org.eclipse.jgit/org.eclipse.jgit/5.5.0.201909110433-r : org/eclipse/jgit/lib/ObjectReader.java

ObjectReader
http://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)
Eclipse Distribution License (New BSD License)
Andrey Loskutov
Christian Halstrick
Dave Borowitz
David Pursehouse
Gunnar Wagenknecht
Jonathan Nieder
Jonathan Tan
Matthias Sohn
Sasa Zivkov
Terry Parker
Thomas Wolf
/*
 * Copyright (C) 2010, 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.lib;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;

Reads an ObjectDatabase for a single thread.  Readers that can support efficient reuse of pack encoded objects should also implement the companion interface ObjectReuseAsIs. /**
 * Reads an {@link org.eclipse.jgit.lib.ObjectDatabase} for a single thread.
 * <p>
 * Readers that can support efficient reuse of pack encoded objects should also
 * implement the companion interface
 * {@link org.eclipse.jgit.internal.storage.pack.ObjectReuseAsIs}.
 */
public abstract class ObjectReader implements AutoCloseable {
	Type hint indicating the caller doesn't know the type. /** Type hint indicating the caller doesn't know the type. */
	public static final int OBJ_ANY = -1;

	The threshold at which a file will be streamed rather than loaded
entirely into memory.
Since: 4.6/**
	 * The threshold at which a file will be streamed rather than loaded
	 * entirely into memory.
	 * @since 4.6
	 */
	protected int streamFileThreshold;

	Construct a new reader from the same data.

Applications can use this method to build a new reader from the same data
source, but for an different thread.
Returns: a brand new reader, using the same data source./**
	 * Construct a new reader from the same data.
	 * <p>
	 * Applications can use this method to build a new reader from the same data
	 * source, but for an different thread.
	 *
	 * @return a brand new reader, using the same data source.
	 */
	public abstract ObjectReader newReader();

	Obtain a unique abbreviation (prefix) of an object SHA-1. This method uses a reasonable default for the minimum length. Callers who don't care about the minimum length should prefer this method. The returned abbreviation would expand back to the argument ObjectId when passed to resolve(AbbreviatedObjectId), assuming no new objects are added to this repository between calls. 
Params: objectId – 
           object identity that needs to be abbreviated.
Throws: IOException – 
            the object store cannot be read.
Returns: SHA-1 abbreviation./**
	 * Obtain a unique abbreviation (prefix) of an object SHA-1.
	 *
	 * This method uses a reasonable default for the minimum length. Callers who
	 * don't care about the minimum length should prefer this method.
	 *
	 * The returned abbreviation would expand back to the argument ObjectId when
	 * passed to {@link #resolve(AbbreviatedObjectId)}, assuming no new objects
	 * are added to this repository between calls.
	 *
	 * @param objectId
	 *            object identity that needs to be abbreviated.
	 * @return SHA-1 abbreviation.
	 * @throws java.io.IOException
	 *             the object store cannot be read.
	 */
	public AbbreviatedObjectId abbreviate(AnyObjectId objectId)
			throws IOException {
		return abbreviate(objectId, 7);
	}

	Obtain a unique abbreviation (prefix) of an object SHA-1. The returned abbreviation would expand back to the argument ObjectId when passed to resolve(AbbreviatedObjectId), assuming no new objects are added to this repository between calls. The default implementation of this method abbreviates the id to the minimum length, then resolves it to see if there are multiple results. When multiple results are found, the length is extended by 1 and resolve is tried again. 
Params: objectId – 
           object identity that needs to be abbreviated.
len –  minimum length of the abbreviated string. Must be in the range [2, 40].
Throws: IOException – 
            the object store cannot be read.
Returns: SHA-1 abbreviation. If no matching objects exist in the
        repository, the abbreviation will match the minimum length./**
	 * Obtain a unique abbreviation (prefix) of an object SHA-1.
	 *
	 * The returned abbreviation would expand back to the argument ObjectId when
	 * passed to {@link #resolve(AbbreviatedObjectId)}, assuming no new objects
	 * are added to this repository between calls.
	 *
	 * The default implementation of this method abbreviates the id to the
	 * minimum length, then resolves it to see if there are multiple results.
	 * When multiple results are found, the length is extended by 1 and resolve
	 * is tried again.
	 *
	 * @param objectId
	 *            object identity that needs to be abbreviated.
	 * @param len
	 *            minimum length of the abbreviated string. Must be in the range
	 *            [2, {@value Constants#OBJECT_ID_STRING_LENGTH}].
	 * @return SHA-1 abbreviation. If no matching objects exist in the
	 *         repository, the abbreviation will match the minimum length.
	 * @throws java.io.IOException
	 *             the object store cannot be read.
	 */
	public AbbreviatedObjectId abbreviate(AnyObjectId objectId, int len)
			throws IOException {
		if (len == Constants.OBJECT_ID_STRING_LENGTH)
			return AbbreviatedObjectId.fromObjectId(objectId);

		AbbreviatedObjectId abbrev = objectId.abbreviate(len);
		Collection<ObjectId> matches = resolve(abbrev);
		while (1 < matches.size() && len < Constants.OBJECT_ID_STRING_LENGTH) {
			abbrev = objectId.abbreviate(++len);
			List<ObjectId> n = new ArrayList<>(8);
			for (ObjectId candidate : matches) {
				if (abbrev.prefixCompare(candidate) == 0)
					n.add(candidate);
			}
			if (1 < n.size())
				matches = n;
			else
				matches = resolve(abbrev);
		}
		return abbrev;
	}

	Resolve an abbreviated ObjectId to its full form.
This method searches for an ObjectId that begins with the abbreviation,
and returns at least some matching candidates.
If the returned collection is empty, no objects start with this
abbreviation. The abbreviation doesn't belong to this repository, or the
repository lacks the necessary objects to complete it.
If the collection contains exactly one member, the abbreviation is
(currently) unique within this database. There is a reasonably high
probability that the returned id is what was previously abbreviated.
If the collection contains 2 or more members, the abbreviation is not
unique. In this case the implementation is only required to return at
least 2 candidates to signal the abbreviation has conflicts. User
friendly implementations should return as many candidates as reasonably
possible, as the caller may be able to disambiguate further based on
context. However since databases can be very large (e.g. 10 million
objects) returning 625,000 candidates for the abbreviation "0" is simply
unreasonable, so implementors should draw the line at around 256 matches.
Params: id – 
           abbreviated id to resolve to a complete identity. The
           abbreviation must have a length of at least 2.
Throws: IOException – 
            the object store cannot be read.
Returns: candidates that begin with the abbreviated identity./**
	 * Resolve an abbreviated ObjectId to its full form.
	 *
	 * This method searches for an ObjectId that begins with the abbreviation,
	 * and returns at least some matching candidates.
	 *
	 * If the returned collection is empty, no objects start with this
	 * abbreviation. The abbreviation doesn't belong to this repository, or the
	 * repository lacks the necessary objects to complete it.
	 *
	 * If the collection contains exactly one member, the abbreviation is
	 * (currently) unique within this database. There is a reasonably high
	 * probability that the returned id is what was previously abbreviated.
	 *
	 * If the collection contains 2 or more members, the abbreviation is not
	 * unique. In this case the implementation is only required to return at
	 * least 2 candidates to signal the abbreviation has conflicts. User
	 * friendly implementations should return as many candidates as reasonably
	 * possible, as the caller may be able to disambiguate further based on
	 * context. However since databases can be very large (e.g. 10 million
	 * objects) returning 625,000 candidates for the abbreviation "0" is simply
	 * unreasonable, so implementors should draw the line at around 256 matches.
	 *
	 * @param id
	 *            abbreviated id to resolve to a complete identity. The
	 *            abbreviation must have a length of at least 2.
	 * @return candidates that begin with the abbreviated identity.
	 * @throws java.io.IOException
	 *             the object store cannot be read.
	 */
	public abstract Collection<ObjectId> resolve(AbbreviatedObjectId id)
			throws IOException;

	Does the requested object exist in this database?
Params: objectId – 
           identity of the object to test for existence of.
Throws: IOException – 
            the object store cannot be accessed.
Returns: true if the specified object is stored in this database./**
	 * Does the requested object exist in this database?
	 *
	 * @param objectId
	 *            identity of the object to test for existence of.
	 * @return true if the specified object is stored in this database.
	 * @throws java.io.IOException
	 *             the object store cannot be accessed.
	 */
	public boolean has(AnyObjectId objectId) throws IOException {
		return has(objectId, OBJ_ANY);
	}

	Does the requested object exist in this database?
Params: objectId – 
           identity of the object to test for existence of.
typeHint –  hint about the type of object being requested, e.g. Constants.OBJ_BLOB; OBJ_ANY if the object type is not known, or does not matter to the caller.
Throws: IncorrectObjectTypeException – 
            typeHint was not OBJ_ANY, and the object's actual type does
            not match typeHint.
IOException – 
            the object store cannot be accessed.
Returns: true if the specified object is stored in this database./**
	 * Does the requested object exist in this database?
	 *
	 * @param objectId
	 *            identity of the object to test for existence of.
	 * @param typeHint
	 *            hint about the type of object being requested, e.g.
	 *            {@link org.eclipse.jgit.lib.Constants#OBJ_BLOB};
	 *            {@link #OBJ_ANY} if the object type is not known, or does not
	 *            matter to the caller.
	 * @return true if the specified object is stored in this database.
	 * @throws IncorrectObjectTypeException
	 *             typeHint was not OBJ_ANY, and the object's actual type does
	 *             not match typeHint.
	 * @throws java.io.IOException
	 *             the object store cannot be accessed.
	 */
	public boolean has(AnyObjectId objectId, int typeHint) throws IOException {
		try {
			open(objectId, typeHint);
			return true;
		} catch (MissingObjectException notFound) {
			return false;
		}
	}

	Open an object from this database.
Params: objectId – 
           identity of the object to open.
Throws: MissingObjectException – 
            the object does not exist.
IOException – 
            the object store cannot be accessed.
Returns: a ObjectLoader for accessing the object./**
	 * Open an object from this database.
	 *
	 * @param objectId
	 *            identity of the object to open.
	 * @return a {@link org.eclipse.jgit.lib.ObjectLoader} for accessing the
	 *         object.
	 * @throws org.eclipse.jgit.errors.MissingObjectException
	 *             the object does not exist.
	 * @throws java.io.IOException
	 *             the object store cannot be accessed.
	 */
	public ObjectLoader open(AnyObjectId objectId)
			throws MissingObjectException, IOException {
		return open(objectId, OBJ_ANY);
	}

	Open an object from this database.
Params: objectId – 
           identity of the object to open.
typeHint –  hint about the type of object being requested, e.g. Constants.OBJ_BLOB; OBJ_ANY if the object type is not known, or does not matter to the caller.
Throws: MissingObjectException – 
            the object does not exist.
IncorrectObjectTypeException – 
            typeHint was not OBJ_ANY, and the object's actual type does
            not match typeHint.
IOException – 
            the object store cannot be accessed.
Returns: a ObjectLoader for accessing the object./**
	 * Open an object from this database.
	 *
	 * @param objectId
	 *            identity of the object to open.
	 * @param typeHint
	 *            hint about the type of object being requested, e.g.
	 *            {@link org.eclipse.jgit.lib.Constants#OBJ_BLOB};
	 *            {@link #OBJ_ANY} if the object type is not known, or does not
	 *            matter to the caller.
	 * @return a {@link org.eclipse.jgit.lib.ObjectLoader} for accessing the
	 *         object.
	 * @throws org.eclipse.jgit.errors.MissingObjectException
	 *             the object does not exist.
	 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
	 *             typeHint was not OBJ_ANY, and the object's actual type does
	 *             not match typeHint.
	 * @throws java.io.IOException
	 *             the object store cannot be accessed.
	 */
	public abstract ObjectLoader open(AnyObjectId objectId, int typeHint)
			throws MissingObjectException, IncorrectObjectTypeException,
			IOException;

	Returns IDs for those commits which should be considered as shallow.
Throws: IOException – 
Returns: IDs of shallow commits/**
	 * Returns IDs for those commits which should be considered as shallow.
	 *
	 * @return IDs of shallow commits
	 * @throws java.io.IOException
	 */
	public abstract Set<ObjectId> getShallowCommits() throws IOException;

	Asynchronous object opening.
Params: objectIds – 
           objects to open from the object store. The supplied collection
           must not be modified until the queue has finished.
reportMissing – 
           if true missing objects are reported by calling failure with a
           MissingObjectException. This may be more expensive for the
           implementation to guarantee. If false the implementation may
           choose to report MissingObjectException, or silently skip over
           the object with no warning.
Returns: queue to read the objects from./**
	 * Asynchronous object opening.
	 *
	 * @param objectIds
	 *            objects to open from the object store. The supplied collection
	 *            must not be modified until the queue has finished.
	 * @param reportMissing
	 *            if true missing objects are reported by calling failure with a
	 *            MissingObjectException. This may be more expensive for the
	 *            implementation to guarantee. If false the implementation may
	 *            choose to report MissingObjectException, or silently skip over
	 *            the object with no warning.
	 * @return queue to read the objects from.
	 */
	public <T extends ObjectId> AsyncObjectLoaderQueue<T> open(
			Iterable<T> objectIds, final boolean reportMissing) {
		final Iterator<T> idItr = objectIds.iterator();
		return new AsyncObjectLoaderQueue<T>() {
			private T cur;

			@Override
			public boolean next() throws MissingObjectException, IOException {
				if (idItr.hasNext()) {
					cur = idItr.next();
					return true;
				} else {
					return false;
				}
			}

			@Override
			public T getCurrent() {
				return cur;
			}

			@Override
			public ObjectId getObjectId() {
				return cur;
			}

			@Override
			public ObjectLoader open() throws IOException {
				return ObjectReader.this.open(cur, OBJ_ANY);
			}

			@Override
			public boolean cancel(boolean mayInterruptIfRunning) {
				return true;
			}

			@Override
			public void release() {
				// Since we are sequential by default, we don't
				// have any state to clean up if we terminate early.
			}
		};
	}

	Get only the size of an object.

The default implementation of this method opens an ObjectLoader.
Databases are encouraged to override this if a faster access method is
available to them.
Params: objectId – 
           identity of the object to open.
typeHint –  hint about the type of object being requested, e.g. Constants.OBJ_BLOB; OBJ_ANY if the object type is not known, or does not matter to the caller.
Throws: MissingObjectException – 
            the object does not exist.
IncorrectObjectTypeException – 
            typeHint was not OBJ_ANY, and the object's actual type does
            not match typeHint.
IOException – 
            the object store cannot be accessed.
Returns: size of object in bytes./**
	 * Get only the size of an object.
	 * <p>
	 * The default implementation of this method opens an ObjectLoader.
	 * Databases are encouraged to override this if a faster access method is
	 * available to them.
	 *
	 * @param objectId
	 *            identity of the object to open.
	 * @param typeHint
	 *            hint about the type of object being requested, e.g.
	 *            {@link org.eclipse.jgit.lib.Constants#OBJ_BLOB};
	 *            {@link #OBJ_ANY} if the object type is not known, or does not
	 *            matter to the caller.
	 * @return size of object in bytes.
	 * @throws org.eclipse.jgit.errors.MissingObjectException
	 *             the object does not exist.
	 * @throws org.eclipse.jgit.errors.IncorrectObjectTypeException
	 *             typeHint was not OBJ_ANY, and the object's actual type does
	 *             not match typeHint.
	 * @throws java.io.IOException
	 *             the object store cannot be accessed.
	 */
	public long getObjectSize(AnyObjectId objectId, int typeHint)
			throws MissingObjectException, IncorrectObjectTypeException,
			IOException {
		return open(objectId, typeHint).getSize();
	}

	Asynchronous object size lookup.
Params: objectIds – 
           objects to get the size of from the object store. The supplied
           collection must not be modified until the queue has finished.
reportMissing – 
           if true missing objects are reported by calling failure with a
           MissingObjectException. This may be more expensive for the
           implementation to guarantee. If false the implementation may
           choose to report MissingObjectException, or silently skip over
           the object with no warning.
Returns: queue to read object sizes from./**
	 * Asynchronous object size lookup.
	 *
	 * @param objectIds
	 *            objects to get the size of from the object store. The supplied
	 *            collection must not be modified until the queue has finished.
	 * @param reportMissing
	 *            if true missing objects are reported by calling failure with a
	 *            MissingObjectException. This may be more expensive for the
	 *            implementation to guarantee. If false the implementation may
	 *            choose to report MissingObjectException, or silently skip over
	 *            the object with no warning.
	 * @return queue to read object sizes from.
	 */
	public <T extends ObjectId> AsyncObjectSizeQueue<T> getObjectSize(
			Iterable<T> objectIds, final boolean reportMissing) {
		final Iterator<T> idItr = objectIds.iterator();
		return new AsyncObjectSizeQueue<T>() {
			private T cur;

			private long sz;

			@Override
			public boolean next() throws MissingObjectException, IOException {
				if (idItr.hasNext()) {
					cur = idItr.next();
					sz = getObjectSize(cur, OBJ_ANY);
					return true;
				} else {
					return false;
				}
			}

			@Override
			public T getCurrent() {
				return cur;
			}

			@Override
			public ObjectId getObjectId() {
				return cur;
			}

			@Override
			public long getSize() {
				return sz;
			}

			@Override
			public boolean cancel(boolean mayInterruptIfRunning) {
				return true;
			}

			@Override
			public void release() {
				// Since we are sequential by default, we don't
				// have any state to clean up if we terminate early.
			}
		};
	}

	Advise the reader to avoid unreachable objects.

While enabled the reader will skip over anything previously proven to be
unreachable. This may be dangerous in the face of concurrent writes.
Params: avoid – 
           true to avoid unreachable objects.
Since: 3.0/**
	 * Advise the reader to avoid unreachable objects.
	 * <p>
	 * While enabled the reader will skip over anything previously proven to be
	 * unreachable. This may be dangerous in the face of concurrent writes.
	 *
	 * @param avoid
	 *            true to avoid unreachable objects.
	 * @since 3.0
	 */
	public void setAvoidUnreachableObjects(boolean avoid) {
		// Do nothing by default.
	}

	An index that can be used to speed up ObjectWalks.
Throws: IOException – 
            when the index fails to load
Returns: the index or null if one does not exist.
Since: 3.0/**
	 * An index that can be used to speed up ObjectWalks.
	 *
	 * @return the index or null if one does not exist.
	 * @throws java.io.IOException
	 *             when the index fails to load
	 * @since 3.0
	 */
	public BitmapIndex getBitmapIndex() throws IOException {
		return null;
	}

	Get the ObjectInserter from which this reader was created using inserter.newReader() 
Returns: the ObjectInserter from which this reader was created using inserter.newReader(), or null if this reader was not created from an inserter.
Since: 4.4/**
	 * Get the {@link org.eclipse.jgit.lib.ObjectInserter} from which this
	 * reader was created using {@code inserter.newReader()}
	 *
	 * @return the {@link org.eclipse.jgit.lib.ObjectInserter} from which this
	 *         reader was created using {@code inserter.newReader()}, or null if
	 *         this reader was not created from an inserter.
	 * @since 4.4
	 */
	@Nullable
	public ObjectInserter getCreatedFromInserter() {
		return null;
	}

	{@inheritDoc}

Release any resources used by this reader.

A reader that has been released can be used again, but may need to be
released after the subsequent usage.
Since: 4.0/**
	 * {@inheritDoc}
	 * <p>
	 * Release any resources used by this reader.
	 * <p>
	 * A reader that has been released can be used again, but may need to be
	 * released after the subsequent usage.
	 *
	 * @since 4.0
	 */
	@Override
	public abstract void close();

	Sets the threshold at which a file will be streamed rather than loaded
entirely into memory
Params: threshold – 
           the new threshold
Since: 4.6/**
	 * Sets the threshold at which a file will be streamed rather than loaded
	 * entirely into memory
	 *
	 * @param threshold
	 *            the new threshold
	 * @since 4.6
	 */
	public void setStreamFileThreshold(int threshold) {
		streamFileThreshold = threshold;
	}

	Returns the threshold at which a file will be streamed rather than loaded
entirely into memory
Returns: the threshold in bytes
Since: 4.6/**
	 * Returns the threshold at which a file will be streamed rather than loaded
	 * entirely into memory
	 *
	 * @return the threshold in bytes
	 * @since 4.6
	 */
	public int getStreamFileThreshold() {
		return streamFileThreshold;
	}

	Wraps a delegate ObjectReader.
Since: 4.4/**
	 * Wraps a delegate ObjectReader.
	 *
	 * @since 4.4
	 */
	public static abstract class Filter extends ObjectReader {
		Returns: delegate ObjectReader to handle all processing.
Since: 4.4/**
		 * @return delegate ObjectReader to handle all processing.
		 * @since 4.4
		 */
		protected abstract ObjectReader delegate();

		@Override
		public ObjectReader newReader() {
			return delegate().newReader();
		}

		@Override
		public AbbreviatedObjectId abbreviate(AnyObjectId objectId)
				throws IOException {
			return delegate().abbreviate(objectId);
		}

		@Override
		public AbbreviatedObjectId abbreviate(AnyObjectId objectId, int len)
				throws IOException {
			return delegate().abbreviate(objectId, len);
		}

		@Override
		public Collection<ObjectId> resolve(AbbreviatedObjectId id)
				throws IOException {
			return delegate().resolve(id);
		}

		@Override
		public boolean has(AnyObjectId objectId) throws IOException {
			return delegate().has(objectId);
		}

		@Override
		public boolean has(AnyObjectId objectId, int typeHint) throws IOException {
			return delegate().has(objectId, typeHint);
		}

		@Override
		public ObjectLoader open(AnyObjectId objectId)
				throws MissingObjectException, IOException {
			return delegate().open(objectId);
		}

		@Override
		public ObjectLoader open(AnyObjectId objectId, int typeHint)
				throws MissingObjectException, IncorrectObjectTypeException,
				IOException {
			return delegate().open(objectId, typeHint);
		}

		@Override
		public Set<ObjectId> getShallowCommits() throws IOException {
			return delegate().getShallowCommits();
		}

		@Override
		public <T extends ObjectId> AsyncObjectLoaderQueue<T> open(
				Iterable<T> objectIds, boolean reportMissing) {
			return delegate().open(objectIds, reportMissing);
		}

		@Override
		public long getObjectSize(AnyObjectId objectId, int typeHint)
				throws MissingObjectException, IncorrectObjectTypeException,
				IOException {
			return delegate().getObjectSize(objectId, typeHint);
		}

		@Override
		public <T extends ObjectId> AsyncObjectSizeQueue<T> getObjectSize(
				Iterable<T> objectIds, boolean reportMissing) {
			return delegate().getObjectSize(objectIds, reportMissing);
		}

		@Override
		public void setAvoidUnreachableObjects(boolean avoid) {
			delegate().setAvoidUnreachableObjects(avoid);
		}

		@Override
		public BitmapIndex getBitmapIndex() throws IOException {
			return delegate().getBitmapIndex();
		}

		@Override
		@Nullable
		public ObjectInserter getCreatedFromInserter() {
			return delegate().getCreatedFromInserter();
		}

		@Override
		public void close() {
			delegate().close();
		}
	}
}
Params:	objectId – object identity that needs to be abbreviated.
Throws:	IOException – the object store cannot be read.
Returns:	SHA-1 abbreviation.
Params:	id – abbreviated id to resolve to a complete identity. The abbreviation must have a length of at least 2.
Throws:	IOException – the object store cannot be read.
Returns:	candidates that begin with the abbreviated identity.
Params:	objectId – identity of the object to test for existence of.
Throws:	IOException – the object store cannot be accessed.
Returns:	true if the specified object is stored in this database.
Params:	objectId – identity of the object to open.
Throws:	MissingObjectException – the object does not exist. IOException – the object store cannot be accessed.
Returns:	a `ObjectLoader` for accessing the object.
Params:	avoid – true to avoid unreachable objects.
Since:	3.0
Throws:	IOException – when the index fails to load
Returns:	the index or null if one does not exist.
Since:	3.0
Returns:	the `ObjectInserter` from which this reader was created using `inserter.newReader()`, or null if this reader was not created from an inserter.
Since:	4.4
Returns:	delegate ObjectReader to handle all processing.
Since:	4.4
/

org.eclipse.jgit/ org.eclipse.jgit/ 5.5.0.201909110433-r/ org/eclipse/jgit/lib/ObjectReader.java
