/*
    * Copyright (C) 2010, 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.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);
 	}
 }