blob: 16f80bc3598df5970bdcac0b1daf1f6158613eee [file] [log] [blame]
/*
* 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;
}
}