org.fusesource.hawtdb.api

Interface Allocator

All Known Implementing Classes:

SimpleAllocator

public interface Allocator

Handles allocation management of resources. Used for page allocations in a Paged resource.

Author:

Hiram Chirino

Method Summary

Modifier and Type	Method and Description
int	alloc(int count) Allocates a continuous number of items and returns the position of first item in the sequence.
void	clear() Frees all previous allocations.
void	free(int firstPage, int count) Frees a given number of items at a given position.
Ranges	getFreeRanges()
int	getLimit()
boolean	isAllocated(int page)
void	setFreeRanges(Ranges freeList)
void	unfree(int firstPage, int count) Undoes a previous free method call.

Method Detail

alloc

int alloc(int count)
   throws OutOfSpaceException

Allocates a continuous number of items and returns the position of first item in the sequence.

Throws:

OutOfSpaceException

free

void free(int firstPage,
          int count)

Frees a given number of items at a given position.

unfree

void unfree(int firstPage,
            int count)
     throws UnsupportedOperationException

Undoes a previous free method call. optional method. implementations my throw UnsupportedOperationException

Throws:

UnsupportedOperationException - may be thrown by some allocators.

clear

void clear()
    throws UnsupportedOperationException

Frees all previous allocations. optional method. implementations my throw UnsupportedOperationException

Throws:

UnsupportedOperationException

getLimit

int getLimit()

Returns:

the maximum number of pages that this allocator will allocate.

isAllocated

boolean isAllocated(int page)

Parameters:

page -

Returns:

true if the page has been allocated.

setFreeRanges

void setFreeRanges(Ranges freeList)

getFreeRanges

Ranges getFreeRanges()