ewe.database
Class RandomAccessDatabaseStream

java.lang.Object
  ewe.database.RandomAccessDatabaseStream

All Implemented Interfaces:

DatabaseStream

public class RandomAccessDatabaseStream

extends Object

implements DatabaseStream

Field Summary

int	maxBufferSize
static boolean	unsafe

Constructor Summary

RandomAccessDatabaseStream(File file, String mode)

RandomAccessDatabaseStream(File file, String mode, boolean ignoreInconsistentState)

RandomAccessDatabaseStream(RandomAccessStream stream, String mode)

RandomAccessDatabaseStream(RandomAccessStream stream, String mode, boolean ignoreInconsistentState)

Method Summary

boolean	atEOF(long location)
boolean	canWrite() Tests if the DatabaseStream was opened in read-write mode as opposed to read-ony mode.
void	close()
void	delete()
void	flush()
int	getFirstDataLocation() Return the location of where you can store your data.
Time	getModifiedTime()
long	length()
protected int	read(byte[] data, int offset, int length)
void	readAll(long location, byte[] data, int offset, int length) This throws an exception if all the specified bytes are not found at the specified location.
int	readIntAt(long location)
void	rename(String newName)
void	reopen() Reopen the stream after a temporaryClose().
void	safeWrite(long location, int data) A safeWrite() is one where the integer data is either stored completely at the specified location or not at all.
void	safeWrite(long loc1, int data1, long loc2, int data2)
void	safeWrite(long loc1, int data1, long loc2, int data2, long loc3, int data3, long loc4, int data4)
boolean	setDecryptor(DataProcessor decryptor)
boolean	setDecryptorAndEncryptor(DataProcessor decryptor, DataProcessor encryptor)
boolean	setModifiedTime(Time t)
boolean	temporaryClose() Close the stream temporarily.
boolean	truncateTo(long length) Try to truncate to a particular length.
protected void	write(byte[] data, int offset, int length)
void	writeAll(long location, byte[] data, int offset, int length)
void	writeIntAt(long location, int value)
void	zero(long location, int numBytes) This should extend the Stream if necessary.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, toString

Field Detail

unsafe

public static boolean unsafe

maxBufferSize

public int maxBufferSize

Constructor Detail

RandomAccessDatabaseStream

public RandomAccessDatabaseStream(File file,
                                  String mode)
                           throws IOException

RandomAccessDatabaseStream

public RandomAccessDatabaseStream(File file,
                                  String mode,
                                  boolean ignoreInconsistentState)
                           throws IOException

RandomAccessDatabaseStream

public RandomAccessDatabaseStream(RandomAccessStream stream,
                                  String mode)
                           throws InconsistentDatabaseStateException,
                                  IOException

RandomAccessDatabaseStream

public RandomAccessDatabaseStream(RandomAccessStream stream,
                                  String mode,
                                  boolean ignoreInconsistentState)
                           throws InconsistentDatabaseStateException,
                                  IOException

Method Detail

canWrite

public boolean canWrite()

Description copied from interface: DatabaseStream

Tests if the DatabaseStream was opened in read-write mode as opposed to read-ony mode.

Specified by:

canWrite in interface DatabaseStream

temporaryClose

public boolean temporaryClose()
                       throws IOException

Description copied from interface: DatabaseStream

Close the stream temporarily. Can be opened with re-open.

Specified by:

temporaryClose in interface DatabaseStream

Returns:

true if it was actually closed.

Throws:

IOException - if an error occurs.

reopen

public void reopen()
            throws IOException

Description copied from interface: DatabaseStream

Reopen the stream after a temporaryClose(). The file position will be unspecified after this call.

Specified by:

reopen in interface DatabaseStream

Throws:

IOException - if an error occurs.

getFirstDataLocation

public int getFirstDataLocation()

Description copied from interface: DatabaseStream

Return the location of where you can store your data. This should be at a 16-byte border.

Specified by:

getFirstDataLocation in interface DatabaseStream

write

protected void write(byte[] data,
                     int offset,
                     int length)
              throws IOException

Throws:

IOException

read

protected int read(byte[] data,
                   int offset,
                   int length)
            throws IOException

Throws:

IOException

writeAll

public void writeAll(long location,
                     byte[] data,
                     int offset,
                     int length)
              throws IOException

Specified by:

writeAll in interface DatabaseStream

Throws:

IOException

readAll

public void readAll(long location,
                    byte[] data,
                    int offset,
                    int length)
             throws IOException

Description copied from interface: DatabaseStream

This throws an exception if all the specified bytes are not found at the specified location.

Specified by:

readAll in interface DatabaseStream

Throws:

IOException

zero

public void zero(long location,
                 int numBytes)
          throws IOException

Description copied from interface: DatabaseStream

This should extend the Stream if necessary.

Specified by:

zero in interface DatabaseStream

Throws:

IOException

flush

public void flush()
           throws IOException

Specified by:

flush in interface DatabaseStream

Throws:

IOException

truncateTo

public boolean truncateTo(long length)
                   throws IOException

Description copied from interface: DatabaseStream

Try to truncate to a particular length. If the truncate is not possible because of restrictions on the underlying Stream, this returns false. An IOException is only thrown if there is a serious IO error which indicates IO should be abandonded.

Specified by:

truncateTo in interface DatabaseStream

Throws:

IOException

readIntAt

public int readIntAt(long location)
              throws IOException

Specified by:

readIntAt in interface DatabaseStream

Throws:

IOException

writeIntAt

public void writeIntAt(long location,
                       int value)
                throws IOException

Specified by:

writeIntAt in interface DatabaseStream

Throws:

IOException

safeWrite

public void safeWrite(long location,
                      int data)
               throws IOException

Description copied from interface: DatabaseStream

A safeWrite() is one where the integer data is either stored completely at the specified location or not at all. If for some reason, the application should fail during the safe write (assuming that there is no problem with the file) then either the write had no effect, OR, the write would be completed the next time the file is opened.

Specified by:

safeWrite in interface DatabaseStream

Throws:

IOException

safeWrite

public void safeWrite(long loc1,
                      int data1,
                      long loc2,
                      int data2)
               throws IOException

Specified by:

safeWrite in interface DatabaseStream

Throws:

IOException

safeWrite

public void safeWrite(long loc1,
                      int data1,
                      long loc2,
                      int data2,
                      long loc3,
                      int data3,
                      long loc4,
                      int data4)
               throws IOException

Specified by:

safeWrite in interface DatabaseStream

Throws:

IOException

atEOF

public boolean atEOF(long location)
              throws IOException

Specified by:

atEOF in interface DatabaseStream

Throws:

IOException

length

public long length()
            throws IOException

Specified by:

length in interface DatabaseStream

Throws:

IOException

setDecryptor

public boolean setDecryptor(DataProcessor decryptor)
                     throws IOException

Specified by:

setDecryptor in interface DatabaseStream

Throws:

IOException

setDecryptorAndEncryptor

public boolean setDecryptorAndEncryptor(DataProcessor decryptor,
                                        DataProcessor encryptor)
                                 throws IOException

Specified by:

setDecryptorAndEncryptor in interface DatabaseStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface DatabaseStream

Throws:

IOException

delete

public void delete()
            throws IOException

Specified by:

delete in interface DatabaseStream

Throws:

IOException

rename

public void rename(String newName)
            throws IOException

Specified by:

rename in interface DatabaseStream

Throws:

IOException

getModifiedTime

public Time getModifiedTime()

Specified by:

getModifiedTime in interface DatabaseStream

setModifiedTime

public boolean setModifiedTime(Time t)

Specified by:

setModifiedTime in interface DatabaseStream