Package com.mckoi.store

Interface JournalledResource

All Known Implementing Classes:

JournalledSystem.AbstractResource, JournalledSystem.NonLoggingResource, JournalledSystem.Resource

interface JournalledResource

An interface that allows for the reading and writing of pages to/from a journalled.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the resource.
void	delete()	Deletes the resource.
boolean	exists()	Returns true if the resource currently exists.
long	getID()	Returns a unique id for this resource.
int	getPageSize()	Returns the page size.
long	getSize()	Returns the current size of this resource.
void	open(boolean read_only)	Opens the resource.
void	read(long page_number, byte[] buf, int off)	Reads a page of some previously specified size into the byte array.
void	setSize(long size)	Sets the new size of the resource.
void	write(long page_number, byte[] buf, int off, int len)	Writes a page of some previously specified size to the top log.

Method Detail

getPageSize

int getPageSize()

Returns the page size.

getID

long getID()

Returns a unique id for this resource.

read

void read(long page_number,
          byte[] buf,
          int off)
   throws java.io.IOException

Reads a page of some previously specified size into the byte array.

Throws:

java.io.IOException

write

void write(long page_number,
           byte[] buf,
           int off,
           int len)
    throws java.io.IOException

Writes a page of some previously specified size to the top log. This will add a single entry to the log and any 'read' operations after will contain the written data.

Throws:

java.io.IOException

setSize

void setSize(long size)
      throws java.io.IOException

Sets the new size of the resource. This will add a single entry to the log.

Throws:

java.io.IOException

getSize

long getSize()
      throws java.io.IOException

Returns the current size of this resource.

Throws:

java.io.IOException

open

void open(boolean read_only)
   throws java.io.IOException

Opens the resource.

Throws:

java.io.IOException

close

void close()
    throws java.io.IOException

Closes the resource. This will actually simply log that the resource has been closed.

Throws:

java.io.IOException

delete

void delete()
     throws java.io.IOException

Deletes the resource. This will actually simply log that the resource has been deleted.

Throws:

java.io.IOException

exists

boolean exists()

Returns true if the resource currently exists.