HDFS-4076. Support snapshot of single files. (szetszwo)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2802@1400245 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Tsz-wo Sze 2012-10-19 19:35:19 +00:00
parent d5d2628e44
commit 5c1a7b9d5d
6 changed files with 143 additions and 1 deletions

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@ -1,5 +1,11 @@
Hadoop HDFS Change Log
Branch-2802 Snapshot (Unreleased)
NEW FEATURES
HDFS-4076. Support snapshot of single files. (szetszwo)
Trunk (Unreleased)
INCOMPATIBLE CHANGES

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@ -44,10 +44,10 @@
import org.apache.hadoop.hdfs.protocol.Block;
import org.apache.hadoop.hdfs.protocol.ClientProtocol;
import org.apache.hadoop.hdfs.protocol.DirectoryListing;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.protocol.FSLimitException;
import org.apache.hadoop.hdfs.protocol.FSLimitException.MaxDirectoryItemsExceededException;
import org.apache.hadoop.hdfs.protocol.FSLimitException.PathComponentTooLongException;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
@ -57,6 +57,8 @@
import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileSnapshot;
import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileWithLink;
import org.apache.hadoop.hdfs.util.ByteArray;
import com.google.common.base.Preconditions;
@ -300,6 +302,40 @@ INode unprotectedAddFile( String path,
return newNode;
}
/** Add an INodeFileSnapshot to the source file. */
INodeFileSnapshot addFileSnapshot(String srcPath, String dstPath
) throws IOException, QuotaExceededException {
waitForReady();
final INodeFile src = rootDir.getINodeFile(srcPath);
INodeFileSnapshot snapshot = new INodeFileSnapshot(src, src.computeFileSize(true));
writeLock();
try {
//add destination snaplink
snapshot = addNode(dstPath, snapshot, UNKNOWN_DISK_SPACE);
if (snapshot != null && src.getClass() == INodeFile.class) {
//created a snapshot and the source is an INodeFile, replace the source.
replaceNode(srcPath, src, new INodeFileWithLink(src));
}
} finally {
writeUnlock();
if (snapshot == null) {
NameNode.stateChangeLog.info(
"DIR* FSDirectory.addFileSnapshot: failed to add " + dstPath);
return null;
}
}
if (NameNode.stateChangeLog.isDebugEnabled()) {
NameNode.stateChangeLog.debug("DIR* FSDirectory.addFileSnapshot: "
+ dstPath + " is added to the file system");
}
return snapshot;
}
INodeDirectory addToParent(byte[] src, INodeDirectory parentINode,
INode newNode, boolean propagateModTime) {
// NOTE: This does not update space counts for parents

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@ -130,6 +130,21 @@ INode getNode(String path, boolean resolveLink)
return getNode(getPathComponents(path), resolveLink);
}
/** @return the INodeFile corresponding to the path. */
INodeFile getINodeFile(String path) throws FileNotFoundException,
UnresolvedLinkException {
final INode inode = getNode(path, false);
if (inode == null) {
throw new FileNotFoundException("File \"" + path
+ "\" not found");
}
if (!(inode instanceof INodeFile)) {
throw new FileNotFoundException("Path \"" + path
+ "\" is not a file");
}
return (INodeFile)inode;
}
/**
* Retrieve existing INodes from a path. If existing is big enough to store
* all path components (existing and non-existing), then existing INodes

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@ -54,6 +54,11 @@ public class INodeFile extends INode implements BlockCollection {
blocks = blklist;
}
protected INodeFile(INodeFile f) {
this(f.getPermissionStatus(), f.getBlocks(), f.getBlockReplication(),
f.getModificationTime(), f.getAccessTime(), f.getPreferredBlockSize());
}
/**
* Set the {@link FsPermission} of this {@link INodeFile}.
* Since this is a file,

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@ -0,0 +1,35 @@
/**
* 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.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.namenode.INodeFile;
/**
* INode representing a snapshot of a file.
*/
@InterfaceAudience.Private
public class INodeFileSnapshot extends INodeFileWithLink {
/** The file size at snapshot creation time. */
final long size;
public INodeFileSnapshot(INodeFile f, long size) {
super(f);
this.size = size;
}
}

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@ -0,0 +1,45 @@
/**
* 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.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.namenode.INodeFile;
/**
* INodeFile with a link to the next element.
* This class is used to represent the original file that is snapshotted.
* The snapshot files are represented by {@link INodeFileSnapshot}.
* The link of all the snapshot files and the original file form a circular
* linked list so that all elements are accessible by any of the elements.
*/
@InterfaceAudience.Private
public class INodeFileWithLink extends INodeFile {
private INodeFileWithLink next;
public INodeFileWithLink(INodeFile f) {
super(f);
}
void setNext(INodeFileWithLink next) {
this.next = next;
}
INodeFileWithLink getNext() {
return next;
}
}