- Add a configurable workspace to `evaluateTargetGraph`

- Break up `Hbt.scala` into `Args.scala` `Target.scala` and `Evaluator.scala`

1 files changed, 63 insertions, 0 deletions

diff --git a/src/main/scala/hbt/Evaluator.scala b/src/main/scala/hbt/Evaluator.scala
new file mode 100644
index 00000000..442ec633
--- /dev/null
+++ b/src/main/scala/hbt/Evaluator.scala
@@ -0,0 +1,63 @@
+package hbt
+
+import java.nio.{file => jnio}
+
+import sourcecode.Enclosing
+
+import scala.collection.mutable
+
+object Evaluator{
+
+
+  def apply[T](t: Target[T],
+               workspacePath: jnio.Path)
+              (implicit enclosing: Enclosing): T = {
+    jnio.Files.createDirectories(workspacePath)
+    val targetPaths = mutable.Map.empty[Target[_], List[String]]
+    def rec(t: Target[_], path: List[String]): Unit = {
+      if (targetPaths.contains(t)) () // do nothing
+      else {
+        val currentPath =
+          if (!t.label.startsWith(enclosing.value)) path.reverse
+          else t.label.stripPrefix(enclosing.value).drop(1).split('.').toList
+
+        targetPaths(t) = currentPath
+        t.inputs.zipWithIndex.foreach{case (c, i) => rec(c, i.toString :: currentPath)}
+      }
+    }
+    rec(t, Nil)
+    val targets = targetPaths.keys.toIndexedSeq
+    val targetIndices = targets.zipWithIndex.toMap
+
+    val numberedEdges =
+      for(i <- targets.indices)
+      yield targets(i).inputs.map(targetIndices)
+
+    val sortedClusters = Tarjans(numberedEdges)
+    val nonTrivialClusters = sortedClusters.filter(_.length > 1)
+    assert(nonTrivialClusters.isEmpty, nonTrivialClusters)
+
+    val results = mutable.Map.empty[Target[_], Any]
+    for (cluster <- sortedClusters){
+      val Seq(singletonIndex) = cluster
+      val target = targets(singletonIndex)
+      val inputResults = target.inputs.map(results)
+      val targetDestPath = workspacePath.resolve(
+        jnio.Paths.get(targetPaths(target).mkString("/"))
+      )
+      import collection.JavaConverters._
+      if (jnio.Files.exists(targetDestPath)){
+        jnio.Files.walk(targetDestPath).iterator()
+          .asScala
+          .toArray
+          .reverseIterator
+          .map(jnio.Files.deleteIfExists)
+      }
+
+      results(target) = target.evaluate(
+        new Args(inputResults.toIndexedSeq, targetDestPath)
+      )
+    }
+    results(t).asInstanceOf[T]
+  }
+}