AdlFileSystem (Apache Hadoop Main 3.0.1 API)

java.lang.Object
- org.apache.hadoop.conf.Configured
- - org.apache.hadoop.fs.FileSystem
  - - org.apache.hadoop.fs.adl.AdlFileSystem

All Implemented Interfaces:

Closeable, AutoCloseable, Configurable
```
@InterfaceAudience.Public
 @InterfaceStability.Evolving
public class AdlFileSystem
extends FileSystem
```
A FileSystem to access Azure Data Lake Store.

Field Summary

Fields
Modifier and Type Field and Description

static String SCHEME
- Fields inherited from class org.apache.hadoop.fs.FileSystem
  DEFAULT_FS, FS_DEFAULT_NAME_KEY, SHUTDOWN_HOOK_PRIORITY, statistics, TRASH_PREFIX, USER_HOME_PREFIX

Fields
Modifier and Type	Field and Description
`static String`	`SCHEME`

Constructor Summary

Constructors
Constructor and Description

AdlFileSystem()

Constructors
Constructor and Description
`AdlFileSystem()`

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`access(Path path, FsAction mode)` Checks if the user can access a path.
`FSDataOutputStream`	`append(Path f, int bufferSize, Progressable progress)` Append to an existing file (optional operation).
`void`	`concat(Path trg, Path[] srcs)` Concat existing files together.
`FSDataOutputStream`	`create(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress)` Create call semantic is handled differently in case of ADL.
`FSDataOutputStream`	`createNonRecursive(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress)` Deprecated. API only for 0.20-append
`boolean`	`delete(Path path, boolean recursive)` Delete a file.
`AclStatus`	`getAclStatus(Path path)` Gets the ACL of a file or directory.
`long`	`getBlockSize(Path f)` Deprecated. Use getFileStatus() instead
`ContentSummary`	`getContentSummary(Path f)` Return the `ContentSummary` of a given `Path`.
`protected AzureADTokenProvider`	`getCustomAccessTokenProvider(Configuration conf)` This method is provided for convenience for derived classes to define custom `AzureADTokenProvider` instance.
`long`	`getDefaultBlockSize()` Deprecated. use `getDefaultBlockSize(Path)` instead
`long`	`getDefaultBlockSize(Path f)` Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
`int`	`getDefaultPort()` Get the default port for this FileSystem.
`BlockLocation[]`	`getFileBlockLocations(FileStatus status, long offset, long length)` Return an array containing hostnames, offset and size of portions of the given file.
`BlockLocation[]`	`getFileBlockLocations(Path p, long offset, long length)` Return an array containing hostnames, offset and size of portions of the given file.
`FileStatus`	`getFileStatus(Path f)` Return a file status object that represents the path.
`Path`	`getHomeDirectory()` Constructing home directory locally is fine as long as Hadoop local user name and ADL user name relationship story is not fully baked yet.
`short`	`getReplication(Path src)` Deprecated. Use getFileStatus() instead
`String`	`getScheme()` Return the protocol scheme for this FileSystem.
`protected String`	`getTransportScheme()`
`URI`	`getUri()` Returns a URI which identifies this FileSystem.
`Path`	`getWorkingDirectory()` Get the current working directory for the given file system.
`void`	`initialize(URI storeUri, Configuration conf)` Called after a new FileSystem instance is constructed.
`FileStatus[]`	`listStatus(Path f)` List the statuses of the files/directories in the given path if the path is a directory.
`boolean`	`mkdirs(Path path, FsPermission permission)` Make the given file and all non-existent parents into directories.
`void`	`modifyAclEntries(Path path, List<AclEntry> aclSpec)` Modifies ACL entries of files and directories.
`FSDataInputStream`	`open(Path f, int buffersize)` Open call semantic is handled differently in case of ADL.
`void`	`removeAcl(Path path)` Removes all but the base ACL entries of files and directories.
`void`	`removeAclEntries(Path path, List<AclEntry> aclSpec)` Removes ACL entries from files and directories.
`void`	`removeDefaultAcl(Path path)` Removes all default ACL entries from files and directories.
`boolean`	`rename(Path src, Path dst)` Renames Path src to Path dst.
`void`	`rename(Path src, Path dst, org.apache.hadoop.fs.Options.Rename... options)` Deprecated.
`void`	`setAcl(Path path, List<AclEntry> aclSpec)` Fully replaces ACL of files and directories, discarding all existing entries.
`void`	`setOwner(Path path, String owner, String group)` Set owner of a path (i.e.
`void`	`setPermission(Path path, FsPermission permission)` Set permission of a path.
`boolean`	`setReplication(Path p, short replication)` Azure data lake does not support user configuration for data replication hence not leaving system to query on azure data lake.
`void`	`setUserGroupRepresentationAsUPN(boolean enableUPN)`
`void`	`setWorkingDirectory(Path dir)` Set the current working directory for the given file system.
`boolean`	`supportsSymlinks()` See `AbstractFileSystem.supportsSymlinks()`.

Methods inherited from class org.apache.hadoop.fs.FileSystem
addDelegationTokens, append, append, appendFile, areSymlinksEnabled, cancelDeleteOnExit, canonicalizeUri, checkPath, clearStatistics, close, closeAll, closeAllForUGI, completeLocalOutput, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, create, create, createFile, createNewFile, createNonRecursive, createNonRecursive, createSnapshot, createSnapshot, createSymlink, delete, deleteOnExit, deleteSnapshot, enableSymlinks, exists, fixRelativePart, get, get, get, getAllStatistics, getAllStoragePolicies, getCanonicalServiceName, getCanonicalUri, getDefaultReplication, getDefaultReplication, getDefaultUri, getFileChecksum, getFileChecksum, getFileLinkStatus, getFileSystemClass, getFSofPath, getGlobalStorageStatistics, getInitialWorkingDirectory, getLength, getLinkTarget, getLocal, getName, getNamed, getQuotaUsage, getServerDefaults, getServerDefaults, getStatistics, getStatistics, getStatus, getStatus, getStoragePolicy, getStorageStatistics, getTrashRoot, getTrashRoots, getUsed, getUsed, getXAttr, getXAttrs, getXAttrs, globStatus, globStatus, isDirectory, isFile, listCorruptFileBlocks, listFiles, listLocatedStatus, listLocatedStatus, listStatus, listStatus, listStatus, listStatusIterator, listXAttrs, makeQualified, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, newInstance, newInstance, newInstance, newInstanceLocal, open, primitiveCreate, primitiveMkdir, primitiveMkdir, printStatistics, processDeleteOnExit, removeXAttr, renameSnapshot, resolveLink, resolvePath, setDefaultUri, setDefaultUri, setStoragePolicy, setTimes, setVerifyChecksum, setWriteChecksum, setXAttr, setXAttr, startLocalOutput, truncate, unsetStoragePolicy

Methods inherited from class org.apache.hadoop.conf.Configured
getConf, setConf

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SCHEME
```
public static final String SCHEME
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - AdlFileSystem
```
public AdlFileSystem()
```
- Method Detail
  - getScheme
```
public String getScheme()
```
    Description copied from class: FileSystem
    
    Return the protocol scheme for this FileSystem.
    This implementation throws an UnsupportedOperationException.
    
    Overrides:
    
    getScheme in class FileSystem
    
    Returns:
    
    the protocol scheme for this FileSystem.
  - getUri
```
public URI getUri()
```
    Description copied from class: FileSystem
    
    Returns a URI which identifies this FileSystem.
    
    Specified by:
    
    getUri in class FileSystem
    
    Returns:
    
    the URI of this filesystem.
  - getDefaultPort
```
public int getDefaultPort()
```
    Description copied from class: FileSystem
    
    Get the default port for this FileSystem.
    
    Overrides:
    
    getDefaultPort in class FileSystem
    
    Returns:
    
    the default port or 0 if there isn't one
  - supportsSymlinks
```
public boolean supportsSymlinks()
```
    Description copied from class: FileSystem
    
    See AbstractFileSystem.supportsSymlinks().
    
    Overrides:
    
    supportsSymlinks in class FileSystem
  - initialize
```
public void initialize(URI storeUri,
                       Configuration conf)
                throws IOException
```
    Called after a new FileSystem instance is constructed.
    
    Overrides:
    
    initialize in class FileSystem
    
    Parameters:
    
    storeUri - a uri whose authority section names the host, port, etc. for this FileSystem
    
    conf - the configuration
    
    Throws:
    
    IOException - on any failure to initialize this instance.
  - getCustomAccessTokenProvider
```
protected AzureADTokenProvider getCustomAccessTokenProvider(Configuration conf)
                                                     throws IOException
```
    This method is provided for convenience for derived classes to define custom AzureADTokenProvider instance. In order to ensure secure hadoop infrastructure and user context for which respective AdlFileSystem instance is initialized, Loading AzureADTokenProvider is not sufficient. The order of loading AzureADTokenProvider is to first invoke getCustomAccessTokenProvider(Configuration), If method return null which means no implementation provided by derived classes, then configuration object is loaded to retrieve token configuration as specified is documentation. Custom token management takes the higher precedence during initialization.
    
    Parameters:
    
    conf - Configuration object
    
    Returns:
    
    null if the no custom AzureADTokenProvider token management is specified.
    
    Throws:
    
    IOException - if failed to initialize token provider.
  - getHomeDirectory
```
public Path getHomeDirectory()
```
    Constructing home directory locally is fine as long as Hadoop local user name and ADL user name relationship story is not fully baked yet.
    
    Overrides:
    
    getHomeDirectory in class FileSystem
    
    Returns:
    
    Hadoop local user home directory.
  - create
```
public FSDataOutputStream create(Path f,
                                 FsPermission permission,
                                 boolean overwrite,
                                 int bufferSize,
                                 short replication,
                                 long blockSize,
                                 Progressable progress)
                          throws IOException
```
    Create call semantic is handled differently in case of ADL. Create semantics is translated to Create/Append semantics. 1. No dedicated connection to server. 2. Buffering is locally done, Once buffer is full or flush is invoked on the by the caller. All the pending data is pushed to ADL as APPEND operation code. 3. On close - Additional call is send to server to close the stream, and release lock from the stream. Necessity of Create/Append semantics is 1. ADL backend server does not allow idle connection for longer duration . In case of slow writer scenario, observed connection timeout/Connection reset causing occasional job failures. 2. Performance boost to jobs which are slow writer, avoided network latency 3. ADL equally better performing with multiple of 4MB chunk as append calls.
    
    Specified by:
    
    create in class FileSystem
    
    Parameters:
    
    f - File path
    
    permission - Access permission for the newly created file
    
    overwrite - Remove existing file and recreate new one if true otherwise throw error if file exist
    
    bufferSize - Buffer size, ADL backend does not honour
    
    replication - Replication count, ADL backend does not honour
    
    blockSize - Block size, ADL backend does not honour
    
    progress - Progress indicator
    
    Returns:
    
    FSDataOutputStream OutputStream on which application can push stream of bytes
    
    Throws:
    
    IOException - when system error, internal server error or user error
    
    See Also:
    
    FileSystem.setPermission(Path, FsPermission)
  - createNonRecursive
```
public FSDataOutputStream createNonRecursive(Path f,
                                             FsPermission permission,
                                             EnumSet<CreateFlag> flags,
                                             int bufferSize,
                                             short replication,
                                             long blockSize,
                                             Progressable progress)
                                      throws IOException
```
    Deprecated. API only for 0.20-append
    
    Opens an FSDataOutputStream at the indicated Path with write-progress reporting. Same as create(), except fails if parent directory doesn't already exist.
    
    Overrides:
    
    createNonRecursive in class FileSystem
    
    Parameters:
    
    f - the file name to open
    
    permission - Access permission for the newly created file
    
    flags - CreateFlags to use for this stream.
    
    bufferSize - the size of the buffer to be used. ADL backend does not honour
    
    replication - required block replication for the file. ADL backend does not honour
    
    blockSize - Block size, ADL backend does not honour
    
    progress - Progress indicator
    
    Throws:
    
    IOException - when system error, internal server error or user error
    
    See Also:
    
    setPermission(Path, FsPermission)
  - append
```
public FSDataOutputStream append(Path f,
                                 int bufferSize,
                                 Progressable progress)
                          throws IOException
```
    Append to an existing file (optional operation).
    
    Specified by:
    
    append in class FileSystem
    
    Parameters:
    
    f - the existing file to be appended.
    
    bufferSize - the size of the buffer to be used. ADL backend does not honour
    
    progress - Progress indicator
    
    Throws:
    
    IOException - when system error, internal server error or user error
  - setReplication
```
public boolean setReplication(Path p,
                              short replication)
                       throws IOException
```
    Azure data lake does not support user configuration for data replication hence not leaving system to query on azure data lake. Stub implementation
    
    Overrides:
    
    setReplication in class FileSystem
    
    Parameters:
    
    p - Not honoured
    
    replication - Not honoured
    
    Returns:
    
    True hard coded since ADL file system does not support replication configuration
    
    Throws:
    
    IOException - No exception would not thrown in this case however aligning with parent api definition.
  - open
```
public FSDataInputStream open(Path f,
                              int buffersize)
                       throws IOException
```
    Open call semantic is handled differently in case of ADL. Instead of network stream is returned to the user, Overridden FsInputStream is returned.
    
    Specified by:
    
    open in class FileSystem
    
    Parameters:
    
    f - File path
    
    buffersize - Buffer size, Not honoured
    
    Returns:
    
    FSDataInputStream InputStream on which application can read stream of bytes
    
    Throws:
    
    IOException - when system error, internal server error or user error
  - getFileStatus
```
public FileStatus getFileStatus(Path f)
                         throws IOException
```
    Return a file status object that represents the path.
    
    Specified by:
    
    getFileStatus in class FileSystem
    
    Parameters:
    
    f - The path we want information from
    
    Returns:
    
    a FileStatus object
    
    Throws:
    
    IOException - when the path does not exist or any other error; IOException see specific implementation
  - listStatus
```
public FileStatus[] listStatus(Path f)
                        throws IOException
```
    List the statuses of the files/directories in the given path if the path is a directory.
    
    Specified by:
    
    listStatus in class FileSystem
    
    Parameters:
    
    f - given path
    
    Returns:
    
    the statuses of the files/directories in the given patch
    
    Throws:
    
    IOException - when the path does not exist or any other error; IOException see specific implementation
  - rename
```
public boolean rename(Path src,
                      Path dst)
               throws IOException
```
    Renames Path src to Path dst. Can take place on local fs or remote DFS. ADLS support POSIX standard for rename operation.
    
    Specified by:
    
    rename in class FileSystem
    
    Parameters:
    
    src - path to be renamed
    
    dst - new path after rename
    
    Returns:
    
    true if rename is successful
    
    Throws:
    
    IOException - on failure
  - rename
```
@Deprecated
public void rename(Path src,
                               Path dst,
                               org.apache.hadoop.fs.Options.Rename... options)
                        throws IOException
```
    Deprecated.
    
    Description copied from class: FileSystem
    Renames Path src to Path dst
    - Fails if src is a file and dst is a directory.
    - Fails if src is a directory and dst is a file.
    - Fails if the parent of dst does not exist or is a file.
    If OVERWRITE option is not passed as an argument, rename fails if the dst already exists.
    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.
    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.
    This method is deprecated since it is a temporary method added to support the transition from FileSystem to FileContext for user applications.
    Overrides:
    
    rename in class FileSystem
    
    Parameters:
    
    src - path to be renamed
    
    dst - new path after rename
    
    Throws:
    
    FileNotFoundException - src path does not exist, or the parent path of dst does not exist.
    
    FileAlreadyExistsException - dest path exists and is a file
    
    ParentNotDirectoryException - if the parent path of dest is not a directory
    
    IOException - on failure
  - concat
```
public void concat(Path trg,
                   Path[] srcs)
            throws IOException
```
    Concat existing files together.
    
    Overrides:
    
    concat in class FileSystem
    
    Parameters:
    
    trg - the path to the target destination.
    
    srcs - the paths to the sources to use for the concatenation.
    
    Throws:
    
    IOException - when system error, internal server error or user error
  - delete
```
public boolean delete(Path path,
                      boolean recursive)
               throws IOException
```
    Delete a file.
    
    Specified by:
    
    delete in class FileSystem
    
    Parameters:
    
    path - the path to delete.
    
    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.
    
    Returns:
    
    true if delete is successful else false.
    
    Throws:
    
    IOException - when system error, internal server error or user error
  - mkdirs
```
public boolean mkdirs(Path path,
                      FsPermission permission)
               throws IOException
```
    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.
    
    Specified by:
    
    mkdirs in class FileSystem
    
    Parameters:
    
    path - path to create
    
    permission - to apply to path
    
    Throws:
    
    IOException - IO failure
  - setOwner
```
public void setOwner(Path path,
                     String owner,
                     String group)
              throws IOException
```
    Set owner of a path (i.e. a file or a directory). The parameters owner and group cannot both be null.
    
    Overrides:
    
    setOwner in class FileSystem
    
    Parameters:
    
    path - The path
    
    owner - If it is null, the original username remains unchanged.
    
    group - If it is null, the original groupname remains unchanged.
    
    Throws:
    
    IOException - IO failure
  - setPermission
```
public void setPermission(Path path,
                          FsPermission permission)
                   throws IOException
```
    Set permission of a path.
    
    Overrides:
    
    setPermission in class FileSystem
    
    Parameters:
    
    path - The path
    
    permission - Access permission
    
    Throws:
    
    IOException - IO failure
  - modifyAclEntries
```
public void modifyAclEntries(Path path,
                             List<AclEntry> aclSpec)
                      throws IOException
```
    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.)
    
    Overrides:
    
    modifyAclEntries in class FileSystem
    
    Parameters:
    
    path - Path to modify
    
    aclSpec - List of AclEntry describing modifications
    
    Throws:
    
    IOException - if an ACL could not be modified
  - removeAclEntries
```
public void removeAclEntries(Path path,
                             List<AclEntry> aclSpec)
                      throws IOException
```
    Removes ACL entries from files and directories. Other ACL entries are retained.
    
    Overrides:
    
    removeAclEntries in class FileSystem
    
    Parameters:
    
    path - Path to modify
    
    aclSpec - List of AclEntry describing entries to remove
    
    Throws:
    
    IOException - if an ACL could not be modified
  - removeDefaultAcl
```
public void removeDefaultAcl(Path path)
                      throws IOException
```
    Removes all default ACL entries from files and directories.
    
    Overrides:
    
    removeDefaultAcl in class FileSystem
    
    Parameters:
    
    path - Path to modify
    
    Throws:
    
    IOException - if an ACL could not be modified
  - removeAcl
```
public void removeAcl(Path path)
               throws IOException
```
    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.
    
    Overrides:
    
    removeAcl in class FileSystem
    
    Parameters:
    
    path - Path to modify
    
    Throws:
    
    IOException - if an ACL could not be removed
  - setAcl
```
public void setAcl(Path path,
                   List<AclEntry> aclSpec)
            throws IOException
```
    Fully replaces ACL of files and directories, discarding all existing entries.
    
    Overrides:
    
    setAcl in class FileSystem
    
    Parameters:
    
    path - Path to modify
    
    aclSpec - List of 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
  - getAclStatus
```
public AclStatus getAclStatus(Path path)
                       throws IOException
```
    Gets the ACL of a file or directory.
    
    Overrides:
    
    getAclStatus in class FileSystem
    
    Parameters:
    
    path - Path to get
    
    Returns:
    
    AclStatus describing the ACL of the file or directory
    
    Throws:
    
    IOException - if an ACL could not be read
  - access
```
public void access(Path path,
                   FsAction mode)
            throws IOException
```
    Checks if the user can access a path. The mode specifies which access checks to perform. If the requested permissions are granted, then the method returns normally. If access is denied, then the method throws an AccessControlException.
    
    Parameters:
    
    path - Path to check
    
    mode - type of access to check
    
    Throws:
    
    AccessControlException - if access is denied
    
    FileNotFoundException - if the path does not exist
    
    IOException - see specific implementation
  - getContentSummary
```
public ContentSummary getContentSummary(Path f)
                                 throws IOException
```
    Return the ContentSummary of a given Path.
    
    Overrides:
    
    getContentSummary in class FileSystem
    
    Parameters:
    
    f - path to use
    
    Throws:
    
    FileNotFoundException - if the path does not resolve
    
    IOException - IO failure
  - getTransportScheme
```
protected String getTransportScheme()
```
  - getWorkingDirectory
```
public Path getWorkingDirectory()
```
    Get the current working directory for the given file system.
    
    Specified by:
    
    getWorkingDirectory in class FileSystem
    
    Returns:
    
    the directory pathname
  - setWorkingDirectory
```
public void setWorkingDirectory(Path dir)
```
    Set the current working directory for the given file system. All relative paths will be resolved relative to it.
    
    Specified by:
    
    setWorkingDirectory in class FileSystem
    
    Parameters:
    
    dir - Working directory path.
  - getDefaultBlockSize
```
@Deprecated
public long getDefaultBlockSize()
```
    Deprecated. use getDefaultBlockSize(Path) instead
    
    Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
    
    Overrides:
    
    getDefaultBlockSize in class FileSystem
  - getDefaultBlockSize
```
public long getDefaultBlockSize(Path f)
```
    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.
    
    Overrides:
    
    getDefaultBlockSize in class FileSystem
    
    Parameters:
    
    f - path of file
    
    Returns:
    
    the default block size for the path's filesystem
  - getBlockSize
```
@Deprecated
public long getBlockSize(Path f)
                              throws IOException
```
    Deprecated. Use getFileStatus() instead
    
    Description copied from class: FileSystem
    
    Get the block size for a particular file.
    
    Overrides:
    
    getBlockSize in class FileSystem
    
    Parameters:
    
    f - the filename
    
    Returns:
    
    the number of bytes in a block
    
    Throws:
    
    FileNotFoundException - if the path is not present
    
    IOException - IO failure
  - getFileBlockLocations
```
public BlockLocation[] getFileBlockLocations(FileStatus status,
                                             long offset,
                                             long length)
                                      throws IOException
```
    Description copied from class: FileSystem
    Return an array containing hostnames, offset and size of portions of the given file. For nonexistent file or regions, null is returned.
```
   if f == null :
     result = null
   elif f.getLen() <= start:
     result = []
   else result = [ locations(FS, b) for b in blocks(FS, p, s, s+l)]
 
```
    This call is most helpful with and distributed filesystem where the hostnames of machines that contain blocks of the given file can be determined. The default implementation returns an array containing one element:
```
 BlockLocation( { "localhost:9866" },  { "localhost" }, 0, file.getLen())
 
```
    In HDFS, if file is three-replicated, the returned array contains elements like:
```
 BlockLocation(offset: 0, length: BLOCK_SIZE,
   hosts: {"host1:9866", "host2:9866, host3:9866"})
 BlockLocation(offset: BLOCK_SIZE, length: BLOCK_SIZE,
   hosts: {"host2:9866", "host3:9866, host4:9866"})
 
```
    And if a file is erasure-coded, the returned BlockLocation are logical block groups. Suppose we have a RS_3_2 coded file (3 data units and 2 parity units). 1. If the file size is less than one stripe size, say 2 * CELL_SIZE, then there will be one BlockLocation returned, with 0 offset, actual file size and 4 hosts (2 data blocks and 2 parity blocks) hosting the actual blocks. 3. If the file size is less than one group size but greater than one stripe size, then there will be one BlockLocation returned, with 0 offset, actual file size with 5 hosts (3 data blocks and 2 parity blocks) hosting the actual blocks. 4. If the file size is greater than one group size, 3 * BLOCK_SIZE + 123 for example, then the result will be like:
```
 BlockLocation(offset: 0, length: 3 * BLOCK_SIZE, hosts: {"host1:9866",
   "host2:9866","host3:9866","host4:9866","host5:9866"})
 BlockLocation(offset: 3 * BLOCK_SIZE, length: 123, hosts: {"host1:9866",
   "host4:9866", "host5:9866"})
 
```
    Overrides:
    
    getFileBlockLocations in class FileSystem
    
    Parameters:
    
    status - FilesStatus to get data from
    
    offset - offset into the given file
    
    length - length for which to get locations for
    
    Throws:
    
    IOException - IO failure
  - getFileBlockLocations
```
public BlockLocation[] getFileBlockLocations(Path p,
                                             long offset,
                                             long length)
                                      throws IOException
```
    Description copied from class: FileSystem
    
    Return an array containing hostnames, offset and size of portions of the given file. For a nonexistent file or regions, null is returned. This call is most helpful with location-aware distributed filesystems, where it returns hostnames of machines that contain the given file. A FileSystem will normally return the equivalent result of passing the FileStatus of the path to FileSystem.getFileBlockLocations(FileStatus, long, long)
    
    Overrides:
    
    getFileBlockLocations in class FileSystem
    
    Parameters:
    
    p - path is used to identify an FS since an FS could have another FS that it could be delegating the call to
    
    offset - offset into the given file
    
    length - length for which to get locations for
    
    Throws:
    
    FileNotFoundException - when the path does not exist
    
    IOException - IO failure
  - getReplication
```
@Deprecated
public short getReplication(Path src)
```
    Deprecated. Use getFileStatus() instead
    
    Get replication.
    
    Overrides:
    
    getReplication in class FileSystem
    
    Parameters:
    
    src - file name
    
    Returns:
    
    file replication
  - setUserGroupRepresentationAsUPN
```
public void setUserGroupRepresentationAsUPN(boolean enableUPN)
```

Class AdlFileSystem

Field Summary

Fields inherited from class org.apache.hadoop.fs.FileSystem

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.fs.FileSystem

Methods inherited from class org.apache.hadoop.conf.Configured

Methods inherited from class java.lang.Object

Field Detail

SCHEME

Constructor Detail

AdlFileSystem

Method Detail

getScheme

getUri

getDefaultPort

supportsSymlinks

initialize

getCustomAccessTokenProvider

getHomeDirectory

create

createNonRecursive

append

setReplication

open

getFileStatus

listStatus

rename

rename

concat

delete

mkdirs

setOwner

setPermission

modifyAclEntries

removeAclEntries

removeDefaultAcl

removeAcl

setAcl

getAclStatus

access

getContentSummary

getTransportScheme

getWorkingDirectory

setWorkingDirectory

getDefaultBlockSize

getDefaultBlockSize

getBlockSize

getFileBlockLocations

getFileBlockLocations

getReplication

setUserGroupRepresentationAsUPN