/*
* Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
* 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
* 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.treewalk.filter;
import java.util.Collection;
import org.eclipse.jgit.errors.StopWalkException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.filter.ByteArraySet.Hasher;
import org.eclipse.jgit.util.RawParseUtils;
/**
* Includes tree entries only if they match one or more configured paths.
* <p>
* Operates like {@link PathFilter} but causes the walk to abort as soon as the
* tree can no longer match any of the paths within the group. This may bypass
* the boolean logic of a higher level AND or OR group, but does improve
* performance for the common case of examining one or more modified paths.
* <p>
* This filter is effectively an OR group around paths, with the early abort
* feature described above.
*/
public class PathFilterGroup {
/**
* Create a collection of path filters from Java strings.
* <p>
* Path strings are relative to the root of the repository. If the user's
* input should be assumed relative to a subdirectory of the repository the
* caller must prepend the subdirectory's path prior to creating the filter.
* <p>
* Path strings use '/' to delimit directories on all platforms.
* <p>
* Paths may appear in any order within the collection. Sorting may be done
* internally when the group is constructed if doing so will improve path
* matching performance.
*
* @param paths
* the paths to test against. Must have at least one entry.
* @return a new filter for the list of paths supplied.
*/
public static TreeFilter createFromStrings(final Collection<String> paths) {
if (paths.isEmpty())
throw new IllegalArgumentException(
JGitText.get().atLeastOnePathIsRequired);
final PathFilter[] p = new PathFilter[paths.size()];
int i = 0;
for (final String s : paths)
p[i++] = PathFilter.create(s);
return create(p);
}
/**
* Create a collection of path filters from Java strings.
* <p>
* Path strings are relative to the root of the repository. If the user's
* input should be assumed relative to a subdirectory of the repository the
* caller must prepend the subdirectory's path prior to creating the filter.
* <p>
* Path strings use '/' to delimit directories on all platforms.
* <p>
* Paths may appear in any order. Sorting may be done internally when the
* group is constructed if doing so will improve path matching performance.
*
* @param paths
* the paths to test against. Must have at least one entry.
* @return a new filter for the paths supplied.
*/
public static TreeFilter createFromStrings(final String... paths) {
if (paths.length == 0)
throw new IllegalArgumentException(
JGitText.get().atLeastOnePathIsRequired);
final int length = paths.length;
final PathFilter[] p = new PathFilter[length];
for (int i = 0; i < length; i++)
p[i] = PathFilter.create(paths[i]);
return create(p);
}
/**
* Create a collection of path filters.
* <p>
* Paths may appear in any order within the collection. Sorting may be done
* internally when the group is constructed if doing so will improve path
* matching performance.
*
* @param paths
* the paths to test against. Must have at least one entry.
* @return a new filter for the list of paths supplied.
*/
public static TreeFilter create(final Collection<PathFilter> paths) {
if (paths.isEmpty())
throw new IllegalArgumentException(
JGitText.get().atLeastOnePathIsRequired);
final PathFilter[] p = new PathFilter[paths.size()];
paths.toArray(p);
return create(p);
}
private static TreeFilter create(final PathFilter[] p) {
if (p.length == 1)
return new Single(p[0]);
return new Group(p);
}
static class Single extends TreeFilter {
private final PathFilter path;
private final byte[] raw;
private Single(final PathFilter p) {
path = p;
raw = path.pathRaw;
}
@Override
public boolean include(final TreeWalk walker) {
final int cmp = walker.isPathPrefix(raw, raw.length);
if (cmp > 0)
throw StopWalkException.INSTANCE;
return cmp == 0;
}
@Override
public boolean shouldBeRecursive() {
return path.shouldBeRecursive();
}
@Override
public TreeFilter clone() {
return this;
}
public String toString() {
return "FAST_" + path.toString(); //$NON-NLS-1$
}
}
static class Group extends TreeFilter {
private ByteArraySet fullpaths;
private ByteArraySet prefixes;
private byte[] max;
private Group(final PathFilter[] pathFilters) {
fullpaths = new ByteArraySet(pathFilters.length);
prefixes = new ByteArraySet(pathFilters.length / 5);
// 5 is an empirically derived ratio of #paths/#prefixes from:
// egit/jgit: 8
// git: 5
// linux kernel: 13
// eclipse.platform.ui: 7
max = pathFilters[0].pathRaw;
Hasher hasher = new Hasher(null, 0);
for (PathFilter pf : pathFilters) {
hasher.init(pf.pathRaw, pf.pathRaw.length);
while (hasher.hasNext()) {
int hash = hasher.nextHash();
if (hasher.hasNext())
prefixes.addIfAbsent(pf.pathRaw, hasher.length(), hash);
}
fullpaths.addIfAbsent(pf.pathRaw, pf.pathRaw.length,
hasher.getHash());
if (compare(max, pf.pathRaw) < 0)
max = pf.pathRaw;
}
// Adjust max for the git sort order. A path we compare
// with may end with a slash at any position (but the
// first, but we ignore that here since it's not relevant).
// Such paths must be included in the processing
// before we can give up and throw a StopWalkException.
byte[] newMax = new byte[max.length + 1];
for (int i = 0; i < max.length; ++i)
if ((max[i] & 0xFF) < '/')
newMax[i] = '/';
else
newMax[i] = max[i];
newMax[newMax.length - 1] = '/';
max = newMax;
}
private static int compare(byte[] a, byte[] b) {
int i = 0;
while (i < a.length && i < b.length) {
int ba = a[i] & 0xFF;
int bb = b[i] & 0xFF;
int cmp = ba - bb;
if (cmp != 0)
return cmp;
++i;
}
return a.length - b.length;
}
@Override
public boolean include(final TreeWalk walker) {
byte[] rp = walker.getRawPath();
Hasher hasher = new Hasher(rp, walker.getPathLength());
while (hasher.hasNext()) {
int hash = hasher.nextHash();
if (fullpaths.contains(rp, hasher.length(), hash))
return true;
if (!hasher.hasNext() && walker.isSubtree()
&& prefixes.contains(rp, hasher.length(), hash))
return true;
}
final int cmp = walker.isPathPrefix(max, max.length);
if (cmp > 0)
throw StopWalkException.INSTANCE;
return false;
}
@Override
public boolean shouldBeRecursive() {
return !prefixes.isEmpty();
}
@Override
public TreeFilter clone() {
return this;
}
public String toString() {
final StringBuilder r = new StringBuilder();
r.append("FAST("); //$NON-NLS-1$
boolean first = true;
for (byte[] p : fullpaths.toArray()) {
if (!first) {
r.append(" OR "); //$NON-NLS-1$
}
r.append(RawParseUtils.decode(p));
first = false;
}
r.append(")"); //$NON-NLS-1$
return r.toString();
}
}
}