From a1542ce2f33ad365ff437d2d3014b9de2f6670e5 Mon Sep 17 00:00:00 2001 From: Cheng Lian Date: Wed, 2 Dec 2015 09:36:12 -0800 Subject: [SPARK-12094][SQL] Prettier tree string for TreeNode When examining plans of complex queries with multiple joins, a pain point of mine is that, it's hard to immediately see the sibling node of a specific query plan node. This PR adds tree lines for the tree string of a `TreeNode`, so that the result can be visually more intuitive. Author: Cheng Lian Closes #10099 from liancheng/prettier-tree-string. --- .../apache/spark/sql/catalyst/trees/TreeNode.scala | 31 ++++++++++++++++++---- 1 file changed, 26 insertions(+), 5 deletions(-) (limited to 'sql/catalyst') diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala index ad2bd78430..dfea583e01 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/trees/TreeNode.scala @@ -393,7 +393,7 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product { override def toString: String = treeString /** Returns a string representation of the nodes in this tree */ - def treeString: String = generateTreeString(0, new StringBuilder).toString + def treeString: String = generateTreeString(0, Nil, new StringBuilder).toString /** * Returns a string representation of the nodes in this tree, where each operator is numbered. @@ -419,12 +419,33 @@ abstract class TreeNode[BaseType <: TreeNode[BaseType]] extends Product { } } - /** Appends the string represent of this node and its children to the given StringBuilder. */ - protected def generateTreeString(depth: Int, builder: StringBuilder): StringBuilder = { - builder.append(" " * depth) + /** + * Appends the string represent of this node and its children to the given StringBuilder. + * + * The `i`-th element in `lastChildren` indicates whether the ancestor of the current node at + * depth `i + 1` is the last child of its own parent node. The depth of the root node is 0, and + * `lastChildren` for the root node should be empty. + */ + protected def generateTreeString( + depth: Int, lastChildren: Seq[Boolean], builder: StringBuilder): StringBuilder = { + if (depth > 0) { + lastChildren.init.foreach { isLast => + val prefixFragment = if (isLast) " " else ": " + builder.append(prefixFragment) + } + + val branch = if (lastChildren.last) "+- " else ":- " + builder.append(branch) + } + builder.append(simpleString) builder.append("\n") - children.foreach(_.generateTreeString(depth + 1, builder)) + + if (children.nonEmpty) { + children.init.foreach(_.generateTreeString(depth + 1, lastChildren :+ false, builder)) + children.last.generateTreeString(depth + 1, lastChildren :+ true, builder) + } + builder } -- cgit v1.2.3