Performance improvements in CSS compiler

Author: dwins

geocss/src/main/scala/org/geoscript/geocss/Converter.scala

@@ -44,7 +44,7 @@ object Converter {
     writer.close()
   }
 
-  def main(args: Array[String]) = {
+  def main(args: Array[String]) {
     val (options, filenames) = parse(args)
 
     val write: (Seq[Rule], java.net.URL, OutputStream) => Unit = 

geocss/src/main/scala/org/geoscript/geocss/CssParser.scala

@@ -118,7 +118,7 @@ object CssParser extends RegexParsers {
       op <- "[><=]".r
       num <- number
       _ <- literal("]")
-    } yield PseudoSelector(id, op, num)
+    } yield PseudoSelector(id, op, num.toDouble)
 
   val pseudoClass = (":" ~> identifier) ^^ PseudoClass
 

geocss/src/main/scala/org/geoscript/geocss/Selector.scala

@@ -40,9 +40,9 @@ object Selector {
         case (Not(p), Not(q)) => implies(q, p)
         case (p, Not(q)) => !allows(p, q)
         case (PseudoSelector("scale", ">", a), PseudoSelector("scale", ">", b)) => 
-          b.toDouble <= a.toDouble
+          b <= a
         case (PseudoSelector("scale", "<", a), PseudoSelector("scale", "<", b)) => 
-          b.toDouble >= a.toDouble
+          b >= a
         case (DataFilter(f), DataFilter(g)) =>
           try {
             given(f).reduce(g) == ogc.Filter.INCLUDE
@@ -68,9 +68,9 @@ object Selector {
         case (Not(p), Not(q)) => allows(q, p)
         case (Not(p), q) => !implies(q, p)
         case (PseudoSelector("scale", ">", a), PseudoSelector("scale", "<", b)) => 
-          b.toDouble > a.toDouble
+          b > a
         case (PseudoSelector("scale", "<", a), PseudoSelector("scale", ">", b)) => 
-          b.toDouble < a.toDouble
+          b < a
         case (DataFilter(f), DataFilter(g)) =>
           try {
             given(f).reduce(g) != ogc.Filter.EXCLUDE
@@ -247,7 +247,7 @@ case class Typename(typename: String) extends MetaSelector {
  * property such as the scale denominator at render time.  This corresponds to
  * the [&64;scale &gt; 10000] syntax in CSS, for example.
  */
-case class PseudoSelector(property: String, operator: String, value: String)
+case class PseudoSelector(property: String, operator: String, value: Double)
 extends MetaSelector {
   override def toString = "@%s%s%s".format(property, operator, value)
 }

geocss/src/main/scala/org/geoscript/geocss/Translator.scala

@@ -590,8 +590,8 @@ class Translator(val baseURL: Option[java.net.URL]) {
     val scales = 
       flatten(And(rule.selectors))
         .collect { 
-          case PseudoSelector("scale", _, d) => d.toDouble
-          case Not(PseudoSelector("scale", _, d)) => d.toDouble
+          case PseudoSelector("scale", _, d) => d
+          case Not(PseudoSelector("scale", _, d)) => d
         }
         .sorted
         .distinct
@@ -613,8 +613,8 @@ class Translator(val baseURL: Option[java.net.URL]) {
     for {
       (rule, syms) <- group if syms.nonEmpty
       range @ (min, max) <- extractScaleRanges(rule)
-      minSelector = min.map(x => PseudoSelector("scale", ">", x.toString))
-      maxSelector = max.map(x => PseudoSelector("scale", "<", x.toString))
+      minSelector = min.map(x => PseudoSelector("scale", ">", x))
+      maxSelector = max.map(x => PseudoSelector("scale", "<", x))
       filter = reduce(allOf(rule.selectors ++ minSelector ++ maxSelector))
       if (filter != Exclude)
     } yield createSLDRule(min, max, realize(filter), rule.description.title, rule.description.abstrakt, syms)
@@ -687,7 +687,7 @@ class Translator(val baseURL: Option[java.net.URL]) {
         }
       reduced match {
         case And(sels) => sels
-        case sel               => Seq(sel)
+        case sel       => Seq(sel)
       }
     }
   }
@@ -736,7 +736,9 @@ class Translator(val baseURL: Option[java.net.URL]) {
       reduce[Selector](And(a.selectors ++ b.selectors)) == Exclude
 
     val cliques = maximalCliques(xs.toSet, mutuallyExclusive)
-    val combinations = enumerateCombinations(cliques)
+    val combinations = visit(cliques).map(_.toSet).toSet
+    // val oldCombinations = enumerateCombinations(cliques)
+    // println(s"${oldCombinations.size}, ${combinations.size}")
 
     val ExclusiveRule = EmptyRule.copy(selectors = Seq(Exclude))
 
@@ -751,13 +753,39 @@ class Translator(val baseURL: Option[java.net.URL]) {
       for {
         combo <- combinations
         remainder = xs filterNot(combo contains _)
-        included = include(combo)
+        included = include(combo.toSet)
         excluded = exclude(remainder)
         constrained = constrain(included, excluded)
         ruleset = simplifySelector(constrained)
-        if ruleset.isSatisfiable
+        if ruleset.isSatisfiable 
       } yield ruleset
 
+    // println(rulesets.size)
+    // rulesets.toSeq
+    Nil
     rulesets.toSeq
   }
+
+  import scala.annotation.tailrec
+
+  // @tailrec
+  def visit(cliques: Set[Set[Rule]]): Seq[List[Rule]] = {
+    def work[Rule](path: List[Rule], cliques: List[Set[Rule]]): Seq[List[Rule]] =
+        cliques match {
+          case Nil => 
+            Seq(path)
+          case top :: remainingCliques =>
+            val includingThisLevel: Seq[List[Rule]] = 
+              top.toSeq flatMap { i =>
+                val culledRemaining = 
+                  remainingCliques.filterNot(_ contains i).map(_ -- top)
+                work(i :: path, culledRemaining) // remainingCliques filterNot (_ contains i))
+              }
+           val excludingThisLevel: Seq[List[Rule]] =
+             work(path, remainingCliques)
+
+          includingThisLevel ++ excludingThisLevel
+        }
+    work(Nil, cliques.toList.sortBy(- _.size))
+  }
 }

geocss/src/main/scala/org/geoscript/geocss/filter/package.scala

@@ -134,15 +134,21 @@ package object filter {
     }
 
     class Value(val text: String) {
+      lazy val asDouble =
+        try {
+          Some(text.toDouble)
+        } catch {
+          case (_: NumberFormatException) => None
+        }
+
       override def toString = text
       override def equals(that: Any) =
         that match {
           case (that: Value) => 
-            try {
-              this.text.toDouble == that.text.toDouble
-            } catch {
-              case (_: NumberFormatException) => this.text == that.text
-            }
+            if (this.asDouble.isDefined && that.asDouble.isDefined) 
+              this.asDouble == that.asDouble
+            else
+              this.text == that.text
           case _ => false 
         }
     }
@@ -153,12 +159,14 @@ package object filter {
         apply(literal.getValue.toString)
 
       implicit val valuesAreOrdered: Ordering[Value] =
-        Ordering.fromLessThan { (a: Value, b: Value) =>
-          try {
-            a.text.toDouble < b.text.toDouble
-          } catch {
-            case (_: NumberFormatException) => a.text < b.text
-          }
+        new Ordering[Value] {
+          val dbl = implicitly[Ordering[Double]]
+          val str = implicitly[Ordering[String]]
+          def compare(x: Value, y: Value): Int =
+            if (x.asDouble.isDefined && y.asDouble.isDefined)
+              dbl.compare(x.asDouble.get, y.asDouble.get)
+            else
+              str.compare(x.text, y.text)
         }
     }
     case object Unconstrained extends Constraint