/*
 * Copyright (C) 2011, 2012 Google Inc. and others. and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.eclipse.jgit.internal.storage.dfs;

import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;

import org.eclipse.jgit.internal.storage.pack.PackExt;

Output stream to create a file on the DFS.
See Also:
  • writeFile.writeFile(DfsPackDescription, PackExt)
/** * Output stream to create a file on the DFS. * * @see DfsObjDatabase#writeFile(DfsPackDescription, PackExt) */
public abstract class DfsOutputStream extends OutputStream {
Get the recommended alignment for writing.

Starting a write at multiples of the blockSize is more efficient than starting a write at any other position. If 0 or -1 the channel does not have any specific block size recommendation.

Channels should not recommend large block sizes. Sizes up to 1-4 MiB may be reasonable, but sizes above that may be horribly inefficient.

Returns:recommended alignment size for randomly positioned reads. Does not need to be a power of 2.
/** * Get the recommended alignment for writing. * <p> * Starting a write at multiples of the blockSize is more efficient than * starting a write at any other position. If 0 or -1 the channel does not * have any specific block size recommendation. * <p> * Channels should not recommend large block sizes. Sizes up to 1-4 MiB may * be reasonable, but sizes above that may be horribly inefficient. * * @return recommended alignment size for randomly positioned reads. Does * not need to be a power of 2. */
public int blockSize() { return 0; }
{@inheritDoc}
/** {@inheritDoc} */
@Override public void write(int b) throws IOException { write(new byte[] { (byte) b }); }
{@inheritDoc}
/** {@inheritDoc} */
@Override public abstract void write(byte[] buf, int off, int len) throws IOException;
Read back a portion of already written data.

The writing position of the output stream is not affected by a read.

Params:
  • position – offset to read from.
  • buf – buffer to populate. Up to buf.remaining() bytes will be read from position.
Throws:
  • IOException – reading is not supported, or the read cannot be performed due to DFS errors.
Returns:number of bytes actually read.
/** * Read back a portion of already written data. * <p> * The writing position of the output stream is not affected by a read. * * @param position * offset to read from. * @param buf * buffer to populate. Up to {@code buf.remaining()} bytes will * be read from {@code position}. * @return number of bytes actually read. * @throws java.io.IOException * reading is not supported, or the read cannot be performed due * to DFS errors. */
public abstract int read(long position, ByteBuffer buf) throws IOException; }