Stop Stamped from inheriting File and TypedPath

In the FileTreeDataView use case, we were previously working with
FileTreeDataView[Stamped], which actually contained a lot of redundant
information because FileTreeDataView.Entry[_] has a toTypedPath method
that could be used to read the path related fields in Stamped. Instead,
we can just return the Stamp itself in FileTreeDataView.list* methods
and convert to Stamped.File where needed (i.e. in ExternalHooks).

Also move BasicKeys.globalFileTreeView to Keys since it isn't actually
used in the main-command project.

main-command/src/main/scala/sbt/BasicKeys.scala

@@ -15,6 +15,7 @@ import sbt.internal.server.ServerHandler
 import sbt.io.FileTreeDataView
 import sbt.librarymanagement.ModuleID
 import sbt.util.Level
+import xsbti.compile.analysis.Stamp
 
 object BasicKeys {
   val historyPath = AttributeKey[Option[File]](
@@ -102,11 +103,6 @@ object BasicKeys {
     "List of template resolver infos.",
     1000
   )
-  private[sbt] val globalFileTreeView = AttributeKey[FileTreeDataView[Stamped]](
-    "globalFileTreeView",
-    "provides a view into the file system that may or may not cache the tree in memory",
-    1000
-  )
 }
 
 case class TemplateResolverInfo(module: ModuleID, implementationClass: String)

main-command/src/main/scala/sbt/FileTreeViewConfig.scala

@@ -11,6 +11,7 @@ import sbt.internal.io.{ HybridPollingFileTreeRepository, WatchServiceBackedObse
 import sbt.io._
 import FileTreeDataView.{ Observable, Observer }
 import sbt.util.Logger
+import xsbti.compile.analysis.Stamp
 
 import scala.concurrent.duration._
 
@@ -18,15 +19,15 @@ import scala.concurrent.duration._
  * Configuration for viewing and monitoring the file system.
  */
 final class FileTreeViewConfig private (
-    val newDataView: () => FileTreeDataView[Stamped],
+    val newDataView: () => FileTreeDataView[Stamp],
     val newMonitor: (
-        FileTreeDataView[Stamped],
+        FileTreeDataView[Stamp],
         Seq[WatchSource],
         Logger
-    ) => FileEventMonitor[Stamped]
+    ) => FileEventMonitor[Stamp]
 )
 object FileTreeViewConfig {
-  private implicit class RepositoryOps(val repository: FileTreeRepository[Stamped]) {
+  private implicit class RepositoryOps(val repository: FileTreeRepository[Stamp]) {
     def register(sources: Seq[WatchSource]): Unit = sources foreach { s =>
       repository.register(s.base.toPath, if (s.recursive) Integer.MAX_VALUE else 0)
     }
@@ -34,10 +35,10 @@ object FileTreeViewConfig {
 
   /**
    * Create a new FileTreeViewConfig. This factory takes a generic parameter, T, that is bounded
-   * by {{{sbt.io.FileTreeDataView[Stamped]}}}. The reason for this is to ensure that a
+   * by {{{sbt.io.FileTreeDataView[Stamp]}}}. The reason for this is to ensure that a
    * sbt.io.FileTreeDataView that is instantiated by [[FileTreeViewConfig.newDataView]] can be
    * passed into [[FileTreeViewConfig.newMonitor]] without constraining the type of view to be
-   * {{{sbt.io.FileTreeDataView[Stamped]}}}.
+   * {{{sbt.io.FileTreeDataView[Stamp]}}}.
    * @param newDataView create a new sbt.io.FileTreeDataView. This value may be cached in a global
    *                    attribute
    * @param newMonitor create a new sbt.io.FileEventMonitor using the sbt.io.FileTreeDataView
@@ -45,13 +46,13 @@ object FileTreeViewConfig {
    * @tparam T the subtype of sbt.io.FileTreeDataView that is returned by [[FileTreeViewConfig.newDataView]]
    * @return a [[FileTreeViewConfig]] instance.
    */
-  def apply[T <: FileTreeDataView[Stamped]](
+  def apply[T <: FileTreeDataView[Stamp]](
       newDataView: () => T,
-      newMonitor: (T, Seq[WatchSource], Logger) => FileEventMonitor[Stamped]
+      newMonitor: (T, Seq[WatchSource], Logger) => FileEventMonitor[Stamp]
   ): FileTreeViewConfig =
     new FileTreeViewConfig(
       newDataView,
-      (view: FileTreeDataView[Stamped], sources: Seq[WatchSource], logger: Logger) =>
+      (view: FileTreeDataView[Stamp], sources: Seq[WatchSource], logger: Logger) =>
         newMonitor(view.asInstanceOf[T], sources, logger)
     )
 
@@ -71,7 +72,7 @@ object FileTreeViewConfig {
   ): FileTreeViewConfig =
     FileTreeViewConfig(
       () => FileTreeView.DEFAULT.asDataView(Stamped.converter),
-      (_: FileTreeDataView[Stamped], sources, logger) => {
+      (_: FileTreeDataView[Stamp], sources, logger) => {
         val ioLogger: sbt.io.WatchLogger = msg => logger.debug(msg.toString)
         FileEventMonitor.antiEntropy(
           new WatchServiceBackedObservable(
@@ -98,10 +99,10 @@ object FileTreeViewConfig {
   def default(antiEntropy: FiniteDuration): FileTreeViewConfig =
     FileTreeViewConfig(
       () => FileTreeRepository.default(Stamped.converter),
-      (repository: FileTreeRepository[Stamped], sources: Seq[WatchSource], logger: Logger) => {
+      (repository: FileTreeRepository[Stamp], sources: Seq[WatchSource], logger: Logger) => {
         repository.register(sources)
-        val copied = new Observable[Stamped] {
+        val copied = new Observable[Stamp] {
-          override def addObserver(observer: Observer[Stamped]): Int =
+          override def addObserver(observer: Observer[Stamp]): Int =
             repository.addObserver(observer)
           override def removeObserver(handle: Int): Unit = repository.removeObserver(handle)
           override def close(): Unit = {} // Don't close the underlying observable
@@ -156,7 +157,7 @@ object FileTreeViewConfig {
   ): FileTreeViewConfig = FileTreeViewConfig(
     () => FileTreeRepository.hybrid(Stamped.converter, pollingSources: _*),
     (
-        repository: HybridPollingFileTreeRepository[Stamped],
+        repository: HybridPollingFileTreeRepository[Stamp],
         sources: Seq[WatchSource],
         logger: Logger
     ) => {

main-command/src/main/scala/sbt/Stamped.scala

@@ -7,7 +7,7 @@
 
 package sbt
 
-import java.io.File
+import java.io.{ File => JFile }
 import java.nio.file.Path
 
 import sbt.internal.inc.Stamper
@@ -15,11 +15,12 @@ import sbt.io.TypedPath
 import xsbti.compile.analysis.Stamp
 
 /**
- * A File that has a [[Stamp]] value associated with it. In general, the stamp method should be
+ * A File that has a compile analysis Stamp value associated with it. In general, the stamp method
- * a cached value that can be read without doing any io. This can be used to improve performance
+ * should be a cached value that can be read without doing any io. This can be used to improve
- * anywhere where we need to check if files have changed before doing potentially expensive work.
+ * performance anywhere where we need to check if files have changed before doing potentially
+ * expensive work.
  */
-trait Stamped extends File with TypedPath {
+trait Stamped {
   def stamp: Stamp
 }
 
@@ -27,24 +28,25 @@ trait Stamped extends File with TypedPath {
  * Provides converter functions from TypedPath to [[Stamped]].
  */
 object Stamped {
+  type File = JFile with Stamped with TypedPath
+  def file(typedPath: TypedPath, stamp: Stamp): JFile with Stamped with TypedPath =
+    new StampedFileImpl(typedPath, stamp)
 
   /**
    * Converts a TypedPath instance to a [[Stamped]] by calculating the file hash.
    */
-  val sourceConverter: TypedPath => Stamped =
+  val sourceConverter: TypedPath => Stamp = tp => Stamper.forHash(tp.toPath.toFile)
-    new StampedImpl(_: TypedPath, forceLastModified = false)
 
   /**
    * Converts a TypedPath instance to a [[Stamped]] using the last modified time.
    */
-  val binaryConverter: TypedPath => Stamped =
+  val binaryConverter: TypedPath => Stamp = tp => Stamper.forLastModified(tp.toPath.toFile)
-    new StampedImpl(_: TypedPath, forceLastModified = true)
 
   /**
    * A combined convert that converts TypedPath instances representing *.jar and *.class files
    * using the last modified time and all other files using the file hash.
    */
-  val converter: TypedPath => Stamped = (tp: TypedPath) =>
+  val converter: TypedPath => Stamp = (tp: TypedPath) =>
     tp.toPath.toString match {
       case s if s.endsWith(".jar")   => binaryConverter(tp)
       case s if s.endsWith(".class") => binaryConverter(tp)
@@ -54,16 +56,15 @@ object Stamped {
   /**
    * Adds a default ordering that just delegates to the java.io.File.compareTo method.
    */
-  implicit case object ordering extends Ordering[Stamped] {
+  implicit case object ordering extends Ordering[Stamped.File] {
-    override def compare(left: Stamped, right: Stamped): Int = left.compareTo(right)
+    override def compare(left: Stamped.File, right: Stamped.File): Int = left.compareTo(right)
   }
 
-  private class StampedImpl(typedPath: TypedPath, forceLastModified: Boolean)
+  private final class StampedImpl(override val stamp: Stamp) extends Stamped
+  private final class StampedFileImpl(typedPath: TypedPath, override val stamp: Stamp)
       extends java.io.File(typedPath.toPath.toString)
-      with Stamped {
+      with Stamped
-    override val stamp: Stamp =
+      with TypedPath {
-      if (forceLastModified || typedPath.isDirectory) Stamper.forLastModified(this)
-      else Stamper.forHash(this)
     override def exists: Boolean = typedPath.exists
     override def isDirectory: Boolean = typedPath.isDirectory
     override def isFile: Boolean = typedPath.isFile

main-command/src/main/scala/sbt/Watched.scala

@@ -26,6 +26,7 @@ import sbt.internal.util.{ AttributeKey, JLine }
 import sbt.io.FileEventMonitor.{ Creation, Deletion, Event, Update }
 import sbt.io._
 import sbt.util.{ Level, Logger }
+import xsbti.compile.analysis.Stamp
 
 import scala.annotation.tailrec
 import scala.concurrent.duration._
@@ -146,11 +147,11 @@ object Watched {
   private[sbt] def onEvent(
       sources: Seq[WatchSource],
       projectSources: Seq[WatchSource]
-  ): Event[Stamped] => Watched.Action =
+  ): Event[Stamp] => Watched.Action =
     event =>
       if (sources.exists(_.accept(event.entry.typedPath.toPath))) Watched.Trigger
       else if (projectSources.exists(_.accept(event.entry.typedPath.toPath))) event match {
-        case Update(prev, cur, _) if prev.value.map(_.stamp) != cur.value.map(_.stamp) => Reload
+        case Update(prev, cur, _) if prev.value != cur.value => Reload
         case _: Creation[_] | _: Deletion[_]                 => Reload
         case _                                               => Ignore
       } else Ignore
@@ -458,7 +459,7 @@ trait WatchConfig {
    *
    * @return an sbt.io.FileEventMonitor instance.
    */
-  def fileEventMonitor: FileEventMonitor[Stamped]
+  def fileEventMonitor: FileEventMonitor[Stamp]
 
   /**
    * A function that is periodically invoked to determine whether the watch should stop or
@@ -481,7 +482,7 @@ trait WatchConfig {
    * @param event the detected sbt.io.FileEventMonitor.Event.
    * @return the next [[Watched.Action Action]] to run.
    */
-  def onWatchEvent(event: Event[Stamped]): Watched.Action
+  def onWatchEvent(event: Event[Stamp]): Watched.Action
 
   /**
    * Transforms the state after the watch terminates.
@@ -537,10 +538,10 @@ object WatchConfig {
    */
   def default(
       logger: Logger,
-      fileEventMonitor: FileEventMonitor[Stamped],
+      fileEventMonitor: FileEventMonitor[Stamp],
       handleInput: InputStream => Watched.Action,
       preWatch: (Int, Boolean) => Watched.Action,
-      onWatchEvent: Event[Stamped] => Watched.Action,
+      onWatchEvent: Event[Stamp] => Watched.Action,
       onWatchTerminated: (Watched.Action, String, State) => State,
       triggeredMessage: (TypedPath, Int) => Option[String],
       watchingMessage: Int => Option[String]
@@ -555,11 +556,11 @@ object WatchConfig {
     val wm = watchingMessage
     new WatchConfig {
       override def logger: Logger = l
-      override def fileEventMonitor: FileEventMonitor[Stamped] = fem
+      override def fileEventMonitor: FileEventMonitor[Stamp] = fem
       override def handleInput(inputStream: InputStream): Watched.Action = hi(inputStream)
       override def preWatch(count: Int, lastResult: Boolean): Watched.Action =
         pw(count, lastResult)
-      override def onWatchEvent(event: Event[Stamped]): Watched.Action = owe(event)
+      override def onWatchEvent(event: Event[Stamp]): Watched.Action = owe(event)
       override def onWatchTerminated(action: Watched.Action, command: String, state: State): State =
         owt(action, command, state)
       override def triggeredMessage(typedPath: TypedPath, count: Int): Option[String] =

main-command/src/test/scala/sbt/WatchedSpec.scala

@@ -17,6 +17,7 @@ import sbt.WatchedSpec._
 import sbt.io.FileEventMonitor.Event
 import sbt.io.{ FileEventMonitor, IO, TypedPath }
 import sbt.util.Logger
+import xsbti.compile.analysis.Stamp
 
 import scala.collection.mutable
 import scala.concurrent.duration._
@@ -26,11 +27,11 @@ class WatchedSpec extends FlatSpec with Matchers {
     private val fileTreeViewConfig = FileTreeViewConfig.default(50.millis)
     def config(
         sources: Seq[WatchSource],
-        fileEventMonitor: Option[FileEventMonitor[Stamped]] = None,
+        fileEventMonitor: Option[FileEventMonitor[Stamp]] = None,
         logger: Logger = NullLogger,
         handleInput: InputStream => Action = _ => Ignore,
         preWatch: (Int, Boolean) => Action = (_, _) => CancelWatch,
-        onWatchEvent: Event[Stamped] => Action = _ => Ignore,
+        onWatchEvent: Event[Stamp] => Action = _ => Ignore,
         triggeredMessage: (TypedPath, Int) => Option[String] = (_, _) => None,
         watchingMessage: Int => Option[String] = _ => None
     ): WatchConfig = {

main/src/main/scala/sbt/Defaults.scala

@@ -273,7 +273,7 @@ object Defaults extends BuildCommon {
       watchStartMessage := Watched.defaultStartWatch,
       fileTreeViewConfig := FileManagement.defaultFileTreeView.value,
       fileTreeView := state.value
-        .get(BasicKeys.globalFileTreeView)
+        .get(Keys.globalFileTreeView)
         .getOrElse(FileTreeView.DEFAULT.asDataView(Stamped.converter)),
       externalHooks := {
         val view = fileTreeView.value

main/src/main/scala/sbt/Keys.scala

@@ -31,6 +31,7 @@ import sbt.librarymanagement.ivy.{ Credentials, IvyConfiguration, IvyPaths, Upda
 import sbt.testing.Framework
 import sbt.util.{ Level, Logger }
 import xsbti.compile._
+import xsbti.compile.analysis.Stamp
 
 import scala.concurrent.duration.{ Duration, FiniteDuration }
 import scala.xml.{ NodeSeq, Node => XNode }
@@ -93,14 +94,14 @@ object Keys {
   @deprecated("This is no longer used for continuous execution", "1.3.0")
   val watch = SettingKey(BasicKeys.watch)
   val suppressSbtShellNotification = settingKey[Boolean]("""True to suppress the "Executing in batch mode.." message.""").withRank(CSetting)
-  val fileTreeView = taskKey[FileTreeDataView[Stamped]]("A view of the file system")
+  val fileTreeView = taskKey[FileTreeDataView[Stamp]]("A view of the file system")
   val pollInterval = settingKey[FiniteDuration]("Interval between checks for modified sources by the continuous execution command.").withRank(BMinusSetting)
   val pollingDirectories = settingKey[Seq[Watched.WatchSource]]("Directories that cannot be cached and must always be rescanned. Typically these will be NFS mounted or something similar.").withRank(DSetting)
   val watchAntiEntropy = settingKey[FiniteDuration]("Duration for which the watch EventMonitor will ignore events for a file after that file has triggered a build.").withRank(BMinusSetting)
   val watchConfig = taskKey[WatchConfig]("The configuration for continuous execution.").withRank(BMinusSetting)
   val watchLogger = taskKey[Logger]("A logger that reports watch events.").withRank(DSetting)
   val watchHandleInput = settingKey[InputStream => Watched.Action]("Function that is periodically invoked to determine if the continous build should be stopped or if a build should be triggered. It will usually read from stdin to respond to user commands.").withRank(BMinusSetting)
-  val watchOnEvent = taskKey[Event[Stamped] => Watched.Action]("Determines how to handle a file event").withRank(BMinusSetting)
+  val watchOnEvent = taskKey[Event[Stamp] => Watched.Action]("Determines how to handle a file event").withRank(BMinusSetting)
   val watchOnTermination = taskKey[(Watched.Action, String, State) => State]("Transforms the input state after the continuous build completes.").withRank(BMinusSetting)
   val watchService = settingKey[() => WatchService]("Service to use to monitor file system changes.").withRank(BMinusSetting)
   val watchProjectSources = taskKey[Seq[Watched.WatchSource]]("Defines the sources for the sbt meta project to watch to trigger a reload.").withRank(CSetting)
@@ -456,6 +457,11 @@ object Keys {
   val (executionRoots, dummyRoots) = Def.dummy[Seq[ScopedKey[_]]]("executionRoots", "The list of root tasks for this task execution.  Roots are the top-level tasks that were directly requested to be run.")
   val state = Def.stateKey
   val streamsManager = Def.streamsManagerKey
+  private[sbt] val globalFileTreeView = AttributeKey[FileTreeDataView[Stamp]](
+    "globalFileTreeView",
+    "Provides a view into the file system that may or may not cache the tree in memory",
+    1000
+  )
 
   val stateStreams = AttributeKey[Streams]("stateStreams", "Streams manager, which provides streams for different contexts.  Setting this on State will override the default Streams implementation.")
   val resolvedScoped = Def.resolvedScoped

main/src/main/scala/sbt/Main.scala

@@ -25,6 +25,7 @@ import sbt.io.syntax._
 import sbt.io.{ FileTreeDataView, IO }
 import sbt.util.{ Level, Logger, Show }
 import xsbti.compile.CompilerCache
+import xsbti.compile.analysis.Stamp
 
 import scala.annotation.tailrec
 import scala.concurrent.ExecutionContext
@@ -855,18 +856,18 @@ object BuiltinCommands {
     val extracted = Project.extract(s)
     try {
       def cleanup(): Unit = {
-        s.get(BasicKeys.globalFileTreeView).foreach(_.close())
+        s.get(Keys.globalFileTreeView).foreach(_.close())
-        s.attributes.remove(BasicKeys.globalFileTreeView)
+        s.attributes.remove(Keys.globalFileTreeView)
         s.get(Keys.taskRepository).foreach(_.close())
         s.attributes.remove(Keys.taskRepository)
         ()
       }
       val (_, config: FileTreeViewConfig) = extracted.runTask(Keys.fileTreeViewConfig, s)
-      val view: FileTreeDataView[Stamped] = config.newDataView()
+      val view: FileTreeDataView[Stamp] = config.newDataView()
       val newState = s.addExitHook(cleanup())
       cleanup()
       newState
-        .put(BasicKeys.globalFileTreeView, view)
+        .put(Keys.globalFileTreeView, view)
         .put(Keys.taskRepository, new TaskRepository.Repr)
     } catch {
       case NonFatal(_) => s

main/src/main/scala/sbt/internal/ExternalHooks.scala

@@ -20,17 +20,17 @@ import scala.collection.mutable
 
 private[sbt] object ExternalHooks {
   private val javaHome = Option(System.getProperty("java.home")).map(Paths.get(_))
-  def apply(options: CompileOptions, view: FileTreeDataView[Stamped]): DefaultExternalHooks = {
+  def apply(options: CompileOptions, view: FileTreeDataView[Stamp]): DefaultExternalHooks = {
     import scala.collection.JavaConverters._
     val sources = options.sources()
     val cachedSources = new java.util.HashMap[File, Stamp]
-    val converter: File => Stamp = f => Stamped.sourceConverter(TypedPath(f.toPath)).stamp
+    val converter: File => Stamp = f => Stamped.sourceConverter(TypedPath(f.toPath))
     sources.foreach {
       case sf: Stamped => cachedSources.put(sf, sf.stamp)
       case f: File     => cachedSources.put(f, converter(f))
     }
     view match {
-      case r: FileTreeRepository[Stamped] =>
+      case r: FileTreeRepository[Stamp] =>
         r.register(options.classesDirectory.toPath, Integer.MAX_VALUE)
         options.classpath.foreach { f =>
           r.register(f.toPath, Integer.MAX_VALUE)
@@ -41,7 +41,7 @@ private[sbt] object ExternalHooks {
     options.classpath.foreach { f =>
       view.listEntries(f.toPath, Integer.MAX_VALUE, _ => true) foreach { e =>
         e.value match {
-          case Right(value) => allBinaries.put(e.typedPath.toPath.toFile, value.stamp)
+          case Right(value) => allBinaries.put(e.typedPath.toPath.toFile, value)
           case _            =>
         }
       }
@@ -49,7 +49,7 @@ private[sbt] object ExternalHooks {
       // rather than a directory.
       view.listEntries(f.toPath, -1, _ => true) foreach { e =>
         e.value match {
-          case Right(value) => allBinaries.put(e.typedPath.toPath.toFile, value.stamp)
+          case Right(value) => allBinaries.put(e.typedPath.toPath.toFile, value)
           case _            =>
         }
       }

main/src/main/scala/sbt/internal/FileManagement.scala

@@ -16,6 +16,7 @@ import sbt.io.syntax.File
 import sbt.io.{ FileFilter, FileTreeDataView, FileTreeRepository }
 import sbt._
 import BasicCommandStrings.ContinuousExecutePrefix
+import xsbti.compile.analysis.Stamp
 
 private[sbt] object FileManagement {
   private[sbt] def defaultFileTreeView: Def.Initialize[Task[FileTreeViewConfig]] = Def.task {
@@ -51,17 +52,19 @@ private[sbt] object FileManagement {
       val view = fileTreeView.value
       val include = filter.toTask.value
       val ex = excludes.toTask.value
-      val sourceFilter: Entry[Stamped] => Boolean = (entry: Entry[Stamped]) => {
+      val sourceFilter: Entry[Stamp] => Boolean = (entry: Entry[Stamp]) => {
-        entry.value match {
+        val typedPath = entry.typedPath
-          case Right(sf) => include.accept(sf) && !ex.accept(sf)
+        val file = new java.io.File(typedPath.toPath.toString) {
-          case _         => false
+          override def isDirectory: Boolean = typedPath.isDirectory
+          override def isFile: Boolean = typedPath.isFile
         }
+        include.accept(file) && !ex.accept(file)
       }
       sourceDirs.flatMap { dir =>
         view.register(dir.toPath, maxDepth = Integer.MAX_VALUE)
         view
           .listEntries(dir.toPath, maxDepth = Integer.MAX_VALUE, sourceFilter)
-          .map(e => e.value.getOrElse(e.typedPath.toPath.toFile))
+          .flatMap(e => e.value.toOption.map(Stamped.file(e.typedPath, _)))
       }
     }
 
@@ -93,7 +96,7 @@ private[sbt] object FileManagement {
                 f.accept(file) && !excl.accept(file)
               }
             )
-            .flatMap(_.value.toOption)
+            .flatMap(e => e.value.toOption.map(Stamped.file(e.typedPath, _)))
       } else sources
     }
   )