spark VertexPartitionBaseOps 源码

spark VertexPartitionBaseOps 代码

文件路径：/graphx/src/main/scala/org/apache/spark/graphx/impl/VertexPartitionBaseOps.scala

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.spark.graphx.impl

import scala.language.higherKinds
import scala.language.implicitConversions
import scala.reflect.ClassTag

import org.apache.spark.graphx._
import org.apache.spark.graphx.util.collection.GraphXPrimitiveKeyOpenHashMap
import org.apache.spark.internal.Logging
import org.apache.spark.util.collection.BitSet

/**
 * A class containing additional operations for subclasses of VertexPartitionBase that provide
 * implicit evidence of membership in the `VertexPartitionBaseOpsConstructor` typeclass (for
 * example, `VertexPartition.VertexPartitionOpsConstructor`).
 */
private[graphx] abstract class VertexPartitionBaseOps
    [VD: ClassTag, Self[X] <: VertexPartitionBase[X]: VertexPartitionBaseOpsConstructor]
    (self: Self[VD])
  extends Serializable with Logging {

  def withIndex(index: VertexIdToIndexMap): Self[VD]
  def withValues[VD2: ClassTag](values: Array[VD2]): Self[VD2]
  def withMask(mask: BitSet): Self[VD]

  /**
   * Pass each vertex attribute along with the vertex id through a map
   * function and retain the original RDD's partitioning and index.
   *
   * @tparam VD2 the type returned by the map function
   *
   * @param f the function applied to each vertex id and vertex
   * attribute in the RDD
   *
   * @return a new VertexPartition with values obtained by applying `f` to
   * each of the entries in the original VertexRDD.  The resulting
   * VertexPartition retains the same index.
   */
  def map[VD2: ClassTag](f: (VertexId, VD) => VD2): Self[VD2] = {
    // Construct a view of the map transformation
    val newValues = new Array[VD2](self.capacity)
    var i = self.mask.nextSetBit(0)
    while (i >= 0) {
      newValues(i) = f(self.index.getValue(i), self.values(i))
      i = self.mask.nextSetBit(i + 1)
    }
    this.withValues(newValues)
  }

  /**
   * Restrict the vertex set to the set of vertices satisfying the given predicate.
   *
   * @param pred the user defined predicate
   *
   * @note The vertex set preserves the original index structure which means that the returned
   *       RDD can be easily joined with the original vertex-set. Furthermore, the filter only
   *       modifies the bitmap index and so no new values are allocated.
   */
  def filter(pred: (VertexId, VD) => Boolean): Self[VD] = {
    // Allocate the array to store the results into
    val newMask = new BitSet(self.capacity)
    // Iterate over the active bits in the old mask and evaluate the predicate
    var i = self.mask.nextSetBit(0)
    while (i >= 0) {
      if (pred(self.index.getValue(i), self.values(i))) {
        newMask.set(i)
      }
      i = self.mask.nextSetBit(i + 1)
    }
    this.withMask(newMask)
  }

  /** Hides the VertexId's that are the same between `this` and `other`. */
  def minus(other: Self[VD]): Self[VD] = {
    if (self.index != other.index) {
      logWarning("Minus operations on two VertexPartitions with different indexes is slow.")
      minus(createUsingIndex(other.iterator))
    } else {
      self.withMask(self.mask.andNot(other.mask))
    }
  }

  /** Hides the VertexId's that are the same between `this` and `other`. */
  def minus(other: Iterator[(VertexId, VD)]): Self[VD] = {
    minus(createUsingIndex(other))
  }

  /**
   * Hides vertices that are the same between this and other. For vertices that are different, keeps
   * the values from `other`. The indices of `this` and `other` must be the same.
   */
  def diff(other: Self[VD]): Self[VD] = {
    if (self.index != other.index) {
      logWarning("Diffing two VertexPartitions with different indexes is slow.")
      diff(createUsingIndex(other.iterator))
    } else {
      val newMask = self.mask & other.mask
      var i = newMask.nextSetBit(0)
      while (i >= 0) {
        if (self.values(i) == other.values(i)) {
          newMask.unset(i)
        }
        i = newMask.nextSetBit(i + 1)
      }
      this.withValues(other.values).withMask(newMask)
    }
  }

  /** Left outer join another VertexPartition. */
  def leftJoin[VD2: ClassTag, VD3: ClassTag]
      (other: Self[VD2])
      (f: (VertexId, VD, Option[VD2]) => VD3): Self[VD3] = {
    if (self.index != other.index) {
      logWarning("Joining two VertexPartitions with different indexes is slow.")
      leftJoin(createUsingIndex(other.iterator))(f)
    } else {
      val newValues = new Array[VD3](self.capacity)

      var i = self.mask.nextSetBit(0)
      while (i >= 0) {
        val otherV: Option[VD2] = if (other.mask.get(i)) Some(other.values(i)) else None
        newValues(i) = f(self.index.getValue(i), self.values(i), otherV)
        i = self.mask.nextSetBit(i + 1)
      }
      this.withValues(newValues)
    }
  }

  /** Left outer join another iterator of messages. */
  def leftJoin[VD2: ClassTag, VD3: ClassTag]
      (other: Iterator[(VertexId, VD2)])
      (f: (VertexId, VD, Option[VD2]) => VD3): Self[VD3] = {
    leftJoin(createUsingIndex(other))(f)
  }

  /** Inner join another VertexPartition. */
  def innerJoin[U: ClassTag, VD2: ClassTag]
      (other: Self[U])
      (f: (VertexId, VD, U) => VD2): Self[VD2] = {
    if (self.index != other.index) {
      logWarning("Joining two VertexPartitions with different indexes is slow.")
      innerJoin(createUsingIndex(other.iterator))(f)
    } else {
      val newMask = self.mask & other.mask
      val newValues = new Array[VD2](self.capacity)
      var i = newMask.nextSetBit(0)
      while (i >= 0) {
        newValues(i) = f(self.index.getValue(i), self.values(i), other.values(i))
        i = newMask.nextSetBit(i + 1)
      }
      this.withValues(newValues).withMask(newMask)
    }
  }

  /**
   * Inner join an iterator of messages.
   */
  def innerJoin[U: ClassTag, VD2: ClassTag]
      (iter: Iterator[Product2[VertexId, U]])
      (f: (VertexId, VD, U) => VD2): Self[VD2] = {
    innerJoin(createUsingIndex(iter))(f)
  }

  /**
   * Similar effect as aggregateUsingIndex((a, b) => a)
   */
  def createUsingIndex[VD2: ClassTag](iter: Iterator[Product2[VertexId, VD2]])
    : Self[VD2] = {
    val newMask = new BitSet(self.capacity)
    val newValues = new Array[VD2](self.capacity)
    iter.foreach { pair =>
      val pos = self.index.getPos(pair._1)
      if (pos >= 0) {
        newMask.set(pos)
        newValues(pos) = pair._2
      }
    }
    this.withValues(newValues).withMask(newMask)
  }

  /**
   * Similar to innerJoin, but vertices from the left side that don't appear in iter will remain in
   * the partition, hidden by the bitmask.
   */
  def innerJoinKeepLeft(iter: Iterator[Product2[VertexId, VD]]): Self[VD] = {
    val newMask = new BitSet(self.capacity)
    val newValues = new Array[VD](self.capacity)
    System.arraycopy(self.values, 0, newValues, 0, newValues.length)
    iter.foreach { pair =>
      val pos = self.index.getPos(pair._1)
      if (pos >= 0) {
        newMask.set(pos)
        newValues(pos) = pair._2
      }
    }
    this.withValues(newValues).withMask(newMask)
  }

  def aggregateUsingIndex[VD2: ClassTag](
      iter: Iterator[Product2[VertexId, VD2]],
      reduceFunc: (VD2, VD2) => VD2): Self[VD2] = {
    val newMask = new BitSet(self.capacity)
    val newValues = new Array[VD2](self.capacity)
    iter.foreach { product =>
      val vid = product._1
      val vdata = product._2
      val pos = self.index.getPos(vid)
      if (pos >= 0) {
        if (newMask.get(pos)) {
          newValues(pos) = reduceFunc(newValues(pos), vdata)
        } else { // otherwise just store the new value
          newMask.set(pos)
          newValues(pos) = vdata
        }
      }
    }
    this.withValues(newValues).withMask(newMask)
  }

  /**
   * Construct a new VertexPartition whose index contains only the vertices in the mask.
   */
  def reindex(): Self[VD] = {
    val hashMap = new GraphXPrimitiveKeyOpenHashMap[VertexId, VD]
    val arbitraryMerge = (a: VD, b: VD) => a
    for ((k, v) <- self.iterator) {
      hashMap.setMerge(k, v, arbitraryMerge)
    }
    this.withIndex(hashMap.keySet).withValues(hashMap._values).withMask(hashMap.keySet.getBitSet)
  }

  /**
   * Converts a vertex partition (in particular, one of type `Self`) into a
   * `VertexPartitionBaseOps`. Within this class, this allows chaining the methods defined above,
   * because these methods return a `Self` and this implicit conversion re-wraps that in a
   * `VertexPartitionBaseOps`. This relies on the context bound on `Self`.
   */
  private implicit def toOps[VD2: ClassTag](partition: Self[VD2])
    : VertexPartitionBaseOps[VD2, Self] = {
    implicitly[VertexPartitionBaseOpsConstructor[Self]].toOps(partition)
  }
}

相关信息

spark 源码目录

相关文章

spark EdgePartition 源码

spark EdgePartitionBuilder 源码

spark EdgeRDDImpl 源码

spark GraphImpl 源码

spark ReplicatedVertexView 源码

spark RoutingTablePartition 源码

spark ShippableVertexPartition 源码

spark VertexPartition 源码

spark VertexPartitionBase 源码

spark VertexRDDImpl 源码