mirror of
https://github.com/twitter/the-algorithm.git
synced 2024-06-13 06:38:52 +02:00
ef4c5eb65e
Please note we have force-pushed a new initial commit in order to remove some publicly-available Twitter user information. Note that this process may be required in the future.
84 lines
3.2 KiB
Scala
84 lines
3.2 KiB
Scala
package com.twitter.home_mixer.functional_component.selector
|
|
|
|
import com.twitter.home_mixer.functional_component.selector.DebunchCandidates.TrailingTweetsMinSize
|
|
import com.twitter.home_mixer.functional_component.selector.DebunchCandidates.TrailingTweetsPortionToKeep
|
|
import com.twitter.home_mixer.model.HomeFeatures.GetNewerFeature
|
|
import com.twitter.product_mixer.core.functional_component.common.CandidateScope
|
|
import com.twitter.product_mixer.core.functional_component.common.CandidateScope.PartitionedCandidates
|
|
import com.twitter.product_mixer.core.functional_component.selector.Selector
|
|
import com.twitter.product_mixer.core.functional_component.selector.SelectorResult
|
|
import com.twitter.product_mixer.core.model.common.presentation.CandidateWithDetails
|
|
import com.twitter.product_mixer.core.pipeline.PipelineQuery
|
|
|
|
trait MustDebunch {
|
|
def apply(candidate: CandidateWithDetails): Boolean
|
|
}
|
|
|
|
object DebunchCandidates {
|
|
val TrailingTweetsMinSize = 5
|
|
val TrailingTweetsPortionToKeep = 0.1
|
|
}
|
|
|
|
/**
|
|
* This selector rearranges the candidates to only allow bunches of size [[maxBunchSize]], where a
|
|
* bunch is a consecutive sequence of candidates that meet [[mustDebunch]].
|
|
*/
|
|
case class DebunchCandidates(
|
|
override val pipelineScope: CandidateScope,
|
|
mustDebunch: MustDebunch,
|
|
maxBunchSize: Int)
|
|
extends Selector[PipelineQuery] {
|
|
|
|
override def apply(
|
|
query: PipelineQuery,
|
|
remainingCandidates: Seq[CandidateWithDetails],
|
|
result: Seq[CandidateWithDetails]
|
|
): SelectorResult = {
|
|
val PartitionedCandidates(selectedCandidates, otherCandidates) =
|
|
pipelineScope.partition(remainingCandidates)
|
|
val mutableCandidates = collection.mutable.ListBuffer(selectedCandidates: _*)
|
|
|
|
var candidatePointer = 0
|
|
var nonDebunchPointer = 0
|
|
var bunchSize = 0
|
|
var finalNonDebunch = -1
|
|
|
|
while (candidatePointer < mutableCandidates.size) {
|
|
if (mustDebunch(mutableCandidates(candidatePointer))) bunchSize += 1
|
|
else {
|
|
bunchSize = 0
|
|
finalNonDebunch = candidatePointer
|
|
}
|
|
|
|
if (bunchSize > maxBunchSize) {
|
|
nonDebunchPointer = Math.max(candidatePointer, nonDebunchPointer)
|
|
while (nonDebunchPointer < mutableCandidates.size &&
|
|
mustDebunch(mutableCandidates(nonDebunchPointer))) {
|
|
nonDebunchPointer += 1
|
|
}
|
|
if (nonDebunchPointer == mutableCandidates.size)
|
|
candidatePointer = mutableCandidates.size
|
|
else {
|
|
val nextNonDebunch = mutableCandidates(nonDebunchPointer)
|
|
mutableCandidates.remove(nonDebunchPointer)
|
|
mutableCandidates.insert(candidatePointer, nextNonDebunch)
|
|
bunchSize = 0
|
|
finalNonDebunch = candidatePointer
|
|
}
|
|
}
|
|
|
|
candidatePointer += 1
|
|
}
|
|
|
|
val debunchedCandidates = if (query.features.exists(_.getOrElse(GetNewerFeature, false))) {
|
|
val trailingTweetsSize = mutableCandidates.size - finalNonDebunch - 1
|
|
val keepCandidates = finalNonDebunch + 1 +
|
|
Math.max(TrailingTweetsMinSize, TrailingTweetsPortionToKeep * trailingTweetsSize).toInt
|
|
mutableCandidates.toList.take(keepCandidates)
|
|
} else mutableCandidates.toList
|
|
|
|
val updatedCandidates = otherCandidates ++ debunchedCandidates
|
|
SelectorResult(remainingCandidates = updatedCandidates, result = result)
|
|
}
|
|
}
|