io.p8e.util.IterableExtensions.kt Maven / Gradle / Ivy

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A collection of services and libraries that iteract and run Provenance Java based contracts.

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package io.p8e.util

import org.slf4j.LoggerFactory
import java.time.Duration
import java.util.*
import java.util.concurrent.Callable
import java.util.concurrent.ExecutorService
import java.util.concurrent.TimeUnit

private val  Iterable.sizeOrDefault get() = if (this is Collection<*>) size else 10

private val defaultParmapTimeout = Duration.ofSeconds(10)
private val defaultMinThreadCount = 4
private val cpuBufferCount = 2

private val defaultThreadCount = Runtime.getRuntime().availableProcessors().let { cpus ->
    if (cpus < (defaultMinThreadCount + cpuBufferCount)) defaultMinThreadCount else cpus - cpuBufferCount
}.also {
    LoggerFactory.getLogger("defaultThreadPooler").info("defaultThreadCount:$it")
}

private val SHARED_FIXED_SIZE_THREAD_POOL: ExecutorService = ThreadPoolFactory.newFixedThreadPool(defaultThreadCount, "default-parmap-%d")

private fun  List.copy(): List = ArrayList(this)

private fun  Map.copy(): Map = HashMap(this)

fun  Iterable.parmapProv(exec: ExecutorService = SHARED_FIXED_SIZE_THREAD_POOL, transform: (T) -> R): List =
    Collections.synchronizedList(ArrayList(sizeOrDefault)).also { dest ->
        exec.invokeAll(this
            .map { Callable { dest += transform(it) } })
            .map { it.get() }
    }.copy()

fun  Map.parmapProv(exec: ExecutorService = SHARED_FIXED_SIZE_THREAD_POOL, transform: (K, V) -> R): Map =
    Collections.synchronizedMap(HashMap()).also { dest ->
        exec.invokeAll(this
            .map { Callable { dest += it.key to transform(it.key, it.value) } })
            .map { it.get(defaultParmapTimeout.toMillis(), TimeUnit.MILLISECONDS) }
    }.copy()