mb.pie.runtime.exec.DistinctTaskKeyPriorityQueue.kt Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of pie.runtime Show documentation

PIE runtime

The newest version!

package mb.pie.runtime.exec

import mb.pie.api.Store
import mb.pie.api.TaskKey
import java.util.*

class DistinctTaskKeyPriorityQueue(comparator: Comparator) {
  private val queue = PriorityQueue(comparator)
  private val set = hashSetOf()

  companion object {
    fun withTransitiveDependencyComparator(store: Store) = DistinctTaskKeyPriorityQueue(DependencyComparator(store))
  }

  fun isNotEmpty(): Boolean {
    return queue.isNotEmpty()
  }

  fun contains(key: TaskKey): Boolean {
    return set.contains(key)
  }

  fun poll(): TaskKey {
    val key = queue.remove()
    set.remove(key)
    return key
  }

  fun pollLeastTaskWithDepTo(key: TaskKey, store: Store): TaskKey? {
    val queueCopy = PriorityQueue(queue)
    while(queueCopy.isNotEmpty()) {
      val queuedKey = queueCopy.poll()
      if(queuedKey == key || store.readTxn().use { txn -> txn.hasTransitiveTaskReq(key, queuedKey) }) {
        queue.remove(queuedKey)
        set.remove(queuedKey)
        return queuedKey
      }
    }
    return null
  }

  fun add(key: TaskKey) {
    if(set.contains(key)) return
    queue.add(key)
    set.add(key)
  }

  override fun toString() = queue.toString()
}

class DependencyComparator(private val store: Store) : Comparator {
  override fun compare(key1: TaskKey, key2: TaskKey): Int {
    return when {
      key1 == key2 -> 0
      store.readTxn().use { txn -> txn.hasTransitiveTaskReq(key1, key2) } -> 1
      else -> -1
    }
  }
}