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/*
* Copyright 2015 Terracotta, Inc., a Software AG company.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.terracotta.offheapstore.paging;
/**
*
* @author cdennis
*/
public interface PageSource {
/**
* Attempt to allocate a page of the given size.
*
* Allocations identified as thieves will if necessary 'steal' space from
* previous allocations identified as 'victims' in order to fulfill the
* allocation request. owner is the area from which the
* returned page can subsequently be stolen or recovered. This is most likely
* to be the calling instance.
*
* @param size size of page to allocate
* @param thief {@code true} if the allocation can steal space from victims
* @param victim {@code true} if the allocated page should be eligible for stealing
* @param owner owner from which subsequent steal should occur
* @return an allocated page, or {@code null} in the case of failure
*/
Page allocate(int size, boolean thief, boolean victim, OffHeapStorageArea owner);
void free(Page page);
}