63 lines
2.0 KiB
Scala
63 lines
2.0 KiB
Scala
package com.twitter.recos.user_video_graph
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import com.twitter.graphjet.bipartite.api.EdgeTypeMask
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import com.twitter.recos.util.Action
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/**
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* The bit mask is used to encode edge types in the top bits of an integer,
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* e.g. favorite, retweet, reply and click. Under current segment configuration, each segment
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* stores up to 128M edges. Assuming that each node on one side is unique, each segment
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* stores up to 128M unique nodes on one side, which occupies the lower 27 bits of an integer.
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* This leaves five bits to encode the edge types, which at max can store 32 edge types.
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* The following implementation utilizes the top four bits and leaves one free bit out.
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*/
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class UserVideoEdgeTypeMask extends EdgeTypeMask {
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import UserVideoEdgeTypeMask._
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override def encode(node: Int, edgeType: Byte): Int = {
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if (edgeType < 0 || edgeType > SIZE) {
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throw new IllegalArgumentException("encode: Illegal edge type argument " + edgeType)
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} else {
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node | (edgeType << 28)
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}
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}
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override def edgeType(node: Int): Byte = {
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(node >>> 28).toByte
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}
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override def restore(node: Int): Int = {
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node & MASK
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}
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}
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object UserVideoEdgeTypeMask extends Enumeration {
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type UserTweetEdgeTypeMask = Value
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/**
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* Byte values corresponding to the action taken on a tweet, which will be encoded in the
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* top 4 bits in a tweet Id
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* NOTE: THERE CAN ONLY BE UP TO 16 TYPES
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*/
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val VideoPlayback50: UserTweetEdgeTypeMask = Value(1)
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/**
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* Reserve the top four bits of each integer to encode the edge type information.
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*/
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val MASK: Int = Integer.parseInt("00001111111111111111111111111111", 2)
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val SIZE: Int = this.values.size
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/**
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* Converts the action byte in the RecosHoseMessage into GraphJet internal byte mapping
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*/
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def actionTypeToEdgeType(actionByte: Byte): Byte = {
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val edgeType = Action(actionByte) match {
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case Action.VideoPlayback50 => VideoPlayback50.id
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case _ =>
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throw new IllegalArgumentException("getEdgeType: Illegal edge type argument " + actionByte)
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}
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edgeType.toByte
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}
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}
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