/**
*
* Licensed 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.
*
* We need to provide the ability to the code in fs/kfs without really
* having a KFS deployment. For this purpose, use the LocalFileSystem
* as a way to "emulate" KFS.
*/
package com.quantcast.qfs.hadoop;
import java.io.*;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.permission.FsPermission;
import com.quantcast.qfs.access.KfsFileAttr;
public class QFSEmulationImpl implements IFSImpl {
FileSystem localFS;
public QFSEmulationImpl(Configuration conf) throws IOException {
localFS = FileSystem.getLocal(conf);
}
public boolean exists(String path) throws IOException {
return localFS.exists(new Path(path));
}
public boolean isDirectory(String path) throws IOException {
return localFS.isDirectory(new Path(path));
}
public boolean isFile(String path) throws IOException {
return localFS.isFile(new Path(path));
}
public String[] readdir(String path) throws IOException {
FileStatus[] p = localFS.listStatus(new Path(path));
String[] entries = null;
if (p == null) {
return null;
}
entries = new String[p.length];
for (int i = 0; i < p.length; i++) {
entries[i] = p[i].getPath().toString();
}
return entries;
}
public FileStatus[] readdirplus(Path path) throws IOException {
return localFS.listStatus(new Path(path.toUri().getPath()));
}
public FileStatus stat(Path path) throws IOException {
return localFS.getFileStatus(new Path(path.toUri().getPath()));
}
public KfsFileAttr fullStat(Path path) throws IOException {
FileStatus fs = localFS.getFileStatus(new Path(path.toUri().getPath()));
KfsFileAttr fa = new KfsFileAttr();
fa.filename = fs.getPath().toUri().getPath();
fa.isDirectory = fs.isDir();
fa.filesize = fs.getLen();
fa.replication = fs.getReplication();
fa.modificationTime = fs.getModificationTime();
return fa;
}
public int mkdir(String path, int mode) throws IOException {
if (localFS.mkdirs(new Path(path))) {
return 0;
}
return -1;
}
public int mkdirs(String path, int mode) throws IOException {
if (localFS.mkdirs(new Path(path))) {
return 0;
}
return -1;
}
public int rename(String source, String dest) throws IOException {
if (localFS.rename(new Path(source), new Path(dest))) {
return 0;
}
return -1;
}
public int rename2(String source, String dest,
boolean overwrite) throws IOException {
if (localFS.rename(new Path(source), new Path(dest))) {
return 0;
}
return -1;
}
public int rmdir(String path) throws IOException {
if (isDirectory(path)) {
// the directory better be empty
String[] dirEntries = readdir(path);
if ((dirEntries.length <= 2) && (localFS.delete(new Path(path), true))) {
return 0;
}
}
return -1;
}
public int remove(String path) throws IOException {
if (isFile(path) && (localFS.delete(new Path(path), true))) {
return 0;
}
return -1;
}
public int rmdirs(String path) throws IOException {
if (isFile(path)) {
return -1;
}
return localFS.delete(new Path(path), true) ? 0 : -1;
}
public long filesize(String path) throws IOException {
return localFS.getLength(new Path(path));
}
public short getReplication(String path) throws IOException {
return 1;
}
public short setReplication(String path, short replication)
throws IOException {
return 1;
}
public String[][] getDataLocation(String path, long start, long len)
throws IOException {
final BlockLocation[] blkLocations = localFS.getFileBlockLocations(
localFS.getFileStatus(new Path(path)), start, len);
if ((blkLocations == null) || (blkLocations.length == 0)) {
return new String[0][];
}
final int blkCount = blkLocations.length;
final String[][]hints = new String[blkCount][];
for (int i=0; i < blkCount ; i++) {
hints[i] = blkLocations[i].getHosts();;
}
return hints;
}
public String[][] getBlocksLocation(String path, long start, long len)
throws IOException {
final BlockLocation[] blkLocations = localFS.getFileBlockLocations(
localFS.getFileStatus(new Path(path)), start, len);
if ((blkLocations == null) || (blkLocations.length == 0)) {
return new String[0][];
}
final int blkCount = blkLocations.length + 1;
final String[][]hints = new String[blkCount][];
hints[0] = new String[1];
hints[0][0] = Long.toHexString(
blkCount <= 0 ? 1L : blkLocations[0].getLength());
for (int i=1; i < blkCount ; i++) {
hints[i] = blkLocations[i].getHosts();;
}
return hints;
}
public long getModificationTime(String path) throws IOException {
FileStatus s = localFS.getFileStatus(new Path(path));
if (s == null) {
return 0;
}
return s.getModificationTime();
}
public FSDataOutputStream create(String path, short replication,
int bufferSize, boolean overwrite, int mode, boolean append) throws IOException {
// besides path/overwrite, the other args don't matter for
// testing purposes.
return localFS.create(new Path(path));
}
public FSDataOutputStream create(String path, short replication,
int bufferSize, boolean overwrite, int mode) throws IOException {
// besides path/overwrite, the other args don't matter for
// testing purposes.
return localFS.create(new Path(path));
}
public FSDataInputStream open(String path, int bufferSize)
throws IOException {
return localFS.open(new Path(path));
}
public FSDataOutputStream append(String path, short replication,
int bufferSize) throws IOException {
return localFS.create(new Path(path));
}
public void setPermission(String path, int mode) throws IOException {
localFS.setPermission(new Path(path), new FsPermission((short)mode));
}
public void setOwner(String path, String username, String groupname)
throws IOException {
localFS.setOwner(new Path(path), username, groupname);
}
public CloseableIterator<FileStatus> getFileStatusIterator(FileSystem fs, Path path)
throws IOException {
return null;
}
public void retToIoException(int status)
throws IOException {
if (status < 0) {
throw new IOException("IO exception status: " + status);
}
}
}