Package org.apache.hadoop.fs.viewfs

Class ViewFileSystem

java.lang.Object
org.apache.hadoop.conf.Configured
org.apache.hadoop.fs.FileSystem
org.apache.hadoop.fs.viewfs.ViewFileSystem
All Implemented Interfaces:
Closeable, AutoCloseable, Configurable, BulkDeleteSource, org.apache.hadoop.fs.PathCapabilities, org.apache.hadoop.security.token.DelegationTokenIssuer
@Public @Evolving public class ViewFileSystem extends FileSystem
ViewFileSystem (extends the FileSystem interface) implements a client-side mount table. Its spec and implementation is identical to ViewFs.

  • Constructor Details

    • ViewFileSystem

      public ViewFileSystem() throws IOException
      This is the constructor with the signature needed by FileSystem.createFileSystem(URI, Configuration) After this constructor is called initialize() is called.
      Throws:
      IOException - raised on errors performing I/O.

    • ViewFileSystem

      public ViewFileSystem(Configuration conf) throws IOException
      Convenience Constructor for apps to call directly.
      Parameters:
      conf - configuration.
      Throws:
      IOException - raised on errors performing I/O.

  • Method Details

    • fsGetter

      protected org.apache.hadoop.fs.viewfs.FsGetter fsGetter()
      Gets file system creator instance.
      Returns:
      fs getter.

    • getScheme

      public String getScheme()
      Return the protocol scheme for the FileSystem.
      Overrides:
      getScheme in class FileSystem
      Returns:
      viewfs

    • initialize

      public void initialize(URI theUri, Configuration conf) throws IOException
      Called after a new FileSystem instance is constructed.
      Overrides:
      initialize in class FileSystem
      Parameters:
      theUri - 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.

    • 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.

    • resolvePath

      public Path resolvePath(Path f) throws IOException
      Description copied from class: FileSystem
      Return the fully-qualified path of path, resolving the path through any symlinks or mount point.
      Overrides:
      resolvePath in class FileSystem
      Parameters:
      f - path to be resolved
      Returns:
      fully qualified path
      Throws:
      FileNotFoundException - if the path is not present
      IOException - for any other error

    • getHomeDirectory

      public Path getHomeDirectory()
      Description copied from class: FileSystem
      Return the current user's home directory in this FileSystem. The default implementation returns "/user/$USER/".
      Overrides:
      getHomeDirectory in class FileSystem
      Returns:
      the path.

    • getWorkingDirectory

      public Path getWorkingDirectory()
      Description copied from class: FileSystem
      Get the current working directory for the given FileSystem
      Specified by:
      getWorkingDirectory in class FileSystem
      Returns:
      the directory pathname

    • setWorkingDirectory

      public void setWorkingDirectory(Path new_dir)
      Description copied from class: FileSystem
      Set the current working directory for the given FileSystem. All relative paths will be resolved relative to it.
      Specified by:
      setWorkingDirectory in class FileSystem
      Parameters:
      new_dir - Path of new working directory

    • append

      public FSDataOutputStream append(Path f, int bufferSize, Progressable progress) throws IOException
      Description copied from class: FileSystem
      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.
      progress - for reporting progress if it is not null.
      Returns:
      output stream.
      Throws:
      IOException - IO failure

    • createNonRecursive

      public FSDataOutputStream createNonRecursive(Path f, FsPermission permission, EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize, Progressable progress) throws IOException
      Description copied from class: FileSystem
      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 - file permission
      flags - CreateFlags to use for this stream.
      bufferSize - the size of the buffer to be used.
      replication - required block replication for the file.
      blockSize - block size
      progress - the progress reporter
      Returns:
      output stream.
      Throws:
      IOException - IO failure
      See Also:

    • create

      public FSDataOutputStream create(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) throws IOException
      Description copied from class: FileSystem
      Create an FSDataOutputStream at the indicated Path with write-progress reporting.
      Specified by:
      create in class FileSystem
      Parameters:
      f - the file name to open
      permission - file permission
      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.
      bufferSize - the size of the buffer to be used.
      replication - required block replication for the file.
      blockSize - block size
      progress - the progress reporter
      Returns:
      output stream.
      Throws:
      IOException - IO failure
      See Also:

    • delete

      public boolean delete(Path f, boolean recursive) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Delete a file.
      Specified by:
      delete in class FileSystem
      Parameters:
      f - 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 - IO failure
      AccessControlException
      FileNotFoundException

    • delete

      public boolean delete(Path f) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Delete a file/directory.
      Overrides:
      delete in class FileSystem
      Parameters:
      f - the path.
      Returns:
      if delete success true, not false.
      Throws:
      IOException - IO failure.
      AccessControlException
      FileNotFoundException

    • getFileBlockLocations

      public BlockLocation[] getFileBlockLocations(FileStatus fs, long start, long len) 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:
      fs - FilesStatus to get data from
      start - offset into the given file
      len - length for which to get locations for
      Returns:
      block location array.
      Throws:
      IOException - IO failure

    • getFileChecksum

      public FileChecksum getFileChecksum(Path f) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Get the checksum of a file, if the FS supports checksums.
      Overrides:
      getFileChecksum in class FileSystem
      Parameters:
      f - The file path
      Returns:
      The file checksum. The default return value is null, which indicates that no checksum algorithm is implemented in the corresponding FileSystem.
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • getFileChecksum

      public FileChecksum getFileChecksum(Path f, long length) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Get the checksum of a file, from the beginning of the file till the specific length.
      Overrides:
      getFileChecksum in class FileSystem
      Parameters:
      f - The file path
      length - The length of the file range for checksum calculation
      Returns:
      The file checksum or null if checksums are not supported.
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • getFileStatus

      public FileStatus getFileStatus(Path f) throws AccessControlException, FileNotFoundException, IOException
      Return a file status object that represents the path. If the given path is a symlink(mount link), the path will be resolved to a target path and it will get the resolved path's FileStatus object. It will not be represented as a symlink and isDirectory API returns true if the resolved path is a directory, false otherwise.
      Specified by:
      getFileStatus in class FileSystem
      Parameters:
      f - The path we want information from
      Returns:
      a FileStatus object
      Throws:
      FileNotFoundException - when the path does not exist
      IOException - see specific implementation
      AccessControlException

    • access

      public void access(Path path, FsAction mode) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      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.

      The default implementation calls FileSystem.getFileStatus(Path) and checks the returned permissions against the requested permissions. Note that the FileSystem.getFileStatus(Path) call will be subject to authorization checks. Typically, this requires search (execute) permissions on each directory in the path's prefix, but this is implementation-defined. Any file system that provides a richer authorization model (such as ACLs) may override the default implementation so that it checks against that model instead.

      In general, applications should avoid using this method, due to the risk of time-of-check/time-of-use race conditions. The permissions on a file may change immediately after the access call returns. Most applications should prefer running specific file system actions as the desired user represented by a UserGroupInformation.

      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

    • listStatus

      public FileStatus[] listStatus(Path f) throws AccessControlException, FileNotFoundException, IOException
      List the statuses of the files/directories in the given path if the path is a directory.

      Does not guarantee to return the List of files/directories status in a sorted order.

      Will not return null. Expect IOException upon access error. Note: listStatus considers listing from fallbackLink if available. If the same directory path is present in configured mount path as well as in fallback fs, then only the fallback path will be listed in the returned result except for link. If any of the the immediate children of the given path f is a symlink(mount link), the returned FileStatus object of that children would be represented as a symlink. It will not be resolved to the target path and will not get the target path FileStatus object. The target path will be available via getSymlink on that children's FileStatus object. Since it represents as symlink, isDirectory on that children's FileStatus will return false. This behavior can be changed by setting an advanced configuration fs.viewfs.mount.links.as.symlinks to false. In this case, mount points will be represented as non-symlinks and all the file/directory attributes like permissions, isDirectory etc will be assigned from it's resolved target directory/file. If you want to get the FileStatus of target path for that children, you may want to use GetFileStatus API with that children's symlink path. Please see getFileStatus(Path f) Note: In ViewFileSystem, by default the mount links are represented as symlinks.

      Specified by:
      listStatus in class FileSystem
      Parameters:
      f - given path
      Returns:
      the statuses of the files/directories in the given patch
      Throws:
      FileNotFoundException - when the path does not exist
      IOException - see specific implementation
      AccessControlException

    • listLocatedStatus

      public org.apache.hadoop.fs.RemoteIterator<LocatedFileStatus> listLocatedStatus(Path f, PathFilter filter) throws FileNotFoundException, IOException
      Description copied from class: FileSystem
      List a directory. The returned results include its block location if it is a file The results are filtered by the given path filter
      Overrides:
      listLocatedStatus in class FileSystem
      Parameters:
      f - a path
      filter - a path filter
      Returns:
      an iterator that traverses statuses of the files/directories in the given path
      Throws:
      FileNotFoundException - if f does not exist
      IOException - if any I/O error occurred

    • mkdirs

      public boolean mkdirs(Path dir) throws IOException
      Description copied from class: FileSystem
      Call FileSystem.mkdirs(Path, FsPermission) with default permission.
      Overrides:
      mkdirs in class FileSystem
      Parameters:
      dir - path
      Returns:
      true if the directory was created
      Throws:
      IOException - IO failure

    • mkdirs

      public boolean mkdirs(Path dir, FsPermission permission) throws IOException
      Description copied from class: FileSystem
      Make the given file and all non-existent parents into directories. Has roughly the semantics of Unix @{code mkdir -p}. Existence of the directory hierarchy is not an error.
      Specified by:
      mkdirs in class FileSystem
      Parameters:
      dir - path to create
      permission - to apply to f
      Returns:
      if mkdir success true, not false.
      Throws:
      IOException - IO failure

    • open

      public FSDataInputStream open(Path f, int bufferSize) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Opens an FSDataInputStream at the indicated Path.
      Specified by:
      open in class FileSystem
      Parameters:
      f - the file name to open
      bufferSize - the size of the buffer to be used.
      Returns:
      input stream.
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • rename

      public boolean rename(Path src, Path dst) throws IOException
      Description copied from class: FileSystem
      Renames Path src to Path dst.
      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

    • truncate

      public boolean truncate(Path f, long newLength) throws IOException
      Description copied from class: FileSystem
      Truncate the file in the indicated path to the indicated size.
      • Fails if path is a directory.
      • Fails if path does not exist.
      • Fails if path is not closed.
      • Fails if new size is greater than current size.
      Overrides:
      truncate in class FileSystem
      Parameters:
      f - The path to the file to be truncated
      newLength - The size the file is to be truncated to
      Returns:
      true if the file has been truncated to the desired newLength and is immediately available to be reused for write operations such as append, or false if a background process of adjusting the length of the last block has been started, and clients should wait for it to complete before proceeding with further file updates.
      Throws:
      IOException - IO failure

    • setOwner

      public void setOwner(Path f, String username, String groupname) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Set owner of a path (i.e. a file or a directory). The parameters username and groupname cannot both be null.
      Overrides:
      setOwner in class FileSystem
      Parameters:
      f - The path
      username - If it is null, the original username remains unchanged.
      groupname - If it is null, the original groupname remains unchanged.
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • setPermission

      public void setPermission(Path f, FsPermission permission) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Set permission of a path.
      Overrides:
      setPermission in class FileSystem
      Parameters:
      f - The path
      permission - permission
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • setReplication

      public boolean setReplication(Path f, short replication) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Set the replication for an existing file. If a filesystem does not support replication, it will always return true: the check for a file existing may be bypassed. This is the default behavior.
      Overrides:
      setReplication in class FileSystem
      Parameters:
      f - file name
      replication - new replication
      Returns:
      true if successful, or the feature in unsupported; false if replication is supported but the file does not exist, or is a directory
      Throws:
      IOException - an IO failure.
      AccessControlException
      FileNotFoundException

    • setTimes

      public void setTimes(Path f, long mtime, long atime) throws AccessControlException, FileNotFoundException, IOException
      Description copied from class: FileSystem
      Set access time of a file.
      Overrides:
      setTimes in class FileSystem
      Parameters:
      f - The path
      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.
      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.
      Throws:
      IOException - IO failure
      AccessControlException
      FileNotFoundException

    • modifyAclEntries

      public void modifyAclEntries(Path path, List<AclEntry> aclSpec) throws IOException
      Description copied from class: FileSystem
      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<AclEntry> describing modifications
      Throws:
      IOException - if an ACL could not be modified

    • removeAclEntries

      public void removeAclEntries(Path path, List<AclEntry> aclSpec) throws IOException
      Description copied from class: FileSystem
      Removes ACL entries from files and directories. Other ACL entries are retained.
      Overrides:
      removeAclEntries in class FileSystem
      Parameters:
      path - Path to modify
      aclSpec - List describing entries to remove
      Throws:
      IOException - if an ACL could not be modified

    • removeDefaultAcl

      public void removeDefaultAcl(Path path) throws IOException
      Description copied from class: FileSystem
      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
      Description copied from class: FileSystem
      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
      Description copied from class: FileSystem
      Fully replaces ACL of files and directories, discarding all existing entries.
      Overrides:
      setAcl in class FileSystem
      Parameters:
      path - Path to modify
      aclSpec - List describing modifications, which 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
      Description copied from class: FileSystem
      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

    • setXAttr

      public void setXAttr(Path path, String name, byte[] value, EnumSet<XAttrSetFlag> flag) throws IOException
      Description copied from class: FileSystem
      Set an xattr of a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      setXAttr in class FileSystem
      Parameters:
      path - Path to modify
      name - xattr name.
      value - xattr value.
      flag - xattr set flag
      Throws:
      IOException - IO failure

    • getXAttr

      public byte[] getXAttr(Path path, String name) throws IOException
      Description copied from class: FileSystem
      Get an xattr name and value for a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      getXAttr in class FileSystem
      Parameters:
      path - Path to get extended attribute
      name - xattr name.
      Returns:
      byte[] xattr value.
      Throws:
      IOException - IO failure

    • getXAttrs

      public Map<String,byte[]> getXAttrs(Path path) throws IOException
      Description copied from class: FileSystem
      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.

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      getXAttrs in class FileSystem
      Parameters:
      path - Path to get extended attributes
      Returns:
      Map describing the XAttrs of the file or directory
      Throws:
      IOException - IO failure

    • getXAttrs

      public Map<String,byte[]> getXAttrs(Path path, List<String> names) throws IOException
      Description copied from class: FileSystem
      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.

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      getXAttrs in class FileSystem
      Parameters:
      path - Path to get extended attributes
      names - XAttr names.
      Returns:
      Map describing the XAttrs of the file or directory
      Throws:
      IOException - IO failure

    • listXAttrs

      public List<String> listXAttrs(Path path) throws IOException
      Description copied from class: FileSystem
      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.

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      listXAttrs in class FileSystem
      Parameters:
      path - Path to get extended attributes
      Returns:
      List<String> of the XAttr names of the file or directory
      Throws:
      IOException - IO failure

    • removeXAttr

      public void removeXAttr(Path path, String name) throws IOException
      Description copied from class: FileSystem
      Remove an xattr of a file or directory. The name must be prefixed with the namespace followed by ".". For example, "user.attr".

      Refer to the HDFS extended attributes user documentation for details.

      Overrides:
      removeXAttr in class FileSystem
      Parameters:
      path - Path to remove extended attribute
      name - xattr name
      Throws:
      IOException - IO failure

    • setVerifyChecksum

      public void setVerifyChecksum(boolean verifyChecksum)
      Description copied from class: FileSystem
      Set the verify checksum flag. This is only applicable if the corresponding filesystem supports checksums. By default doesn't do anything.
      Overrides:
      setVerifyChecksum in class FileSystem
      Parameters:
      verifyChecksum - Verify checksum flag

    • getDefaultBlockSize

      public long getDefaultBlockSize()
      Description copied from class: FileSystem
      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
      Returns:
      default block size.

    • getDefaultReplication

      public short getDefaultReplication()
      Description copied from class: FileSystem
      Get the default replication.
      Overrides:
      getDefaultReplication in class FileSystem
      Returns:
      the replication; the default value is "1".

    • getServerDefaults

      public FsServerDefaults getServerDefaults() throws IOException
      Description copied from class: FileSystem
      Return a set of server default configuration values.
      Overrides:
      getServerDefaults in class FileSystem
      Returns:
      server default configuration values
      Throws:
      IOException - IO failure

    • getDefaultBlockSize

      public long getDefaultBlockSize(Path f)
      Description copied from class: FileSystem
      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

    • getDefaultReplication

      public short getDefaultReplication(Path f)
      Description copied from class: FileSystem
      Get the default replication for a path. The given path will be used to locate the actual FileSystem to query. The full path does not have to exist.
      Overrides:
      getDefaultReplication in class FileSystem
      Parameters:
      f - of the file
      Returns:
      default replication for the path's filesystem

    • getServerDefaults

      public FsServerDefaults getServerDefaults(Path f) throws IOException
      Description copied from class: FileSystem
      Return a set of server default configuration values.
      Overrides:
      getServerDefaults in class FileSystem
      Parameters:
      f - path is used to identify an FS since an FS could have another FS that it could be delegating the call to
      Returns:
      server default configuration values
      Throws:
      IOException - IO failure

    • getContentSummary

      public ContentSummary getContentSummary(Path f) throws IOException
      Description copied from class: FileSystem
      Return the ContentSummary of a given Path.
      Overrides:
      getContentSummary in class FileSystem
      Parameters:
      f - path to use
      Returns:
      content summary.
      Throws:
      FileNotFoundException - if the path does not resolve
      IOException - IO failure

    • getQuotaUsage

      public QuotaUsage getQuotaUsage(Path f) throws IOException
      Description copied from class: FileSystem
      Return the QuotaUsage of a given Path.
      Overrides:
      getQuotaUsage in class FileSystem
      Parameters:
      f - path to use
      Returns:
      the quota usage
      Throws:
      IOException - IO failure

    • setWriteChecksum

      public void setWriteChecksum(boolean writeChecksum)
      Description copied from class: FileSystem
      Set the write checksum flag. This is only applicable if the corresponding filesystem supports checksums. By default doesn't do anything.
      Overrides:
      setWriteChecksum in class FileSystem
      Parameters:
      writeChecksum - Write checksum flag

    • getChildFileSystems

      public FileSystem[] getChildFileSystems()
      Description copied from class: FileSystem
      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 must return a unique list of those FileSystems. Default is to return null to signify no children.
      Returns:
      FileSystems that are direct children of this FileSystem, or null for "no children"

    • getMountPoints

      public org.apache.hadoop.fs.viewfs.ViewFileSystem.MountPoint[] getMountPoints()

    • createSnapshot

      public Path createSnapshot(Path path, String snapshotName) throws IOException
      Description copied from class: FileSystem
      Create a snapshot.
      Overrides:
      createSnapshot in class FileSystem
      Parameters:
      path - The directory where snapshots will be taken.
      snapshotName - The name of the snapshot
      Returns:
      the snapshot path.
      Throws:
      IOException - IO failure

    • renameSnapshot

      public void renameSnapshot(Path path, String snapshotOldName, String snapshotNewName) throws IOException
      Description copied from class: FileSystem
      Rename a snapshot.
      Overrides:
      renameSnapshot in class FileSystem
      Parameters:
      path - The directory path where the snapshot was taken
      snapshotOldName - Old name of the snapshot
      snapshotNewName - New name of the snapshot
      Throws:
      IOException - IO failure

    • deleteSnapshot

      public void deleteSnapshot(Path path, String snapshotName) throws IOException
      Description copied from class: FileSystem
      Delete a snapshot of a directory.
      Overrides:
      deleteSnapshot in class FileSystem
      Parameters:
      path - The directory that the to-be-deleted snapshot belongs to
      snapshotName - The name of the snapshot
      Throws:
      IOException - IO failure

    • satisfyStoragePolicy

      public void satisfyStoragePolicy(Path src) throws IOException
      Description copied from class: FileSystem
      Set the source path to satisfy storage policy.
      Overrides:
      satisfyStoragePolicy in class FileSystem
      Parameters:
      src - The source path referring to either a directory or a file.
      Throws:
      IOException - If an I/O error occurred.

    • setStoragePolicy

      public void setStoragePolicy(Path src, String policyName) throws IOException
      Description copied from class: FileSystem
      Set the storage policy for a given file or directory.
      Overrides:
      setStoragePolicy in class FileSystem
      Parameters:
      src - file or directory path.
      policyName - the name of the target storage policy. The list of supported Storage policies can be retrieved via FileSystem.getAllStoragePolicies().
      Throws:
      IOException - IO failure

    • unsetStoragePolicy

      public void unsetStoragePolicy(Path src) throws IOException
      Description copied from class: FileSystem
      Unset the storage policy set for a given file or directory.
      Overrides:
      unsetStoragePolicy in class FileSystem
      Parameters:
      src - file or directory path.
      Throws:
      IOException - IO failure

    • getStoragePolicy

      public BlockStoragePolicySpi getStoragePolicy(Path src) throws IOException
      Description copied from class: FileSystem
      Query the effective storage policy ID for the given file or directory.
      Overrides:
      getStoragePolicy in class FileSystem
      Parameters:
      src - file or directory path.
      Returns:
      storage policy for give file.
      Throws:
      IOException - IO failure

    • getAllStoragePolicies

      public Collection<? extends BlockStoragePolicySpi> getAllStoragePolicies() throws IOException
      Description copied from class: FileSystem
      Retrieve all the storage policies supported by this file system.
      Overrides:
      getAllStoragePolicies in class FileSystem
      Returns:
      all storage policies supported by this filesystem.
      Throws:
      IOException - IO failure

    • getTrashRoot

      public Path getTrashRoot(Path path)
      Get the trash root directory for current user when the path specified is deleted. If FORCE_INSIDE_MOUNT_POINT flag is not set, return the default trash root from targetFS. When FORCE_INSIDE_MOUNT_POINT is set to true,
      1. If the trash root for path p is in the same mount point as path p, and one of:
        1. The mount point isn't at the top of the target fs.
        2. The resolved path of path is root (in fallback FS).
        3. The trash isn't in user's target fs home directory get the corresponding viewFS path for the trash root and return it.
      2. else, return the trash root under the root of the mount point (/{mntpoint}/.Trash/{user}).
      These conditions handle several different important cases:
      • File systems may need to have more local trash roots, such as encryption zones or snapshot roots.
      • The fallback mount should use the user's home directory.
      • Cloud storage systems should not use trash in an implicity defined home directory, per a container, unless it is the fallback fs.
      Overrides:
      getTrashRoot in class FileSystem
      Parameters:
      path - the trash root of the path to be determined.
      Returns:
      the trash root path.

    • getTrashRoots

      public Collection<FileStatus> getTrashRoots(boolean allUsers)
      Get all the trash roots for current user or all users. When FORCE_INSIDE_MOUNT_POINT is set to true, we also return trash roots under the root of each mount point, with their viewFS paths.
      Overrides:
      getTrashRoots in class FileSystem
      Parameters:
      allUsers - return trash roots for all users if true.
      Returns:
      all Trash root directories.

    • getStatus

      public FsStatus getStatus() throws IOException
      Description copied from class: FileSystem
      Returns a status object describing the use and capacity of the filesystem. If the filesystem has multiple partitions, the use and capacity of the root partition is reflected.
      Overrides:
      getStatus in class FileSystem
      Returns:
      a FsStatus object
      Throws:
      IOException - see specific implementation

    • getStatus

      public FsStatus getStatus(Path p) throws IOException
      Description copied from class: FileSystem
      Returns a status object describing the use and capacity of the filesystem. If the filesystem has multiple partitions, the use and capacity of the partition pointed to by the specified path is reflected.
      Overrides:
      getStatus in class FileSystem
      Parameters:
      p - Path for which status should be obtained. null means the default partition.
      Returns:
      a FsStatus object
      Throws:
      IOException - see specific implementation

    • getUsed

      public long getUsed() throws IOException
      Return the total size of all files under "/", if Constants.CONFIG_VIEWFS_LINK_MERGE_SLASH is supported and is a valid mount point. Else, throw NotInMountpointException.
      Overrides:
      getUsed in class FileSystem
      Returns:
      the number of path used.
      Throws:
      IOException - raised on errors performing I/O.

    • getLinkTarget

      public Path getLinkTarget(Path path) throws IOException
      Description copied from class: FileSystem
      See FileContext.getLinkTarget(Path).
      Overrides:
      getLinkTarget in class FileSystem
      Parameters:
      path - the path.
      Returns:
      the path.
      Throws:
      IOException - IO failure.

    • hasPathCapability

      public boolean hasPathCapability(Path path, String capability) throws IOException
      Reject the concat operation; forward the rest to the viewed FS.
      Specified by:
      hasPathCapability in interface org.apache.hadoop.fs.PathCapabilities
      Overrides:
      hasPathCapability in class FileSystem
      Parameters:
      path - path to query the capability of.
      capability - string to query the stream support for.
      Returns:
      the capability
      Throws:
      IOException - if there is no resolved FS, or it raises an IOE.

    • getEnclosingRoot

      public Path getEnclosingRoot(Path path) throws IOException
      Description copied from class: FileSystem
      Return path of the enclosing root for a given path. The enclosing root path is a common ancestor that should be used for temp and staging dirs as well as within encryption zones and other restricted directories. Call makeQualified on the param path to ensure its part of the correct filesystem.
      Overrides:
      getEnclosingRoot in class FileSystem
      Parameters:
      path - file path to find the enclosing root path for
      Returns:
      a path to the enclosing root
      Throws:
      IOException - early checks like failure to resolve path cause IO failures

    • close

      public void close() throws IOException
      Description copied from class: FileSystem
      Close this FileSystem instance. Will release any held locks, delete all files queued for deletion through calls to FileSystem.deleteOnExit(Path), and remove this FS instance from the cache, if cached. After this operation, the outcome of any method call on this FileSystem instance, or any input/output stream created by it is undefined.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FileSystem
      Throws:
      IOException - IO failure