com.aspc.DBObj.Internal.Holders

Class RootClassHolder

java.lang.Object

com.aspc.DBObj.Internal.Holders.RootClassHolder

All Implemented Interfaces:

MemoryHandler

public final class RootClassHolder
extends java.lang.Object
implements MemoryHandler

secondary cache for classes. THREAD MODE: MULTI-THREADED shared

Since:

17 December, 2002

Author:

Nigel Leck

Nested Class Summary

Nested classes/interfaces inherited from interface com.aspc.remote.memory.MemoryHandler

MemoryHandler.Cost

Field Summary

Fields

Modifier and Type	Field and Description
java.util.concurrent.atomic.AtomicBoolean	fullLoad full load.

Constructor Summary

Constructors

Constructor and Description
RootClassHolder(DBClass dbClass, VirtualDB layer) create a new secondary cache holder.

Method Summary

Modifier and Type	Method and Description
void	checkFullList(long rowUID) check that the row exist in the full list
PossibleRowsHolder	fetchFullPR() fetch the full list
PossibleRowsHolder	findFullList(boolean lock) find the full list of rows for this class.
long	freeMemory(double percentage) free the memory
MemoryHandler.Cost	getCost() the memory cost for this memory handler
long	getEstimatedSize() how much size are we holding ?
DBField[]	getFieldList() the field list
long	getLastAccessed() when was it last accessed ?
FieldValuesHolder	getValues(java.lang.String fieldId) return the values for this field
boolean	hasFieldCache() do we have any field cache ?
long	panicFreeMemory() Clear all memory ASAP.
long	queuedFreeMemory(double percentage) queue to free the memory
void	removeValues(java.lang.String fieldId) remove the values for this field
void	setHoldHardLink(boolean flag) turn on/off the hard links for this class
static void	simulateSlowLoad(long sleepMS) simulate heavy load by sleeping in select spots.
long	tidyUp() tidy up the memory used
java.lang.String	toString() display the details of this holder
void	unlockFullList() unlock the list.

Methods inherited from class java.lang.Object

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

Field Detail

fullLoad

public final java.util.concurrent.atomic.AtomicBoolean fullLoad

full load.

Constructor Detail

RootClassHolder

public RootClassHolder(@Nonnull
                       DBClass dbClass,
                       @Nonnull
                       VirtualDB layer)
                throws java.lang.InterruptedException

create a new secondary cache holder.

Parameters:

dbClass - the class to hold.

layer - the layer.

Throws:

java.lang.InterruptedException - was interrupted.

Method Detail

unlockFullList

public void unlockFullList()

unlock the list.

setHoldHardLink

public void setHoldHardLink(boolean flag)

turn on/off the hard links for this class

Parameters:

flag - turn on/off

checkFullList

public void checkFullList(long rowUID)

check that the row exist in the full list

Parameters:

rowUID - the row to check

fetchFullPR

@CheckReturnValue
 @Nullable
public PossibleRowsHolder fetchFullPR()

fetch the full list

Returns:

the full list of rows for this class

findFullList

@CheckReturnValue
 @Nonnull
public PossibleRowsHolder findFullList(boolean lock)
                                                            throws java.lang.Exception

find the full list of rows for this class.

Parameters:

lock - lock the

Returns:

the full list of rows for this class

Throws:

java.lang.Exception - a serious problem

removeValues

public void removeValues(@Nonnull
                         java.lang.String fieldId)

remove the values for this field

Parameters:

fieldId - the field to remove the values for

getValues

@CheckReturnValue
 @Nonnull
public FieldValuesHolder getValues(@Nonnull
                                                               java.lang.String fieldId)

return the values for this field

Parameters:

fieldId - the field to get the values for

Returns:

the values

getFieldList

@CheckReturnValue
 @Nonnull
public DBField[] getFieldList()

the field list

Returns:

the field list

freeMemory

@Nonnegative
public long freeMemory(@Nonnegative
                                    double percentage)

free the memory

Specified by:

freeMemory in interface MemoryHandler

Parameters:

percentage - the percentage of the memory to free

Returns:

the amount freed

getCost

@CheckReturnValue
public MemoryHandler.Cost getCost()

the memory cost for this memory handler

Specified by:

getCost in interface MemoryHandler

Returns:

the cost

getEstimatedSize

@CheckReturnValue
 @Nonnegative
public long getEstimatedSize()

how much size are we holding ?

Specified by:

getEstimatedSize in interface MemoryHandler

Returns:

the size in bytes

getLastAccessed

@CheckReturnValue
 @Nonnegative
public long getLastAccessed()

when was it last accessed ?

Specified by:

getLastAccessed in interface MemoryHandler

Returns:

the last accessed time

panicFreeMemory

@Nonnegative
public long panicFreeMemory()

Clear all memory ASAP.

Specified by:

panicFreeMemory in interface MemoryHandler

Returns:

The estimated total number of bytes released.

queuedFreeMemory

@Nonnegative
public long queuedFreeMemory(@Nonnegative
                                          double percentage)

queue to free the memory

Specified by:

queuedFreeMemory in interface MemoryHandler

Parameters:

percentage - the percentage of the memory to free

Returns:

the amount cleared

tidyUp

@Nonnegative
public long tidyUp()

tidy up the memory used

Specified by:

tidyUp in interface MemoryHandler

Returns:

amount cleared

toString

@CheckReturnValue
 @Nonnull
public java.lang.String toString()

display the details of this holder

Overrides:

toString in class java.lang.Object

Returns:

the details

hasFieldCache

@CheckReturnValue
public boolean hasFieldCache()

do we have any field cache ?

Returns:

true if we have some cache.

simulateSlowLoad

public static void simulateSlowLoad(@Nonnegative
                                    long sleepMS)

simulate heavy load by sleeping in select spots.

Parameters:

sleepMS - number of milliseconds to sleep