/**
* 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.Closeable;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.net.URI;
import java.net.URISyntaxException;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.EnumSet;
import java.util.HashMap;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.ServiceLoader;
import java.util.Set;
import java.util.Stack;
import java.util.TreeSet;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Options.ChecksumOpt;
import org.apache.hadoop.fs.Options.Rename;
import org.apache.hadoop.fs.permission.AclEntry;
import org.apache.hadoop.fs.permission.AclStatus;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.io.MultipleIOException;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.SecurityUtil;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.DataChecksum;
import org.apache.hadoop.util.Progressable;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.ShutdownHookManager;
import com.google.common.annotations.VisibleForTesting;
/****************************************************************
* An abstract base class for a fairly generic filesystem. It
* may be implemented as a distributed filesystem, or as a "local"
* one that reflects the locally-connected disk. The local version
* exists for small Hadoop instances and for testing.
*
* <p>
*
* All user code that may potentially use the Hadoop Distributed
* File System should be written to use a FileSystem object. The
* Hadoop DFS is a multi-machine system that appears as a single
* disk. It's useful because of its fault tolerance and potentially
* very large capacity.
*
* <p>
* The local implementation is {@link LocalFileSystem} and distributed
* implementation is DistributedFileSystem.
*****************************************************************/
@InterfaceAudience.Public
@InterfaceStability.Stable
public abstract class FileSystem extends Configured implements Closeable {
public static final String FS_DEFAULT_NAME_KEY =
CommonConfigurationKeys.FS_DEFAULT_NAME_KEY;
public static final String DEFAULT_FS =
CommonConfigurationKeys.FS_DEFAULT_NAME_DEFAULT;
public static final Log LOG = LogFactory.getLog(FileSystem.class);
/**
* Priority of the FileSystem shutdown hook.
*/
public static final int SHUTDOWN_HOOK_PRIORITY = 10;
/** FileSystem cache */
static final Cache CACHE = new Cache();
/** The key this instance is stored under in the cache. */
private Cache.Key key;
/** Recording statistics per a FileSystem class */
private static final Map<Class<? extends FileSystem>, Statistics>
statisticsTable =
new IdentityHashMap<Class<? extends FileSystem>, Statistics>();
/**
* The statistics for this file system.
*/
protected Statistics statistics;
/**
* A cache of files that should be deleted when filsystem is closed
* or the JVM is exited.
*/
private Set<Path> deleteOnExit = new TreeSet<Path>();
boolean resolveSymlinks;
/**
* This method adds a file system for testing so that we can find it later. It
* is only for testing.
* @param uri the uri to store it under
* @param conf the configuration to store it under
* @param fs the file system to store
* @throws IOException
*/
static void addFileSystemForTesting(URI uri, Configuration conf,
FileSystem fs) throws IOException {
CACHE.map.put(new Cache.Key(uri, conf), fs);
}
/**
* Get a filesystem instance based on the uri, the passed
* configuration and the user
* @param uri of the filesystem
* @param conf the configuration to use
* @param user to perform the get as
* @return the filesystem instance
* @throws IOException
* @throws InterruptedException
*/
public static FileSystem get(final URI uri, final Configuration conf,
final String user) throws IOException, InterruptedException {
String ticketCachePath =
conf.get(CommonConfigurationKeys.KERBEROS_TICKET_CACHE_PATH);
UserGroupInformation ugi =
UserGroupInformation.getBestUGI(ticketCachePath, user);
return ugi.doAs(new PrivilegedExceptionAction<FileSystem>() {
@Override
public FileSystem run() throws IOException {
return get(uri, conf);
}
});
}
/**
* Returns the configured filesystem implementation.
* @param conf the configuration to use
*/
public static FileSystem get(Configuration conf) throws IOException {
return get(getDefaultUri(conf), conf);
}
/** Get the default filesystem URI from a configuration.
* @param conf the configuration to use
* @return the uri of the default filesystem
*/
public static URI getDefaultUri(Configuration conf) {
return URI.create(fixName(conf.get(FS_DEFAULT_NAME_KEY, DEFAULT_FS)));
}
/** Set the default filesystem URI in a configuration.
* @param conf the configuration to alter
* @param uri the new default filesystem uri
*/
public static void setDefaultUri(Configuration conf, URI uri) {
conf.set(FS_DEFAULT_NAME_KEY, uri.toString());
}
/** Set the default filesystem URI in a configuration.
* @param conf the configuration to alter
* @param uri the new default filesystem uri
*/
public static void setDefaultUri(Configuration conf, String uri) {
setDefaultUri(conf, URI.create(fixName(uri)));
}
/** Called after a new FileSystem instance is constructed.
* @param name a uri whose authority section names the host, port, etc.
* for this FileSystem
* @param conf the configuration
*/
public void initialize(URI name, Configuration conf) throws IOException {
statistics = getStatistics(name.getScheme(), getClass());
resolveSymlinks = conf.getBoolean(
CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_KEY,
CommonConfigurationKeys.FS_CLIENT_RESOLVE_REMOTE_SYMLINKS_DEFAULT);
}
/**
* Return the protocol scheme for the FileSystem.
* <p/>
* This implementation throws an <code>UnsupportedOperationException</code>.
*
* @return the protocol scheme for the FileSystem.
*/
public String getScheme() {
throw new UnsupportedOperationException("Not implemented by the " + getClass().getSimpleName() + " FileSystem implementation");
}
/** Returns a URI whose scheme and authority identify this FileSystem.*/
public abstract URI getUri();
/**
* Return a canonicalized form of this FileSystem's URI.
*
* The default implementation simply calls {@link #canonicalizeUri(URI)}
* on the filesystem's own URI, so subclasses typically only need to
* implement that method.
*
* @see #canonicalizeUri(URI)
*/
protected URI getCanonicalUri() {
return canonicalizeUri(getUri());
}
/**
* Canonicalize the given URI.
*
* This is filesystem-dependent, but may for example consist of
* canonicalizing the hostname using DNS and adding the default
* port if not specified.
*
* The default implementation simply fills in the default port if
* not specified and if the filesystem has a default port.
*
* @return URI
* @see NetUtils#getCanonicalUri(URI, int)
*/
protected URI canonicalizeUri(URI uri) {
if (uri.getPort() == -1 && getDefaultPort() > 0) {
// reconstruct the uri with the default port set
try {
uri = new URI(uri.getScheme(), uri.getUserInfo(),
uri.getHost(), getDefaultPort(),
uri.getPath(), uri.getQuery(), uri.getFragment());
} catch (URISyntaxException e) {
// Should never happen!
throw new AssertionError("Valid URI became unparseable: " +
uri);
}
}
return uri;
}
/**
* Get the default port for this file system.
* @return the default port or 0 if there isn't one
*/
protected int getDefaultPort() {
return 0;
}
protected static FileSystem getFSofPath(final Path absOrFqPath,
final Configuration conf)
throws UnsupportedFileSystemException, IOException {
absOrFqPath.checkNotSchemeWithRelative();
absOrFqPath.checkNotRelative();
// Uses the default file system if not fully qualified
return get(absOrFqPath.toUri(), conf);
}
/**
* Get a canonical service name for this file system. The token cache is
* the only user of the canonical service name, and uses it to lookup this
* filesystem's service tokens.
* If file system provides a token of its own then it must have a canonical
* name, otherwise canonical name can be null.
*
* Default Impl: If the file system has child file systems
* (such as an embedded file system) then it is assumed that the fs has no
* tokens of its own and hence returns a null name; otherwise a service
* name is built using Uri and port.
*
* @return a service string that uniquely identifies this file system, null
* if the filesystem does not implement tokens
* @see SecurityUtil#buildDTServiceName(URI, int)
*/
@InterfaceAudience.LimitedPrivate({ "HDFS", "MapReduce" })
public String getCanonicalServiceName() {
return (getChildFileSystems() == null)
? SecurityUtil.buildDTServiceName(getUri(), getDefaultPort())
: null;
}
/** @deprecated call #getUri() instead.*/
@Deprecated
public String getName() { return getUri().toString(); }
/** @deprecated call #get(URI,Configuration) instead. */
@Deprecated
public static FileSystem getNamed(String name, Configuration conf)
throws IOException {
return get(URI.create(fixName(name)), conf);
}
/** Update old-format filesystem names, for back-compatibility. This should
* eventually be replaced with a checkName() method that throws an exception
* for old-format names. */
private static String fixName(String name) {
// convert old-format name to new-format name
if (name.equals("local")) { // "local" is now "file:///".
LOG.warn("\"local\" is a deprecated filesystem name."
+" Use \"file:///\" instead.");
name = "file:///";
} else if (name.indexOf('/')==-1) { // unqualified is "hdfs://"
LOG.warn("\""+name+"\" is a deprecated filesystem name."
+" Use \"hdfs://"+name+"/\" instead.");
name = "hdfs://"+name;
}
return name;
}
/**
* Get the local file system.
* @param conf the configuration to configure the file system with
* @return a LocalFileSystem
*/
public static LocalFileSystem getLocal(Configuration conf)
throws IOException {
return (LocalFileSystem)get(LocalFileSystem.NAME, conf);
}
/** Returns the FileSystem for this URI's scheme and authority. The scheme
* of the URI determines a configuration property name,
* <tt>fs.<i>scheme</i>.class</tt> whose value names the FileSystem class.
* The entire URI is passed to the FileSystem instance's initialize method.
*/
public static FileSystem get(URI uri, Configuration conf) throws IOException {
String scheme = uri.getScheme();
String authority = uri.getAuthority();
if (scheme == null && authority == null) { // use default FS
return get(conf);
}
if (scheme != null && authority == null) { // no authority
URI defaultUri = getDefaultUri(conf);
if (scheme.equals(defaultUri.getScheme()) // if scheme matches default
&& defaultUri.getAuthority() != null) { // & default has authority
return get(defaultUri, conf); // return default
}
}
String disableCacheName = String.format("fs.%s.impl.disable.cache", scheme);
if (conf.getBoolean(disableCacheName, false)) {
return createFileSystem(uri, conf);
}
return CACHE.get(uri, conf);
}
/**
* Returns the FileSystem for this URI's scheme and authority and the
* passed user. Internally invokes {@link #newInstance(URI, Configuration)}
* @param uri of the filesystem
* @param conf the configuration to use
* @param user to perform the get as
* @return filesystem instance
* @throws IOException
* @throws InterruptedException
*/
public static FileSystem newInstance(final URI uri, final Configuration conf,
final String user) throws IOException, InterruptedException {
String ticketCachePath =
conf.get(CommonConfigurationKeys.KERBEROS_TICKET_CACHE_PATH);
UserGroupInformation ugi =
UserGroupInformation.getBestUGI(ticketCachePath, user);
return ugi.doAs(new PrivilegedExceptionAction<FileSystem>() {
@Override
public FileSystem run() throws IOException {
return newInstance(uri,conf);
}
});
}
/** Returns the FileSystem for this URI's scheme and authority. The scheme
* of the URI determines a configuration property name,
* <tt>fs.<i>scheme</i>.class</tt> whose value names the FileSystem class.
* The entire URI is passed to the FileSystem instance's initialize method.
* This always returns a new FileSystem object.
*/
public static FileSystem newInstance(URI uri, Configuration conf) throws IOException {
String scheme = uri.getScheme();
String authority = uri.getAuthority();
if (scheme == null) { // no scheme: use default FS
return newInstance(conf);
}
if (authority == null) { // no authority
URI defaultUri = getDefaultUri(conf);
if (scheme.equals(defaultUri.getScheme()) // if scheme matches default
&& defaultUri.getAuthority() != null) { // & default has authority
return newInstance(defaultUri, conf); // return default
}
}
return CACHE.getUnique(uri, conf);
}
/** Returns a unique configured filesystem implementation.
* This always returns a new FileSystem object.
* @param conf the configuration to use
*/
public static FileSystem newInstance(Configuration conf) throws IOException {
return newInstance(getDefaultUri(conf), conf);
}
/**
* Get a unique local file system object
* @param conf the configuration to configure the file system with
* @return a LocalFileSystem
* This always returns a new FileSystem object.
*/
public static LocalFileSystem newInstanceLocal(Configuration conf)
throws IOException {
return (LocalFileSystem)newInstance(LocalFileSystem.NAME, conf);
}
/**
* Close all cached filesystems. Be sure those filesystems are not
* used anymore.
*
* @throws IOException
*/
public static void closeAll() throws IOException {
CACHE.closeAll();
}
/**
* Close all cached filesystems for a given UGI. Be sure those filesystems
* are not used anymore.
* @param ugi user group info to close
* @throws IOException
*/
public static void closeAllForUGI(UserGroupInformation ugi)
throws IOException {
CACHE.closeAll(ugi);
}
/**
* Make sure that a path specifies a FileSystem.
* @param path to use
*/
public Path makeQualified(Path path) {
checkPath(path);
return path.makeQualified(this.getUri(), this.getWorkingDirectory());
}
/**
* Get a new delegation token for this file system.
* This is an internal method that should have been declared protected
* but wasn't historically.
* Callers should use {@link #addDelegationTokens(String, Credentials)}
*
* @param renewer the account name that is allowed to renew the token.
* @return a new delegation token
* @throws IOException
*/
@InterfaceAudience.Private()
public Token<?> getDelegationToken(String renewer) throws IOException {
return null;
}
/**
* Obtain all delegation tokens used by this FileSystem that are not
* already present in the given Credentials. Existing tokens will neither
* be verified as valid nor having the given renewer. Missing tokens will
* be acquired and added to the given Credentials.
*
* Default Impl: works for simple fs with its own token
* and also for an embedded fs whose tokens are those of its
* children file system (i.e. the embedded fs has not tokens of its
* own).
*
* @param renewer the user allowed to renew the delegation tokens
* @param credentials cache in which to add new delegation tokens
* @return list of new delegation tokens
* @throws IOException
*/
@InterfaceAudience.LimitedPrivate({ "HDFS", "MapReduce" })
public Token<?>[] addDelegationTokens(
final String renewer, Credentials credentials) throws IOException {
if (credentials == null) {
credentials = new Credentials();
}
final List<Token<?>> tokens = new ArrayList<Token<?>>();
collectDelegationTokens(renewer, credentials, tokens);
return tokens.toArray(new Token<?>[tokens.size()]);
}
/**
* Recursively obtain the tokens for this FileSystem and all descended
* FileSystems as determined by getChildFileSystems().
* @param renewer the user allowed to renew the delegation tokens
* @param credentials cache in which to add the new delegation tokens
* @param tokens list in which to add acquired tokens
* @throws IOException
*/
private void collectDelegationTokens(final String renewer,
final Credentials credentials,
final List<Token<?>> tokens)
throws IOException {
final String serviceName = getCanonicalServiceName();
// Collect token of the this filesystem and then of its embedded children
if (serviceName != null) { // fs has token, grab it
final Text service = new Text(serviceName);
Token<?> token = credentials.getToken(service);
if (token == null) {
token = getDelegationToken(renewer);
if (token != null) {
tokens.add(token);
credentials.addToken(service, token);
}
}
}
// Now collect the tokens from the children
final FileSystem[] children = getChildFileSystems();
if (children != null) {
for (final FileSystem fs : children) {
fs.collectDelegationTokens(renewer, credentials, tokens);
}
}
}
/**
* Get all the immediate child FileSystems embedded in this FileSystem.
* It does not recurse and get grand children. If a FileSystem
* has multiple child FileSystems, then it should return a unique list
* of those FileSystems. Default is to return null to signify no children.
*
* @return FileSystems used by this FileSystem
*/
@InterfaceAudience.LimitedPrivate({ "HDFS" })
@VisibleForTesting
public FileSystem[] getChildFileSystems() {
return null;
}
/** create a file with the provided permission
* The permission of the file is set to be the provided permission as in
* setPermission, not permission&~umask
*
* It is implemented using two RPCs. It is understood that it is inefficient,
* but the implementation is thread-safe. The other option is to change the
* value of umask in configuration to be 0, but it is not thread-safe.
*
* @param fs file system handle
* @param file the name of the file to be created
* @param permission the permission of the file
* @return an output stream
* @throws IOException
*/
public static FSDataOutputStream create(FileSystem fs,
Path file, FsPermission permission) throws IOException {
// create the file with default permission
FSDataOutputStream out = fs.create(file);
// set its permission to the supplied one
fs.setPermission(file, permission);
return out;
}
/** create a directory with the provided permission
* The permission of the directory is set to be the provided permission as in
* setPermission, not permission&~umask
*
* @see #create(FileSystem, Path, FsPermission)
*
* @param fs file system handle
* @param dir the name of the directory to be created
* @param permission the permission of the directory
* @return true if the directory creation succeeds; false otherwise
* @throws IOException
*/
public static boolean mkdirs(FileSystem fs, Path dir, FsPermission permission)
throws IOException {
// create the directory using the default permission
boolean result = fs.mkdirs(dir);
// set its permission to be the supplied one
fs.setPermission(dir, permission);
return result;
}
///////////////////////////////////////////////////////////////
// FileSystem
///////////////////////////////////////////////////////////////
protected FileSystem() {
super(null);
}
/**
* Check that a Path belongs to this FileSystem.
* @param path to check
*/
protected void checkPath(Path path) {
URI uri = path.toUri();
String thatScheme = uri.getScheme();
if (thatScheme == null) // fs is relative
return;
URI thisUri = getCanonicalUri();
String thisScheme = thisUri.getScheme();
//authority and scheme are not case sensitive
if (thisScheme.equalsIgnoreCase(thatScheme)) {// schemes match
String thisAuthority = thisUri.getAuthority();
String thatAuthority = uri.getAuthority();
if (thatAuthority == null && // path's authority is null
thisAuthority != null) { // fs has an authority
URI defaultUri = getDefaultUri(getConf());
if (thisScheme.equalsIgnoreCase(defaultUri.getScheme())) {
uri = defaultUri; // schemes match, so use this uri instead
} else {
uri = null; // can't determine auth of the path
}
}
if (uri != null) {
// canonicalize uri before comparing with this fs
uri = canonicalizeUri(uri);
thatAuthority = uri.getAuthority();
if (thisAuthority == thatAuthority || // authorities match
(thisAuthority != null &&
thisAuthority.equalsIgnoreCase(thatAuthority)))
return;
}
}
throw new IllegalArgumentException("Wrong FS: "+path+
", expected: "+this.getUri());
}
/**
* Return an array containing hostnames, offset and size of
* portions of the given file. For a nonexistent
* file or regions, null will be returned.
*
* This call is most helpful with DFS, where it returns
* hostnames of machines that contain the given file.
*
* The FileSystem will simply return an elt containing 'localhost'.
*
* @param file FilesStatus to get data from
* @param start offset into the given file
* @param len length for which to get locations for
*/
public BlockLocation[] getFileBlockLocations(FileStatus file,
long start, long len) throws IOException {
if (file == null) {
return null;
}
if (start < 0 || len < 0) {
throw new IllegalArgumentException("Invalid start or len parameter");
}
if (file.getLen() <= start) {
return new BlockLocation[0];
}
String[] name = { "localhost:50010" };
String[] host = { "localhost" };
return new BlockLocation[] {
new BlockLocation(name, host, 0, file.getLen()) };
}
/**
* Return an array containing hostnames, offset and size of
* portions of the given file. For a nonexistent
* file or regions, null will be returned.
*
* This call is most helpful with DFS, where it returns
* hostnames of machines that contain the given file.
*
* The FileSystem will simply return an elt containing 'localhost'.
*
* @param p path is used to identify an FS since an FS could have
* another FS that it could be delegating the call to
* @param start offset into the given file
* @param len length for which to get locations for
*/
public BlockLocation[] getFileBlockLocations(Path p,
long start, long len) throws IOException {
if (p == null) {
throw new NullPointerException();
}
FileStatus file = getFileStatus(p);
return getFileBlockLocations(file, start, len);
}
/**
* Return a set of server default configuration values
* @return server default configuration values
* @throws IOException
* @deprecated use {@link #getServerDefaults(Path)} instead
*/
@Deprecated
public FsServerDefaults getServerDefaults() throws IOException {
Configuration conf = getConf();
// CRC32 is chosen as default as it is available in all
// releases that support checksum.
// The client trash configuration is ignored.
return new FsServerDefaults(getDefaultBlockSize(),
conf.getInt("io.bytes.per.checksum", 512),
64 * 1024,
getDefaultReplication(),
conf.getInt("io.file.buffer.size", 4096),
false,
CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_DEFAULT,
DataChecksum.Type.CRC32);
}
/**
* Return a set of server default configuration values
* @param p path is used to identify an FS since an FS could have
* another FS that it could be delegating the call to
* @return server default configuration values
* @throws IOException
*/
public FsServerDefaults getServerDefaults(Path p) throws IOException {
return getServerDefaults();
}
/**
* Return the fully-qualified path of path f resolving the path
* through any symlinks or mount point
* @param p path to be resolved
* @return fully qualified path
* @throws FileNotFoundException
*/
public Path resolvePath(final Path p) throws IOException {
checkPath(p);
return getFileStatus(p).getPath();
}
/**
* Opens an FSDataInputStream at the indicated Path.
* @param f the file name to open
* @param bufferSize the size of the buffer to be used.
*/
public abstract FSDataInputStream open(Path f, int bufferSize)
throws IOException;
/**
* Opens an FSDataInputStream at the indicated Path.
* @param f the file to open
*/
public FSDataInputStream open(Path f) throws IOException {
return open(f, getConf().getInt("io.file.buffer.size", 4096));
}
/**
* Create an FSDataOutputStream at the indicated Path.
* Files are overwritten by default.
* @param f the file to create
*/
public FSDataOutputStream create(Path f) throws IOException {
return create(f, true);
}
/**
* Create an FSDataOutputStream at the indicated Path.
* @param f the file to create
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an exception will be thrown.
*/
public FSDataOutputStream create(Path f, boolean overwrite)
throws IOException {
return create(f, overwrite,
getConf().getInt("io.file.buffer.size", 4096),
getDefaultReplication(f),
getDefaultBlockSize(f));
}
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* Files are overwritten by default.
* @param f the file to create
* @param progress to report progress
*/
public FSDataOutputStream create(Path f, Progressable progress)
throws IOException {
return create(f, true,
getConf().getInt("io.file.buffer.size", 4096),
getDefaultReplication(f),
getDefaultBlockSize(f), progress);
}
/**
* Create an FSDataOutputStream at the indicated Path.
* Files are overwritten by default.
* @param f the file to create
* @param replication the replication factor
*/
public FSDataOutputStream create(Path f, short replication)
throws IOException {
return create(f, true,
getConf().getInt("io.file.buffer.size", 4096),
replication,
getDefaultBlockSize(f));
}
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* Files are overwritten by default.
* @param f the file to create
* @param replication the replication factor
* @param progress to report progress
*/
public FSDataOutputStream create(Path f, short replication,
Progressable progress) throws IOException {
return create(f, true,
getConf().getInt(
CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_KEY,
CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT),
replication,
getDefaultBlockSize(f), progress);
}
/**
* Create an FSDataOutputStream at the indicated Path.
* @param f the file name to create
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
*/
public FSDataOutputStream create(Path f,
boolean overwrite,
int bufferSize
) throws IOException {
return create(f, overwrite, bufferSize,
getDefaultReplication(f),
getDefaultBlockSize(f));
}
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* @param f the path of the file to open
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
*/
public FSDataOutputStream create(Path f,
boolean overwrite,
int bufferSize,
Progressable progress
) throws IOException {
return create(f, overwrite, bufferSize,
getDefaultReplication(f),
getDefaultBlockSize(f), progress);
}
/**
* Create an FSDataOutputStream at the indicated Path.
* @param f the file name to open
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
*/
public FSDataOutputStream create(Path f,
boolean overwrite,
int bufferSize,
short replication,
long blockSize
) throws IOException {
return create(f, overwrite, bufferSize, replication, blockSize, null);
}
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* @param f the file name to open
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
*/
public FSDataOutputStream create(Path f,
boolean overwrite,
int bufferSize,
short replication,
long blockSize,
Progressable progress
) throws IOException {
return this.create(f, FsPermission.getFileDefault().applyUMask(
FsPermission.getUMask(getConf())), overwrite, bufferSize,
replication, blockSize, progress);
}
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* @param f the file name to open
* @param permission
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @throws IOException
* @see #setPermission(Path, FsPermission)
*/
public abstract FSDataOutputStream create(Path f,
FsPermission permission,
boolean overwrite,
int bufferSize,
short replication,
long blockSize,
Progressable progress) throws IOException;
/**
* Create an FSDataOutputStream at the indicated Path with write-progress
* reporting.
* @param f the file name to open
* @param permission
* @param flags {@link CreateFlag}s to use for this stream.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @throws IOException
* @see #setPermission(Path, FsPermission)
*/
public FSDataOutputStream create(Path f,
FsPermission permission,
EnumSet<CreateFlag> flags,
int bufferSize,
short replication,
long blockSize,
Progressable progress) throws IOException {
return create(f, permission, flags, bufferSize, replication,
blockSize, progress, null);
}
/**
* Create an FSDataOutputStream at the indicated Path with a custom
* checksum option
* @param f the file name to open
* @param permission
* @param flags {@link CreateFlag}s to use for this stream.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @param checksumOpt checksum parameter. If null, the values
* found in conf will be used.
* @throws IOException
* @see #setPermission(Path, FsPermission)
*/
public FSDataOutputStream create(Path f,
FsPermission permission,
EnumSet<CreateFlag> flags,
int bufferSize,
short replication,
long blockSize,
Progressable progress,
ChecksumOpt checksumOpt) throws IOException {
// Checksum options are ignored by default. The file systems that
// implement checksum need to override this method. The full
// support is currently only available in DFS.
return create(f, permission, flags.contains(CreateFlag.OVERWRITE),
bufferSize, replication, blockSize, progress);
}
/*.
* This create has been added to support the FileContext that processes
* the permission
* with umask before calling this method.
* This a temporary method added to support the transition from FileSystem
* to FileContext for user applications.
*/
@Deprecated
protected FSDataOutputStream primitiveCreate(Path f,
FsPermission absolutePermission, EnumSet<CreateFlag> flag, int bufferSize,
short replication, long blockSize, Progressable progress,
ChecksumOpt checksumOpt) throws IOException {
boolean pathExists = exists(f);
CreateFlag.validate(f, pathExists, flag);
// Default impl assumes that permissions do not matter and
// nor does the bytesPerChecksum hence
// calling the regular create is good enough.
// FSs that implement permissions should override this.
if (pathExists && flag.contains(CreateFlag.APPEND)) {
return append(f, bufferSize, progress);
}
return this.create(f, absolutePermission,
flag.contains(CreateFlag.OVERWRITE), bufferSize, replication,
blockSize, progress);
}
/**
* This version of the mkdirs method assumes that the permission is absolute.
* It has been added to support the FileContext that processes the permission
* with umask before calling this method.
* This a temporary method added to support the transition from FileSystem
* to FileContext for user applications.
*/
@Deprecated
protected boolean primitiveMkdir(Path f, FsPermission absolutePermission)
throws IOException {
// Default impl is to assume that permissions do not matter and hence
// calling the regular mkdirs is good enough.
// FSs that implement permissions should override this.
return this.mkdirs(f, absolutePermission);
}
/**
* This version of the mkdirs method assumes that the permission is absolute.
* It has been added to support the FileContext that processes the permission
* with umask before calling this method.
* This a temporary method added to support the transition from FileSystem
* to FileContext for user applications.
*/
@Deprecated
protected void primitiveMkdir(Path f, FsPermission absolutePermission,
boolean createParent)
throws IOException {
if (!createParent) { // parent must exist.
// since the this.mkdirs makes parent dirs automatically
// we must throw exception if parent does not exist.
final FileStatus stat = getFileStatus(f.getParent());
if (stat == null) {
throw new FileNotFoundException("Missing parent:" + f);
}
if (!stat.isDirectory()) {
throw new ParentNotDirectoryException("parent is not a dir");
}
// parent does exist - go ahead with mkdir of leaf
}
// Default impl is to assume that permissions do not matter and hence
// calling the regular mkdirs is good enough.
// FSs that implement permissions should override this.
if (!this.mkdirs(f, absolutePermission)) {
throw new IOException("mkdir of "+ f + " failed");
}
}
/**
* Opens an FSDataOutputStream at the indicated Path with write-progress
* reporting. Same as create(), except fails if parent directory doesn't
* already exist.
* @param f the file name to open
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @throws IOException
* @see #setPermission(Path, FsPermission)
* @deprecated API only for 0.20-append
*/
@Deprecated
public FSDataOutputStream createNonRecursive(Path f,
boolean overwrite,
int bufferSize, short replication, long blockSize,
Progressable progress) throws IOException {
return this.createNonRecursive(f, FsPermission.getFileDefault(),
overwrite, bufferSize, replication, blockSize, progress);
}
/**
* Opens an FSDataOutputStream at the indicated Path with write-progress
* reporting. Same as create(), except fails if parent directory doesn't
* already exist.
* @param f the file name to open
* @param permission
* @param overwrite if a file with this name already exists, then if true,
* the file will be overwritten, and if false an error will be thrown.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @throws IOException
* @see #setPermission(Path, FsPermission)
* @deprecated API only for 0.20-append
*/
@Deprecated
public FSDataOutputStream createNonRecursive(Path f, FsPermission permission,
boolean overwrite, int bufferSize, short replication, long blockSize,
Progressable progress) throws IOException {
return createNonRecursive(f, permission,
overwrite ? EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE)
: EnumSet.of(CreateFlag.CREATE), bufferSize,
replication, blockSize, progress);
}
/**
* Opens an FSDataOutputStream at the indicated Path with write-progress
* reporting. Same as create(), except fails if parent directory doesn't
* already exist.
* @param f the file name to open
* @param permission
* @param flags {@link CreateFlag}s to use for this stream.
* @param bufferSize the size of the buffer to be used.
* @param replication required block replication for the file.
* @param blockSize
* @param progress
* @throws IOException
* @see #setPermission(Path, FsPermission)
* @deprecated API only for 0.20-append
*/
@Deprecated
public FSDataOutputStream createNonRecursive(Path f, FsPermission permission,
EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize,
Progressable progress) throws IOException {
throw new IOException("createNonRecursive unsupported for this filesystem "
+ this.getClass());
}
/**
* Creates the given Path as a brand-new zero-length file. If
* create fails, or if it already existed, return false.
*
* @param f path to use for create
*/
public boolean createNewFile(Path f) throws IOException {
if (exists(f)) {
return false;
} else {
create(f, false, getConf().getInt("io.file.buffer.size", 4096)).close();
return true;
}
}
/**
* Append to an existing file (optional operation).
* Same as append(f, getConf().getInt("io.file.buffer.size", 4096), null)
* @param f the existing file to be appended.
* @throws IOException
*/
public FSDataOutputStream append(Path f) throws IOException {
return append(f, getConf().getInt("io.file.buffer.size", 4096), null);
}
/**
* Append to an existing file (optional operation).
* Same as append(f, bufferSize, null).
* @param f the existing file to be appended.
* @param bufferSize the size of the buffer to be used.
* @throws IOException
*/
public FSDataOutputStream append(Path f, int bufferSize) throws IOException {
return append(f, bufferSize, null);
}
/**
* Append to an existing file (optional operation).
* @param f the existing file to be appended.
* @param bufferSize the size of the buffer to be used.
* @param progress for reporting progress if it is not null.
* @throws IOException
*/
public abstract FSDataOutputStream append(Path f, int bufferSize,
Progressable progress) throws IOException;
/**
* Concat existing files together.
* @param trg the path to the target destination.
* @param psrcs the paths to the sources to use for the concatenation.
* @throws IOException
*/
public void concat(final Path trg, final Path [] psrcs) throws IOException {
throw new UnsupportedOperationException("Not implemented by the " +
getClass().getSimpleName() + " FileSystem implementation");
}
/**
* Get replication.
*
* @deprecated Use getFileStatus() instead
* @param src file name
* @return file replication
* @throws IOException
*/
@Deprecated
public short getReplication(Path src) throws IOException {
return getFileStatus(src).getReplication();
}
/**
* Set replication for an existing file.
*
* @param src file name
* @param replication new replication
* @throws IOException
* @return true if successful;
* false if file does not exist or is a directory
*/
public boolean setReplication(Path src, short replication)
throws IOException {
return true;
}
/**
* Renames Path src to Path dst. Can take place on local fs
* or remote DFS.
* @param src path to be renamed
* @param dst new path after rename
* @throws IOException on failure
* @return true if rename is successful
*/
public abstract boolean rename(Path src, Path dst) throws IOException;
/**
* Renames Path src to Path dst
* <ul>
* <li
* <li>Fails if src is a file and dst is a directory.
* <li>Fails if src is a directory and dst is a file.
* <li>Fails if the parent of dst does not exist or is a file.
* </ul>
* <p>
* If OVERWRITE option is not passed as an argument, rename fails
* if the dst already exists.
* <p>
* If OVERWRITE option is passed as an argument, rename overwrites
* the dst if it is a file or an empty directory. Rename fails if dst is
* a non-empty directory.
* <p>
* Note that atomicity of rename is dependent on the file system
* implementation. Please refer to the file system documentation for
* details. This default implementation is non atomic.
* <p>
* This method is deprecated since it is a temporary method added to
* support the transition from FileSystem to FileContext for user
* applications.
*
* @param src path to be renamed
* @param dst new path after rename
* @throws IOException on failure
*/
@Deprecated
protected void rename(final Path src, final Path dst,
final Rename... options) throws IOException {
// Default implementation
final FileStatus srcStatus = getFileLinkStatus(src);
if (srcStatus == null) {
throw new FileNotFoundException("rename source " + src + " not found.");
}
boolean overwrite = false;
if (null != options) {
for (Rename option : options) {
if (option == Rename.OVERWRITE) {
overwrite = true;
}
}
}
FileStatus dstStatus;
try {
dstStatus = getFileLinkStatus(dst);
} catch (IOException e) {
dstStatus = null;
}
if (dstStatus != null) {
if (srcStatus.isDirectory() != dstStatus.isDirectory()) {
throw new IOException("Source " + src + " Destination " + dst
+ " both should be either file or directory");
}
if (!overwrite) {
throw new FileAlreadyExistsException("rename destination " + dst
+ " already exists.");
}
// Delete the destination that is a file or an empty directory
if (dstStatus.isDirectory()) {
FileStatus[] list = listStatus(dst);
if (list != null && list.length != 0) {
throw new IOException(
"rename cannot overwrite non empty destination directory " + dst);
}
}
delete(dst, false);
} else {
final Path parent = dst.getParent();
final FileStatus parentStatus = getFileStatus(parent);
if (parentStatus == null) {
throw new FileNotFoundException("rename destination parent " + parent
+ " not found.");
}
if (!parentStatus.isDirectory()) {
throw new ParentNotDirectoryException("rename destination parent " + parent
+ " is a file.");
}
}
if (!rename(src, dst)) {
throw new IOException("rename from " + src + " to " + dst + " failed.");
}
}
/**
* Delete a file
* @deprecated Use {@link #delete(Path, boolean)} instead.
*/
@Deprecated
public boolean delete(Path f) throws IOException {
return delete(f, true);
}
/** Delete a file.
*
* @param f the path to delete.
* @param recursive if path is a directory and set to
* true, the directory is deleted else throws an exception. In
* case of a file the recursive can be set to either true or false.
* @return true if delete is successful else false.
* @throws IOException
*/
public abstract boolean delete(Path f, boolean recursive) throws IOException;
/**
* Mark a path to be deleted when FileSystem is closed.
* When the JVM shuts down,
* all FileSystem objects will be closed automatically.
* Then,
* the marked path will be deleted as a result of closing the FileSystem.
*
* The path has to exist in the file system.
*
* @param f the path to delete.
* @return true if deleteOnExit is successful, otherwise false.
* @throws IOException
*/
public boolean deleteOnExit(Path f) throws IOException {
if (!exists(f)) {
return false;
}
synchronized (deleteOnExit) {
deleteOnExit.add(f);
}
return true;
}
/**
* Cancel the deletion of the path when the FileSystem is closed
* @param f the path to cancel deletion
*/
public boolean cancelDeleteOnExit(Path f) {
synchronized (deleteOnExit) {
return deleteOnExit.remove(f);
}
}
/**
* Delete all files that were marked as delete-on-exit. This recursively
* deletes all files in the specified paths.
*/
protected void processDeleteOnExit() {
synchronized (deleteOnExit) {
for (Iterator<Path> iter = deleteOnExit.iterator(); iter.hasNext();) {
Path path = iter.next();
try {
if (exists(path)) {
delete(path, true);
}
}
catch (IOException e) {
LOG.info("Ignoring failure to deleteOnExit for path " + path);
}
iter.remove();
}
}
}
/** Check if exists.
* @param f source file
*/
public boolean exists(Path f) throws IOException {
try {
return getFileStatus(f) != null;
} catch (FileNotFoundException e) {
return false;
}
}
/** True iff the named path is a directory.
* Note: Avoid using this method. Instead reuse the FileStatus
* returned by getFileStatus() or listStatus() methods.
* @param f path to check
*/
public boolean isDirectory(Path f) throws IOException {
try {
return getFileStatus(f).isDirectory();
} catch (FileNotFoundException e) {
return false; // f does not exist
}
}
/** True iff the named path is a regular file.
* Note: Avoid using this method. Instead reuse the FileStatus
* returned by getFileStatus() or listStatus() methods.
* @param f path to check
*/
public boolean isFile(Path f) throws IOException {
try {
return getFileStatus(f).isFile();
} catch (FileNotFoundException e) {
return false; // f does not exist
}
}
/** The number of bytes in a file. */
/** @deprecated Use getFileStatus() instead */
@Deprecated
public long getLength(Path f) throws IOException {
return getFileStatus(f).getLen();
}
/** Return the {@link ContentSummary} of a given {@link Path}.
* @param f path to use
*/
public ContentSummary getContentSummary(Path f) throws IOException {
FileStatus status = getFileStatus(f);
if (status.isFile()) {
// f is a file
return new ContentSummary(status.getLen(), 1, 0);
}
// f is a directory
long[] summary = {0, 0, 1};
for(FileStatus s : listStatus(f)) {
ContentSummary c = s.isDirectory() ? getContentSummary(s.getPath()) :
new ContentSummary(s.getLen(), 1, 0);
summary[0] += c.getLength();
summary[1] += c.getFileCount();
summary[2] += c.getDirectoryCount();
}
return new ContentSummary(summary[0], summary[1], summary[2]);
}
final private static PathFilter DEFAULT_FILTER = new PathFilter() {
@Override
public boolean accept(Path file) {
return true;
}
};
/**
* List the statuses of the files/directories in the given path if the path is
* a directory.
*
* @param f given path
* @return the statuses of the files/directories in the given patch
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public abstract FileStatus[] listStatus(Path f) throws FileNotFoundException,
IOException;
/*
* Filter files/directories in the given path using the user-supplied path
* filter. Results are added to the given array <code>results</code>.
*/
private void listStatus(ArrayList<FileStatus> results, Path f,
PathFilter filter) throws FileNotFoundException, IOException {
FileStatus listing[] = listStatus(f);
if (listing == null) {
throw new IOException("Error accessing " + f);
}
for (int i = 0; i < listing.length; i++) {
if (filter.accept(listing[i].getPath())) {
results.add(listing[i]);
}
}
}
/**
* @return an iterator over the corrupt files under the given path
* (may contain duplicates if a file has more than one corrupt block)
* @throws IOException
*/
public RemoteIterator<Path> listCorruptFileBlocks(Path path)
throws IOException {
throw new UnsupportedOperationException(getClass().getCanonicalName() +
" does not support" +
" listCorruptFileBlocks");
}
/**
* Filter files/directories in the given path using the user-supplied path
* filter.
*
* @param f
* a path name
* @param filter
* the user-supplied path filter
* @return an array of FileStatus objects for the files under the given path
* after applying the filter
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public FileStatus[] listStatus(Path f, PathFilter filter)
throws FileNotFoundException, IOException {
ArrayList<FileStatus> results = new ArrayList<FileStatus>();
listStatus(results, f, filter);
return results.toArray(new FileStatus[results.size()]);
}
/**
* Filter files/directories in the given list of paths using default
* path filter.
*
* @param files
* a list of paths
* @return a list of statuses for the files under the given paths after
* applying the filter default Path filter
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public FileStatus[] listStatus(Path[] files)
throws FileNotFoundException, IOException {
return listStatus(files, DEFAULT_FILTER);
}
/**
* Filter files/directories in the given list of paths using user-supplied
* path filter.
*
* @param files
* a list of paths
* @param filter
* the user-supplied path filter
* @return a list of statuses for the files under the given paths after
* applying the filter
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public FileStatus[] listStatus(Path[] files, PathFilter filter)
throws FileNotFoundException, IOException {
ArrayList<FileStatus> results = new ArrayList<FileStatus>();
for (int i = 0; i < files.length; i++) {
listStatus(results, files[i], filter);
}
return results.toArray(new FileStatus[results.size()]);
}
/**
* <p>Return all the files that match filePattern and are not checksum
* files. Results are sorted by their names.
*
* <p>
* A filename pattern is composed of <i>regular</i> characters and
* <i>special pattern matching</i> characters, which are:
*
* <dl>
* <dd>
* <dl>
* <p>
* <dt> <tt> ? </tt>
* <dd> Matches any single character.
*
* <p>
* <dt> <tt> * </tt>
* <dd> Matches zero or more characters.
*
* <p>
* <dt> <tt> [<i>abc</i>] </tt>
* <dd> Matches a single character from character set
* <tt>{<i>a,b,c</i>}</tt>.
*
* <p>
* <dt> <tt> [<i>a</i>-<i>b</i>] </tt>
* <dd> Matches a single character from the character range
* <tt>{<i>a...b</i>}</tt>. Note that character <tt><i>a</i></tt> must be
* lexicographically less than or equal to character <tt><i>b</i></tt>.
*
* <p>
* <dt> <tt> [^<i>a</i>] </tt>
* <dd> Matches a single character that is not from character set or range
* <tt>{<i>a</i>}</tt>. Note that the <tt>^</tt> character must occur
* immediately to the right of the opening bracket.
*
* <p>
* <dt> <tt> \<i>c</i> </tt>
* <dd> Removes (escapes) any special meaning of character <i>c</i>.
*
* <p>
* <dt> <tt> {ab,cd} </tt>
* <dd> Matches a string from the string set <tt>{<i>ab, cd</i>} </tt>
*
* <p>
* <dt> <tt> {ab,c{de,fh}} </tt>
* <dd> Matches a string from the string set <tt>{<i>ab, cde, cfh</i>}</tt>
*
* </dl>
* </dd>
* </dl>
*
* @param pathPattern a regular expression specifying a pth pattern
* @return an array of paths that match the path pattern
* @throws IOException
*/
public FileStatus[] globStatus(Path pathPattern) throws IOException {
return new Globber(this, pathPattern, DEFAULT_FILTER).glob();
}
/**
* Return an array of FileStatus objects whose path names match pathPattern
* and is accepted by the user-supplied path filter. Results are sorted by
* their path names.
* Return null if pathPattern has no glob and the path does not exist.
* Return an empty array if pathPattern has a glob and no path matches it.
*
* @param pathPattern
* a regular expression specifying the path pattern
* @param filter
* a user-supplied path filter
* @return an array of FileStatus objects
* @throws IOException if any I/O error occurs when fetching file status
*/
public FileStatus[] globStatus(Path pathPattern, PathFilter filter)
throws IOException {
return new Globber(this, pathPattern, filter).glob();
}
/**
* List the statuses of the files/directories in the given path if the path is
* a directory.
* Return the file's status and block locations If the path is a file.
*
* If a returned status is a file, it contains the file's block locations.
*
* @param f is the path
*
* @return an iterator that traverses statuses of the files/directories
* in the given path
*
* @throws FileNotFoundException If <code>f</code> does not exist
* @throws IOException If an I/O error occurred
*/
public RemoteIterator<LocatedFileStatus> listLocatedStatus(final Path f)
throws FileNotFoundException, IOException {
return listLocatedStatus(f, DEFAULT_FILTER);
}
/**
* Listing a directory
* The returned results include its block location if it is a file
* The results are filtered by the given path filter
* @param f a path
* @param filter a path filter
* @return an iterator that traverses statuses of the files/directories
* in the given path
* @throws FileNotFoundException if <code>f</code> does not exist
* @throws IOException if any I/O error occurred
*/
protected RemoteIterator<LocatedFileStatus> listLocatedStatus(final Path f,
final PathFilter filter)
throws FileNotFoundException, IOException {
return new RemoteIterator<LocatedFileStatus>() {
private final FileStatus[] stats = listStatus(f, filter);
private int i = 0;
@Override
public boolean hasNext() {
return i<stats.length;
}
@Override
public LocatedFileStatus next() throws IOException {
if (!hasNext()) {
throw new NoSuchElementException("No more entry in " + f);
}
FileStatus result = stats[i++];
BlockLocation[] locs = result.isFile() ?
getFileBlockLocations(result.getPath(), 0, result.getLen()) :
null;
return new LocatedFileStatus(result, locs);
}
};
}
/**
* List the statuses and block locations of the files in the given path.
*
* If the path is a directory,
* if recursive is false, returns files in the directory;
* if recursive is true, return files in the subtree rooted at the path.
* If the path is a file, return the file's status and block locations.
*
* @param f is the path
* @param recursive if the subdirectories need to be traversed recursively
*
* @return an iterator that traverses statuses of the files
*
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public RemoteIterator<LocatedFileStatus> listFiles(
final Path f, final boolean recursive)
throws FileNotFoundException, IOException {
return new RemoteIterator<LocatedFileStatus>() {
private Stack<RemoteIterator<LocatedFileStatus>> itors =
new Stack<RemoteIterator<LocatedFileStatus>>();
private RemoteIterator<LocatedFileStatus> curItor =
listLocatedStatus(f);
private LocatedFileStatus curFile;
@Override
public boolean hasNext() throws IOException {
while (curFile == null) {
if (curItor.hasNext()) {
handleFileStat(curItor.next());
} else if (!itors.empty()) {
curItor = itors.pop();
} else {
return false;
}
}
return true;
}
/**
* Process the input stat.
* If it is a file, return the file stat.
* If it is a directory, traverse the directory if recursive is true;
* ignore it if recursive is false.
* @param stat input status
* @throws IOException if any IO error occurs
*/
private void handleFileStat(LocatedFileStatus stat) throws IOException {
if (stat.isFile()) { // file
curFile = stat;
} else if (recursive) { // directory
itors.push(curItor);
curItor = listLocatedStatus(stat.getPath());
}
}
@Override
public LocatedFileStatus next() throws IOException {
if (hasNext()) {
LocatedFileStatus result = curFile;
curFile = null;
return result;
}
throw new java.util.NoSuchElementException("No more entry in " + f);
}
};
}
/** Return the current user's home directory in this filesystem.
* The default implementation returns "/user/$USER/".
*/
public Path getHomeDirectory() {
return this.makeQualified(
new Path("/user/"+System.getProperty("user.name")));
}
/**
* Set the current working directory for the given file system. All relative
* paths will be resolved relative to it.
*
* @param new_dir
*/
public abstract void setWorkingDirectory(Path new_dir);
/**
* Get the current working directory for the given file system
* @return the directory pathname
*/
public abstract Path getWorkingDirectory();
/**
* Note: with the new FilesContext class, getWorkingDirectory()
* will be removed.
* The working directory is implemented in FilesContext.
*
* Some file systems like LocalFileSystem have an initial workingDir
* that we use as the starting workingDir. For other file systems
* like HDFS there is no built in notion of an initial workingDir.
*
* @return if there is built in notion of workingDir then it
* is returned; else a null is returned.
*/
protected Path getInitialWorkingDirectory() {
return null;
}
/**
* Call {@link #mkdirs(Path, FsPermission)} with default permission.
*/
public boolean mkdirs(Path f) throws IOException {
return mkdirs(f, FsPermission.getDirDefault());
}
/**
* Make the given file and all non-existent parents into
* directories. Has the semantics of Unix 'mkdir -p'.
* Existence of the directory hierarchy is not an error.
* @param f path to create
* @param permission to apply to f
*/
public abstract boolean mkdirs(Path f, FsPermission permission
) throws IOException;
/**
* The src file is on the local disk. Add it to FS at
* the given dst name and the source is kept intact afterwards
* @param src path
* @param dst path
*/
public void copyFromLocalFile(Path src, Path dst)
throws IOException {
copyFromLocalFile(false, src, dst);
}
/**
* The src files is on the local disk. Add it to FS at
* the given dst name, removing the source afterwards.
* @param srcs path
* @param dst path
*/
public void moveFromLocalFile(Path[] srcs, Path dst)
throws IOException {
copyFromLocalFile(true, true, srcs, dst);
}
/**
* The src file is on the local disk. Add it to FS at
* the given dst name, removing the source afterwards.
* @param src path
* @param dst path
*/
public void moveFromLocalFile(Path src, Path dst)
throws IOException {
copyFromLocalFile(true, src, dst);
}
/**
* The src file is on the local disk. Add it to FS at
* the given dst name.
* delSrc indicates if the source should be removed
* @param delSrc whether to delete the src
* @param src path
* @param dst path
*/
public void copyFromLocalFile(boolean delSrc, Path src, Path dst)
throws IOException {
copyFromLocalFile(delSrc, true, src, dst);
}
/**
* The src files are on the local disk. Add it to FS at
* the given dst name.
* delSrc indicates if the source should be removed
* @param delSrc whether to delete the src
* @param overwrite whether to overwrite an existing file
* @param srcs array of paths which are source
* @param dst path
*/
public void copyFromLocalFile(boolean delSrc, boolean overwrite,
Path[] srcs, Path dst)
throws IOException {
Configuration conf = getConf();
FileUtil.copy(getLocal(conf), srcs, this, dst, delSrc, overwrite, conf);
}
/**
* The src file is on the local disk. Add it to FS at
* the given dst name.
* delSrc indicates if the source should be removed
* @param delSrc whether to delete the src
* @param overwrite whether to overwrite an existing file
* @param src path
* @param dst path
*/
public void copyFromLocalFile(boolean delSrc, boolean overwrite,
Path src, Path dst)
throws IOException {
Configuration conf = getConf();
FileUtil.copy(getLocal(conf), src, this, dst, delSrc, overwrite, conf);
}
/**
* The src file is under FS, and the dst is on the local disk.
* Copy it from FS control to the local dst name.
* @param src path
* @param dst path
*/
public void copyToLocalFile(Path src, Path dst) throws IOException {
copyToLocalFile(false, src, dst);
}
/**
* The src file is under FS, and the dst is on the local disk.
* Copy it from FS control to the local dst name.
* Remove the source afterwards
* @param src path
* @param dst path
*/
public void moveToLocalFile(Path src, Path dst) throws IOException {
copyToLocalFile(true, src, dst);
}
/**
* The src file is under FS, and the dst is on the local disk.
* Copy it from FS control to the local dst name.
* delSrc indicates if the src will be removed or not.
* @param delSrc whether to delete the src
* @param src path
* @param dst path
*/
public void copyToLocalFile(boolean delSrc, Path src, Path dst)
throws IOException {
copyToLocalFile(delSrc, src, dst, false);
}
/**
* The src file is under FS, and the dst is on the local disk. Copy it from FS
* control to the local dst name. delSrc indicates if the src will be removed
* or not. useRawLocalFileSystem indicates whether to use RawLocalFileSystem
* as local file system or not. RawLocalFileSystem is non crc file system.So,
* It will not create any crc files at local.
*
* @param delSrc
* whether to delete the src
* @param src
* path
* @param dst
* path
* @param useRawLocalFileSystem
* whether to use RawLocalFileSystem as local file system or not.
*
* @throws IOException
* - if any IO error
*/
public void copyToLocalFile(boolean delSrc, Path src, Path dst,
boolean useRawLocalFileSystem) throws IOException {
Configuration conf = getConf();
FileSystem local = null;
if (useRawLocalFileSystem) {
local = getLocal(conf).getRawFileSystem();
} else {
local = getLocal(conf);
}
FileUtil.copy(this, src, local, dst, delSrc, conf);
}
/**
* Returns a local File that the user can write output to. The caller
* provides both the eventual FS target name and the local working
* file. If the FS is local, we write directly into the target. If
* the FS is remote, we write into the tmp local area.
* @param fsOutputFile path of output file
* @param tmpLocalFile path of local tmp file
*/
public Path startLocalOutput(Path fsOutputFile, Path tmpLocalFile)
throws IOException {
return tmpLocalFile;
}
/**
* Called when we're all done writing to the target. A local FS will
* do nothing, because we've written to exactly the right place. A remote
* FS will copy the contents of tmpLocalFile to the correct target at
* fsOutputFile.
* @param fsOutputFile path of output file
* @param tmpLocalFile path to local tmp file
*/
public void completeLocalOutput(Path fsOutputFile, Path tmpLocalFile)
throws IOException {
moveFromLocalFile(tmpLocalFile, fsOutputFile);
}
/**
* No more filesystem operations are needed. Will
* release any held locks.
*/
@Override
public void close() throws IOException {
// delete all files that were marked as delete-on-exit.
processDeleteOnExit();
CACHE.remove(this.key, this);
}
/** Return the total size of all files in the filesystem.*/
public long getUsed() throws IOException{
long used = 0;
FileStatus[] files = listStatus(new Path("/"));
for(FileStatus file:files){
used += file.getLen();
}
return used;
}
/**
* Get the block size for a particular file.
* @param f the filename
* @return the number of bytes in a block
*/
/** @deprecated Use getFileStatus() instead */
@Deprecated
public long getBlockSize(Path f) throws IOException {
return getFileStatus(f).getBlockSize();
}
/**
* Return the number of bytes that large input files should be optimally
* be split into to minimize i/o time.
* @deprecated use {@link #getDefaultBlockSize(Path)} instead
*/
@Deprecated
public long getDefaultBlockSize() {
// default to 32MB: large enough to minimize the impact of seeks
return getConf().getLong("fs.local.block.size", 32 * 1024 * 1024);
}
/** Return the number of bytes that large input files should be optimally
* be split into to minimize i/o time. The given path will be used to
* locate the actual filesystem. The full path does not have to exist.
* @param f path of file
* @return the default block size for the path's filesystem
*/
public long getDefaultBlockSize(Path f) {
return getDefaultBlockSize();
}
/**
* Get the default replication.
* @deprecated use {@link #getDefaultReplication(Path)} instead
*/
@Deprecated
public short getDefaultReplication() { return 1; }
/**
* Get the default replication for a path. The given path will be used to
* locate the actual filesystem. The full path does not have to exist.
* @param path of the file
* @return default replication for the path's filesystem
*/
public short getDefaultReplication(Path path) {
return getDefaultReplication();
}
/**
* Return a file status object that represents the path.
* @param f The path we want information from
* @return a FileStatus object
* @throws FileNotFoundException when the path does not exist;
* IOException see specific implementation
*/
public abstract FileStatus getFileStatus(Path f) throws IOException;
/**
* See {@link FileContext#fixRelativePart}
*/
protected Path fixRelativePart(Path p) {
if (p.isUriPathAbsolute()) {
return p;
} else {
return new Path(getWorkingDirectory(), p);
}
}
/**
* See {@link FileContext#createSymlink(Path, Path, boolean)}
*/
public void createSymlink(final Path target, final Path link,
final boolean createParent) throws AccessControlException,
FileAlreadyExistsException, FileNotFoundException,
ParentNotDirectoryException, UnsupportedFileSystemException,
IOException {
// Supporting filesystems should override this method
throw new UnsupportedOperationException(
"Filesystem does not support symlinks!");
}
/**
* See {@link FileContext#getFileLinkStatus(Path)}
*/
public FileStatus getFileLinkStatus(final Path f)
throws AccessControlException, FileNotFoundException,
UnsupportedFileSystemException, IOException {
// Supporting filesystems should override this method
return getFileStatus(f);
}
/**
* See {@link AbstractFileSystem#supportsSymlinks()}
*/
public boolean supportsSymlinks() {
return false;
}
/**
* See {@link FileContext#getLinkTarget(Path)}
*/
public Path getLinkTarget(Path f) throws IOException {
// Supporting filesystems should override this method
throw new UnsupportedOperationException(
"Filesystem does not support symlinks!");
}
/**
* See {@link AbstractFileSystem#getLinkTarget(Path)}
*/
protected Path resolveLink(Path f) throws IOException {
// Supporting filesystems should override this method
throw new UnsupportedOperationException(
"Filesystem does not support symlinks!");
}
/**
* Get the checksum of a file.
*
* @param f The file path
* @return The file checksum. The default return value is null,
* which indicates that no checksum algorithm is implemented
* in the corresponding FileSystem.
*/
public FileChecksum getFileChecksum(Path f) throws IOException {
return getFileChecksum(f, Long.MAX_VALUE);
}
/**
* Get the checksum of a file, from the beginning of the file till the
* specific length.
* @param f The file path
* @param length The length of the file range for checksum calculation
* @return The file checksum.
*/
public FileChecksum getFileChecksum(Path f, final long length)
throws IOException {
return null;
}
/**
* Set the verify checksum flag. This is only applicable if the
* corresponding FileSystem supports checksum. By default doesn't do anything.
* @param verifyChecksum
*/
public void setVerifyChecksum(boolean verifyChecksum) {
//doesn't do anything
}
/**
* Set the write checksum flag. This is only applicable if the
* corresponding FileSystem supports checksum. By default doesn't do anything.
* @param writeChecksum
*/
public void setWriteChecksum(boolean writeChecksum) {
//doesn't do anything
}
/**
* Returns a status object describing the use and capacity of the
* file system. If the file system has multiple partitions, the
* use and capacity of the root partition is reflected.
*
* @return a FsStatus object
* @throws IOException
* see specific implementation
*/
public FsStatus getStatus() throws IOException {
return getStatus(null);
}
/**
* Returns a status object describing the use and capacity of the
* file system. If the file system has multiple partitions, the
* use and capacity of the partition pointed to by the specified
* path is reflected.
* @param p Path for which status should be obtained. null means
* the default partition.
* @return a FsStatus object
* @throws IOException
* see specific implementation
*/
public FsStatus getStatus(Path p) throws IOException {
return new FsStatus(Long.MAX_VALUE, 0, Long.MAX_VALUE);
}
/**
* Set permission of a path.
* @param p
* @param permission
*/
public void setPermission(Path p, FsPermission permission
) throws IOException {
}
/**
* Set owner of a path (i.e. a file or a directory).
* The parameters username and groupname cannot both be null.
* @param p The path
* @param username If it is null, the original username remains unchanged.
* @param groupname If it is null, the original groupname remains unchanged.
*/
public void setOwner(Path p, String username, String groupname
) throws IOException {
}
/**
* Set access time of a file
* @param p The path
* @param mtime Set the modification time of this file.
* The number of milliseconds since Jan 1, 1970.
* A value of -1 means that this call should not set modification time.
* @param atime Set the access time of this file.
* The number of milliseconds since Jan 1, 1970.
* A value of -1 means that this call should not set access time.
*/
public void setTimes(Path p, long mtime, long atime
) throws IOException {
}
/**
* Create a snapshot with a default name.
* @param path The directory where snapshots will be taken.
* @return the snapshot path.
*/
public final Path createSnapshot(Path path) throws IOException {
return createSnapshot(path, null);
}
/**
* Create a snapshot
* @param path The directory where snapshots will be taken.
* @param snapshotName The name of the snapshot
* @return the snapshot path.
*/
public Path createSnapshot(Path path, String snapshotName)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support createSnapshot");
}
/**
* Rename a snapshot
* @param path The directory path where the snapshot was taken
* @param snapshotOldName Old name of the snapshot
* @param snapshotNewName New name of the snapshot
* @throws IOException
*/
public void renameSnapshot(Path path, String snapshotOldName,
String snapshotNewName) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support renameSnapshot");
}
/**
* Delete a snapshot of a directory
* @param path The directory that the to-be-deleted snapshot belongs to
* @param snapshotName The name of the snapshot
*/
public void deleteSnapshot(Path path, String snapshotName)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support deleteSnapshot");
}
/**
* Modifies ACL entries of files and directories. This method can add new ACL
* entries or modify the permissions on existing ACL entries. All existing
* ACL entries that are not specified in this call are retained without
* changes. (Modifications are merged into the current ACL.)
*
* @param path Path to modify
* @param aclSpec List<AclEntry> describing modifications
* @throws IOException if an ACL could not be modified
*/
public void modifyAclEntries(Path path, List<AclEntry> aclSpec)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support modifyAclEntries");
}
/**
* Removes ACL entries from files and directories. Other ACL entries are
* retained.
*
* @param path Path to modify
* @param aclSpec List<AclEntry> describing entries to remove
* @throws IOException if an ACL could not be modified
*/
public void removeAclEntries(Path path, List<AclEntry> aclSpec)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support removeAclEntries");
}
/**
* Removes all default ACL entries from files and directories.
*
* @param path Path to modify
* @throws IOException if an ACL could not be modified
*/
public void removeDefaultAcl(Path path)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support removeDefaultAcl");
}
/**
* Removes all but the base ACL entries of files and directories. The entries
* for user, group, and others are retained for compatibility with permission
* bits.
*
* @param path Path to modify
* @throws IOException if an ACL could not be removed
*/
public void removeAcl(Path path)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support removeAcl");
}
/**
* Fully replaces ACL of files and directories, discarding all existing
* entries.
*
* @param path Path to modify
* @param aclSpec List<AclEntry> describing modifications, must include entries
* for user, group, and others for compatibility with permission bits.
* @throws IOException if an ACL could not be modified
*/
public void setAcl(Path path, List<AclEntry> aclSpec) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support setAcl");
}
/**
* Gets the ACL of a file or directory.
*
* @param path Path to get
* @return AclStatus describing the ACL of the file or directory
* @throws IOException if an ACL could not be read
*/
public AclStatus getAclStatus(Path path) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support getAclStatus");
}
/**
* Set an xattr of a file or directory.
* The name must be prefixed with user/trusted/security/system and
* followed by ".". For example, "user.attr".
* <p/>
* A regular user can only set an xattr for the "user" namespace.
* The super user can set an xattr of either the "user" or "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* The access permissions of an xattr in the "user" namespace are
* defined by the file and directory permission bits.
* An xattr can only be set when the logged-in user has the correct permissions.
* If the xattr exists, it will be replaced.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to modify
* @param name xattr name.
* @param value xattr value.
* @throws IOException
*/
public void setXAttr(Path path, String name, byte[] value)
throws IOException {
setXAttr(path, name, value, EnumSet.of(XAttrSetFlag.CREATE,
XAttrSetFlag.REPLACE));
}
/**
* Set an xattr of a file or directory.
* The name must be prefixed with user/trusted/security/system and
* followed by ".". For example, "user.attr".
* <p/>
* A regular user can only set an xattr for the "user" namespace.
* The super user can set an xattr of either the "user" or "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* The access permissions of an xattr in the "user" namespace are
* defined by the file and directory permission bits.
* An xattr can only be set if the logged-in user has the correct permissions.
* If the xattr exists, it is replaced.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to modify
* @param name xattr name.
* @param value xattr value.
* @param flag xattr set flag
* @throws IOException
*/
public void setXAttr(Path path, String name, byte[] value,
EnumSet<XAttrSetFlag> flag) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support setXAttr");
}
/**
* Get an xattr name and value for a file or directory.
* The name must be prefixed with user/trusted/security/system and
* followed by ".". For example, "user.attr".
* <p/>
*
* A regular user can only get an xattr for the "user" namespace.
* The super user can get an xattr of either the "user" or "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* An xattr will only be returned if the logged-in user has the
* correct permissions.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to get extended attribute
* @param name xattr name.
* @return byte[] xattr value.
* @throws IOException
*/
public byte[] getXAttr(Path path, String name) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support getXAttr");
}
/**
* Get all of the xattr name/value pairs for a file or directory.
* Only those xattrs which the logged-in user has permissions to view
* are returned.
* <p/>
* A regular user can only get xattrs for the "user" namespace.
* The super user can only get xattrs for "user" and "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to get extended attributes
* @return Map<String, byte[]> describing the XAttrs of the file or directory
* @throws IOException
*/
public Map<String, byte[]> getXAttrs(Path path) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support getXAttrs");
}
/**
* Get all of the xattrs name/value pairs for a file or directory.
* Only those xattrs which the logged-in user has permissions to view
* are returned.
* <p/>
* A regular user can only get xattrs for the "user" namespace.
* The super user can only get xattrs for "user" and "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to get extended attributes
* @param names XAttr names.
* @return Map<String, byte[]> describing the XAttrs of the file or directory
* @throws IOException
*/
public Map<String, byte[]> getXAttrs(Path path, List<String> names)
throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support getXAttrs");
}
/**
* Get all of the xattr names for a file or directory.
* Only those xattr names which the logged-in user has permissions to view
* are returned.
* <p/>
* A regular user can only get xattr names for the "user" namespace.
* The super user can only get xattr names for "user" and "trusted"
* namespaces.
* The xattrs of the "security" and "system" namespaces are only
* used/exposed internally by/to the FS impl.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to get extended attributes
* @return Map<String, byte[]> describing the XAttrs of the file or directory
* @throws IOException
*/
public List<String> listXAttrs(Path path) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support listXAttrs");
}
/**
* Remove an xattr of a file or directory.
* The name must be prefixed with user/trusted/security/system and
* followed by ".". For example, "user.attr".
* <p/>
* A regular user can only remove an xattr for the "user" namespace.
* The super user can remove an xattr of either the "user" or "trusted" namespaces.
* The xattrs of the "security" and "system" namespaces are only used/exposed
* internally by/to the FS impl.
* <p/>
* The access permissions of an xattr in the "user" namespace are
* defined by the file and directory permission bits.
* An xattr can only be set when the logged-in user has the correct permissions.
* If the xattr exists, it will be replaced.
* <p/>
* @see <a href="http://en.wikipedia.org/wiki/Extended_file_attributes">
* http://en.wikipedia.org/wiki/Extended_file_attributes</a>
*
* @param path Path to remove extended attribute
* @param name xattr name
* @throws IOException
*/
public void removeXAttr(Path path, String name) throws IOException {
throw new UnsupportedOperationException(getClass().getSimpleName()
+ " doesn't support removeXAttr");
}
// making it volatile to be able to do a double checked locking
private volatile static boolean FILE_SYSTEMS_LOADED = false;
private static final Map<String, Class<? extends FileSystem>>
SERVICE_FILE_SYSTEMS = new HashMap<String, Class<? extends FileSystem>>();
private static void loadFileSystems() {
synchronized (FileSystem.class) {
if (!FILE_SYSTEMS_LOADED) {
ServiceLoader<FileSystem> serviceLoader = ServiceLoader.load(FileSystem.class);
for (FileSystem fs : serviceLoader) {
SERVICE_FILE_SYSTEMS.put(fs.getScheme(), fs.getClass());
}
FILE_SYSTEMS_LOADED = true;
}
}
}
public static Class<? extends FileSystem> getFileSystemClass(String scheme,
Configuration conf) throws IOException {
if (!FILE_SYSTEMS_LOADED) {
loadFileSystems();
}
Class<? extends FileSystem> clazz = null;
if (conf != null) {
clazz = (Class<? extends FileSystem>) conf.getClass("fs." + scheme + ".impl", null);
}
if (clazz == null) {
clazz = SERVICE_FILE_SYSTEMS.get(scheme);
}
if (clazz == null) {
throw new IOException("No FileSystem for scheme: " + scheme);
}
return clazz;
}
private static FileSystem createFileSystem(URI uri, Configuration conf
) throws IOException {
Class<?> clazz = getFileSystemClass(uri.getScheme(), conf);
if (clazz == null) {
throw new IOException("No FileSystem for scheme: " + uri.getScheme());
}
FileSystem fs = (FileSystem)ReflectionUtils.newInstance(clazz, conf);
fs.initialize(uri, conf);
return fs;
}
/** Caching FileSystem objects */
static class Cache {
private final ClientFinalizer clientFinalizer = new ClientFinalizer();
private final Map<Key, FileSystem> map = new HashMap<Key, FileSystem>();
private final Set<Key> toAutoClose = new HashSet<Key>();
/** A variable that makes all objects in the cache unique */
private static AtomicLong unique = new AtomicLong(1);
FileSystem get(URI uri, Configuration conf) throws IOException{
Key key = new Key(uri, conf);
return getInternal(uri, conf, key);
}
/** The objects inserted into the cache using this method are all unique */
FileSystem getUnique(URI uri, Configuration conf) throws IOException{
Key key = new Key(uri, conf, unique.getAndIncrement());
return getInternal(uri, conf, key);
}
private FileSystem getInternal(URI uri, Configuration conf, Key key) throws IOException{
FileSystem fs;
synchronized (this) {
fs = map.get(key);
}
if (fs != null) {
return fs;
}
fs = createFileSystem(uri, conf);
synchronized (this) { // refetch the lock again
FileSystem oldfs = map.get(key);
if (oldfs != null) { // a file system is created while lock is releasing
fs.close(); // close the new file system
return oldfs; // return the old file system
}
// now insert the new file system into the map
if (map.isEmpty()
&& !ShutdownHookManager.get().isShutdownInProgress()) {
ShutdownHookManager.get().addShutdownHook(clientFinalizer, SHUTDOWN_HOOK_PRIORITY);
}
fs.key = key;
map.put(key, fs);
if (conf.getBoolean("fs.automatic.close", true)) {
toAutoClose.add(key);
}
return fs;
}
}
synchronized void remove(Key key, FileSystem fs) {
if (map.containsKey(key) && fs == map.get(key)) {
map.remove(key);
toAutoClose.remove(key);
}
}
synchronized void closeAll() throws IOException {
closeAll(false);
}
/**
* Close all FileSystem instances in the Cache.
* @param onlyAutomatic only close those that are marked for automatic closing
*/
synchronized void closeAll(boolean onlyAutomatic) throws IOException {
List<IOException> exceptions = new ArrayList<IOException>();
// Make a copy of the keys in the map since we'll be modifying
// the map while iterating over it, which isn't safe.
List<Key> keys = new ArrayList<Key>();
keys.addAll(map.keySet());
for (Key key : keys) {
final FileSystem fs = map.get(key);
if (onlyAutomatic && !toAutoClose.contains(key)) {
continue;
}
//remove from cache
remove(key, fs);
if (fs != null) {
try {
fs.close();
}
catch(IOException ioe) {
exceptions.add(ioe);
}
}
}
if (!exceptions.isEmpty()) {
throw MultipleIOException.createIOException(exceptions);
}
}
private class ClientFinalizer implements Runnable {
@Override
public synchronized void run() {
try {
closeAll(true);
} catch (IOException e) {
LOG.info("FileSystem.Cache.closeAll() threw an exception:\n" + e);
}
}
}
synchronized void closeAll(UserGroupInformation ugi) throws IOException {
List<FileSystem> targetFSList = new ArrayList<FileSystem>();
//Make a pass over the list and collect the filesystems to close
//we cannot close inline since close() removes the entry from the Map
for (Map.Entry<Key, FileSystem> entry : map.entrySet()) {
final Key key = entry.getKey();
final FileSystem fs = entry.getValue();
if (ugi.equals(key.ugi) && fs != null) {
targetFSList.add(fs);
}
}
List<IOException> exceptions = new ArrayList<IOException>();
//now make a pass over the target list and close each
for (FileSystem fs : targetFSList) {
try {
fs.close();
}
catch(IOException ioe) {
exceptions.add(ioe);
}
}
if (!exceptions.isEmpty()) {
throw MultipleIOException.createIOException(exceptions);
}
}
/** FileSystem.Cache.Key */
static class Key {
final String scheme;
final String authority;
final UserGroupInformation ugi;
final long unique; // an artificial way to make a key unique
Key(URI uri, Configuration conf) throws IOException {
this(uri, conf, 0);
}
Key(URI uri, Configuration conf, long unique) throws IOException {
scheme = uri.getScheme()==null?"":uri.getScheme().toLowerCase();
authority = uri.getAuthority()==null?"":uri.getAuthority().toLowerCase();
this.unique = unique;
this.ugi = UserGroupInformation.getCurrentUser();
}
@Override
public int hashCode() {
return (scheme + authority).hashCode() + ugi.hashCode() + (int)unique;
}
static boolean isEqual(Object a, Object b) {
return a == b || (a != null && a.equals(b));
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj != null && obj instanceof Key) {
Key that = (Key)obj;
return isEqual(this.scheme, that.scheme)
&& isEqual(this.authority, that.authority)
&& isEqual(this.ugi, that.ugi)
&& (this.unique == that.unique);
}
return false;
}
@Override
public String toString() {
return "("+ugi.toString() + ")@" + scheme + "://" + authority;
}
}
}
/**
* Tracks statistics about how many reads, writes, and so forth have been
* done in a FileSystem.
*
* Since there is only one of these objects per FileSystem, there will
* typically be many threads writing to this object. Almost every operation
* on an open file will involve a write to this object. In contrast, reading
* statistics is done infrequently by most programs, and not at all by others.
* Hence, this is optimized for writes.
*
* Each thread writes to its own thread-local area of memory. This removes
* contention and allows us to scale up to many, many threads. To read
* statistics, the reader thread totals up the contents of all of the
* thread-local data areas.
*/
public static final class Statistics {
/**
* Statistics data.
*
* There is only a single writer to thread-local StatisticsData objects.
* Hence, volatile is adequate here-- we do not need AtomicLong or similar
* to prevent lost updates.
* The Java specification guarantees that updates to volatile longs will
* be perceived as atomic with respect to other threads, which is all we
* need.
*/
public static class StatisticsData {
volatile long bytesRead;
volatile long bytesWritten;
volatile int readOps;
volatile int largeReadOps;
volatile int writeOps;
/**
* Stores a weak reference to the thread owning this StatisticsData.
* This allows us to remove StatisticsData objects that pertain to
* threads that no longer exist.
*/
final WeakReference<Thread> owner;
StatisticsData(WeakReference<Thread> owner) {
this.owner = owner;
}
/**
* Add another StatisticsData object to this one.
*/
void add(StatisticsData other) {
this.bytesRead += other.bytesRead;
this.bytesWritten += other.bytesWritten;
this.readOps += other.readOps;
this.largeReadOps += other.largeReadOps;
this.writeOps += other.writeOps;
}
/**
* Negate the values of all statistics.
*/
void negate() {
this.bytesRead = -this.bytesRead;
this.bytesWritten = -this.bytesWritten;
this.readOps = -this.readOps;
this.largeReadOps = -this.largeReadOps;
this.writeOps = -this.writeOps;
}
@Override
public String toString() {
return bytesRead + " bytes read, " + bytesWritten + " bytes written, "
+ readOps + " read ops, " + largeReadOps + " large read ops, "
+ writeOps + " write ops";
}
public long getBytesRead() {
return bytesRead;
}
public long getBytesWritten() {
return bytesWritten;
}
public int getReadOps() {
return readOps;
}
public int getLargeReadOps() {
return largeReadOps;
}
public int getWriteOps() {
return writeOps;
}
}
private interface StatisticsAggregator<T> {
void accept(StatisticsData data);
T aggregate();
}
private final String scheme;
/**
* rootData is data that doesn't belong to any thread, but will be added
* to the totals. This is useful for making copies of Statistics objects,
* and for storing data that pertains to threads that have been garbage
* collected. Protected by the Statistics lock.
*/
private final StatisticsData rootData;
/**
* Thread-local data.
*/
private final ThreadLocal<StatisticsData> threadData;
/**
* List of all thread-local data areas. Protected by the Statistics lock.
*/
private LinkedList<StatisticsData> allData;
public Statistics(String scheme) {
this.scheme = scheme;
this.rootData = new StatisticsData(null);
this.threadData = new ThreadLocal<StatisticsData>();
this.allData = null;
}
/**
* Copy constructor.
*
* @param other The input Statistics object which is cloned.
*/
public Statistics(Statistics other) {
this.scheme = other.scheme;
this.rootData = new StatisticsData(null);
other.visitAll(new StatisticsAggregator<Void>() {
@Override
public void accept(StatisticsData data) {
rootData.add(data);
}
public Void aggregate() {
return null;
}
});
this.threadData = new ThreadLocal<StatisticsData>();
}
/**
* Get or create the thread-local data associated with the current thread.
*/
public StatisticsData getThreadStatistics() {
StatisticsData data = threadData.get();
if (data == null) {
data = new StatisticsData(
new WeakReference<Thread>(Thread.currentThread()));
threadData.set(data);
synchronized(this) {
if (allData == null) {
allData = new LinkedList<StatisticsData>();
}
allData.add(data);
}
}
return data;
}
/**
* Increment the bytes read in the statistics
* @param newBytes the additional bytes read
*/
public void incrementBytesRead(long newBytes) {
getThreadStatistics().bytesRead += newBytes;
}
/**
* Increment the bytes written in the statistics
* @param newBytes the additional bytes written
*/
public void incrementBytesWritten(long newBytes) {
getThreadStatistics().bytesWritten += newBytes;
}
/**
* Increment the number of read operations
* @param count number of read operations
*/
public void incrementReadOps(int count) {
getThreadStatistics().readOps += count;
}
/**
* Increment the number of large read operations
* @param count number of large read operations
*/
public void incrementLargeReadOps(int count) {
getThreadStatistics().largeReadOps += count;
}
/**
* Increment the number of write operations
* @param count number of write operations
*/
public void incrementWriteOps(int count) {
getThreadStatistics().writeOps += count;
}
/**
* Apply the given aggregator to all StatisticsData objects associated with
* this Statistics object.
*
* For each StatisticsData object, we will call accept on the visitor.
* Finally, at the end, we will call aggregate to get the final total.
*
* @param The visitor to use.
* @return The total.
*/
private synchronized <T> T visitAll(StatisticsAggregator<T> visitor) {
visitor.accept(rootData);
if (allData != null) {
for (Iterator<StatisticsData> iter = allData.iterator();
iter.hasNext(); ) {
StatisticsData data = iter.next();
visitor.accept(data);
if (data.owner.get() == null) {
/*
* If the thread that created this thread-local data no
* longer exists, remove the StatisticsData from our list
* and fold the values into rootData.
*/
rootData.add(data);
iter.remove();
}
}
}
return visitor.aggregate();
}
/**
* Get the total number of bytes read
* @return the number of bytes
*/
public long getBytesRead() {
return visitAll(new StatisticsAggregator<Long>() {
private long bytesRead = 0;
@Override
public void accept(StatisticsData data) {
bytesRead += data.bytesRead;
}
public Long aggregate() {
return bytesRead;
}
});
}
/**
* Get the total number of bytes written
* @return the number of bytes
*/
public long getBytesWritten() {
return visitAll(new StatisticsAggregator<Long>() {
private long bytesWritten = 0;
@Override
public void accept(StatisticsData data) {
bytesWritten += data.bytesWritten;
}
public Long aggregate() {
return bytesWritten;
}
});
}
/**
* Get the number of file system read operations such as list files
* @return number of read operations
*/
public int getReadOps() {
return visitAll(new StatisticsAggregator<Integer>() {
private int readOps = 0;
@Override
public void accept(StatisticsData data) {
readOps += data.readOps;
readOps += data.largeReadOps;
}
public Integer aggregate() {
return readOps;
}
});
}
/**
* Get the number of large file system read operations such as list files
* under a large directory
* @return number of large read operations
*/
public int getLargeReadOps() {
return visitAll(new StatisticsAggregator<Integer>() {
private int largeReadOps = 0;
@Override
public void accept(StatisticsData data) {
largeReadOps += data.largeReadOps;
}
public Integer aggregate() {
return largeReadOps;
}
});
}
/**
* Get the number of file system write operations such as create, append
* rename etc.
* @return number of write operations
*/
public int getWriteOps() {
return visitAll(new StatisticsAggregator<Integer>() {
private int writeOps = 0;
@Override
public void accept(StatisticsData data) {
writeOps += data.writeOps;
}
public Integer aggregate() {
return writeOps;
}
});
}
@Override
public String toString() {
return visitAll(new StatisticsAggregator<String>() {
private StatisticsData total = new StatisticsData(null);
@Override
public void accept(StatisticsData data) {
total.add(data);
}
public String aggregate() {
return total.toString();
}
});
}
/**
* Resets all statistics to 0.
*
* In order to reset, we add up all the thread-local statistics data, and
* set rootData to the negative of that.
*
* This may seem like a counterintuitive way to reset the statsitics. Why
* can't we just zero out all the thread-local data? Well, thread-local
* data can only be modified by the thread that owns it. If we tried to
* modify the thread-local data from this thread, our modification might get
* interleaved with a read-modify-write operation done by the thread that
* owns the data. That would result in our update getting lost.
*
* The approach used here avoids this problem because it only ever reads
* (not writes) the thread-local data. Both reads and writes to rootData
* are done under the lock, so we're free to modify rootData from any thread
* that holds the lock.
*/
public void reset() {
visitAll(new StatisticsAggregator<Void>() {
private StatisticsData total = new StatisticsData(null);
@Override
public void accept(StatisticsData data) {
total.add(data);
}
public Void aggregate() {
total.negate();
rootData.add(total);
return null;
}
});
}
/**
* Get the uri scheme associated with this statistics object.
* @return the schema associated with this set of statistics
*/
public String getScheme() {
return scheme;
}
}
/**
* Get the Map of Statistics object indexed by URI Scheme.
* @return a Map having a key as URI scheme and value as Statistics object
* @deprecated use {@link #getAllStatistics} instead
*/
@Deprecated
public static synchronized Map<String, Statistics> getStatistics() {
Map<String, Statistics> result = new HashMap<String, Statistics>();
for(Statistics stat: statisticsTable.values()) {
result.put(stat.getScheme(), stat);
}
return result;
}
/**
* Return the FileSystem classes that have Statistics
*/
public static synchronized List<Statistics> getAllStatistics() {
return new ArrayList<Statistics>(statisticsTable.values());
}
/**
* Get the statistics for a particular file system
* @param cls the class to lookup
* @return a statistics object
*/
public static synchronized
Statistics getStatistics(String scheme, Class<? extends FileSystem> cls) {
Statistics result = statisticsTable.get(cls);
if (result == null) {
result = new Statistics(scheme);
statisticsTable.put(cls, result);
}
return result;
}
/**
* Reset all statistics for all file systems
*/
public static synchronized void clearStatistics() {
for(Statistics stat: statisticsTable.values()) {
stat.reset();
}
}
/**
* Print all statistics for all file systems
*/
public static synchronized
void printStatistics() throws IOException {
for (Map.Entry<Class<? extends FileSystem>, Statistics> pair:
statisticsTable.entrySet()) {
System.out.println(" FileSystem " + pair.getKey().getName() +
": " + pair.getValue());
}
}
// Symlinks are temporarily disabled - see HADOOP-10020 and HADOOP-10052
private static boolean symlinksEnabled = false;
private static Configuration conf = null;
@VisibleForTesting
public static boolean areSymlinksEnabled() {
return symlinksEnabled;
}
@VisibleForTesting
public static void enableSymlinks() {
symlinksEnabled = true;
}
}