/
VariableLengthStepTrail.scala
151 lines (116 loc) · 4.8 KB
/
VariableLengthStepTrail.scala
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/**
* Copyright (c) 2002-2012 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.cypher.internal.pipes.matching
import org.neo4j.graphdb.{Relationship, Node, PropertyContainer, Direction}
import org.neo4j.cypher.internal.commands.{True, Pattern}
import org.neo4j.cypher.internal.pipes.MutableMaps
import org.neo4j.cypher.internal.symbols._
import org.neo4j.graphdb.DynamicRelationshipType._
import org.neo4j.cypher.PathImpl
final case class VariableLengthStepTrail(next: Trail,
dir: Direction,
typ: Seq[String],
min: Int,
max: Option[Int],
path: String,
relIterator: Option[String],
start: String,
pattern: Pattern) extends Trail {
def contains(target: String) = false
protected[matching] def decompose(p: Seq[PropertyContainer], m: Map[String, Any]) = {
var idx = min
var curr: Seq[PropertyContainer] = null
var left: Seq[PropertyContainer] = null
def checkRel(last: Node, r: Relationship) = (typ.contains(r.getType.name()) || typ.isEmpty) && (dir match {
case Direction.OUTGOING => r.getStartNode == last
case Direction.INCOMING => r.getEndNode == last
case _ => true
})
def checkPath(in: Seq[PropertyContainer]) = in.isEmpty || {
var last: Node = in.head.asInstanceOf[Node]
in.forall {
case n: Node => last = n; true
case r: Relationship => checkRel(last, r)
}
}
val x = p.splitAt(idx * 2)
curr = x._1
left = x._2
var result: Seq[(Seq[PropertyContainer], Map[String, Any])] = Seq.empty
val newNode = p.head
val oldNode = m.get(start)
if (oldNode.isEmpty || oldNode.get == newNode) {
val map = MutableMaps.create(m)
map += (start -> newNode)
var validRelationship = checkPath(curr)
while (validRelationship &&
idx <= max.getOrElse(idx) &&
left.nonEmpty) {
val currentPath = curr :+ left.head
map += (path -> PathImpl(currentPath: _*))
relIterator.foreach {
key => map += (key -> currentPath.filter(_.isInstanceOf[Relationship]))
}
//Add this result to the stack
//if our downstreams trail doesn't return anything,
//we'll also not return anything
result = result ++ next.decompose(left, map.toMap)
//Get more stuff from the remaining path
idx += 1
val x = p.splitAt(idx * 2)
curr = x._1
left = x._2
validRelationship = checkPath(curr)
}
}
result.toIterator
}
def pathDescription = next.pathDescription ++ Seq(path, end) ++ relIterator
def patterns = next.patterns :+ pattern
def predicates = next.predicates
def size = next.size + min + 1
def end = next.end
def symbols(table: SymbolTable) = {
val symbolTable = next.symbols(table).add(start, NodeType()).add(path, PathType())
//If we have a rel-iterator, let's include it
relIterator match {
case None => symbolTable
case Some(r) => symbolTable.add(r, new CollectionType(RelationshipType()))
}
}
def toSteps(id: Int): Option[ExpanderStep] = {
val steps = next.toSteps(id + 1)
Some(VarLengthStep(id, typ, dir, min, max, steps, True(), True()))
}
override def toString = {
val left = if (Direction.INCOMING == dir) "<" else ""
val right = if (Direction.OUTGOING == dir) ">" else ""
val t = typ match {
case List() => ""
case x => typ.mkString(":", "|", "")
}
val minimum = min.toString
val maximum = if(max.nonEmpty) max.get.toString else ""
"(%s)%s-[%s*%s..%s]-%s%s".format(start, left, t, minimum, maximum, right, next.toString)
}
def nodeNames = Seq(start) ++ next.nodeNames
def add(f: (String) => Trail) = copy(next = next.add(f))
def filter(f: (Trail) => Boolean):Iterable[Trail] = Some(this).filter(f) ++ next.filter(f)
}