1 files changed, 70 insertions, 0 deletions
diff --git a/main/api/src/mill/api/IO.scala b/main/api/src/mill/api/IO.scala
new file mode 100644
index 00000000..8fa5003d
--- /dev/null
+++ b/main/api/src/mill/api/IO.scala
@@ -0,0 +1,70 @@
+package mill.api
+
+import java.io.{InputStream, OutputStream}
+
+/**
+ * Misc IO utilities, eventually probably should be pushed upstream into
+ * ammonite-ops
+ */
+object IO {
+
+  /**
+    * Pump the data from the `src` stream into the `dest` stream.
+    */
+  def stream(src: InputStream, dest: OutputStream): Unit = {
+    val buffer = new Array[Byte](4096)
+    while ({
+      src.read(buffer) match {
+        case -1 => false
+        case n =>
+          dest.write(buffer, 0, n)
+          true
+      }
+    }) ()
+  }
+
+  /**
+   * Unpacks the given `src` path into the context specific destination directory.
+   * @param src The ZIP file
+   * @param dest The relative ouput folder under the context specifix destination directory.
+   * @param ctx The target context
+   * @return The [[PathRef]] to the unpacked folder.
+   */
+  def unpackZip(src: os.Path, dest: os.RelPath = "unpacked")(implicit ctx: Ctx.Dest): PathRef = {
+
+    val byteStream = os.read.inputStream(src)
+    val zipStream = new java.util.zip.ZipInputStream(byteStream)
+    while ({
+      zipStream.getNextEntry match {
+        case null => false
+        case entry =>
+          if (!entry.isDirectory) {
+            val entryDest = ctx.dest / dest / os.RelPath(entry.getName)
+            os.makeDir.all(entryDest / os.up)
+            val fileOut = new java.io.FileOutputStream(entryDest.toString)
+            IO.stream(zipStream, fileOut)
+            fileOut.close()
+          }
+          zipStream.closeEntry()
+          true
+      }
+    }) ()
+    PathRef(ctx.dest / dest)
+  }
+}
+
+import java.io.ByteArrayInputStream
+
+/**
+ * A dummy input stream containing an empty byte array.
+ */
+object DummyInputStream extends ByteArrayInputStream(Array())
+
+/**
+ * A dummy output stream that does nothing with what it consumes (think of it as `/dev/null`).
+ */
+object DummyOutputStream extends java.io.OutputStream {
+  override def write(b: Int): Unit = ()
+  override def write(b: Array[Byte]): Unit = ()
+  override def write(b: Array[Byte], off: Int, len: Int): Unit = ()
+}