| /* |
| * Copyright (C) 2008-2011, Google Inc. |
| * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com> |
| * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org> 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.nio.ByteBuffer; |
| import java.util.zip.CRC32; |
| import java.util.zip.DataFormatException; |
| import java.util.zip.Inflater; |
| |
| import org.eclipse.jgit.internal.storage.pack.PackOutputStream; |
| |
| /** A cached slice of a {@link BlockBasedFile}. */ |
| final class DfsBlock { |
| final DfsStreamKey stream; |
| final long start; |
| final long end; |
| private final byte[] block; |
| |
| DfsBlock(DfsStreamKey p, long pos, byte[] buf) { |
| stream = p; |
| start = pos; |
| end = pos + buf.length; |
| block = buf; |
| } |
| |
| int size() { |
| return block.length; |
| } |
| |
| ByteBuffer zeroCopyByteBuffer(int n) { |
| ByteBuffer b = ByteBuffer.wrap(block); |
| b.position(n); |
| return b; |
| } |
| |
| boolean contains(DfsStreamKey want, long pos) { |
| return stream.equals(want) && start <= pos && pos < end; |
| } |
| |
| int copy(long pos, byte[] dstbuf, int dstoff, int cnt) { |
| int ptr = (int) (pos - start); |
| return copy(ptr, dstbuf, dstoff, cnt); |
| } |
| |
| int copy(int p, byte[] b, int o, int n) { |
| n = Math.min(block.length - p, n); |
| System.arraycopy(block, p, b, o, n); |
| return n; |
| } |
| |
| int setInput(long pos, Inflater inf) throws DataFormatException { |
| int ptr = (int) (pos - start); |
| int cnt = block.length - ptr; |
| if (cnt <= 0) { |
| throw new DataFormatException(cnt + " bytes to inflate:" //$NON-NLS-1$ |
| + " at pos=" + pos //$NON-NLS-1$ |
| + "; block.start=" + start //$NON-NLS-1$ |
| + "; ptr=" + ptr //$NON-NLS-1$ |
| + "; block.length=" + block.length); //$NON-NLS-1$ |
| } |
| inf.setInput(block, ptr, cnt); |
| return cnt; |
| } |
| |
| void crc32(CRC32 out, long pos, int cnt) { |
| int ptr = (int) (pos - start); |
| out.update(block, ptr, cnt); |
| } |
| |
| void write(PackOutputStream out, long pos, int cnt) |
| throws IOException { |
| out.write(block, (int) (pos - start), cnt); |
| } |
| |
| void check(Inflater inf, byte[] tmp, long pos, int cnt) |
| throws DataFormatException { |
| // Unlike inflate() above the exact byte count is known by the caller. |
| // Push all of it in a single invocation to avoid unnecessary loops. |
| // |
| inf.setInput(block, (int) (pos - start), cnt); |
| while (inf.inflate(tmp, 0, tmp.length) > 0) |
| continue; |
| } |
| } |