com.sleepycat.db
Class CacheFile

java.lang.Object
  com.sleepycat.db.CacheFile

public class CacheFile

extends Object

This class allows applications to modify settings for a Database using the Database.getCacheFile.

Method Summary

long	getMaximumSize() Return the maximum size for the file backing the database, or 0 if no maximum file size has been configured.
boolean	getNoFile() Return if the opening of backing temporary files for in-memory databases has been disallowed.
CacheFilePriority	getPriority() Return the cache priority for pages from the specified file.
boolean	getUnlink() Return if the file will be removed when the last reference to it is closed.
void	setMaximumSize(long bytes) Set the maximum size for the file backing the database.
void	setNoFile(boolean onoff) Disallow opening backing temporary files for in-memory databases, even if they expand to fill the entire cache.
void	setPriority(CacheFilePriority priority) Set the cache priority for pages from the specified file.
void	setUnlink(boolean onoff) Remove the file when the last reference to it is closed.

Methods inherited from class java.lang.Object

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

Method Detail

getPriority

public CacheFilePriority getPriority()
                              throws DatabaseException

Return the cache priority for pages from the specified file.

This method may be called at any time during the life of the application.

Returns:

The cache priority for pages from the specified file.

Throws:

DatabaseException - if a failure occurs.

setPriority

public void setPriority(CacheFilePriority priority)
                 throws DatabaseException

Set the cache priority for pages from the specified file.

The priority of a page biases the replacement algorithm to be more or less likely to discard a page when space is needed in the buffer pool. The bias is temporary, and pages will eventually be discarded if they are not referenced again. Setting the priority is only advisory, and does not guarantee pages will be treated in a specific way.

This method may be called at any time during the life of the application.

Parameters:

priority - The cache priority for pages from the specified file.

Throws:

DatabaseException - if a failure occurs.

getMaximumSize

public long getMaximumSize()
                    throws DatabaseException

Return the maximum size for the file backing the database, or 0 if no maximum file size has been configured.

This method may be called at any time during the life of the application.

Returns:

The maximum size for the file backing the database, or 0 if no maximum file size has been configured.

Throws:

DatabaseException - if a failure occurs.

setMaximumSize

public void setMaximumSize(long bytes)
                    throws DatabaseException

Set the maximum size for the file backing the database.

Attempts to allocate new pages in the file after the limit has been reached will fail.

This method may be called at any time during the life of the application.

Parameters:

bytes - The maximum size for the file backing the database.

Throws:

DatabaseException - if a failure occurs.

getNoFile

public boolean getNoFile()
                  throws DatabaseException

Return if the opening of backing temporary files for in-memory databases has been disallowed.

This method may be called at any time during the life of the application.

Returns:

If the opening of backing temporary files for in-memory databases has been disallowed.

Throws:

DatabaseException - if a failure occurs.

setNoFile

public void setNoFile(boolean onoff)
               throws DatabaseException

Disallow opening backing temporary files for in-memory databases, even if they expand to fill the entire cache.

Attempts to create new file pages after the cache has been filled will fail.

This method may be called at any time during the life of the application.

Parameters:

onoff - If true, disallow opening backing temporary files for in-memory databases, even if they expand to fill the entire cache.

Throws:

DatabaseException - if a failure occurs.

getUnlink

public boolean getUnlink()
                  throws DatabaseException

Return if the file will be removed when the last reference to it is closed.

This method may be called at any time during the life of the application.

Returns:

If the file will be removed when the last reference to it is closed.

Throws:

DatabaseException - if a failure occurs.

setUnlink

public void setUnlink(boolean onoff)
               throws DatabaseException

Remove the file when the last reference to it is closed.

This method may be called at any time during the life of the application.

Parameters:

onoff - If true, remove the file when the last reference to it is closed.

Throws:

DatabaseException - if a failure occurs.