bisabelle-setup_2.12.1.1.0-RC1.source-code.Tar.scala Maven / Gradle / Ivy
package info.hupel.isabelle.setup
import java.net.URL
import java.nio.file._
import java.nio.file.attribute.PosixFilePermissions
import scala.util.Try
import org.apache.commons.compress.archivers.tar.{TarArchiveEntry, TarArchiveInputStream}
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream
import org.apache.commons.lang3.SystemUtils
/** Downloading and unpacking `tar` archives. All operations are blocking. */
object Tar {
val execPermissions = PosixFilePermissions.fromString("rwxr-xr-x")
def download(url: URL): Try[TarArchiveInputStream] =
Try(new TarArchiveInputStream(new GzipCompressorInputStream(url.openStream())))
def extractTo(path: Path, tar: TarArchiveInputStream): Try[Path] = Try {
def next() = Option(tar.getNextTarEntry())
@annotation.tailrec
def go(entry: Option[TarArchiveEntry], paths: List[Path]): List[Path] = entry match {
case None =>
paths.reverse
case Some(entry) =>
val name = entry.getName
val subpath = path.resolve(name).normalize
if (subpath.startsWith(path) && !Files.exists(subpath, LinkOption.NOFOLLOW_LINKS)) {
Files.createDirectories(subpath.getParent)
if (entry.isDirectory)
Files.createDirectory(subpath)
else if (entry.isSymbolicLink)
Files.createSymbolicLink(subpath, Paths.get(entry.getLinkName))
else if (entry.isLink)
Files.createLink(subpath, path.resolve(Paths.get(entry.getLinkName)))
else if (entry.isFile) {
Files.copy(tar, subpath)
if (!SystemUtils.IS_OS_WINDOWS && (entry.getMode % 2 == 1))
Files.setPosixFilePermissions(subpath, execPermissions)
}
else
sys.error("unknown tar file entry")
}
else
sys.error("malicious tar file or file already exists")
val p = if (entry.isDirectory) List(subpath) else Nil
go(next(), p ::: paths)
}
go(next(), Nil).foldLeft(List.empty[Path]) { (roots, path) =>
if (roots.exists(path.startsWith))
roots
else
path :: roots
} match {
case List(root) => root
case _ => sys.error("untarring created more than one root directory")
}
}
}