Fix #21: Add file.usingLock util

pathikrit · Feb 2, 2017 · 6f95055 · 6f95055
1 parent febffb3
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diff --git a/README.md b/README.md
@@ -1,8 +1,8 @@
-# better-files [![License][licenseImg]][licenseLink] [![CircleCI][circleCiImg]][circleCiLink] [![Codacy][codacyImg]][codacyLink] [![Gitter][gitterImg]][gitterLink]
+# better-files [![License][licenseImg]][licenseLink] [![CircleCI][circleCiImg]][circleCiLink] [![Codacy][codacyImg]][codacyLink]
 
 `better-files` is a [dependency-free](build.sbt) *pragmatic* [thin Scala wrapper](core/src/main/scala/better/files/File.scala) around [Java NIO](https://docs.oracle.com/javase/tutorial/essential/io/fileio.html).
 
-## Talks
+## Talks [![Gitter][gitterImg]][gitterLink]
   - [ScalaDays NYC 2016][scalaDaysNyc2016Event] ([slides][scalaDaysNyc2016Slides])
 
   <a href="http://www.youtube.com/watch?feature=player_embedded&v=uaYKkpqs6CE" target="_blank">
@@ -40,7 +40,7 @@ libraryDependencies ++= Seq(
   "com.typesafe.akka"     %% "akka-actor"         % "2.4.16"
 )
 ```
-Latest `version`: [![Maven][mavenImg]][mavenLink]
+Latest `version`: [![Maven][mavenImg]][mavenLink] [![Scaladex][scaladexImg]][scaladexLink]
 
 Although this library is currently only actively developed for Scala 2.12, 
 you can find reasonably recent versions of this library for Scala 2.10 and 2.11 [here](https://oss.sonatype.org/#nexus-search;quick~better-files).
@@ -78,6 +78,9 @@ you can find reasonably recent versions of this library for Scala 2.10 and 2.11
 [gitterImg2]: https://badges.gitter.im/Join%20Chat.svg
 [gitterLink]: https://gitter.im/pathikrit/better-files
 
+[scaladexImg]: https://index.scala-lang.org/pathikrit/better-files/better-files/latest.svg
+[scaladexLink]: https://index.scala-lang.org/pathikrit/better-files
+
 [scaladocImg]: https://www.javadoc.io/badge/com.github.pathikrit/better-files_2.12.svg?color=blue&label=scaladocs
 <!--[scaladocLink]: https://www.javadoc.io/page/com.github.pathikrit/better-files_2.12/latest/better/files/File.html-->
 [scaladocLink]: http://pathikrit.github.io/better-files/latest/api/better/files/File.html

diff --git a/core/src/main/scala/better/files/File.scala b/core/src/main/scala/better/files/File.scala
@@ -434,17 +434,18 @@ class File private(val path: Path) {
   def isHidden: Boolean =
     Files.isHidden(path)
 
-  def isLocked(mode: File.RandomAccessMode, position: Long = 0L, size: Long = Long.MaxValue, isShared: Boolean = false): Boolean = {
-    val channel = newRandomAccess(mode).getChannel
+  def isLocked(mode: File.RandomAccessMode, position: Long = 0L, size: Long = Long.MaxValue, isShared: Boolean = false): Boolean =
     try {
-      channel.tryLock(position, size, isShared).release()
-      false
+      usingLock(mode) {channel =>
+        channel.tryLock(position, size, isShared).release()
+        false
+      }
     } catch {
       case _: OverlappingFileLockException | _: NonWritableChannelException | _: NonReadableChannelException => true
-    } finally {
-      channel.close()
     }
-  }
+
+  def usingLock[U](mode: File.RandomAccessMode)(f: FileChannel => U): U =
+    using(newRandomAccess(mode).getChannel)(f)
 
   def isReadLocked(position: Long = 0L, size: Long = Long.MaxValue, isShared: Boolean = false) =
     isLocked(File.RandomAccessMode.read, position, size, isShared)

diff --git a/core/src/main/scala/better/files/package.scala b/core/src/main/scala/better/files/package.scala
@@ -15,8 +15,11 @@ package object files extends Implicits {
   private[files] def newMultiMap[A, B]: mutable.MultiMap[A, B] = new mutable.HashMap[A, mutable.Set[B]] with mutable.MultiMap[A, B]
 
   @inline private[files] def when[A](condition: Boolean)(f: => A): Option[A] = if (condition) Some(f) else None
+
   @inline private[files] def repeat[U](n: Int)(f: => U): Unit = (1 to n).foreach(_ => f)
 
+  private[files] def using[A <: Closeable, U](resource: A)(f: A => U): U = try { f(resource) } finally {resource.close()}
+
   private[files] def produce[A](f: => A) = new {
     def till(hasMore: => Boolean): Iterator[A] = new Iterator[A] {
       override def hasNext = hasMore