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/**
* 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.fs;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.EnumSet;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hdfs.DFSClient;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.protocol.DirectoryListing;
import org.apache.hadoop.hdfs.protocol.FSConstants;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
import org.apache.hadoop.hdfs.server.namenode.NameNode;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.util.Progressable;
@InterfaceAudience.Private
@InterfaceStability.Evolving
public class Hdfs extends AbstractFileSystem {
DFSClient dfs;
private boolean verifyChecksum = true;
static {
HdfsConfiguration.init();
}
/**
* This constructor has the signature needed by
* {@link AbstractFileSystem#createFileSystem(URI, Configuration)}
*
* @param theUri
* which must be that of Hdfs
* @param conf
* @throws IOException
*/
Hdfs(final URI theUri, final Configuration conf) throws IOException, URISyntaxException {
super(theUri, FSConstants.HDFS_URI_SCHEME, true, NameNode.DEFAULT_PORT);
if (!theUri.getScheme().equalsIgnoreCase(FSConstants.HDFS_URI_SCHEME)) {
throw new IllegalArgumentException("Passed URI's scheme is not for Hdfs");
}
String host = theUri.getHost();
if (host == null) {
throw new IOException("Incomplete HDFS URI, no host: " + theUri);
}
InetSocketAddress namenode = NameNode.getAddress(theUri.getAuthority());
this.dfs = new DFSClient(namenode, conf, getStatistics());
}
@Override
public int getUriDefaultPort() {
return NameNode.DEFAULT_PORT;
}
@Override
public FSDataOutputStream createInternal(Path f,
EnumSet createFlag, FsPermission absolutePermission,
int bufferSize, short replication, long blockSize, Progressable progress,
int bytesPerChecksum, boolean createParent) throws IOException {
return new FSDataOutputStream(dfs.primitiveCreate(getUriPath(f),
absolutePermission, createFlag, createParent, replication, blockSize,
progress, bufferSize, bytesPerChecksum), getStatistics());
}
@Override
public boolean delete(Path f, boolean recursive)
throws IOException, UnresolvedLinkException {
return dfs.delete(getUriPath(f), recursive);
}
@Override
public BlockLocation[] getFileBlockLocations(Path p, long start, long len)
throws IOException, UnresolvedLinkException {
return dfs.getBlockLocations(getUriPath(p), start, len);
}
@Override
public FileChecksum getFileChecksum(Path f)
throws IOException, UnresolvedLinkException {
return dfs.getFileChecksum(getUriPath(f));
}
@Override
public FileStatus getFileStatus(Path f)
throws IOException, UnresolvedLinkException {
HdfsFileStatus fi = dfs.getFileInfo(getUriPath(f));
if (fi != null) {
return makeQualified(fi, f);
} else {
throw new FileNotFoundException("File does not exist: " + f.toString());
}
}
@Override
public FileStatus getFileLinkStatus(Path f)
throws IOException, UnresolvedLinkException {
HdfsFileStatus fi = dfs.getFileLinkInfo(getUriPath(f));
if (fi != null) {
return makeQualified(fi, f);
} else {
throw new FileNotFoundException("File does not exist: " + f);
}
}
private FileStatus makeQualified(HdfsFileStatus f, Path parent) {
// NB: symlink is made fully-qualified in FileContext.
return new FileStatus(f.getLen(), f.isDir(), f.getReplication(),
f.getBlockSize(), f.getModificationTime(),
f.getAccessTime(),
f.getPermission(), f.getOwner(), f.getGroup(),
f.isSymlink() ? new Path(f.getSymlink()) : null,
(f.getFullPath(parent)).makeQualified(
getUri(), null)); // fully-qualify path
}
private LocatedFileStatus makeQualifiedLocated(
HdfsLocatedFileStatus f, Path parent) {
return new LocatedFileStatus(f.getLen(), f.isDir(), f.getReplication(),
f.getBlockSize(), f.getModificationTime(),
f.getAccessTime(),
f.getPermission(), f.getOwner(), f.getGroup(),
f.isSymlink() ? new Path(f.getSymlink()) : null,
(f.getFullPath(parent)).makeQualified(
getUri(), null), // fully-qualify path
DFSUtil.locatedBlocks2Locations(f.getBlockLocations()));
}
@Override
public FsStatus getFsStatus() throws IOException {
return dfs.getDiskStatus();
}
@Override
public FsServerDefaults getServerDefaults() throws IOException {
return dfs.getServerDefaults();
}
@Override
public RemoteIterator listLocatedStatus(
final Path p)
throws FileNotFoundException, IOException {
return new DirListingIterator(p, true) {
@Override
public LocatedFileStatus next() throws IOException {
return makeQualifiedLocated((HdfsLocatedFileStatus)getNext(), p);
}
};
}
@Override
public RemoteIterator listStatusIterator(final Path f)
throws AccessControlException, FileNotFoundException,
UnresolvedLinkException, IOException {
return new DirListingIterator(f, false) {
@Override
public FileStatus next() throws IOException {
return makeQualified(getNext(), f);
}
};
}
/**
* This class defines an iterator that returns
* the file status of each file/subdirectory of a directory
*
* if needLocation, status contains block location if it is a file
* throws a RuntimeException with the error as its cause.
*
* @param the type of the file status
*/
abstract private class DirListingIterator
implements RemoteIterator {
private DirectoryListing thisListing;
private int i;
final private String src;
final private boolean needLocation; // if status
private DirListingIterator(Path p, boolean needLocation)
throws IOException {
this.src = Hdfs.this.getUriPath(p);
this.needLocation = needLocation;
// fetch the first batch of entries in the directory
thisListing = dfs.listPaths(
src, HdfsFileStatus.EMPTY_NAME, needLocation);
if (thisListing == null) { // the directory does not exist
throw new FileNotFoundException("File " + src + " does not exist.");
}
}
@Override
public boolean hasNext() throws IOException {
if (thisListing == null) {
return false;
}
if (i>=thisListing.getPartialListing().length
&& thisListing.hasMore()) {
// current listing is exhausted & fetch a new listing
thisListing = dfs.listPaths(src, thisListing.getLastName(),
needLocation);
if (thisListing == null) {
return false; // the directory is deleted
}
i = 0;
}
return (i listing =
new ArrayList(totalNumEntries);
// add the first batch of entries to the array list
for (HdfsFileStatus fileStatus : partialListing) {
listing.add(makeQualified(fileStatus, f));
}
// now fetch more entries
do {
thisListing = dfs.listPaths(src, thisListing.getLastName());
if (thisListing == null) {
// the directory is deleted
throw new FileNotFoundException("File " + f + " does not exist.");
}
partialListing = thisListing.getPartialListing();
for (HdfsFileStatus fileStatus : partialListing) {
listing.add(makeQualified(fileStatus, f));
}
} while (thisListing.hasMore());
return listing.toArray(new FileStatus[listing.size()]);
}
@Override
public void mkdir(Path dir, FsPermission permission, boolean createParent)
throws IOException, UnresolvedLinkException {
dfs.mkdirs(getUriPath(dir), permission, createParent);
}
@Override
public FSDataInputStream open(Path f, int bufferSize)
throws IOException, UnresolvedLinkException {
return new DFSClient.DFSDataInputStream(dfs.open(getUriPath(f),
bufferSize, verifyChecksum));
}
@Override
public void renameInternal(Path src, Path dst)
throws IOException, UnresolvedLinkException {
dfs.rename(getUriPath(src), getUriPath(dst), Options.Rename.NONE);
}
@Override
public void renameInternal(Path src, Path dst, boolean overwrite)
throws IOException, UnresolvedLinkException {
dfs.rename(getUriPath(src), getUriPath(dst),
overwrite ? Options.Rename.OVERWRITE : Options.Rename.NONE);
}
@Override
public void setOwner(Path f, String username, String groupname)
throws IOException, UnresolvedLinkException {
dfs.setOwner(getUriPath(f), username, groupname);
}
@Override
public void setPermission(Path f, FsPermission permission)
throws IOException, UnresolvedLinkException {
dfs.setPermission(getUriPath(f), permission);
}
@Override
public boolean setReplication(Path f, short replication)
throws IOException, UnresolvedLinkException {
return dfs.setReplication(getUriPath(f), replication);
}
@Override
public void setTimes(Path f, long mtime, long atime)
throws IOException, UnresolvedLinkException {
dfs.setTimes(getUriPath(f), mtime, atime);
}
@Override
public void setVerifyChecksum(boolean verifyChecksum)
throws IOException {
this.verifyChecksum = verifyChecksum;
}
@Override
public boolean supportsSymlinks() {
return true;
}
@Override
public void createSymlink(Path target, Path link, boolean createParent)
throws IOException, UnresolvedLinkException {
dfs.createSymlink(target.toString(), getUriPath(link), createParent);
}
@Override
public Path getLinkTarget(Path p) throws IOException {
return new Path(dfs.getLinkTarget(getUriPath(p)));
}
}