--- /dev/null
+/*
+ * Sonitus - IntegralWriteOutputStream.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sonitus.io;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * {@link OutputStream} wrapper that always writes a multiple of a fixed amount
+ * of bytes at once.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class IntegralWriteOutputStream extends FilterOutputStream {
+
+ /** The current in-process values. */
+ private final byte[] buffer;
+
+ /** The next position of the buffer that will be written to. */
+ private int bufferPosition;
+
+ /**
+ * Creates a new integral write output stream.
+ *
+ * @param outputStream
+ * The output stream to wrap
+ * @param integralSize
+ * The number of bytes to write at once
+ */
+ public IntegralWriteOutputStream(OutputStream outputStream, int integralSize) {
+ super(outputStream);
+ buffer = new byte[integralSize];
+ }
+
+ //
+ // OUTPUTSTREAM METHODS
+ //
+
+ @Override
+ public void write(int data) throws IOException {
+ buffer[bufferPosition++] = (byte) data;
+ if (bufferPosition == buffer.length) {
+ bufferPosition = 0;
+ out.write(buffer);
+ }
+ }
+
+ @Override
+ public void write(byte[] buffer) throws IOException {
+ write(buffer, 0, buffer.length);
+ }
+
+ @Override
+ public void write(byte[] buffer, int offset, int length) throws IOException {
+ /* are the some bytes in the current buffer? */
+ int sourceOffset = 0;
+ if (bufferPosition != 0) {
+ int bytesToCopy = Math.min(length, this.buffer.length - bufferPosition);
+ System.arraycopy(buffer, offset, this.buffer, bufferPosition, bytesToCopy);
+ sourceOffset += bytesToCopy;
+ bufferPosition += bytesToCopy;
+ if (bufferPosition == this.buffer.length) {
+ bufferPosition = 0;
+ out.write(this.buffer);
+ }
+ }
+
+ /* write the largest possible chunk at once. */
+ int integralBytesLeft = (int) ((length - sourceOffset) / this.buffer.length) * this.buffer.length;
+ if (integralBytesLeft != 0) {
+ out.write(buffer, offset + sourceOffset, integralBytesLeft);
+ }
+
+ /* are there some bytes left? */
+ sourceOffset += integralBytesLeft;
+ if (sourceOffset < length) {
+ System.arraycopy(buffer, offset + sourceOffset, this.buffer, 0, length - sourceOffset);
+ bufferPosition = length - sourceOffset;
+ }
+ }
+
+}
--- /dev/null
+/*
+ * Sonitus - IntegralWriteOutputStreamTest.java - Copyright © 2013 David Roden
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package net.pterodactylus.sonitus.io;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Random;
+
+import org.testng.annotations.Test;
+
+/**
+ * Unit tests for {@link IntegralWriteOutputStream}.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class IntegralWriteOutputStreamTest {
+
+ @Test
+ public void testSingleWritesWithSize2() throws IOException {
+ OutputStream outputStream = mock(OutputStream.class);
+
+ IntegralWriteOutputStream integralWriteOutputStream = new IntegralWriteOutputStream(outputStream, 2);
+ integralWriteOutputStream.write(1);
+ integralWriteOutputStream.write(2);
+ integralWriteOutputStream.write(3);
+ integralWriteOutputStream.write(4);
+ integralWriteOutputStream.write(5);
+
+ verify(outputStream, never()).write(anyInt());
+ verify(outputStream, times(2)).write((byte[]) any());
+ }
+
+ @Test
+ public void testLargeWritesWithSize3() throws IOException {
+ ByteArrayOutputStream byteArrayOutputStream = getOutputStream(3);
+ IntegralWriteOutputStream integralWriteOutputStream = new IntegralWriteOutputStream(byteArrayOutputStream, 3);
+
+ byte[] buffer = generateData(18);
+ integralWriteOutputStream.write(buffer, 0, 7);
+ integralWriteOutputStream.write(buffer, 7, 7);
+ integralWriteOutputStream.write(buffer, 14, 4);
+
+ assertThat(byteArrayOutputStream.toByteArray(), is(buffer));
+ }
+
+ @Test
+ public void testLargeWritesWithSize4() throws IOException {
+ ByteArrayOutputStream byteArrayOutputStream = getOutputStream(1024);
+ IntegralWriteOutputStream integralWriteOutputStream = new IntegralWriteOutputStream(byteArrayOutputStream, 1024);
+
+ byte[] buffer = generateData(32768);
+ integralWriteOutputStream.write(buffer, 0, 123);
+ integralWriteOutputStream.write(buffer, 123, 768);
+ integralWriteOutputStream.write(buffer, 123 + 768, 6285);
+ integralWriteOutputStream.write(buffer, 123 + 768 + 6285, 1234);
+ integralWriteOutputStream.write(buffer, 123 + 768 + 6285 + 1234, 21111);
+ integralWriteOutputStream.write(buffer, 123 + 768 + 6285 + 1234 + 21111, 32768 - (123 + 768 + 6285 + 1234 + 21111));
+
+ assertThat(byteArrayOutputStream.toByteArray(), is(buffer));
+ }
+
+ //
+ // PRIVATE METHODS
+ //
+
+ /**
+ * Creates a {@link ByteArrayOutputStream} that will throw an {@link
+ * IllegalArgumentException} if its {@link OutputStream#write(byte[], int,
+ * int)} method is called with {@code len} not being a multiple of {@code
+ * integralSize}, or if {@link OutputStream#write(int)} is called.
+ *
+ * @param integralSize
+ * The number of bytes to write multiples of
+ * @return The created output stream
+ */
+ private static ByteArrayOutputStream getOutputStream(final int integralSize) {
+ return new ByteArrayOutputStream() {
+
+ @Override
+ public synchronized void write(byte[] b, int off, int len) {
+ if ((len % integralSize) != 0) {
+ throw new IllegalArgumentException(String.format("%d is not a multiple of %d.", len, integralSize));
+ }
+ super.write(b, off, len);
+ }
+
+ @Override
+ public synchronized void write(int b) {
+ throw new IllegalArgumentException("write(int) called.");
+ }
+
+ };
+ }
+
+ /**
+ * Generates a random amount of data.
+ *
+ * @param length
+ * The length of the data
+ * @return The generated random data
+ */
+ private static byte[] generateData(int length) {
+ Random random = new Random();
+ byte[] buffer = new byte[length];
+ random.nextBytes(buffer);
+ return buffer;
+ }
+
+}
projects / sonitus.git / commitdiff