jfilesyslib.filesystems

Class MemoryFs

java.lang.Object

jfilesyslib.FileSystem

jfilesyslib.filesystems.MemoryFs

public class MemoryFs
extends FileSystem

A temporary (virtual) file system.

Author:

Marc Miltenberger

Constructor Summary

Constructors

Constructor and Description
MemoryFs()

Method Summary

Methods

Modifier and Type	Method and Description
void	close(FileHandle fh) Closes the file handle.
void	createDirectory(java.lang.String path) Creates a new, empty directory.
void	createFile(java.lang.String path) Creates a new (blank) file.
void	deleteDirectoryRecursively(java.lang.String directory) Deletes a directory recursively.
void	deleteFile(java.lang.String file) Deletes a file or symbolic link.
void	flush(FileHandle fh) Should write all pending data in the cache.
int	getBlockSize() Returns the block size in bytes
EntityInfo	getFileMetaData(java.lang.String path) Returns some meta data about the path.
java.lang.String	getFileSystemName() Returns the file system name
long	getFreeBlockAvailableCount() Returns the number of free blocks, which are available to the current user.
long	getFreeBlockCount() Returns the number of free blocks.
long	getTotalBlockCount() Returns the number of total blocks.
java.lang.String	getVolumeName() Returns the volume name.
boolean	isCaseSensitive() Returns true if the pathes are case sensitive
java.lang.Iterable<EntityInfo>	listDirectory(java.lang.String path) Reads a given directory and returns an iterator.
FileHandle	openFile(java.lang.String path, boolean read, boolean write) Opens a file.
int	read(FileHandle fh, java.nio.ByteBuffer buffer, long offset) Reads from a file.
void	rename(java.lang.String from, java.lang.String to) Renames a file/directory/symbolic link.
void	setCreationTime(java.lang.String path, long creationTime) Sets the creation time (unix timestamp).
void	setLastAccessTime(java.lang.String path, long atime) Sets the last access time (unix timestamp).
void	setLastModificationTime(java.lang.String path, long mtime) Sets the last modification time (unix timestamp).
void	setLength(FileHandle fh, long length) Truncates or lengthens a file.
void	write(FileHandle fh, java.nio.ByteBuffer buffer, long offset) (Over-)writes the buffer into the specified file handle.

Methods inherited from class jfilesyslib.FileSystem

afterUnmounting, beforeMounting, beforeUnmounting, createHardLink, createSymbolicLink, delete, getExtendedAttribute, getFilesFreeCount, getMaxPathLength, getMountPath, getNumberOfFilesInDirectory, getTotalFilesCount, getUnixPermissions, getVolumeSerialNumber, getWindowsAttributes, isCompressed, isReadOnly, listExtendedAttributes, lockFile, pathExists, removeExtendedAttribute, setExtendedAttribute, setUnixPermissions, setWindowsAttributes, supportsUnicodeFilenames, unlockFile

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MemoryFs

public MemoryFs()

Method Detail

listDirectory

public java.lang.Iterable<EntityInfo> listDirectory(java.lang.String path)
                                             throws NotADirectoryException,
                                                    PathNotFoundException

Description copied from class: FileSystem

Reads a given directory and returns an iterator.

Specified by:

listDirectory in class FileSystem

Parameters:

path - the path

Returns:

the iterator

Throws:

NotADirectoryException - the path is not a directory

PathNotFoundException - the path could not be found

getFileMetaData

public EntityInfo getFileMetaData(java.lang.String path)
                           throws PathNotFoundException

Description copied from class: FileSystem

Returns some meta data about the path.

Specified by:

getFileMetaData in class FileSystem

Parameters:

path - the path

Returns:

the meta data

Throws:

PathNotFoundException - the path could not be found

rename

public void rename(java.lang.String from,
          java.lang.String to)
            throws PathNotFoundException,
                   DestinationAlreadyExistsException,
                   AccessDeniedException

Description copied from class: FileSystem

Renames a file/directory/symbolic link.
It is equivalent to moving a file/directory.

Specified by:

rename in class FileSystem

Parameters:

from - the source path

to - the destination path

Throws:

PathNotFoundException - the source path or the parent directory of the destination could not be found

DestinationAlreadyExistsException - the destination already exists

AccessDeniedException - the access is denied

openFile

public FileHandle openFile(java.lang.String path,
                  boolean read,
                  boolean write)
                    throws PathNotFoundException,
                           AccessDeniedException,
                           NotAFileException

Description copied from class: FileSystem

Opens a file.
It is guaranteed that createFile is called first for new files.
You should not overwrite the file if write is true.

Specified by:

openFile in class FileSystem

Parameters:

path - the file to open

read - whether the file should be open to read

write - whether the file should be open to write

Returns:

the file handle

Throws:

PathNotFoundException - the file was not found

AccessDeniedException - the access is denied

NotAFileException - the given path is not a file

createFile

public void createFile(java.lang.String path)
                throws PathNotFoundException,
                       DestinationAlreadyExistsException

Description copied from class: FileSystem

Creates a new (blank) file.

Specified by:

createFile in class FileSystem

Parameters:

path - the path to the file

Throws:

PathNotFoundException - the parent directory could not be found

DestinationAlreadyExistsException - the destination already exists (regardless whether it is a directory or a file)

createDirectory

public void createDirectory(java.lang.String path)
                     throws PathNotFoundException,
                            DestinationAlreadyExistsException

Description copied from class: FileSystem

Creates a new, empty directory.

Specified by:

createDirectory in class FileSystem

Parameters:

path - the path to the new directory

Throws:

PathNotFoundException - the parent directory could not be found

DestinationAlreadyExistsException - the destination already exists (regardless whether it is a directory or a file)

read

public int read(FileHandle fh,
       java.nio.ByteBuffer buffer,
       long offset)

Description copied from class: FileSystem

Reads from a file.
Offset specifies the offset within the opened file, not within the buffer.
The handle is guaranteed to be a valid file handle.

Specified by:

read in class FileSystem

Parameters:

fh - the file handle

buffer - the buffer to fill

offset - the offset within the file

Returns:

the number of read bytes

setLength

public void setLength(FileHandle fh,
             long length)

Description copied from class: FileSystem

Truncates or lengthens a file.
The handle is guaranteed to be a valid file handle.

Specified by:

setLength in class FileSystem

Parameters:

fh - the file handle

length - the new file size in bytes

write

public void write(FileHandle fh,
         java.nio.ByteBuffer buffer,
         long offset)

Description copied from class: FileSystem

(Over-)writes the buffer into the specified file handle.
Offset specifies the offset within the opened file, not within the buffer.
The handle is guaranteed to be a valid file handle.

Be careful: offset may be larger than the file size!
In this case you should fill everything in between with zeros.

Specified by:

write in class FileSystem

Parameters:

fh - the file handle.

buffer - the buffer to write

offset - the offset within the file

flush

public void flush(FileHandle fh)

Description copied from class: FileSystem

Should write all pending data in the cache.
It is not guaranteed that this method is called before close.
The handle is guaranteed to be a valid file handle.

Specified by:

flush in class FileSystem

Parameters:

fh - the file handle

close

public void close(FileHandle fh)

Description copied from class: FileSystem

Closes the file handle.
The handle is guaranteed to be a valid file handle and not closed yet.

Specified by:

close in class FileSystem

Parameters:

fh - the file handle

deleteFile

public void deleteFile(java.lang.String file)
                throws PathNotFoundException

Description copied from class: FileSystem

Deletes a file or symbolic link.

Specified by:

deleteFile in class FileSystem

Parameters:

file - the file

Throws:

PathNotFoundException - the file could not be found

deleteDirectoryRecursively

public void deleteDirectoryRecursively(java.lang.String directory)
                                throws PathNotFoundException

Description copied from class: FileSystem

Deletes a directory recursively.

Specified by:

deleteDirectoryRecursively in class FileSystem

Parameters:

directory - the directory

Throws:

PathNotFoundException - the directory could not be found

getVolumeName

public java.lang.String getVolumeName()

Description copied from class: FileSystem

Returns the volume name.

Specified by:

getVolumeName in class FileSystem

Returns:

the volume name

getFileSystemName

public java.lang.String getFileSystemName()

Description copied from class: FileSystem

Returns the file system name

Specified by:

getFileSystemName in class FileSystem

Returns:

the file system name

setLastAccessTime

public void setLastAccessTime(java.lang.String path,
                     long atime)
                       throws PathNotFoundException

Description copied from class: FileSystem

Sets the last access time (unix timestamp).

Specified by:

setLastAccessTime in class FileSystem

Parameters:

path - the path

atime - the last access time (unix timestamp)

Throws:

PathNotFoundException - the path could not be found.

setLastModificationTime

public void setLastModificationTime(java.lang.String path,
                           long mtime)
                             throws PathNotFoundException

Description copied from class: FileSystem

Sets the last modification time (unix timestamp).

Specified by:

setLastModificationTime in class FileSystem

Parameters:

path - the path

mtime - the last modification time (unix timestamp)

Throws:

PathNotFoundException - the path could not be found.

setCreationTime

public void setCreationTime(java.lang.String path,
                   long creationTime)
                     throws PathNotFoundException

Description copied from class: FileSystem

Sets the creation time (unix timestamp).

Specified by:

setCreationTime in class FileSystem

Parameters:

path - the path

creationTime - the creation time (unix timestamp)

Throws:

PathNotFoundException - the path could not be found.

isCaseSensitive

public boolean isCaseSensitive()

Description copied from class: FileSystem

Returns true if the pathes are case sensitive

Specified by:

isCaseSensitive in class FileSystem

Returns:

true if the pathes are case sensitive

getBlockSize

public int getBlockSize()

Description copied from class: FileSystem

Returns the block size in bytes

Specified by:

getBlockSize in class FileSystem

Returns:

the block size

getTotalBlockCount

public long getTotalBlockCount()

Description copied from class: FileSystem

Returns the number of total blocks. E.g. a virtual 40 mb hard drive with 1 mb block size has 40 total blocks.

Specified by:

getTotalBlockCount in class FileSystem

Returns:

the number of total blocks

getFreeBlockCount

public long getFreeBlockCount()

Description copied from class: FileSystem

Returns the number of free blocks.

Specified by:

getFreeBlockCount in class FileSystem

Returns:

the number of free blocks

getFreeBlockAvailableCount

public long getFreeBlockAvailableCount()

Description copied from class: FileSystem

Returns the number of free blocks, which are available to the current user.
In the easiast case:
Available Free Block Count = Free Block Count

Specified by:

getFreeBlockAvailableCount in class FileSystem

Returns:

the number of free blocks