global
Class AbstractBufMgrFrameDesc

java.lang.Object
  global.AbstractBufMgrFrameDesc

All Implemented Interfaces:

GlobalConst

Direct Known Subclasses:

FrameDesc

public abstract class AbstractBufMgrFrameDesc

extends java.lang.Object

implements GlobalConst

Field Summary

Fields inherited from interface global.GlobalConst

INVALID_PAGE, MAX_NAME, MAXATTRNAME, MAXFILENAME, MAXINDEXNAME, MINIBASE_BUFFER_POOL_SIZE, MINIBASE_DB_SIZE, MINIBASE_DEFAULT_SHAREDMEM_SIZE, MINIBASE_MAX_TRANSACTIONS, MINIBASE_MAXARRSIZE, NUMBUF, PAGE_SIZE, PAGESIZE

Constructor Summary

AbstractBufMgrFrameDesc()

Method Summary

abstract int	getPageNo()
abstract int	getPinCount() Returns the pin count of a certain frame page.
abstract boolean	isDirty() the dirty bit, 1 (TRUE) stands for this frame is altered, 0 (FALSE) for clean frames.
abstract int	pin() Increments the pin count of a certain frame page when the page is pinned.
abstract int	unpin() Decrements the pin count of a frame when the page is unpinned.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractBufMgrFrameDesc

public AbstractBufMgrFrameDesc()

Method Detail

getPinCount

public abstract int getPinCount()

Returns the pin count of a certain frame page.

Returns:

the pin count number.

pin

public abstract int pin()

Increments the pin count of a certain frame page when the page is pinned.

Returns:

the incremented pin count.

unpin

public abstract int unpin()

Decrements the pin count of a frame when the page is unpinned. If the pin count is equal to or less than zero, the pin count will be zero.

Returns:

the decremented pin count.

getPageNo

public abstract int getPageNo()

isDirty

public abstract boolean isDirty()

the dirty bit, 1 (TRUE) stands for this frame is altered, 0 (FALSE) for clean frames.