/*
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* 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
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* 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.revwalk.filter;
import java.io.IOException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.StopWalkException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
/**
* Selects interesting revisions during walking.
* <p>
* This is an abstract interface. Applications may implement a subclass, or use
* one of the predefined implementations already available within this package.
* Filters may be chained together using <code>AndRevFilter</code> and
* <code>OrRevFilter</code> to create complex boolean expressions.
* <p>
* Applications should install the filter on a RevWalk by
* {@link RevWalk#setRevFilter(RevFilter)} prior to starting traversal.
* <p>
* Unless specifically noted otherwise a RevFilter implementation is not thread
* safe and may not be shared by different RevWalk instances at the same time.
* This restriction allows RevFilter implementations to cache state within their
* instances during {@link #include(RevWalk, RevCommit)} if it is beneficial to
* their implementation. Deep clones created by {@link #clone()} may be used to
* construct a thread-safe copy of an existing filter.
*
* <p>
* <b>Message filters:</b>
* <ul>
* <li>Author name/email: {@link AuthorRevFilter}</li>
* <li>Committer name/email: {@link CommitterRevFilter}</li>
* <li>Message body: {@link MessageRevFilter}</li>
* </ul>
*
* <p>
* <b>Merge filters:</b>
* <ul>
* <li>Skip all merges: {@link #NO_MERGES}.</li>
* <li>Skip all non-merges: {@link #ONLY_MERGES}</li>
* </ul>
*
* <p>
* <b>Boolean modifiers:</b>
* <ul>
* <li>AND: {@link AndRevFilter}</li>
* <li>OR: {@link OrRevFilter}</li>
* <li>NOT: {@link NotRevFilter}</li>
* </ul>
*/
public abstract class RevFilter {
/** Default filter that always returns true (thread safe). */
public static final RevFilter ALL = new AllFilter();
private static final class AllFilter extends RevFilter {
@Override
public boolean include(final RevWalk walker, final RevCommit c) {
return true;
}
@Override
public RevFilter clone() {
return this;
}
@Override
public boolean requiresCommitBody() {
return false;
}
@Override
public String toString() {
return "ALL"; //$NON-NLS-1$
}
}
/** Default filter that always returns false (thread safe). */
public static final RevFilter NONE = new NoneFilter();
private static final class NoneFilter extends RevFilter {
@Override
public boolean include(final RevWalk walker, final RevCommit c) {
return false;
}
@Override
public RevFilter clone() {
return this;
}
@Override
public boolean requiresCommitBody() {
return false;
}
@Override
public String toString() {
return "NONE"; //$NON-NLS-1$
}
}
/**
* Filter including only merge commits, excluding all commits with less than
* two parents (thread safe).
*
* @since 4.4
*/
public static final RevFilter ONLY_MERGES = new OnlyMergesFilter();
private static final class OnlyMergesFilter extends RevFilter {
@Override
public boolean include(RevWalk walker, RevCommit c) {
return c.getParentCount() >= 2;
}
@Override
public RevFilter clone() {
return this;
}
@Override
public boolean requiresCommitBody() {
return false;
}
@Override
public String toString() {
return "ONLY_MERGES"; //$NON-NLS-1$
}
}
/** Excludes commits with more than one parent (thread safe). */
public static final RevFilter NO_MERGES = new NoMergesFilter();
private static final class NoMergesFilter extends RevFilter {
@Override
public boolean include(final RevWalk walker, final RevCommit c) {
return c.getParentCount() < 2;
}
@Override
public RevFilter clone() {
return this;
}
@Override
public boolean requiresCommitBody() {
return false;
}
@Override
public String toString() {
return "NO_MERGES"; //$NON-NLS-1$
}
}
/**
* Selects only merge bases of the starting points (thread safe).
* <p>
* This is a special case filter that cannot be combined with any other
* filter. Its include method always throws an exception as context
* information beyond the arguments is necessary to determine if the
* supplied commit is a merge base.
*/
public static final RevFilter MERGE_BASE = new MergeBaseFilter();
private static final class MergeBaseFilter extends RevFilter {
@Override
public boolean include(final RevWalk walker, final RevCommit c) {
throw new UnsupportedOperationException(JGitText.get().cannotBeCombined);
}
@Override
public RevFilter clone() {
return this;
}
@Override
public boolean requiresCommitBody() {
return false;
}
@Override
public String toString() {
return "MERGE_BASE"; //$NON-NLS-1$
}
}
/**
* Create a new filter that does the opposite of this filter.
*
* @return a new filter that includes commits this filter rejects.
*/
public RevFilter negate() {
return NotRevFilter.create(this);
}
/** @return true if the filter needs the commit body to be parsed. */
public boolean requiresCommitBody() {
// Assume true to be backward compatible with prior behavior.
return true;
}
/**
* Determine if the supplied commit should be included in results.
*
* @param walker
* the active walker this filter is being invoked from within.
* @param cmit
* the commit currently being tested. The commit has been parsed
* and its body is available for inspection only if the filter
* returns true from {@link #requiresCommitBody()}.
* @return true to include this commit in the results; false to have this
* commit be omitted entirely from the results.
* @throws StopWalkException
* the filter knows for certain that no additional commits can
* ever match, and the current commit doesn't match either. The
* walk is halted and no more results are provided.
* @throws MissingObjectException
* an object the filter needs to consult to determine its answer
* does not exist in the Git repository the walker is operating
* on. Filtering this commit is impossible without the object.
* @throws IncorrectObjectTypeException
* an object the filter needed to consult was not of the
* expected object type. This usually indicates a corrupt
* repository, as an object link is referencing the wrong type.
* @throws IOException
* a loose object or pack file could not be read to obtain data
* necessary for the filter to make its decision.
*/
public abstract boolean include(RevWalk walker, RevCommit cmit)
throws StopWalkException, MissingObjectException,
IncorrectObjectTypeException, IOException;
/**
* Clone this revision filter, including its parameters.
* <p>
* This is a deep clone. If this filter embeds objects or other filters it
* must also clone those, to ensure the instances do not share mutable data.
*
* @return another copy of this filter, suitable for another thread.
*/
public abstract RevFilter clone();
@Override
public String toString() {
String n = getClass().getName();
int lastDot = n.lastIndexOf('.');
if (lastDot >= 0) {
n = n.substring(lastDot + 1);
}
return n.replace('$', '.');
}
}