LargePackedWholeObject.java

/*
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 * 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
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 *   notice, this list of conditions and the following disclaimer.
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package org.eclipse.jgit.internal.storage.file;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.InflaterInputStream;

import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectStream;

class LargePackedWholeObject extends ObjectLoader {
    private final int type;

    private final long size;

    private final long objectOffset;

    private final int headerLength;

    private final PackFile pack;

    private final FileObjectDatabase db;

    LargePackedWholeObject(int type, long size, long objectOffset,
            int headerLength, PackFile pack, FileObjectDatabase db) {
        this.type = type;
        this.size = size;
        this.objectOffset = objectOffset;
        this.headerLength = headerLength;
        this.pack = pack;
        this.db = db;
    }

    /** {@inheritDoc} */
    @Override
    public int getType() {
        return type;
    }

    /** {@inheritDoc} */
    @Override
    public long getSize() {
        return size;
    }

    /** {@inheritDoc} */
    @Override
    public boolean isLarge() {
        return true;
    }

    /** {@inheritDoc} */
    @Override
    public byte[] getCachedBytes() throws LargeObjectException {
        try {
            throw new LargeObjectException(getObjectId());
        } catch (IOException cannotObtainId) {
            throw new LargeObjectException(cannotObtainId);
        }
    }

    /** {@inheritDoc} */
    @Override
    public ObjectStream openStream() throws MissingObjectException, IOException {
        WindowCursor wc = new WindowCursor(db);
        InputStream in;
        try {
            in = new PackInputStream(pack, objectOffset + headerLength, wc);
        } catch (IOException packGone) {
            // If the pack file cannot be pinned into the cursor, it
            // probably was repacked recently. Go find the object
            // again and open the stream from that location instead.
            //
            return wc.open(getObjectId(), type).openStream();
        }

        in = new BufferedInputStream( //
                new InflaterInputStream( //
                        in, //
                        wc.inflater(), //
                        8192), //
                8192);
        return new ObjectStream.Filter(type, size, in);
    }

    private ObjectId getObjectId() throws IOException {
        return pack.findObjectForOffset(objectOffset);
    }
}