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/*
* Copyright (C) 2012, Google Inc. 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.file;
import java.io.BufferedOutputStream;
import java.io.DataOutput;
import java.io.IOException;
import java.io.OutputStream;
import java.security.DigestOutputStream;
import java.text.MessageFormat;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.file.PackBitmapIndexBuilder.StoredEntry;
import org.eclipse.jgit.internal.storage.pack.PackBitmapIndexWriter;
import org.eclipse.jgit.lib.Constants;
import com.googlecode.javaewah.EWAHCompressedBitmap;
/**
* Creates the version 1 pack bitmap index files.
*
* @see PackBitmapIndexV1
*/
public class PackBitmapIndexWriterV1 implements PackBitmapIndexWriter {
private final DigestOutputStream out;
private final DataOutput dataOutput;
/**
* Creates the version 1 pack bitmap index files.
*
* @param dst
* the output stream to which the index will be written.
*/
public PackBitmapIndexWriterV1(final OutputStream dst) {
out = new DigestOutputStream(dst instanceof BufferedOutputStream ? dst
: new BufferedOutputStream(dst),
Constants.newMessageDigest());
dataOutput = new SimpleDataOutput(out);
}
/**
* Write all object entries to the index stream.
* <p>
* After writing the stream passed to the factory is flushed but remains
* open. Callers are always responsible for closing the output stream.
*
* @param bitmaps
* the index data for the bitmaps
* @param packDataChecksum
* checksum signature of the entire pack data content. This is
* traditionally the last 20 bytes of the pack file's own stream.
* @throws java.io.IOException
* an error occurred while writing to the output stream, or this
* index format cannot store the object data supplied.
*/
@Override
public void write(PackBitmapIndexBuilder bitmaps, byte[] packDataChecksum)
throws IOException {
if (bitmaps == null || packDataChecksum.length != 20)
throw new IllegalStateException();
writeHeader(bitmaps.getOptions(), bitmaps.getBitmapCount(),
packDataChecksum);
writeBody(bitmaps);
writeFooter();
out.flush();
}
private void writeHeader(
int options, int bitmapCount, byte[] packDataChecksum)
throws IOException {
out.write(PackBitmapIndexV1.MAGIC);
dataOutput.writeShort(1);
dataOutput.writeShort(options);
dataOutput.writeInt(bitmapCount);
out.write(packDataChecksum);
}
private void writeBody(PackBitmapIndexBuilder bitmaps) throws IOException {
writeBitmap(bitmaps.getCommits());
writeBitmap(bitmaps.getTrees());
writeBitmap(bitmaps.getBlobs());
writeBitmap(bitmaps.getTags());
writeBitmaps(bitmaps);
}
private void writeBitmap(EWAHCompressedBitmap bitmap) throws IOException {
bitmap.serialize(dataOutput);
}
private void writeBitmaps(PackBitmapIndexBuilder bitmaps)
throws IOException {
int bitmapCount = 0;
for (StoredEntry entry : bitmaps.getCompressedBitmaps()) {
writeBitmapEntry(entry);
bitmapCount++;
}
int expectedBitmapCount = bitmaps.getBitmapCount();
if (expectedBitmapCount != bitmapCount)
throw new IOException(MessageFormat.format(
JGitText.get().expectedGot,
String.valueOf(expectedBitmapCount),
String.valueOf(bitmapCount)));
}
private void writeBitmapEntry(StoredEntry entry) throws IOException {
// Write object, XOR offset, and bitmap
dataOutput.writeInt((int) entry.getIdxPosition());
out.write(entry.getXorOffset());
out.write(entry.getFlags());
writeBitmap(entry.getBitmap());
}
private void writeFooter() throws IOException {
out.on(false);
out.write(out.getMessageDigest().digest());
}
}
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