forked from eldersantos/community
/
PathExpression.scala
76 lines (66 loc) · 2.98 KB
/
PathExpression.scala
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
/**
* 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.commands
import expressions.Expression
import org.neo4j.cypher.internal.symbols._
import org.neo4j.cypher.internal.pipes.matching.MatchingContext
import collection.Map
import org.neo4j.helpers.ThisShouldNotHappenError
import org.neo4j.graphdb.Path
import org.neo4j.cypher.internal.executionplan.builders.PatternGraphBuilder
case class PathExpression(pathPattern: Seq[Pattern])
extends Expression
with PathExtractor
with PatternGraphBuilder {
val identifiers: Seq[(String, CypherType)] = pathPattern.flatMap(pattern => pattern.possibleStartPoints.filterNot(p => p._1.startsWith(" UNNAMED")))
val symbols2 = new SymbolTable(identifiers.toMap)
val matchingContext = new MatchingContext(symbols2, Seq(), buildPatternGraph(symbols2, pathPattern))
val interestingPoints: Seq[String] = pathPattern.
flatMap(_.possibleStartPoints.map(_._1)).
filterNot(_.startsWith(" UNNAMED")).
distinct
def apply(m: Map[String, Any]): Any = {
val returnNull = interestingPoints.exists(key => m.get(key) match {
case None => throw new ThisShouldNotHappenError("Andres", "This execution plan should not exist.")
case Some(null) => true
case Some(x) => false
})
if (returnNull) {
null
} else {
getMatches(m.filterKeys(interestingPoints.contains)) //Only pass on to the pattern matcher
} //the points it should care about, nothing else.
}
def getMatches(v1: Map[String, Any]): Traversable[Path] = {
val matches = matchingContext.getMatches(v1)
matches.map(getPath)
}
def filter(f: (Expression) => Boolean): Seq[Expression] = Seq()
def rewrite(f: (Expression) => Expression): Expression = f(PathExpression(pathPattern.map(_.rewrite(f))))
def calculateType(symbols: SymbolTable): CypherType = {
pathPattern.foreach(_.assertTypes(symbols))
new IterableType( PathType() )
}
def symbolTableDependencies = {
val patternDependencies = pathPattern.flatMap(_.symbolTableDependencies).toSet
val startPointDependencies = pathPattern.flatMap(_.possibleStartPoints).map(_._1).filterNot(_.startsWith(" UNNAMED")).toSet
patternDependencies ++ startPointDependencies
}
}