1 files changed, 62 insertions, 0 deletions
diff --git a/javalib/src/main/scala/java/io/ByteArrayOutputStream.scala b/javalib/src/main/scala/java/io/ByteArrayOutputStream.scala
new file mode 100644
index 0000000..916002d
--- /dev/null
+++ b/javalib/src/main/scala/java/io/ByteArrayOutputStream.scala
@@ -0,0 +1,62 @@
+package java.io
+
+import scala.scalajs.js
+
+import scala.annotation.tailrec
+
+class ByteArrayOutputStream(initBufSize: Int) extends OutputStream {
+
+  protected var buf: Array[Byte] = new Array(initBufSize)
+  protected var count: Int = 0
+
+  def this() = this(32)
+
+  override def write(b: Int): Unit = {
+    if (count >= buf.length)
+      growBuf(1)
+
+    buf(count) = b.toByte
+    count += 1
+  }
+
+  override def write(b: Array[Byte], off: Int, len: Int): Unit = {
+    if (off < 0 || len < 0 || len > b.length - off)
+      throw new IndexOutOfBoundsException()
+
+    if (count + len > buf.length)
+      growBuf(len)
+
+    System.arraycopy(b, off, buf, count, len)
+    count += len
+  }
+
+  def writeTo(out: OutputStream): Unit =
+    out.write(buf, 0, count)
+
+  def reset(): Unit =
+    count = 0
+
+  def toByteArray(): Array[Byte] = {
+    val res = new Array[Byte](count)
+    System.arraycopy(buf, 0, res, 0, count)
+    res
+  }
+
+  def size(): Int = count
+
+  override def toString(): String =
+    new String(buf, 0, count)
+
+  def toString(charsetName: String): String =
+    new String(buf, 0, count, charsetName)
+
+  override def close(): Unit = ()
+
+  private def growBuf(minIncrement: Int): Unit = {
+    val newSize = Math.max(count + minIncrement, buf.length * 2)
+    val newBuf = new Array[Byte](newSize)
+    System.arraycopy(buf, 0, newBuf, 0, count)
+    buf = newBuf
+  }
+
+}