1 files changed, 71 insertions, 0 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/ProgressiveOutputStream.java b/src/jogl/classes/jogamp/opengl/util/pngj/ProgressiveOutputStream.java
new file mode 100644
index 000000000..bbec247fb
--- /dev/null
+++ b/src/jogl/classes/jogamp/opengl/util/pngj/ProgressiveOutputStream.java
@@ -0,0 +1,71 @@
+package jogamp.opengl.util.pngj;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+/**
+ * stream that outputs to memory and allows to flush fragments every 'size' bytes to some other destination
+ */
+abstract class ProgressiveOutputStream extends ByteArrayOutputStream {
+	private final int size;
+
+	public ProgressiveOutputStream(int size) {
+		this.size = size;
+	}
+
+	@Override
+	public final void close() throws IOException {
+		flush();
+		super.close();
+	}
+
+	@Override
+	public final void flush() throws IOException {
+		super.flush();
+		checkFlushBuffer(true);
+	}
+
+	@Override
+	public final void write(byte[] b, int off, int len) {
+		super.write(b, off, len);
+		checkFlushBuffer(false);
+	}
+
+	@Override
+	public final void write(byte[] b) throws IOException {
+		super.write(b);
+		checkFlushBuffer(false);
+	}
+
+	@Override
+	public final void write(int arg0) {
+		super.write(arg0);
+		checkFlushBuffer(false);
+	}
+
+	@Override
+	public final synchronized void reset() {
+		super.reset();
+	}
+
+	/**
+	 * if it's time to flush data (or if forced==true) calls abstract method flushBuffer() and cleans those bytes from
+	 * own buffer
+	 */
+	private final void checkFlushBuffer(boolean forced) {
+		while (forced || count >= size) {
+			int nb = size;
+			if (nb > count)
+				nb = count;
+			if (nb == 0)
+				return;
+			flushBuffer(buf, nb);
+			int bytesleft = count - nb;
+			count = bytesleft;
+			if (bytesleft > 0)
+				System.arraycopy(buf, nb, buf, 0, bytesleft);
+		}
+	}
+
+	public abstract void flushBuffer(byte[] b, int n);
+}
+\ No newline at end of file