hadoop DirectoryWithSnapshotFeature 源码
haddop DirectoryWithSnapshotFeature 代码
文件路径：/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/snapshot/DirectoryWithSnapshotFeature.java
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdfs.server.namenode.snapshot;
import org.apache.hadoop.util.Preconditions;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite;
import org.apache.hadoop.hdfs.server.namenode.*;
import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotFSImageFormat.ReferenceMap;
import org.apache.hadoop.hdfs.util.Diff;
import org.apache.hadoop.hdfs.util.Diff.Container;
import org.apache.hadoop.hdfs.util.Diff.UndoInfo;
import org.apache.hadoop.hdfs.util.ReadOnlyList;
import org.apache.hadoop.security.AccessControlException;
import java.io.DataOutput;
import java.io.IOException;
import java.util.*;
import static org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.NO_SNAPSHOT_ID;
/**
* Feature used to store and process the snapshot diff information for a
* directory. In particular, it contains a directory diff list recording changes
* made to the directory and its children for each snapshot.
*/
@InterfaceAudience.Private
public class DirectoryWithSnapshotFeature implements INode.Feature {
/**
* The difference between the current state and a previous snapshot
* of the children list of an INodeDirectory.
*/
static class ChildrenDiff extends Diff<byte[], INode> {
ChildrenDiff() {}
private ChildrenDiff(final List<INode> created, final List<INode> deleted) {
super(created, deleted);
}
/**
* Replace the given child from the created list.
* @return true if the child is replaced; false if the child is not found.
*/
private boolean replaceCreated(final INode oldChild, final INode newChild) {
final List<INode> list = getCreatedUnmodifiable();
final int i = search(list, oldChild.getLocalNameBytes());
if (i < 0 || list.get(i).getId() != oldChild.getId()) {
return false;
}
final INode removed = setCreated(i, newChild);
Preconditions.checkState(removed == oldChild);
return true;
}
/** clear the created list */
private void destroyCreatedList(INode.ReclaimContext reclaimContext,
final INodeDirectory currentINode) {
for (INode c : getCreatedUnmodifiable()) {
c.destroyAndCollectBlocks(reclaimContext);
// c should be contained in the children list, remove it
currentINode.removeChild(c);
}
clearCreated();
}
/** clear the deleted list */
private void destroyDeletedList(INode.ReclaimContext reclaimContext) {
for (INode d : getDeletedUnmodifiable()) {
d.destroyAndCollectBlocks(reclaimContext);
}
clearDeleted();
}
/** Serialize {@link #created} */
private void writeCreated(DataOutput out) throws IOException {
final List<INode> created = getCreatedUnmodifiable();
out.writeInt(created.size());
for (INode node : created) {
// For INode in created list, we only need to record its local name
byte[] name = node.getLocalNameBytes();
out.writeShort(name.length);
out.write(name);
}
}
/** Serialize {@link #deleted} */
private void writeDeleted(DataOutput out,
ReferenceMap referenceMap) throws IOException {
final List<INode> deleted = getDeletedUnmodifiable();
out.writeInt(deleted.size());
for (INode node : deleted) {
FSImageSerialization.saveINode2Image(node, out, true, referenceMap);
}
}
/** Serialize to out */
private void write(DataOutput out, ReferenceMap referenceMap
) throws IOException {
writeCreated(out);
writeDeleted(out, referenceMap);
}
/** Get the list of INodeDirectory contained in the deleted list */
private void getDirsInDeleted(List<INodeDirectory> dirList) {
for (INode node : getDeletedUnmodifiable()) {
if (node.isDirectory()) {
dirList.add(node.asDirectory());
}
}
}
}
/**
* The difference of an {@link INodeDirectory} between two snapshots.
*/
public static class DirectoryDiff extends
AbstractINodeDiff<INodeDirectory, INodeDirectoryAttributes, DirectoryDiff> {
/** The size of the children list at snapshot creation time. */
private final int childrenSize;
/** The children list diff. */
private final ChildrenDiff diff;
private boolean isSnapshotRoot = false;
private DirectoryDiff(int snapshotId, INodeDirectory dir) {
this(snapshotId, dir, new ChildrenDiff());
}
public DirectoryDiff(int snapshotId, INodeDirectory dir,
ChildrenDiff diff) {
super(snapshotId, null, null);
this.childrenSize = dir.getChildrenList(Snapshot.CURRENT_STATE_ID).size();
this.diff = diff;
}
/** Constructor used by FSImage loading */
DirectoryDiff(int snapshotId, INodeDirectoryAttributes snapshotINode,
DirectoryDiff posteriorDiff, int childrenSize, List<INode> createdList,
List<INode> deletedList, boolean isSnapshotRoot) {
super(snapshotId, snapshotINode, posteriorDiff);
this.childrenSize = childrenSize;
this.diff = new ChildrenDiff(createdList, deletedList);
this.isSnapshotRoot = isSnapshotRoot;
}
public ChildrenDiff getChildrenDiff() {
return diff;
}
void setSnapshotRoot(INodeDirectoryAttributes root) {
this.snapshotINode = root;
this.isSnapshotRoot = true;
}
public boolean isSnapshotRoot() {
return isSnapshotRoot;
}
@Override
void combinePosteriorAndCollectBlocks(
final INode.ReclaimContext reclaimContext,
final INodeDirectory currentDir,
final DirectoryDiff posterior) {
// DeletionOrdered: must not combine posterior
assert !SnapshotManager.isDeletionOrdered();
diff.combinePosterior(posterior.diff, new Diff.Processor<INode>() {
/** Collect blocks for deleted files. */
@Override
public void process(INode inode) {
if (inode != null) {
inode.destroyAndCollectBlocks(reclaimContext);
}
}
});
}
/**
* @return The children list of a directory in a snapshot.
* Since the snapshot is read-only, the logical view of the list is
* never changed although the internal data structure may mutate.
*/
private ReadOnlyList<INode> getChildrenList(final INodeDirectory currentDir) {
return new ReadOnlyList<INode>() {
private List<INode> children = null;
private List<INode> initChildren() {
if (children == null) {
final ChildrenDiff combined = new ChildrenDiff();
DirectoryDiffList directoryDiffList =
currentDir.getDirectoryWithSnapshotFeature().diffs;
final int diffIndex =
directoryDiffList.getDiffIndexById(getSnapshotId());
List<DirectoryDiff> diffList = directoryDiffList
.getDiffListBetweenSnapshots(diffIndex,
directoryDiffList.asList().size(), currentDir);
for (DirectoryDiff d : diffList) {
combined.combinePosterior(d.diff, null);
}
children = combined.apply2Current(ReadOnlyList.Util
.asList(currentDir.getChildrenList(Snapshot.CURRENT_STATE_ID)));
}
return children;
}
@Override
public Iterator<INode> iterator() {
return initChildren().iterator();
}
@Override
public boolean isEmpty() {
return childrenSize == 0;
}
@Override
public int size() {
return childrenSize;
}
@Override
public INode get(int i) {
return initChildren().get(i);
}
};
}
/** @return the child with the given name. */
INode getChild(byte[] name, boolean checkPosterior,
INodeDirectory currentDir) {
for(DirectoryDiff d = this; ; d = d.getPosterior()) {
final Container<INode> returned = d.diff.accessPrevious(name);
if (returned != null) {
// the diff is able to determine the inode
return returned.getElement();
} else if (!checkPosterior) {
// Since checkPosterior is false, return null, i.e. not found.
return null;
} else if (d.getPosterior() == null) {
// no more posterior diff, get from current inode.
return currentDir.getChild(name, Snapshot.CURRENT_STATE_ID);
}
}
}
@Override
public String toString() {
return super.toString() + " childrenSize=" + childrenSize + ", " + diff;
}
int getChildrenSize() {
return childrenSize;
}
@Override
void write(DataOutput out, ReferenceMap referenceMap) throws IOException {
writeSnapshot(out);
out.writeInt(childrenSize);
// Write snapshotINode
out.writeBoolean(isSnapshotRoot);
if (!isSnapshotRoot) {
if (snapshotINode != null) {
out.writeBoolean(true);
FSImageSerialization.writeINodeDirectoryAttributes(snapshotINode, out);
} else {
out.writeBoolean(false);
}
}
// Write diff. Node need to write poseriorDiff, since diffs is a list.
diff.write(out, referenceMap);
}
@Override
void destroyDiffAndCollectBlocks(
INode.ReclaimContext reclaimContext, INodeDirectory currentINode) {
// this diff has been deleted
diff.destroyDeletedList(reclaimContext);
INodeDirectoryAttributes snapshotINode = getSnapshotINode();
if (snapshotINode != null && snapshotINode.getAclFeature() != null) {
AclStorage.removeAclFeature(snapshotINode.getAclFeature());
}
}
}
/** A list of directory diffs. */
public static class DirectoryDiffList
extends AbstractINodeDiffList<INodeDirectory, INodeDirectoryAttributes, DirectoryDiff> {
@Override
DirectoryDiff createDiff(int snapshot, INodeDirectory currentDir) {
return new DirectoryDiff(snapshot, currentDir);
}
@Override
INodeDirectoryAttributes createSnapshotCopy(INodeDirectory currentDir) {
return currentDir.isQuotaSet()?
new INodeDirectoryAttributes.CopyWithQuota(currentDir)
: new INodeDirectoryAttributes.SnapshotCopy(currentDir);
}
@Override
DiffList<DirectoryDiff> newDiffs() {
return DirectoryDiffListFactory
.createDiffList(INodeDirectory.DEFAULT_FILES_PER_DIRECTORY);
}
/** Replace the given child in the created/deleted list, if there is any. */
public boolean replaceCreatedChild(final INode oldChild,
final INode newChild) {
final DiffList<DirectoryDiff> diffList = asList();
for(int i = diffList.size() - 1; i >= 0; i--) {
final ChildrenDiff diff = diffList.get(i).diff;
if (diff.replaceCreated(oldChild, newChild)) {
return true;
}
}
return false;
}
/** Remove the given child from the deleted list, if there is any. */
public boolean removeDeletedChild(final INode child) {
final DiffList<DirectoryDiff> diffList = asList();
for(int i = diffList.size() - 1; i >= 0; i--) {
final ChildrenDiff diff = diffList.get(i).diff;
if (diff.removeDeleted(child)) {
return true;
}
}
return false;
}
/**
* Find the corresponding snapshot whose deleted list contains the given
* inode.
* @return the id of the snapshot. {@link Snapshot#NO_SNAPSHOT_ID} if the
* given inode is not in any of the snapshot.
*/
public int findSnapshotDeleted(final INode child) {
final DiffList<DirectoryDiff> diffList = asList();
for(int i = diffList.size() - 1; i >= 0; i--) {
final DirectoryDiff diff = diffList.get(i);
if (diff.getChildrenDiff().containsDeleted(child)) {
return diff.getSnapshotId();
}
}
return NO_SNAPSHOT_ID;
}
/**
* Returns the list of diffs between two indexes corresponding to two
* snapshots.
* @param fromIndex Index of the diff corresponding to the earlier snapshot
* @param toIndex Index of the diff corresponding to the later snapshot
* @param dir The Directory to which the diffList belongs
* @return list of directory diffs
*/
List<DirectoryDiff> getDiffListBetweenSnapshots(int fromIndex, int toIndex,
INodeDirectory dir) {
return asList().getMinListForRange(fromIndex, toIndex, dir);
}
}
private static Map<INode, INode> cloneDiffList(List<INode> diffList) {
if (diffList == null || diffList.size() == 0) {
return null;
}
Map<INode, INode> map = new HashMap<>(diffList.size());
for (INode node : diffList) {
map.put(node, node);
}
return map;
}
/**
* Destroy a subtree under a DstReference node.
*/
public static void destroyDstSubtree(INode.ReclaimContext reclaimContext,
INode inode, final int snapshot, final int prior) {
Preconditions.checkArgument(prior != NO_SNAPSHOT_ID);
if (inode.isReference()) {
if (inode instanceof INodeReference.WithName
&& snapshot != Snapshot.CURRENT_STATE_ID) {
// this inode has been renamed before the deletion of the DstReference
// subtree
inode.cleanSubtree(reclaimContext, snapshot, prior);
} else {
// for DstReference node, continue this process to its subtree
destroyDstSubtree(reclaimContext,
inode.asReference().getReferredINode(), snapshot, prior);
}
} else if (inode.isFile()) {
inode.cleanSubtree(reclaimContext, snapshot, prior);
} else if (inode.isDirectory()) {
Map<INode, INode> excludedNodes = null;
INodeDirectory dir = inode.asDirectory();
DirectoryWithSnapshotFeature sf = dir.getDirectoryWithSnapshotFeature();
if (sf != null) {
DirectoryDiffList diffList = sf.getDiffs();
DirectoryDiff priorDiff = diffList.getDiffById(prior);
if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
List<INode> dList = priorDiff.diff.getDeletedUnmodifiable();
excludedNodes = cloneDiffList(dList);
}
if (snapshot != Snapshot.CURRENT_STATE_ID) {
diffList.deleteSnapshotDiff(reclaimContext,
snapshot, prior, dir);
}
priorDiff = diffList.getDiffById(prior);
if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
priorDiff.diff.destroyCreatedList(reclaimContext, dir);
}
}
for (INode child : inode.asDirectory().getChildrenList(prior)) {
if (excludedNodes != null && excludedNodes.containsKey(child)) {
continue;
}
destroyDstSubtree(reclaimContext, child, snapshot, prior);
}
}
}
/**
* Clean an inode while we move it from the deleted list of post to the
* deleted list of prior.
* @param reclaimContext blocks and inodes that need to be reclaimed
* @param inode The inode to clean.
* @param post The post snapshot.
* @param prior The id of the prior snapshot.
*/
private static void cleanDeletedINode(INode.ReclaimContext reclaimContext,
INode inode, final int post, final int prior) {
Deque<INode> queue = new ArrayDeque<>();
queue.addLast(inode);
while (!queue.isEmpty()) {
INode topNode = queue.pollFirst();
if (topNode instanceof INodeReference.WithName) {
INodeReference.WithName wn = (INodeReference.WithName) topNode;
if (wn.getLastSnapshotId() >= post) {
INodeReference.WithCount wc =
(INodeReference.WithCount) wn.getReferredINode();
if (wc.getLastWithName() == wn && wc.getParentReference() == null) {
// this wn is the last wn inside of the wc, also the dstRef node has
// been deleted. In this case, we should treat the referred file/dir
// as normal case
queue.add(wc.getReferredINode());
} else {
wn.cleanSubtree(reclaimContext, post, prior);
}
}
// For DstReference node, since the node is not in the created list of
// prior, we should treat it as regular file/dir
} else if (topNode.isFile() && topNode.asFile().isWithSnapshot()) {
INodeFile file = topNode.asFile();
file.getDiffs().deleteSnapshotDiff(reclaimContext, post, prior, file);
} else if (topNode.isDirectory()) {
INodeDirectory dir = topNode.asDirectory();
ChildrenDiff priorChildrenDiff = null;
DirectoryWithSnapshotFeature sf = dir.getDirectoryWithSnapshotFeature();
if (sf != null) {
// delete files/dirs created after prior. Note that these
// files/dirs, along with inode, were deleted right after post.
DirectoryDiff priorDiff = sf.getDiffs().getDiffById(prior);
if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
priorChildrenDiff = priorDiff.getChildrenDiff();
priorChildrenDiff.destroyCreatedList(reclaimContext, dir);
}
}
for (INode child : dir.getChildrenList(prior)) {
if (priorChildrenDiff != null && priorChildrenDiff.getDeleted(
child.getLocalNameBytes()) != null) {
continue;
}
queue.addLast(child);
}
}
}
}
/** Diff list sorted by snapshot IDs, i.e. in chronological order. */
private final DirectoryDiffList diffs;
public DirectoryWithSnapshotFeature(DirectoryDiffList diffs) {
this.diffs = diffs != null ? diffs : new DirectoryDiffList();
}
/** @return the last snapshot. */
public int getLastSnapshotId() {
return diffs.getLastSnapshotId();
}
/** @return the snapshot diff list. */
public DirectoryDiffList getDiffs() {
return diffs;
}
/**
* Get all the directories that are stored in some snapshot but not in the
* current children list. These directories are equivalent to the directories
* stored in the deletes lists.
*/
public void getSnapshotDirectory(List<INodeDirectory> snapshotDir) {
for (DirectoryDiff sdiff : diffs) {
sdiff.getChildrenDiff().getDirsInDeleted(snapshotDir);
}
}
/**
* Add an inode into parent's children list. The caller of this method needs
* to make sure that parent is in the given snapshot "latest".
*/
public boolean addChild(INodeDirectory parent, INode inode,
boolean setModTime, int latestSnapshotId) {
ChildrenDiff diff = diffs.checkAndAddLatestSnapshotDiff(latestSnapshotId,
parent).diff;
final int undoInfo = diff.create(inode);
boolean added = false;
try {
added = parent.addChild(inode, setModTime, Snapshot.CURRENT_STATE_ID);
} finally {
if (!added) {
diff.undoCreate(inode, undoInfo);
}
}
return added;
}
/**
* Remove an inode from parent's children list. The caller of this method
* needs to make sure that parent is in the given snapshot "latest".
*/
public boolean removeChild(INodeDirectory parent, INode child,
int latestSnapshotId) {
// For a directory that is not a renamed node, if isInLatestSnapshot returns
// false, the directory is not in the latest snapshot, thus we do not need
// to record the removed child in any snapshot.
// For a directory that was moved/renamed, note that if the directory is in
// any of the previous snapshots, we will create a reference node for the
// directory while rename, and isInLatestSnapshot will return true in that
// scenario (if all previous snapshots have been deleted, isInLatestSnapshot
// still returns false). Thus if isInLatestSnapshot returns false, the
// directory node cannot be in any snapshot (not in current tree, nor in
// previous src tree). Thus we do not need to record the removed child in
// any snapshot.
ChildrenDiff diff = diffs.checkAndAddLatestSnapshotDiff(latestSnapshotId,
parent).diff;
final UndoInfo<INode> undoInfo = diff.delete(child);
boolean removed = false;
try {
removed = parent.removeChild(child);
} finally {
if (!removed) {
diff.undoDelete(child, undoInfo);
}
}
return removed;
}
/**
* @return If there is no corresponding directory diff for the given
* snapshot, this means that the current children list should be
* returned for the snapshot. Otherwise we calculate the children list
* for the snapshot and return it.
*/
public ReadOnlyList<INode> getChildrenList(INodeDirectory currentINode,
final int snapshotId) {
final DirectoryDiff diff = diffs.getDiffById(snapshotId);
return diff != null ? diff.getChildrenList(currentINode) : currentINode
.getChildrenList(Snapshot.CURRENT_STATE_ID);
}
public INode getChild(INodeDirectory currentINode, byte[] name,
int snapshotId) {
final DirectoryDiff diff = diffs.getDiffById(snapshotId);
return diff != null ? diff.getChild(name, true, currentINode)
: currentINode.getChild(name, Snapshot.CURRENT_STATE_ID);
}
/** Used to record the modification of a symlink node */
public INode saveChild2Snapshot(INodeDirectory currentINode,
final INode child, final int latestSnapshotId, final INode snapshotCopy) {
Preconditions.checkArgument(!child.isDirectory(),
"child is a directory, child=%s", child);
Preconditions.checkArgument(latestSnapshotId != Snapshot.CURRENT_STATE_ID);
final DirectoryDiff diff = diffs.checkAndAddLatestSnapshotDiff(
latestSnapshotId, currentINode);
if (diff.getChild(child.getLocalNameBytes(), false, currentINode) != null) {
// it was already saved in the latest snapshot earlier.
return child;
}
diff.diff.modify(snapshotCopy, child);
return child;
}
public void clear(
INode.ReclaimContext reclaimContext, INodeDirectory currentINode) {
// destroy its diff list
for (DirectoryDiff diff : diffs) {
diff.destroyDiffAndCollectBlocks(reclaimContext, currentINode);
}
diffs.clear();
}
public QuotaCounts computeQuotaUsage4CurrentDirectory(
BlockStoragePolicySuite bsps, byte storagePolicyId) {
final QuotaCounts counts = new QuotaCounts.Builder().build();
for(DirectoryDiff d : diffs) {
for(INode deleted : d.getChildrenDiff().getDeletedUnmodifiable()) {
final byte childPolicyId = deleted.getStoragePolicyIDForQuota(
storagePolicyId);
counts.add(deleted.computeQuotaUsage(bsps, childPolicyId, false,
Snapshot.CURRENT_STATE_ID));
}
}
return counts;
}
public void computeContentSummary4Snapshot(final BlockStoragePolicySuite bsps,
final ContentCounts counts) throws AccessControlException {
// Create a new blank summary context for blocking processing of subtree.
ContentSummaryComputationContext summary =
new ContentSummaryComputationContext(bsps);
for(DirectoryDiff d : diffs) {
for(INode deleted : d.getChildrenDiff().getDeletedUnmodifiable()) {
deleted.computeContentSummary(Snapshot.CURRENT_STATE_ID, summary);
}
}
// Add the counts from deleted trees.
counts.addContents(summary.getCounts());
}
/**
* Compute the difference between Snapshots.
*
* @param fromSnapshot Start point of the diff computation. Null indicates
* current tree.
* @param toSnapshot End point of the diff computation. Null indicates current
* tree.
* @param diff Used to capture the changes happening to the children. Note
* that the diff still represents (later_snapshot - earlier_snapshot)
* although toSnapshot can be before fromSnapshot.
* @param currentINode The {@link INodeDirectory} this feature belongs to.
* @return Whether changes happened between the startSnapshot and endSnaphsot.
*/
boolean computeDiffBetweenSnapshots(Snapshot fromSnapshot,
Snapshot toSnapshot, ChildrenDiff diff, INodeDirectory currentINode) {
int[] diffIndexPair = diffs.changedBetweenSnapshots(fromSnapshot,
toSnapshot);
if (diffIndexPair == null) {
return false;
}
int earlierDiffIndex = diffIndexPair[0];
int laterDiffIndex = diffIndexPair[1];
boolean dirMetadataChanged = false;
INodeDirectoryAttributes dirCopy = null;
List<DirectoryDiff> difflist = diffs
.getDiffListBetweenSnapshots(earlierDiffIndex, laterDiffIndex,
currentINode);
for (DirectoryDiff sdiff : difflist) {
diff.combinePosterior(sdiff.diff, null);
if (!dirMetadataChanged && sdiff.snapshotINode != null) {
if (dirCopy == null) {
dirCopy = sdiff.snapshotINode;
} else if (!dirCopy.metadataEquals(sdiff.snapshotINode)) {
dirMetadataChanged = true;
}
}
}
if (!diff.isEmpty() || dirMetadataChanged) {
return true;
} else if (dirCopy != null) {
for (int i = laterDiffIndex; i < difflist.size(); i++) {
if (!dirCopy.metadataEquals(difflist.get(i).snapshotINode)) {
return true;
}
}
return !dirCopy.metadataEquals(currentINode);
} else {
return false;
}
}
public void cleanDirectory(INode.ReclaimContext reclaimContext,
final INodeDirectory currentINode, final int snapshot, int prior) {
Map<INode, INode> priorCreated = null;
Map<INode, INode> priorDeleted = null;
QuotaCounts old = reclaimContext.quotaDelta().getCountsCopy();
if (snapshot == Snapshot.CURRENT_STATE_ID) { // delete the current directory
currentINode.recordModification(prior);
// delete everything in created list
DirectoryDiff lastDiff = diffs.getLast();
if (lastDiff != null) {
lastDiff.diff.destroyCreatedList(reclaimContext, currentINode);
}
currentINode.cleanSubtreeRecursively(reclaimContext, snapshot, prior,
null);
} else {
// update prior
prior = getDiffs().updatePrior(snapshot, prior);
// if there is a snapshot diff associated with prior, we need to record
// its original created and deleted list before deleting post
if (prior != NO_SNAPSHOT_ID) {
DirectoryDiff priorDiff = this.getDiffs().getDiffById(prior);
if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
priorCreated = cloneDiffList(priorDiff.diff.getCreatedUnmodifiable());
priorDeleted = cloneDiffList(priorDiff.diff.getDeletedUnmodifiable());
}
}
getDiffs().deleteSnapshotDiff(reclaimContext, snapshot, prior,
currentINode);
currentINode.cleanSubtreeRecursively(reclaimContext, snapshot, prior,
priorDeleted);
// check priorDiff again since it may be created during the diff deletion
if (prior != NO_SNAPSHOT_ID) {
DirectoryDiff priorDiff = this.getDiffs().getDiffById(prior);
if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
// For files/directories created between "prior" and "snapshot",
// we need to clear snapshot copies for "snapshot". Note that we must
// use null as prior in the cleanSubtree call. Files/directories that
// were created before "prior" will be covered by the later
// cleanSubtreeRecursively call.
if (priorCreated != null) {
// The nodes in priorCreated must be destroyed if
// (1) this is the last reference, and
// (2) prior is the last snapshot, and
// (3) currentINode is not in the current state.
final boolean destroy = currentINode.isLastReference()
&& currentINode.getDiffs().getLastSnapshotId() == prior
&& !currentINode.isInCurrentState();
// we only check the node originally in prior's created list
for (INode cNode : new ArrayList<>(priorDiff.
diff.getCreatedUnmodifiable())) {
if (priorCreated.containsKey(cNode)) {
if (destroy) {
cNode.destroyAndCollectBlocks(reclaimContext);
currentINode.removeChild(cNode);
priorDiff.diff.removeCreated(cNode);
} else {
cNode.cleanSubtree(reclaimContext, snapshot, NO_SNAPSHOT_ID);
}
}
}
}
// When a directory is moved from the deleted list of the posterior
// diff to the deleted list of this diff, we need to destroy its
// descendants that were 1) created after taking this diff and 2)
// deleted after taking posterior diff.
// For files moved from posterior's deleted list, we also need to
// delete its snapshot copy associated with the posterior snapshot.
for (INode dNode : priorDiff.diff.getDeletedUnmodifiable()) {
if (priorDeleted == null || !priorDeleted.containsKey(dNode)) {
cleanDeletedINode(reclaimContext, dNode, snapshot, prior);
}
}
}
}
}
QuotaCounts current = reclaimContext.quotaDelta().getCountsCopy();
current.subtract(old);
if (currentINode.isQuotaSet()) {
reclaimContext.quotaDelta().addQuotaDirUpdate(currentINode, current);
}
}
@Override
public String toString() {
return "" + diffs;
}
}
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