filebot/source/net/sourceforge/tuned/ByteBufferOutputStream.java

132 lines
3.0 KiB
Java

package net.sourceforge.tuned;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
public class ByteBufferOutputStream extends OutputStream {
private ByteBuffer buffer;
private final float loadFactor;
public ByteBufferOutputStream(long initialCapacity) {
this((int) initialCapacity);
}
public ByteBufferOutputStream(int initialCapacity) {
this(initialCapacity, 1.0f);
}
public ByteBufferOutputStream(int initialCapacity, float loadFactor) {
if (initialCapacity < 0)
throw new IllegalArgumentException("initialCapacity must not be negative");
if (loadFactor <= 0 || Float.isNaN(loadFactor))
throw new IllegalArgumentException("loadFactor must be greater than 0");
this.buffer = ByteBuffer.allocate(initialCapacity + 1);
this.loadFactor = loadFactor;
}
@Override
public void write(int b) throws IOException {
ensureCapacity(buffer.position() + 1);
buffer.put((byte) b);
}
@Override
public void write(byte[] src) throws IOException {
ensureCapacity(buffer.position() + src.length);
buffer.put(src);
}
public void write(ByteBuffer src) throws IOException {
ensureCapacity(buffer.position() + src.remaining());
buffer.put(src);
}
@Override
public void write(byte[] src, int offset, int length) throws IOException {
ensureCapacity(buffer.position() + length);
buffer.put(src, offset, length);
}
public void ensureCapacity(int minCapacity) {
if (minCapacity <= buffer.capacity())
return;
// calculate new buffer size with load factor
int newCapacity = (int) (buffer.capacity() * (1 + loadFactor));
// ensure minCapacity
if (newCapacity < minCapacity)
newCapacity = minCapacity;
// create new buffer with increased capacity
ByteBuffer newBuffer = ByteBuffer.allocate(newCapacity);
// copy current data to new buffer
buffer.flip();
newBuffer.put(buffer);
buffer = newBuffer;
}
public ByteBuffer getByteBuffer() {
ByteBuffer result = buffer.duplicate();
// flip buffer so it can be read
result.flip();
return result;
}
public byte[] getByteArray() {
ByteBuffer data = getByteBuffer();
// copy data to byte array
byte[] bytes = new byte[data.remaining()];
data.get(bytes);
return bytes;
}
public int transferFrom(ReadableByteChannel channel) throws IOException {
// make sure buffer is not at its limit
ensureCapacity(buffer.position() + 1);
return channel.read(buffer);
}
public int transferFully(InputStream inputStream) throws IOException {
return transferFully(Channels.newChannel(inputStream));
}
public int transferFully(ReadableByteChannel channel) throws IOException {
int total = 0, read = 0;
while ((read = transferFrom(channel)) >= 0) {
total += read;
}
return total;
}
public int position() {
return buffer.position();
}
public int capacity() {
return buffer.capacity();
}
public void rewind() {
buffer.rewind();
}
}