org.h2.store

Class FileStore

java.lang.Object

org.h2.store.FileStore

Direct Known Subclasses:

SecureFileStore

public class FileStore
extends Object

This class is an abstraction of a random access file. Each file contains a magic header, and reading / writing is done in blocks. See also SecureFileStore

Field Summary

Fields

Modifier and Type	Field and Description
protected DataHandler	handler The callback object is responsible to check access rights, and free up disk space if required.
static int	HEADER_LENGTH The size of the file header in bytes.
protected String	name The file name.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FileStore(DataHandler handler, String name, String mode) Create a new file using the given settings.

Method Summary

Methods

Modifier and Type	Method and Description
void	autoDelete() Automatically delete the file once it is no longer in use.
void	close() Close the file.
void	closeAndDeleteSilently() Close the file (ignoring exceptions) and delete the file.
void	closeFile() Close the file.
void	closeSilently() Close the file without throwing any exceptions.
protected byte[]	generateSalt() Generate the random salt bytes if required.
long	getFilePointer() Get the current location of the file pointer.
void	init() Initialize the file.
protected void	initKey(byte[] salt) Initialize the key using the given salt.
boolean	isTextMode() Check if the file store is in text mode.
long	length() Get the file size in bytes.
static FileStore	open(DataHandler handler, String name, String mode) Open a non encrypted file store with the given settings.
static FileStore	open(DataHandler handler, String name, String mode, String cipher, byte[] key) Open an encrypted file store with the given settings.
static FileStore	open(DataHandler handler, String name, String mode, String cipher, byte[] key, int keyIterations) Open an encrypted file store with the given settings.
void	openFile() Re-open the file.
void	readFully(byte[] b, int off, int len) Read a number of bytes.
protected void	readFullyDirect(byte[] b, int off, int len) Read a number of bytes without decrypting.
void	releaseLock() Release the file lock.
void	seek(long pos) Go to the specified file location.
void	setCheckedWriting(boolean value)
void	setLength(long newLength) Set the length of the file.
void	stopAutoDelete() No longer automatically delete the file once it is no longer in use.
void	sync() Call fsync.
boolean	tryLock() Try to lock the file.
void	write(byte[] b, int off, int len) Write a number of bytes.
protected void	writeDirect(byte[] b, int off, int len) Write a number of bytes without encrypting.

Methods inherited from class java.lang.Object

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

Field Detail

HEADER_LENGTH

public static final int HEADER_LENGTH

The size of the file header in bytes.

See Also:

Constant Field Values

name

protected String name

The file name.

handler

protected DataHandler handler

The callback object is responsible to check access rights, and free up disk space if required.

Constructor Detail

FileStore

protected FileStore(DataHandler handler,
         String name,
         String mode)

Create a new file using the given settings.

Parameters:

handler - the callback object

name - the file name

mode - the access mode ("r", "rw", "rws", "rwd")

Method Detail

open

public static FileStore open(DataHandler handler,
             String name,
             String mode)

Open a non encrypted file store with the given settings.

Parameters:

handler - the data handler

name - the file name

mode - the access mode (r, rw, rws, rwd)

Returns:

the created object

open

public static FileStore open(DataHandler handler,
             String name,
             String mode,
             String cipher,
             byte[] key)

Open an encrypted file store with the given settings.

Parameters:

handler - the data handler

name - the file name

mode - the access mode (r, rw, rws, rwd)

cipher - the name of the cipher algorithm

key - the encryption key

Returns:

the created object

open

public static FileStore open(DataHandler handler,
             String name,
             String mode,
             String cipher,
             byte[] key,
             int keyIterations)

Open an encrypted file store with the given settings.

Parameters:

handler - the data handler

name - the file name

mode - the access mode (r, rw, rws, rwd)

cipher - the name of the cipher algorithm

key - the encryption key

keyIterations - the number of iterations the key should be hashed

Returns:

the created object

generateSalt

protected byte[] generateSalt()

Generate the random salt bytes if required.

Returns:

the random salt or the magic

initKey

protected void initKey(byte[] salt)

Initialize the key using the given salt.

Parameters:

salt - the salt

setCheckedWriting

public void setCheckedWriting(boolean value)

init

public void init()

Initialize the file. This method will write or check the file header if required.

close

public void close()

Close the file.

closeSilently

public void closeSilently()

Close the file without throwing any exceptions. Exceptions are simply ignored.

closeAndDeleteSilently

public void closeAndDeleteSilently()

Close the file (ignoring exceptions) and delete the file.

readFullyDirect

protected void readFullyDirect(byte[] b,
                   int off,
                   int len)

Read a number of bytes without decrypting.

Parameters:

b - the target buffer

off - the offset

len - the number of bytes to read

readFully

public void readFully(byte[] b,
             int off,
             int len)

Read a number of bytes.

Parameters:

b - the target buffer

off - the offset

len - the number of bytes to read

seek

public void seek(long pos)

Go to the specified file location.

Parameters:

pos - the location

writeDirect

protected void writeDirect(byte[] b,
               int off,
               int len)

Write a number of bytes without encrypting.

Parameters:

b - the source buffer

off - the offset

len - the number of bytes to write

write

public void write(byte[] b,
         int off,
         int len)

Write a number of bytes.

Parameters:

b - the source buffer

off - the offset

len - the number of bytes to write

setLength

public void setLength(long newLength)

Set the length of the file. This will expand or shrink the file.

Parameters:

newLength - the new file size

length

public long length()

Get the file size in bytes.

Returns:

the file size

getFilePointer

public long getFilePointer()

Get the current location of the file pointer.

Returns:

the location

sync

public void sync()

Call fsync. Depending on the operating system and hardware, this may or may not in fact write the changes.

autoDelete

public void autoDelete()

Automatically delete the file once it is no longer in use.

stopAutoDelete

public void stopAutoDelete()

No longer automatically delete the file once it is no longer in use.

closeFile

public void closeFile()
               throws IOException

Close the file. The file may later be re-opened using openFile.

Throws:

IOException

openFile

public void openFile()
              throws IOException

Re-open the file. The file pointer will be reset to the previous location.

Throws:

IOException

isTextMode

public boolean isTextMode()

Check if the file store is in text mode.

Returns:

true if it is

tryLock

public boolean tryLock()

Try to lock the file.

Returns:

true if successful

releaseLock

public void releaseLock()

Release the file lock.