the-algorithm/home-mixer/server/src/main/scala/com/twitter/home_mixer/product/scored_tweets/filter/DuplicateConversationTweetsFilter.scala

38 lines
1.6 KiB
Scala

package com.twitter.home_mixer.product.scored_tweets.filter
import com.twitter.home_mixer.model.HomeFeatures.AncestorsFeature
import com.twitter.home_mixer.util.CandidatesUtil
import com.twitter.product_mixer.component_library.model.candidate.TweetCandidate
import com.twitter.product_mixer.core.functional_component.filter.Filter
import com.twitter.product_mixer.core.functional_component.filter.FilterResult
import com.twitter.product_mixer.core.model.common.CandidateWithFeatures
import com.twitter.product_mixer.core.model.common.identifier.FilterIdentifier
import com.twitter.product_mixer.core.pipeline.PipelineQuery
import com.twitter.stitch.Stitch
/**
* Remove any candidate that is in the ancestor list of any reply, including retweets of ancestors.
*
* E.g. if B replied to A and D was a retweet of A, we would prefer to drop D since otherwise
* we may end up serving the same tweet twice in the timeline (e.g. serving both A->B and D).
*/
object DuplicateConversationTweetsFilter extends Filter[PipelineQuery, TweetCandidate] {
override val identifier: FilterIdentifier = FilterIdentifier("DuplicateConversationTweets")
override def apply(
query: PipelineQuery,
candidates: Seq[CandidateWithFeatures[TweetCandidate]]
): Stitch[FilterResult[TweetCandidate]] = {
val allAncestors = candidates
.flatMap(_.features.getOrElse(AncestorsFeature, Seq.empty))
.map(_.tweetId).toSet
val (kept, removed) = candidates.partition { candidate =>
!allAncestors.contains(CandidatesUtil.getOriginalTweetId(candidate))
}
Stitch.value(FilterResult(kept = kept.map(_.candidate), removed = removed.map(_.candidate)))
}
}