com.sun.electric.database.geometry.btree
Class MemoryPageStorage

java.lang.Object
  com.sun.electric.database.geometry.btree.PageStorage
      com.sun.electric.database.geometry.btree.CachingPageStorage
          com.sun.electric.database.geometry.btree.MemoryPageStorage

public class MemoryPageStorage
extends CachingPageStorage

A PageStorage that uses plain old memory.

Nested Class Summary

Nested classes/interfaces inherited from class com.sun.electric.database.geometry.btree.CachingPageStorage

CachingPageStorage.CachedPage

Constructor Summary

MemoryPageStorage(int pagesize)

Method Summary

void	close() close the PageStorage; invocation of any other methods after close() has undefined results
int	createPage() creates a new page with undefined contents; returns its pageid
void	fsync() no-op
void	fsync(int pageid) no-op
int	getNumPages() returns the number of pages; all pageids strictly less than this are valid
CachingPageStorage.CachedPage	getPage(int pageid, boolean readBytes) Creates space in the cache for pageid, but only actually reads the bytes if readBytes is true; if the page was not already in the cache and readBytes is false, subsequent calls to setDirty()/flush() will overwrite data previously on the page.
void	readPage(int pageid, byte[] buf, int ofs) reads a page
void	writePage(int pageid, byte[] buf, int ofs) Write a page through the cache to nonvolatile storage

Methods inherited from class com.sun.electric.database.geometry.btree.PageStorage

getPageSize

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryPageStorage

public MemoryPageStorage(int pagesize)

Method Detail

getNumPages

public int getNumPages()

Description copied from class: PageStorage

returns the number of pages; all pageids strictly less than this are valid

Specified by:

getNumPages in class PageStorage

createPage

public int createPage()

Description copied from class: PageStorage

creates a new page with undefined contents; returns its pageid

Specified by:

createPage in class PageStorage

fsync

public void fsync(int pageid)

no-op

Specified by:

fsync in class PageStorage

fsync

public void fsync()

no-op

Specified by:

fsync in class PageStorage

writePage

public void writePage(int pageid,
                      byte[] buf,
                      int ofs)

Description copied from class: CachingPageStorage

Write a page through the cache to nonvolatile storage

Specified by:

writePage in class CachingPageStorage

readPage

public void readPage(int pageid,
                     byte[] buf,
                     int ofs)

Description copied from class: PageStorage

reads a page

Specified by:

readPage in class PageStorage

close

public void close()

Description copied from class: PageStorage

close the PageStorage; invocation of any other methods after close() has undefined results

Specified by:

close in class PageStorage

getPage

public CachingPageStorage.CachedPage getPage(int pageid,
                                             boolean readBytes)

Description copied from class: CachingPageStorage

Creates space in the cache for pageid, but only actually reads the bytes if readBytes is true; if the page was not already in the cache and readBytes is false, subsequent calls to setDirty()/flush() will overwrite data previously on the page.

Specified by:

getPage in class CachingPageStorage