sbt.inc.ClassfileManager.scala Maven / Gradle / Ivy
package sbt.inc
import sbt.IO
import java.io.File
import collection.mutable
/**
* During an incremental compilation run, a ClassfileManager deletes class files and is notified of generated class files.
* A ClassfileManager can be used only once.
*/
trait ClassfileManager {
/**
* Called once per compilation step with the class files to delete prior to that step's compilation.
* The files in `classes` must not exist if this method returns normally.
* Any empty ancestor directories of deleted files must not exist either.
*/
def delete(classes: Iterable[File]): Unit
/** Called once per compilation step with the class files generated during that step.*/
def generated(classes: Iterable[File]): Unit
/** Called once at the end of the whole compilation run, with `success` indicating whether compilation succeeded (true) or not (false).*/
def complete(success: Boolean): Unit
}
object ClassfileManager {
/** Constructs a minimal ClassfileManager implementation that immediately deletes class files when requested. */
val deleteImmediately: () => ClassfileManager = () => new ClassfileManager {
def delete(classes: Iterable[File]): Unit = IO.deleteFilesEmptyDirs(classes)
def generated(classes: Iterable[File]): Unit = ()
def complete(success: Boolean): Unit = ()
}
@deprecated("Use overloaded variant that takes additional logger argument, instead.", "0.13.5")
def transactional(tempDir0: File): () => ClassfileManager =
transactional(tempDir0, sbt.Logger.Null)
/** When compilation fails, this ClassfileManager restores class files to the way they were before compilation.*/
def transactional(tempDir0: File, logger: sbt.Logger): () => ClassfileManager = () => new ClassfileManager {
val tempDir = tempDir0.getCanonicalFile
IO.delete(tempDir)
IO.createDirectory(tempDir)
logger.debug(s"Created transactional ClassfileManager with tempDir = $tempDir")
private[this] val generatedClasses = new mutable.HashSet[File]
private[this] val movedClasses = new mutable.HashMap[File, File]
private def showFiles(files: Iterable[File]): String = files.map(f => s"\t$f").mkString("\n")
def delete(classes: Iterable[File]): Unit = {
logger.debug(s"About to delete class files:\n${showFiles(classes)}")
val toBeBackedUp = classes.filter(c => c.exists && !movedClasses.contains(c) && !generatedClasses(c))
logger.debug(s"We backup classs files:\n${showFiles(toBeBackedUp)}")
for (c <- toBeBackedUp) {
movedClasses.put(c, move(c))
}
IO.deleteFilesEmptyDirs(classes)
}
def generated(classes: Iterable[File]): Unit = {
logger.debug(s"Registering generated classes:\n${showFiles(classes)}")
generatedClasses ++= classes
}
def complete(success: Boolean): Unit = {
if (!success) {
logger.debug("Rolling back changes to class files.")
logger.debug(s"Removing generated classes:\n${showFiles(generatedClasses)}")
IO.deleteFilesEmptyDirs(generatedClasses)
logger.debug(s"Restoring class files: \n${showFiles(movedClasses.keys)}")
for ((orig, tmp) <- movedClasses) IO.move(tmp, orig)
}
logger.debug(s"Removing the temporary directory used for backing up class files: $tempDir")
IO.delete(tempDir)
}
def move(c: File): File =
{
val target = File.createTempFile("sbt", ".class", tempDir)
IO.move(c, target)
target
}
}
}