org.basex.io
Class TableMemAccess

java.lang.Object
  org.basex.io.TableAccess
      org.basex.io.TableMemAccess

public final class TableMemAccess
extends TableAccess

This class allows main memory access to the database table representation.

Author:

Workgroup DBIS, University of Konstanz 2005-08, ISC License, Christian Gruen

Constructor Summary

TableMemAccess(java.lang.String db, java.lang.String fn, int size)
Stores the file content in a long array.

Method Summary

void	close() Closes the table access.
void	delete(int pre, int size) Delete a range of entries.
void	flush() Flushes the table contents.
void	insert(int pre, byte[] entries) Insert entries.
int	read1(int p, int o) Reads a byte from the specified position and returns it as integer.
int	read2(int p, int o) Reads a short value from the specified position and returns it as integer.
int	read4(int p, int o) Reads an integer value from the specified position.
long	read5(int p, int o) Reads an integer value from the specified position.
void	write1(int p, int o, int v) Writes a byte to the specified position.
void	write2(int p, int o, int v) Writes 2 bytes to the specified position.
void	write4(int p, int o, int v) Writes an integer value to the specified position.
void	write5(int p, int o, long v) Writes a 5-byte value to the specified position.

Methods inherited from class java.lang.Object

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

Constructor Detail

TableMemAccess

public TableMemAccess(java.lang.String db,
                      java.lang.String fn,
                      int size)
               throws java.io.IOException

Stores the file content in a long array.

Parameters:

db - name of the database

fn - the file to be read

size - table size

Throws:

java.io.IOException - IO Exception

Method Detail

read1

public int read1(int p,
                 int o)

Description copied from class: TableAccess

Reads a byte from the specified position and returns it as integer.

Specified by:

read1 in class TableAccess

Parameters:

p - pre value

o - offset

Returns:

integer value

read2

public int read2(int p,
                 int o)

Description copied from class: TableAccess

Reads a short value from the specified position and returns it as integer.

Specified by:

read2 in class TableAccess

Parameters:

p - pre value

o - offset

Returns:

integer value

read4

public int read4(int p,
                 int o)

Description copied from class: TableAccess

Reads an integer value from the specified position.

Specified by:

read4 in class TableAccess

Parameters:

p - pre value

o - offset

Returns:

integer value

read5

public long read5(int p,
                  int o)

Description copied from class: TableAccess

Reads an integer value from the specified position.

Specified by:

read5 in class TableAccess

Parameters:

p - pre value

o - offset

Returns:

integer value

write1

public void write1(int p,
                   int o,
                   int v)

Description copied from class: TableAccess

Writes a byte to the specified position.

Specified by:

write1 in class TableAccess

Parameters:

p - pre value

o - offset

v - value to be written

write2

public void write2(int p,
                   int o,
                   int v)

Description copied from class: TableAccess

Writes 2 bytes to the specified position.

Specified by:

write2 in class TableAccess

Parameters:

p - pre value

o - offset

v - value to be written

write4

public void write4(int p,
                   int o,
                   int v)

Description copied from class: TableAccess

Writes an integer value to the specified position.

Specified by:

write4 in class TableAccess

Parameters:

p - pre value

o - offset

v - value to be written

write5

public void write5(int p,
                   int o,
                   long v)

Description copied from class: TableAccess

Writes a 5-byte value to the specified position.

Specified by:

write5 in class TableAccess

Parameters:

p - pre value

o - offset

v - value to be written

delete

public void delete(int pre,
                   int size)

Description copied from class: TableAccess

Delete a range of entries.

Specified by:

delete in class TableAccess

Parameters:

pre - pre value of the first node to delete

size - number of entries to be deleted

insert

public void insert(int pre,
                   byte[] entries)

Description copied from class: TableAccess

Insert entries.

Specified by:

insert in class TableAccess

Parameters:

pre - pre value of node to insert after

entries - array of bytes containing the entries to insert

flush

public void flush()

Description copied from class: TableAccess

Flushes the table contents.

Specified by:

flush in class TableAccess

close

public void close()

Description copied from class: TableAccess

Closes the table access.

Specified by:

close in class TableAccess