artifact, res))
.getOrElse(res)
byUrl.putIfAbsent(artifact.url, res0)
res0
}
case Some(res) => S.point(res)
}
}
}