/*
* Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* Copyright (C) 2014, Gustaf Lundh <gustaf.lundh@sonymobile.com>
* 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.revwalk;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.EnumSet;
import java.util.Iterator;
import java.util.List;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.RevWalkException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.AsyncObjectLoaderQueue;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.MutableObjectId;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectIdOwnerMap;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.filter.RevFilter;
import org.eclipse.jgit.treewalk.filter.TreeFilter;
/**
* Walks a commit graph and produces the matching commits in order.
* <p>
* A RevWalk instance can only be used once to generate results. Running a
* second time requires creating a new RevWalk instance, or invoking
* {@link #reset()} before starting again. Resetting an existing instance may be
* faster for some applications as commit body parsing can be avoided on the
* later invocations.
* <p>
* RevWalk instances are not thread-safe. Applications must either restrict
* usage of a RevWalk instance to a single thread, or implement their own
* synchronization at a higher level.
* <p>
* Multiple simultaneous RevWalk instances per {@link Repository} are permitted,
* even from concurrent threads. Equality of {@link RevCommit}s from two
* different RevWalk instances is never true, even if their {@link ObjectId}s
* are equal (and thus they describe the same commit).
* <p>
* The offered iterator is over the list of RevCommits described by the
* configuration of this instance. Applications should restrict themselves to
* using either the provided Iterator or {@link #next()}, but never use both on
* the same RevWalk at the same time. The Iterator may buffer RevCommits, while
* {@link #next()} does not.
*/
public class RevWalk implements Iterable<RevCommit>, AutoCloseable {
private static final int MB = 1 << 20;
/**
* Set on objects whose important header data has been loaded.
* <p>
* For a RevCommit this indicates we have pulled apart the tree and parent
* references from the raw bytes available in the repository and translated
* those to our own local RevTree and RevCommit instances. The raw buffer is
* also available for message and other header filtering.
* <p>
* For a RevTag this indicates we have pulled part the tag references to
* find out who the tag refers to, and what that object's type is.
*/
static final int PARSED = 1 << 0;
/**
* Set on RevCommit instances added to our {@link #pending} queue.
* <p>
* We use this flag to avoid adding the same commit instance twice to our
* queue, especially if we reached it by more than one path.
*/
static final int SEEN = 1 << 1;
/**
* Set on RevCommit instances the caller does not want output.
* <p>
* We flag commits as uninteresting if the caller does not want commits
* reachable from a commit given to {@link #markUninteresting(RevCommit)}.
* This flag is always carried into the commit's parents and is a key part
* of the "rev-list B --not A" feature; A is marked UNINTERESTING.
*/
static final int UNINTERESTING = 1 << 2;
/**
* Set on a RevCommit that can collapse out of the history.
* <p>
* If the {@link #treeFilter} concluded that this commit matches his
* parents' for all of the paths that the filter is interested in then we
* mark the commit REWRITE. Later we can rewrite the parents of a REWRITE
* child to remove chains of REWRITE commits before we produce the child to
* the application.
*
* @see RewriteGenerator
*/
static final int REWRITE = 1 << 3;
/**
* Temporary mark for use within generators or filters.
* <p>
* This mark is only for local use within a single scope. If someone sets
* the mark they must unset it before any other code can see the mark.
*/
static final int TEMP_MARK = 1 << 4;
/**
* Temporary mark for use within {@link TopoSortGenerator}.
* <p>
* This mark indicates the commit could not produce when it wanted to, as at
* least one child was behind it. Commits with this flag are delayed until
* all children have been output first.
*/
static final int TOPO_DELAY = 1 << 5;
/** Number of flag bits we keep internal for our own use. See above flags. */
static final int RESERVED_FLAGS = 6;
private static final int APP_FLAGS = -1 & ~((1 << RESERVED_FLAGS) - 1);
final ObjectReader reader;
private final boolean closeReader;
final MutableObjectId idBuffer;
ObjectIdOwnerMap<RevObject> objects;
int freeFlags = APP_FLAGS;
private int delayFreeFlags;
private int retainOnReset;
int carryFlags = UNINTERESTING;
final ArrayList<RevCommit> roots;
AbstractRevQueue queue;
Generator pending;
private final EnumSet<RevSort> sorting;
private RevFilter filter;
private TreeFilter treeFilter;
private boolean retainBody = true;
private boolean rewriteParents = true;
boolean shallowCommitsInitialized;
/**
* Create a new revision walker for a given repository.
*
* @param repo
* the repository the walker will obtain data from. An
* ObjectReader will be created by the walker, and will be closed
* when the walker is closed.
*/
public RevWalk(final Repository repo) {
this(repo.newObjectReader(), true);
}
/**
* Create a new revision walker for a given repository.
* <p>
*
* @param or
* the reader the walker will obtain data from. The reader is not
* closed when the walker is closed (but is closed by {@link
* #dispose()}.
*/
public RevWalk(ObjectReader or) {
this(or, false);
}
private RevWalk(ObjectReader or, boolean closeReader) {
reader = or;
idBuffer = new MutableObjectId();
objects = new ObjectIdOwnerMap<RevObject>();
roots = new ArrayList<RevCommit>();
queue = new DateRevQueue();
pending = new StartGenerator(this);
sorting = EnumSet.of(RevSort.NONE);
filter = RevFilter.ALL;
treeFilter = TreeFilter.ALL;
this.closeReader = closeReader;
}
/** @return the reader this walker is using to load objects. */
public ObjectReader getObjectReader() {
return reader;
}
/**
* Release any resources used by this walker's reader.
* <p>
* A walker that has been released can be used again, but may need to be
* released after the subsequent usage.
*
* @since 4.0
*/
@Override
public void close() {
if (closeReader) {
reader.close();
}
}
/**
* Mark a commit to start graph traversal from.
* <p>
* Callers are encouraged to use {@link #parseCommit(AnyObjectId)} to obtain
* the commit reference, rather than {@link #lookupCommit(AnyObjectId)}, as
* this method requires the commit to be parsed before it can be added as a
* root for the traversal.
* <p>
* The method will automatically parse an unparsed commit, but error
* handling may be more difficult for the application to explain why a
* RevCommit is not actually a commit. The object pool of this walker would
* also be 'poisoned' by the non-commit RevCommit.
*
* @param c
* the commit to start traversing from. The commit passed must be
* from this same revision walker.
* @throws MissingObjectException
* the commit supplied is not available from the object
* database. This usually indicates the supplied commit is
* invalid, but the reference was constructed during an earlier
* invocation to {@link #lookupCommit(AnyObjectId)}.
* @throws IncorrectObjectTypeException
* the object was not parsed yet and it was discovered during
* parsing that it is not actually a commit. This usually
* indicates the caller supplied a non-commit SHA-1 to
* {@link #lookupCommit(AnyObjectId)}.
* @throws IOException
* a pack file or loose object could not be read.
*/
public void markStart(final RevCommit c) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
if ((c.flags & SEEN) != 0)
return;
if ((c.flags & PARSED) == 0)
c.parseHeaders(this);
c.flags |= SEEN;
roots.add(c);
queue.add(c);
}
/**
* Mark commits to start graph traversal from.
*
* @param list
* commits to start traversing from. The commits passed must be
* from this same revision walker.
* @throws MissingObjectException
* one of the commits supplied is not available from the object
* database. This usually indicates the supplied commit is
* invalid, but the reference was constructed during an earlier
* invocation to {@link #lookupCommit(AnyObjectId)}.
* @throws IncorrectObjectTypeException
* the object was not parsed yet and it was discovered during
* parsing that it is not actually a commit. This usually
* indicates the caller supplied a non-commit SHA-1 to
* {@link #lookupCommit(AnyObjectId)}.
* @throws IOException
* a pack file or loose object could not be read.
*/
public void markStart(final Collection<RevCommit> list)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
for (final RevCommit c : list)
markStart(c);
}
/**
* Mark a commit to not produce in the output.
* <p>
* Uninteresting commits denote not just themselves but also their entire
* ancestry chain, back until the merge base of an uninteresting commit and
* an otherwise interesting commit.
* <p>
* Callers are encouraged to use {@link #parseCommit(AnyObjectId)} to obtain
* the commit reference, rather than {@link #lookupCommit(AnyObjectId)}, as
* this method requires the commit to be parsed before it can be added as a
* root for the traversal.
* <p>
* The method will automatically parse an unparsed commit, but error
* handling may be more difficult for the application to explain why a
* RevCommit is not actually a commit. The object pool of this walker would
* also be 'poisoned' by the non-commit RevCommit.
*
* @param c
* the commit to start traversing from. The commit passed must be
* from this same revision walker.
* @throws MissingObjectException
* the commit supplied is not available from the object
* database. This usually indicates the supplied commit is
* invalid, but the reference was constructed during an earlier
* invocation to {@link #lookupCommit(AnyObjectId)}.
* @throws IncorrectObjectTypeException
* the object was not parsed yet and it was discovered during
* parsing that it is not actually a commit. This usually
* indicates the caller supplied a non-commit SHA-1 to
* {@link #lookupCommit(AnyObjectId)}.
* @throws IOException
* a pack file or loose object could not be read.
*/
public void markUninteresting(final RevCommit c)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
c.flags |= UNINTERESTING;
carryFlagsImpl(c);
markStart(c);
}
/**
* Determine if a commit is reachable from another commit.
* <p>
* A commit <code>base</code> is an ancestor of <code>tip</code> if we
* can find a path of commits that leads from <code>tip</code> and ends at
* <code>base</code>.
* <p>
* This utility function resets the walker, inserts the two supplied
* commits, and then executes a walk until an answer can be obtained.
* Currently allocated RevFlags that have been added to RevCommit instances
* will be retained through the reset.
*
* @param base
* commit the caller thinks is reachable from <code>tip</code>.
* @param tip
* commit to start iteration from, and which is most likely a
* descendant (child) of <code>base</code>.
* @return true if there is a path directly from <code>tip</code> to
* <code>base</code> (and thus <code>base</code> is fully merged
* into <code>tip</code>); false otherwise.
* @throws MissingObjectException
* one or or more of the next commit's parents are not available
* from the object database, but were thought to be candidates
* for traversal. This usually indicates a broken link.
* @throws IncorrectObjectTypeException
* one or or more of the next commit's parents are not actually
* commit objects.
* @throws IOException
* a pack file or loose object could not be read.
*/
public boolean isMergedInto(final RevCommit base, final RevCommit tip)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
final RevFilter oldRF = filter;
final TreeFilter oldTF = treeFilter;
try {
finishDelayedFreeFlags();
reset(~freeFlags & APP_FLAGS);
filter = RevFilter.MERGE_BASE;
treeFilter = TreeFilter.ALL;
markStart(tip);
markStart(base);
RevCommit mergeBase;
while ((mergeBase = next()) != null)
if (mergeBase == base)
return true;
return false;
} finally {
filter = oldRF;
treeFilter = oldTF;
}
}
/**
* Pop the next most recent commit.
*
* @return next most recent commit; null if traversal is over.
* @throws MissingObjectException
* one or or more of the next commit's parents are not available
* from the object database, but were thought to be candidates
* for traversal. This usually indicates a broken link.
* @throws IncorrectObjectTypeException
* one or or more of the next commit's parents are not actually
* commit objects.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevCommit next() throws MissingObjectException,
IncorrectObjectTypeException, IOException {
return pending.next();
}
/**
* Obtain the sort types applied to the commits returned.
*
* @return the sorting strategies employed. At least one strategy is always
* used, but that strategy may be {@link RevSort#NONE}.
*/
public EnumSet<RevSort> getRevSort() {
return sorting.clone();
}
/**
* Check whether the provided sorting strategy is enabled.
*
* @param sort
* a sorting strategy to look for.
* @return true if this strategy is enabled, false otherwise
*/
public boolean hasRevSort(RevSort sort) {
return sorting.contains(sort);
}
/**
* Select a single sorting strategy for the returned commits.
* <p>
* Disables all sorting strategies, then enables only the single strategy
* supplied by the caller.
*
* @param s
* a sorting strategy to enable.
*/
public void sort(final RevSort s) {
assertNotStarted();
sorting.clear();
sorting.add(s);
}
/**
* Add or remove a sorting strategy for the returned commits.
* <p>
* Multiple strategies can be applied at once, in which case some strategies
* may take precedence over others. As an example, {@link RevSort#TOPO} must
* take precedence over {@link RevSort#COMMIT_TIME_DESC}, otherwise it
* cannot enforce its ordering.
*
* @param s
* a sorting strategy to enable or disable.
* @param use
* true if this strategy should be used, false if it should be
* removed.
*/
public void sort(final RevSort s, final boolean use) {
assertNotStarted();
if (use)
sorting.add(s);
else
sorting.remove(s);
if (sorting.size() > 1)
sorting.remove(RevSort.NONE);
else if (sorting.size() == 0)
sorting.add(RevSort.NONE);
}
/**
* Get the currently configured commit filter.
*
* @return the current filter. Never null as a filter is always needed.
*/
public RevFilter getRevFilter() {
return filter;
}
/**
* Set the commit filter for this walker.
* <p>
* Multiple filters may be combined by constructing an arbitrary tree of
* <code>AndRevFilter</code> or <code>OrRevFilter</code> instances to
* describe the boolean expression required by the application. Custom
* filter implementations may also be constructed by applications.
* <p>
* Note that filters are not thread-safe and may not be shared by concurrent
* RevWalk instances. Every RevWalk must be supplied its own unique filter,
* unless the filter implementation specifically states it is (and always
* will be) thread-safe. Callers may use {@link RevFilter#clone()} to create
* a unique filter tree for this RevWalk instance.
*
* @param newFilter
* the new filter. If null the special {@link RevFilter#ALL}
* filter will be used instead, as it matches every commit.
* @see org.eclipse.jgit.revwalk.filter.AndRevFilter
* @see org.eclipse.jgit.revwalk.filter.OrRevFilter
*/
public void setRevFilter(final RevFilter newFilter) {
assertNotStarted();
filter = newFilter != null ? newFilter : RevFilter.ALL;
}
/**
* Get the tree filter used to simplify commits by modified paths.
*
* @return the current filter. Never null as a filter is always needed. If
* no filter is being applied {@link TreeFilter#ALL} is returned.
*/
public TreeFilter getTreeFilter() {
return treeFilter;
}
/**
* Set the tree filter used to simplify commits by modified paths.
* <p>
* If null or {@link TreeFilter#ALL} the path limiter is removed. Commits
* will not be simplified.
* <p>
* If non-null and not {@link TreeFilter#ALL} then the tree filter will be
* installed. Commits will have their ancestry simplified to hide commits that
* do not contain tree entries matched by the filter, unless
* {@code setRewriteParents(false)} is called.
* <p>
* Usually callers should be inserting a filter graph including
* {@link TreeFilter#ANY_DIFF} along with one or more
* {@link org.eclipse.jgit.treewalk.filter.PathFilter} instances.
*
* @param newFilter
* new filter. If null the special {@link TreeFilter#ALL} filter
* will be used instead, as it matches everything.
* @see org.eclipse.jgit.treewalk.filter.PathFilter
*/
public void setTreeFilter(final TreeFilter newFilter) {
assertNotStarted();
treeFilter = newFilter != null ? newFilter : TreeFilter.ALL;
}
/**
* Set whether to rewrite parent pointers when filtering by modified paths.
* <p>
* By default, when {@link #setTreeFilter(TreeFilter)} is called with non-
* null and non-{@link TreeFilter#ALL} filter, commits will have their
* ancestry simplified and parents rewritten to hide commits that do not match
* the filter.
* <p>
* This behavior can be bypassed by passing false to this method.
*
* @param rewrite
* whether to rewrite parents; defaults to true.
* @since 3.4
*/
public void setRewriteParents(boolean rewrite) {
rewriteParents = rewrite;
}
boolean getRewriteParents() {
return rewriteParents;
}
/**
* Should the body of a commit or tag be retained after parsing its headers?
* <p>
* Usually the body is always retained, but some application code might not
* care and would prefer to discard the body of a commit as early as
* possible, to reduce memory usage.
* <p>
* True by default on {@link RevWalk} and false by default for
* {@link ObjectWalk}.
*
* @return true if the body should be retained; false it is discarded.
*/
public boolean isRetainBody() {
return retainBody;
}
/**
* Set whether or not the body of a commit or tag is retained.
* <p>
* If a body of a commit or tag is not retained, the application must
* call {@link #parseBody(RevObject)} before the body can be safely
* accessed through the type specific access methods.
* <p>
* True by default on {@link RevWalk} and false by default for
* {@link ObjectWalk}.
*
* @param retain true to retain bodies; false to discard them early.
*/
public void setRetainBody(final boolean retain) {
retainBody = retain;
}
/**
* Locate a reference to a blob without loading it.
* <p>
* The blob may or may not exist in the repository. It is impossible to tell
* from this method's return value.
*
* @param id
* name of the blob object.
* @return reference to the blob object. Never null.
*/
public RevBlob lookupBlob(final AnyObjectId id) {
RevBlob c = (RevBlob) objects.get(id);
if (c == null) {
c = new RevBlob(id);
objects.add(c);
}
return c;
}
/**
* Locate a reference to a tree without loading it.
* <p>
* The tree may or may not exist in the repository. It is impossible to tell
* from this method's return value.
*
* @param id
* name of the tree object.
* @return reference to the tree object. Never null.
*/
public RevTree lookupTree(final AnyObjectId id) {
RevTree c = (RevTree) objects.get(id);
if (c == null) {
c = new RevTree(id);
objects.add(c);
}
return c;
}
/**
* Locate a reference to a commit without loading it.
* <p>
* The commit may or may not exist in the repository. It is impossible to
* tell from this method's return value.
* <p>
* See {@link #parseHeaders(RevObject)} and {@link #parseBody(RevObject)}
* for loading contents.
*
* @param id
* name of the commit object.
* @return reference to the commit object. Never null.
*/
public RevCommit lookupCommit(final AnyObjectId id) {
RevCommit c = (RevCommit) objects.get(id);
if (c == null) {
c = createCommit(id);
objects.add(c);
}
return c;
}
/**
* Locate a reference to a tag without loading it.
* <p>
* The tag may or may not exist in the repository. It is impossible to tell
* from this method's return value.
*
* @param id
* name of the tag object.
* @return reference to the tag object. Never null.
*/
public RevTag lookupTag(final AnyObjectId id) {
RevTag c = (RevTag) objects.get(id);
if (c == null) {
c = new RevTag(id);
objects.add(c);
}
return c;
}
/**
* Locate a reference to any object without loading it.
* <p>
* The object may or may not exist in the repository. It is impossible to
* tell from this method's return value.
*
* @param id
* name of the object.
* @param type
* type of the object. Must be a valid Git object type.
* @return reference to the object. Never null.
*/
public RevObject lookupAny(final AnyObjectId id, final int type) {
RevObject r = objects.get(id);
if (r == null) {
switch (type) {
case Constants.OBJ_COMMIT:
r = createCommit(id);
break;
case Constants.OBJ_TREE:
r = new RevTree(id);
break;
case Constants.OBJ_BLOB:
r = new RevBlob(id);
break;
case Constants.OBJ_TAG:
r = new RevTag(id);
break;
default:
throw new IllegalArgumentException(MessageFormat.format(
JGitText.get().invalidGitType, Integer.valueOf(type)));
}
objects.add(r);
}
return r;
}
/**
* Locate an object that was previously allocated in this walk.
*
* @param id
* name of the object.
* @return reference to the object if it has been previously located;
* otherwise null.
*/
public RevObject lookupOrNull(AnyObjectId id) {
return objects.get(id);
}
/**
* Locate a reference to a commit and immediately parse its content.
* <p>
* Unlike {@link #lookupCommit(AnyObjectId)} this method only returns
* successfully if the commit object exists, is verified to be a commit, and
* was parsed without error.
*
* @param id
* name of the commit object.
* @return reference to the commit object. Never null.
* @throws MissingObjectException
* the supplied commit does not exist.
* @throws IncorrectObjectTypeException
* the supplied id is not a commit or an annotated tag.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevCommit parseCommit(final AnyObjectId id)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
RevObject c = peel(parseAny(id));
if (!(c instanceof RevCommit))
throw new IncorrectObjectTypeException(id.toObjectId(),
Constants.TYPE_COMMIT);
return (RevCommit) c;
}
/**
* Locate a reference to a tree.
* <p>
* This method only returns successfully if the tree object exists, is
* verified to be a tree.
*
* @param id
* name of the tree object, or a commit or annotated tag that may
* reference a tree.
* @return reference to the tree object. Never null.
* @throws MissingObjectException
* the supplied tree does not exist.
* @throws IncorrectObjectTypeException
* the supplied id is not a tree, a commit or an annotated tag.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevTree parseTree(final AnyObjectId id)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
RevObject c = peel(parseAny(id));
final RevTree t;
if (c instanceof RevCommit)
t = ((RevCommit) c).getTree();
else if (!(c instanceof RevTree))
throw new IncorrectObjectTypeException(id.toObjectId(),
Constants.TYPE_TREE);
else
t = (RevTree) c;
parseHeaders(t);
return t;
}
/**
* Locate a reference to an annotated tag and immediately parse its content.
* <p>
* Unlike {@link #lookupTag(AnyObjectId)} this method only returns
* successfully if the tag object exists, is verified to be a tag, and was
* parsed without error.
*
* @param id
* name of the tag object.
* @return reference to the tag object. Never null.
* @throws MissingObjectException
* the supplied tag does not exist.
* @throws IncorrectObjectTypeException
* the supplied id is not a tag or an annotated tag.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevTag parseTag(final AnyObjectId id) throws MissingObjectException,
IncorrectObjectTypeException, IOException {
RevObject c = parseAny(id);
if (!(c instanceof RevTag))
throw new IncorrectObjectTypeException(id.toObjectId(),
Constants.TYPE_TAG);
return (RevTag) c;
}
/**
* Locate a reference to any object and immediately parse its headers.
* <p>
* This method only returns successfully if the object exists and was parsed
* without error. Parsing an object can be expensive as the type must be
* determined. For blobs this may mean the blob content was unpacked
* unnecessarily, and thrown away.
*
* @param id
* name of the object.
* @return reference to the object. Never null.
* @throws MissingObjectException
* the supplied does not exist.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevObject parseAny(final AnyObjectId id)
throws MissingObjectException, IOException {
RevObject r = objects.get(id);
if (r == null)
r = parseNew(id, reader.open(id));
else
parseHeaders(r);
return r;
}
private RevObject parseNew(AnyObjectId id, ObjectLoader ldr)
throws LargeObjectException, CorruptObjectException,
MissingObjectException, IOException {
RevObject r;
int type = ldr.getType();
switch (type) {
case Constants.OBJ_COMMIT: {
final RevCommit c = createCommit(id);
c.parseCanonical(this, getCachedBytes(c, ldr));
r = c;
break;
}
case Constants.OBJ_TREE: {
r = new RevTree(id);
r.flags |= PARSED;
break;
}
case Constants.OBJ_BLOB: {
r = new RevBlob(id);
r.flags |= PARSED;
break;
}
case Constants.OBJ_TAG: {
final RevTag t = new RevTag(id);
t.parseCanonical(this, getCachedBytes(t, ldr));
r = t;
break;
}
default:
throw new IllegalArgumentException(MessageFormat.format(
JGitText.get().badObjectType, Integer.valueOf(type)));
}
objects.add(r);
return r;
}
byte[] getCachedBytes(RevObject obj) throws LargeObjectException,
MissingObjectException, IncorrectObjectTypeException, IOException {
return getCachedBytes(obj, reader.open(obj, obj.getType()));
}
byte[] getCachedBytes(RevObject obj, ObjectLoader ldr)
throws LargeObjectException, MissingObjectException, IOException {
try {
return ldr.getCachedBytes(5 * MB);
} catch (LargeObjectException tooBig) {
tooBig.setObjectId(obj);
throw tooBig;
}
}
/**
* Asynchronous object parsing.
*
* @param <T>
* any ObjectId type.
* @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> AsyncRevObjectQueue parseAny(
Iterable<T> objectIds, boolean reportMissing) {
List<T> need = new ArrayList<T>();
List<RevObject> have = new ArrayList<RevObject>();
for (T id : objectIds) {
RevObject r = objects.get(id);
if (r != null && (r.flags & PARSED) != 0)
have.add(r);
else
need.add(id);
}
final Iterator<RevObject> objItr = have.iterator();
if (need.isEmpty()) {
return new AsyncRevObjectQueue() {
public RevObject next() {
return objItr.hasNext() ? objItr.next() : null;
}
public boolean cancel(boolean mayInterruptIfRunning) {
return true;
}
public void release() {
// In-memory only, no action required.
}
};
}
final AsyncObjectLoaderQueue<T> lItr = reader.open(need, reportMissing);
return new AsyncRevObjectQueue() {
public RevObject next() throws MissingObjectException,
IncorrectObjectTypeException, IOException {
if (objItr.hasNext())
return objItr.next();
if (!lItr.next())
return null;
ObjectId id = lItr.getObjectId();
ObjectLoader ldr = lItr.open();
RevObject r = objects.get(id);
if (r == null)
r = parseNew(id, ldr);
else if (r instanceof RevCommit) {
byte[] raw = ldr.getCachedBytes();
((RevCommit) r).parseCanonical(RevWalk.this, raw);
} else if (r instanceof RevTag) {
byte[] raw = ldr.getCachedBytes();
((RevTag) r).parseCanonical(RevWalk.this, raw);
} else
r.flags |= PARSED;
return r;
}
public boolean cancel(boolean mayInterruptIfRunning) {
return lItr.cancel(mayInterruptIfRunning);
}
public void release() {
lItr.release();
}
};
}
/**
* Ensure the object's critical headers have been parsed.
* <p>
* This method only returns successfully if the object exists and was parsed
* without error.
*
* @param obj
* the object the caller needs to be parsed.
* @throws MissingObjectException
* the supplied does not exist.
* @throws IOException
* a pack file or loose object could not be read.
*/
public void parseHeaders(final RevObject obj)
throws MissingObjectException, IOException {
if ((obj.flags & PARSED) == 0)
obj.parseHeaders(this);
}
/**
* Ensure the object's full body content is available.
* <p>
* This method only returns successfully if the object exists and was parsed
* without error.
*
* @param obj
* the object the caller needs to be parsed.
* @throws MissingObjectException
* the supplied does not exist.
* @throws IOException
* a pack file or loose object could not be read.
*/
public void parseBody(final RevObject obj)
throws MissingObjectException, IOException {
obj.parseBody(this);
}
/**
* Peel back annotated tags until a non-tag object is found.
*
* @param obj
* the starting object.
* @return If {@code obj} is not an annotated tag, {@code obj}. Otherwise
* the first non-tag object that {@code obj} references. The
* returned object's headers have been parsed.
* @throws MissingObjectException
* a referenced object cannot be found.
* @throws IOException
* a pack file or loose object could not be read.
*/
public RevObject peel(RevObject obj) throws MissingObjectException,
IOException {
while (obj instanceof RevTag) {
parseHeaders(obj);
obj = ((RevTag) obj).getObject();
}
parseHeaders(obj);
return obj;
}
/**
* Create a new flag for application use during walking.
* <p>
* Applications are only assured to be able to create 24 unique flags on any
* given revision walker instance. Any flags beyond 24 are offered only if
* the implementation has extra free space within its internal storage.
*
* @param name
* description of the flag, primarily useful for debugging.
* @return newly constructed flag instance.
* @throws IllegalArgumentException
* too many flags have been reserved on this revision walker.
*/
public RevFlag newFlag(final String name) {
final int m = allocFlag();
return new RevFlag(this, name, m);
}
int allocFlag() {
if (freeFlags == 0)
throw new IllegalArgumentException(MessageFormat.format(
JGitText.get().flagsAlreadyCreated,
Integer.valueOf(32 - RESERVED_FLAGS)));
final int m = Integer.lowestOneBit(freeFlags);
freeFlags &= ~m;
return m;
}
/**
* Automatically carry a flag from a child commit to its parents.
* <p>
* A carried flag is copied from the child commit onto its parents when the
* child commit is popped from the lowest level of walk's internal graph.
*
* @param flag
* the flag to carry onto parents, if set on a descendant.
*/
public void carry(final RevFlag flag) {
if ((freeFlags & flag.mask) != 0)
throw new IllegalArgumentException(MessageFormat.format(JGitText.get().flagIsDisposed, flag.name));
if (flag.walker != this)
throw new IllegalArgumentException(MessageFormat.format(JGitText.get().flagNotFromThis, flag.name));
carryFlags |= flag.mask;
}
/**
* Automatically carry flags from a child commit to its parents.
* <p>
* A carried flag is copied from the child commit onto its parents when the
* child commit is popped from the lowest level of walk's internal graph.
*
* @param set
* the flags to carry onto parents, if set on a descendant.
*/
public void carry(final Collection<RevFlag> set) {
for (final RevFlag flag : set)
carry(flag);
}
/**
* Preserve a RevFlag during all {@code reset} methods.
* <p>
* Calling {@code retainOnReset(flag)} avoids needing to pass the flag
* during each {@code resetRetain()} invocation on this instance.
* <p>
* Clearing flags marked retainOnReset requires disposing of the flag with
* {@code #disposeFlag(RevFlag)} or disposing of the entire RevWalk by
* {@code #dispose()}.
*
* @param flag
* the flag to retain during all resets.
* @since 3.6
*/
public final void retainOnReset(RevFlag flag) {
if ((freeFlags & flag.mask) != 0)
throw new IllegalArgumentException(MessageFormat.format(JGitText.get().flagIsDisposed, flag.name));
if (flag.walker != this)
throw new IllegalArgumentException(MessageFormat.format(JGitText.get().flagNotFromThis, flag.name));
retainOnReset |= flag.mask;
}
/**
* Preserve a set of RevFlags during all {@code reset} methods.
* <p>
* Calling {@code retainOnReset(set)} avoids needing to pass the flags
* during each {@code resetRetain()} invocation on this instance.
* <p>
* Clearing flags marked retainOnReset requires disposing of the flag with
* {@code #disposeFlag(RevFlag)} or disposing of the entire RevWalk by
* {@code #dispose()}.
*
* @param flags
* the flags to retain during all resets.
* @since 3.6
*/
public final void retainOnReset(Collection<RevFlag> flags) {
for (RevFlag f : flags)
retainOnReset(f);
}
/**
* Allow a flag to be recycled for a different use.
* <p>
* Recycled flags always come back as a different Java object instance when
* assigned again by {@link #newFlag(String)}.
* <p>
* If the flag was previously being carried, the carrying request is
* removed. Disposing of a carried flag while a traversal is in progress has
* an undefined behavior.
*
* @param flag
* the to recycle.
*/
public void disposeFlag(final RevFlag flag) {
freeFlag(flag.mask);
}
void freeFlag(final int mask) {
retainOnReset &= ~mask;
if (isNotStarted()) {
freeFlags |= mask;
carryFlags &= ~mask;
} else {
delayFreeFlags |= mask;
}
}
private void finishDelayedFreeFlags() {
if (delayFreeFlags != 0) {
freeFlags |= delayFreeFlags;
carryFlags &= ~delayFreeFlags;
delayFreeFlags = 0;
}
}
/**
* Resets internal state and allows this instance to be used again.
* <p>
* Unlike {@link #dispose()} previously acquired RevObject (and RevCommit)
* instances are not invalidated. RevFlag instances are not invalidated, but
* are removed from all RevObjects.
*/
public final void reset() {
reset(0);
}
/**
* Resets internal state and allows this instance to be used again.
* <p>
* Unlike {@link #dispose()} previously acquired RevObject (and RevCommit)
* instances are not invalidated. RevFlag instances are not invalidated, but
* are removed from all RevObjects.
*
* @param retainFlags
* application flags that should <b>not</b> be cleared from
* existing commit objects.
*/
public final void resetRetain(final RevFlagSet retainFlags) {
reset(retainFlags.mask);
}
/**
* Resets internal state and allows this instance to be used again.
* <p>
* Unlike {@link #dispose()} previously acquired RevObject (and RevCommit)
* instances are not invalidated. RevFlag instances are not invalidated, but
* are removed from all RevObjects.
* <p>
* See {@link #retainOnReset(RevFlag)} for an alternative that does not
* require passing the flags during each reset.
*
* @param retainFlags
* application flags that should <b>not</b> be cleared from
* existing commit objects.
*/
public final void resetRetain(final RevFlag... retainFlags) {
int mask = 0;
for (final RevFlag flag : retainFlags)
mask |= flag.mask;
reset(mask);
}
/**
* Resets internal state and allows this instance to be used again.
* <p>
* Unlike {@link #dispose()} previously acquired RevObject (and RevCommit)
* instances are not invalidated. RevFlag instances are not invalidated, but
* are removed from all RevObjects.
*
* @param retainFlags
* application flags that should <b>not</b> be cleared from
* existing commit objects.
*/
protected void reset(int retainFlags) {
finishDelayedFreeFlags();
retainFlags |= PARSED | retainOnReset;
final int clearFlags = ~retainFlags;
final FIFORevQueue q = new FIFORevQueue();
for (final RevCommit c : roots) {
if ((c.flags & clearFlags) == 0)
continue;
c.flags &= retainFlags;
c.reset();
q.add(c);
}
for (;;) {
final RevCommit c = q.next();
if (c == null)
break;
if (c.parents == null)
continue;
for (final RevCommit p : c.parents) {
if ((p.flags & clearFlags) == 0)
continue;
p.flags &= retainFlags;
p.reset();
q.add(p);
}
}
roots.clear();
queue = new DateRevQueue();
pending = new StartGenerator(this);
}
/**
* Dispose all internal state and invalidate all RevObject instances.
* <p>
* All RevObject (and thus RevCommit, etc.) instances previously acquired
* from this RevWalk are invalidated by a dispose call. Applications must
* not retain or use RevObject instances obtained prior to the dispose call.
* All RevFlag instances are also invalidated, and must not be reused.
*/
public void dispose() {
reader.close();
freeFlags = APP_FLAGS;
delayFreeFlags = 0;
retainOnReset = 0;
carryFlags = UNINTERESTING;
objects.clear();
roots.clear();
queue = new DateRevQueue();
pending = new StartGenerator(this);
shallowCommitsInitialized = false;
}
/**
* Returns an Iterator over the commits of this walker.
* <p>
* The returned iterator is only useful for one walk. If this RevWalk gets
* reset a new iterator must be obtained to walk over the new results.
* <p>
* Applications must not use both the Iterator and the {@link #next()} API
* at the same time. Pick one API and use that for the entire walk.
* <p>
* If a checked exception is thrown during the walk (see {@link #next()})
* it is rethrown from the Iterator as a {@link RevWalkException}.
*
* @return an iterator over this walker's commits.
* @see RevWalkException
*/
public Iterator<RevCommit> iterator() {
final RevCommit first;
try {
first = RevWalk.this.next();
} catch (MissingObjectException e) {
throw new RevWalkException(e);
} catch (IncorrectObjectTypeException e) {
throw new RevWalkException(e);
} catch (IOException e) {
throw new RevWalkException(e);
}
return new Iterator<RevCommit>() {
RevCommit next = first;
public boolean hasNext() {
return next != null;
}
public RevCommit next() {
try {
final RevCommit r = next;
next = RevWalk.this.next();
return r;
} catch (MissingObjectException e) {
throw new RevWalkException(e);
} catch (IncorrectObjectTypeException e) {
throw new RevWalkException(e);
} catch (IOException e) {
throw new RevWalkException(e);
}
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
/** Throws an exception if we have started producing output. */
protected void assertNotStarted() {
if (isNotStarted())
return;
throw new IllegalStateException(JGitText.get().outputHasAlreadyBeenStarted);
}
private boolean isNotStarted() {
return pending instanceof StartGenerator;
}
/**
* Create and return an {@link ObjectWalk} using the same objects.
* <p>
* Prior to using this method, the caller must reset this RevWalk to clean
* any flags that were used during the last traversal.
* <p>
* The returned ObjectWalk uses the same ObjectReader, internal object pool,
* and free RevFlags. Once the ObjectWalk is created, this RevWalk should
* not be used anymore.
*
* @return a new walk, using the exact same object pool.
*/
public ObjectWalk toObjectWalkWithSameObjects() {
ObjectWalk ow = new ObjectWalk(reader);
RevWalk rw = ow;
rw.objects = objects;
rw.freeFlags = freeFlags;
return ow;
}
/**
* Construct a new unparsed commit for the given object.
*
* @param id
* the object this walker requires a commit reference for.
* @return a new unparsed reference for the object.
*/
protected RevCommit createCommit(final AnyObjectId id) {
return new RevCommit(id);
}
void carryFlagsImpl(final RevCommit c) {
final int carry = c.flags & carryFlags;
if (carry != 0)
RevCommit.carryFlags(c, carry);
}
/**
* Assume additional commits are shallow (have no parents).
* <p>
* This method is a No-op if the collection is empty.
*
* @param ids
* commits that should be treated as shallow commits, in addition
* to any commits already known to be shallow by the repository.
* @since 3.3
*/
public void assumeShallow(Collection<? extends ObjectId> ids) {
for (ObjectId id : ids)
lookupCommit(id).parents = RevCommit.NO_PARENTS;
}
void initializeShallowCommits() throws IOException {
if (shallowCommitsInitialized)
throw new IllegalStateException(
JGitText.get().shallowCommitsAlreadyInitialized);
shallowCommitsInitialized = true;
if (reader == null)
return;
for (ObjectId id : reader.getShallowCommits())
lookupCommit(id).parents = RevCommit.NO_PARENTS;
}
}