Spark 之 SparkPlanInfo

src/main/scala/org/apache/spark/sql/execution/SparkPlanInfo.scala

    new SparkPlanInfo(
      plan.nodeName,
      plan.simpleString(SQLConf.get.maxToStringFields),
      children.map(fromSparkPlan),
      metadata,
      metrics)

src/main/scala/org/apache/spark/sql/catalyst/plans/QueryPlan.scala

  override def simpleString(maxFields: Int): String = statePrefix + super.simpleString(maxFields)

src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala

  /**
   * ONE line description of this node.
   * @param maxFields Maximum number of fields that will be converted to strings.
   *                  Any elements beyond the limit will be dropped.
   */
  def simpleString(maxFields: Int): String = s"$nodeName ${argString(maxFields)}".trim

  /** Returns a string representing the arguments to this node, minus any children */
  def argString(maxFields: Int): String = stringArgs.flatMap {
    case tn: TreeNode[_] if allChildren.contains(tn) => Nil
    case Some(tn: TreeNode[_]) if allChildren.contains(tn) => Nil
    case Some(tn: TreeNode[_]) => tn.simpleString(maxFields) :: Nil
    case tn: TreeNode[_] => tn.simpleString(maxFields) :: Nil
    case seq: Seq[Any] if seq.toSet.subsetOf(allChildren.asInstanceOf[Set[Any]]) => Nil
    case iter: Iterable[_] if iter.isEmpty => Nil
    case array: Array[_] if array.isEmpty => Nil
    case xs @ (_: Seq[_] | _: Set[_] | _: Array[_]) =>
      formatArg(xs, maxFields) :: Nil
    case null => Nil
    case None => Nil
    case Some(null) => Nil
    case Some(table: CatalogTable) =>
      stringArgsForCatalogTable(table)
    case Some(any) => any :: Nil
    case map: CaseInsensitiveStringMap =>
      redactMapString(map.asCaseSensitiveMap().asScala, maxFields)
    case map: Map[_, _] =>
      redactMapString(map, maxFields)
    case t: TableSpec =>
      t.copy(properties = Utils.redact(t.properties).toMap,
        options = Utils.redact(t.options).toMap) :: Nil
    case table: CatalogTable =>
      stringArgsForCatalogTable(table)

    case other => other :: Nil
  }.mkString(", ")

src/main/scala/org/apache/spark/sql/catalyst/expressions/namedExpressions.scala

override def toString: String = s"$child AS $name#${exprId.id}$typeSuffix$delaySuffix"