com.bigdata.rwstore.sector

Interface ISectorManager

All Known Implementing Classes:

MemoryManager

public interface ISectorManager

The ISectorManager defines the contract required to manage a set of SectorAllocators. The ISectorManager is passed to the SectorAllocator constructors and they will callback to manage their free list availability, and to trim the allocated storage if required.

Author:

Martyn Cutcher

Method Summary

Methods

Modifier and Type	Method and Description
void	addToFreeList(SectorAllocator sectorAllocator) When sufficient allocations have been freed for recycling that a threshold of availability of reached for all block sizes, then the allocator calls back to the SectorManager to signal it is available to be returned to the free list.
void	removeFromFreeList(SectorAllocator sectorAllocator) This request is made when the sectorAllocator no longer has a full set of block allocations available.
void	trimSector(long trim, SectorAllocator sector) When a sector is first created, it will remain at the head of the free list until one of two conditions has been reached: The allocation has been saturated. The bit space has been filled.

Method Detail

removeFromFreeList

void removeFromFreeList(SectorAllocator sectorAllocator)

This request is made when the sectorAllocator no longer has a full set of block allocations available. The allocator will issue this callback to help the SectorManager manage an effective freelist of available allocators.

Parameters:

sectorAllocator - to be removed

addToFreeList

void addToFreeList(SectorAllocator sectorAllocator)

When sufficient allocations have been freed for recycling that a threshold of availability of reached for all block sizes, then the allocator calls back to the SectorManager to signal it is available to be returned to the free list.

Parameters:

sectorAllocator - to be added

trimSector

void trimSector(long trim,
              SectorAllocator sector)

When a sector is first created, it will remain at the head of the free list until one of two conditions has been reached:

1. The allocation has been saturated.
2. The bit space has been filled.

In the case of (2), then it is possible that significant allocation space cannot be utilized - which will happen if the average allocation is less than 1K. In this situation, the sector can be trimmed and the space made available to the next sector. trimSector will only be called in this condition - on the first occasion that the allocator is removed from the freeList.

Parameters:

trim - - the amount by which the sector allocation can be reduced