+package be.nikiroo.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * A simple {@link OutputStream} that is buffered with a bytes array.
+ * <p>
+ * It is mostly intended to be used as a base class to create new
+ * {@link OutputStream}s with special operation modes, and to give some default
+ * methods.
+ *
+ * @author niki
+ */
+public class BufferedOutputStream extends OutputStream {
+ /** The current position in the buffer. */
+ protected int start;
+ /** The index of the last usable position of the buffer. */
+ protected int stop;
+ /** The buffer itself. */
+ protected byte[] buffer;
+ /** An End-Of-File (or buffer, here) marker. */
+ protected boolean eof;
+
+ private boolean closed;
+ private OutputStream out;
+ private int openCounter;
+
+ private long bytesWritten;
+
+ /**
+ * Create a new {@link BufferedInputStream} that wraps the given
+ * {@link InputStream}.
+ *
+ * @param out
+ * the {@link OutputStream} to wrap
+ */
+ public BufferedOutputStream(OutputStream out) {
+ this.out = out;
+
+ this.buffer = new byte[4096];
+ this.start = 0;
+ this.stop = 0;
+ }
+
+ @Override
+ public void write(int b) throws IOException {
+ checkClose();
+
+ if (available() <= 0) {
+ flush(false);
+ }
+
+ buffer[start++] = (byte) b;
+ }
+
+ @Override
+ public void write(byte[] b) throws IOException {
+ write(b, 0, b.length);
+ }
+
+ @Override
+ public void write(byte[] source, int sourceOffset, int sourceLength)
+ throws IOException {
+
+ checkClose();
+
+ if (source == null) {
+ throw new NullPointerException();
+ } else if ((sourceOffset < 0) || (sourceOffset > source.length)
+ || (sourceLength < 0)
+ || ((sourceOffset + sourceLength) > source.length)
+ || ((sourceOffset + sourceLength) < 0)) {
+ throw new IndexOutOfBoundsException();
+ } else if (sourceLength == 0) {
+ return;
+ }
+
+ if (sourceLength >= buffer.length) {
+ /*
+ * If the request length exceeds the size of the output buffer,
+ * flush the output buffer and then write the data directly. In this
+ * way buffered streams will cascade harmlessly.
+ */
+ flush(false);
+ out.write(source, sourceOffset, sourceLength);
+ return;
+ }
+
+ int done = 0;
+ while (done < sourceLength) {
+ if (available() <= 0) {
+ flush(false);
+ }
+
+ int now = Math.min(sourceLength, available());
+ System.arraycopy(source, sourceOffset + done, buffer, stop, now);
+ stop += now;
+ done += now;
+ }
+ }
+
+ /**
+ * The available space in the buffer.
+ *
+ * @return the space in bytes
+ */
+ private int available() {
+ if (closed) {
+ return 0;
+ }
+
+ return Math.max(0, buffer.length - stop - 1);
+ }
+
+ /**
+ * The number of bytes written to the under-laying {@link OutputStream}.
+ *
+ * @return the number of bytes
+ */
+ public long getBytesWritten() {
+ return bytesWritten;
+ }
+
+ /**
+ * Return this very same {@link BufferedInputStream}, but keep a counter of
+ * how many streams were open this way. When calling
+ * {@link BufferedInputStream#close()}, decrease this counter if it is not
+ * already zero instead of actually closing the stream.
+ * <p>
+ * You are now responsible for it — you <b>must</b> close it.
+ * <p>
+ * This method allows you to use a wrapping stream around this one and still
+ * close the wrapping stream.
+ *
+ * @return the same stream, but you are now responsible for closing it
+ *
+ * @throws IOException
+ * in case of I/O error or if the stream is closed
+ */
+ public synchronized OutputStream open() throws IOException {
+ checkClose();
+ openCounter++;
+ return this;
+ }
+
+ /**
+ * Check that the stream was not closed, and throw an {@link IOException} if
+ * it was.
+ *
+ * @throws IOException
+ * if it was closed
+ */
+ protected void checkClose() throws IOException {
+ if (closed) {
+ throw new IOException(
+ "This BufferedInputStream was closed, you cannot use it anymore.");
+ }
+ }
+
+ @Override
+ public void flush() throws IOException {
+ flush(true);
+ }
+
+ /**
+ * Flush the {@link BufferedOutputStream}, and optionally the under-laying
+ * stream, too.
+ *
+ * @param includingSubStream
+ * also flush the under-laying stream
+ * @throws IOException
+ * in case of I/O error
+ */
+ private void flush(boolean includingSubStream) throws IOException {
+ out.write(buffer, start, stop - start);
+ bytesWritten += (stop - start);
+ start = 0;
+ stop = 0;
+ if (includingSubStream) {
+ out.flush();
+ }
+ }
+
+ /**
+ * Closes this stream and releases any system resources associated with the
+ * stream.
+ * <p>
+ * Including the under-laying {@link InputStream}.
+ * <p>
+ * <b>Note:</b> if you called the {@link BufferedInputStream#open()} method
+ * prior to this one, it will just decrease the internal count of how many
+ * open streams it held and do nothing else. The stream will actually be
+ * closed when you have called {@link BufferedInputStream#close()} once more
+ * than {@link BufferedInputStream#open()}.
+ *
+ * @exception IOException
+ * in case of I/O error
+ */
+ @Override
+ public synchronized void close() throws IOException {
+ close(true);
+ }
+
+ /**
+ * Closes this stream and releases any system resources associated with the
+ * stream.
+ * <p>
+ * Including the under-laying {@link InputStream} if
+ * <tt>incudingSubStream</tt> is true.
+ * <p>
+ * You can call this method multiple times, it will not cause an
+ * {@link IOException} for subsequent calls.
+ * <p>
+ * <b>Note:</b> if you called the {@link BufferedInputStream#open()} method
+ * prior to this one, it will just decrease the internal count of how many
+ * open streams it held and do nothing else. The stream will actually be
+ * closed when you have called {@link BufferedInputStream#close()} once more
+ * than {@link BufferedInputStream#open()}.
+ *
+ * @param includingSubStream
+ * also close the under-laying stream
+ *
+ * @exception IOException
+ * in case of I/O error
+ */
+ public synchronized void close(boolean includingSubStream)
+ throws IOException {
+ if (!closed) {
+ if (openCounter > 0) {
+ openCounter--;
+ } else {
+ closed = true;
+ flush(true);
+ if (includingSubStream && out != null) {
+ out.close();
+ }
+ }
+ }
+ }
+}
git://git.nikiroo.be / nikiroo-utils.git / commitdiff