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- /*
- * Copyright (C) 2012, Google Inc.
- * and other copyright owners as documented in the project's IP log.
- *
- * This program and the accompanying materials are made available
- * under the terms of the Eclipse Distribution License v1.0 which
- * accompanies this distribution, is reproduced below, and is
- * available at http://www.eclipse.org/org/documents/edl-v10.php
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials provided
- * with the distribution.
- *
- * - Neither the name of the Eclipse Foundation, Inc. nor the
- * names of its contributors may be used to endorse or promote
- * products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
- package org.eclipse.jgit.internal.storage.file;
-
- import java.io.File;
- import java.io.FileInputStream;
- import java.io.IOException;
- import java.io.InputStream;
- import java.text.MessageFormat;
-
- import org.eclipse.jgit.errors.CorruptObjectException;
- import org.eclipse.jgit.internal.JGitText;
- import org.eclipse.jgit.lib.AnyObjectId;
- import org.eclipse.jgit.lib.ObjectId;
-
- import com.googlecode.javaewah.EWAHCompressedBitmap;
-
- /**
- * Logical representation of the bitmap data stored in the pack index.
- * {@link ObjectId}s are encoded as a single integer in the range [0,
- * {@link #getObjectCount()}). Compressed bitmaps are available at certain
- * {@code ObjectId}s, which represent all of the objects reachable from that
- * {@code ObjectId} (include the {@code ObjectId} itself). The meaning of the
- * positions in the bitmaps can be decoded using {@link #getObject(int)} and
- * {@link #ofObjectType(EWAHCompressedBitmap, int)}. Furthermore,
- * {@link #findPosition(AnyObjectId)} can be used to build other bitmaps that a
- * compatible with the encoded bitmaps available from the index.
- */
- public abstract class PackBitmapIndex {
- /** Flag bit denoting the bitmap should be reused during index creation. */
- public static final int FLAG_REUSE = 1;
-
- /**
- * Read an existing pack bitmap index file from a buffered stream.
- * <p>
- * The format of the file will be automatically detected and a proper access
- * implementation for that format will be constructed and returned to the
- * caller. The file may or may not be held open by the returned instance.
- *
- * @param idxFile
- * existing pack .bitmap to read.
- * @param packIndex
- * the pack index for the corresponding pack file.
- * @param reverseIndex
- * the pack reverse index for the corresponding pack file.
- * @return a copy of the index in-memory.
- * @throws IOException
- * the stream cannot be read.
- * @throws CorruptObjectException
- * the stream does not contain a valid pack bitmap index.
- */
- public static PackBitmapIndex open(
- File idxFile, PackIndex packIndex, PackReverseIndex reverseIndex)
- throws IOException {
- final FileInputStream fd = new FileInputStream(idxFile);
- try {
- return read(fd, packIndex, reverseIndex);
- } catch (IOException ioe) {
- final String path = idxFile.getAbsolutePath();
- final IOException err;
- err = new IOException(MessageFormat.format(
- JGitText.get().unreadablePackIndex, path));
- err.initCause(ioe);
- throw err;
- } finally {
- try {
- fd.close();
- } catch (IOException err2) {
- // ignore
- }
- }
- }
-
- /**
- * Read an existing pack bitmap index file from a buffered stream.
- * <p>
- * The format of the file will be automatically detected and a proper access
- * implementation for that format will be constructed and returned to the
- * caller. The file may or may not be held open by the returned instance.
- *
- * @param fd
- * stream to read the bitmap index file from. The stream must be
- * buffered as some small IOs are performed against the stream.
- * The caller is responsible for closing the stream.
- * @param packIndex
- * the pack index for the corresponding pack file.
- * @param reverseIndex
- * the pack reverse index for the corresponding pack file.
- * @return a copy of the index in-memory.
- * @throws IOException
- * the stream cannot be read.
- * @throws CorruptObjectException
- * the stream does not contain a valid pack bitmap index.
- */
- public static PackBitmapIndex read(
- InputStream fd, PackIndex packIndex, PackReverseIndex reverseIndex)
- throws IOException {
- return new PackBitmapIndexV1(fd, packIndex, reverseIndex);
- }
-
- /** Footer checksum applied on the bottom of the pack file. */
- byte[] packChecksum;
-
- /**
- * Finds the position in the bitmap of the object.
- *
- * @param objectId
- * the id for which the bitmap position will be found.
- * @return the bitmap id or -1 if the object was not found.
- */
- public abstract int findPosition(AnyObjectId objectId);
-
- /**
- * Get the object at the bitmap position.
- *
- * @param position
- * the id for which the object will be found.
- * @return the ObjectId.
- * @throws IllegalArgumentException
- * when the item is not found.
- */
- public abstract ObjectId getObject(int position) throws IllegalArgumentException;
-
- /**
- * Returns a bitmap containing positions for objects that have the given Git
- * type.
- *
- * @param bitmap
- * the object bitmap.
- * @param type
- * the Git type.
- * @return the object bitmap with only objects of the Git type.
- */
- public abstract EWAHCompressedBitmap ofObjectType(
- EWAHCompressedBitmap bitmap, int type);
-
- /**
- * Returns the previously constructed bitmap for the object.
- *
- * @param objectId
- * the id for which the bitmap will be found.
- * @return the bitmap or null if the object was not found.
- */
- public abstract EWAHCompressedBitmap getBitmap(AnyObjectId objectId);
-
- /**
- * Obtain the total number of objects described by this index.
- * {@code getObjectCount() - 1} is the largest bit that will be set in a
- * bitmap.
- *
- * @return number of objects in this index, and likewise in the associated
- * pack that this index was generated from.
- */
- public abstract int getObjectCount();
-
- /**
- * Returns the number of bitmaps in this bitmap index.
- *
- * @return the number of bitmaps in this bitmap index.
- */
- public abstract int getBitmapCount();
- }
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