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// regarding copyright ownership.  The ASF licenses this file
// to you 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
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package com.cloud.agent.manager.allocator;

import java.util.List;

import com.cloud.deploy.DeploymentPlan;
import com.cloud.deploy.DeploymentPlanner.ExcludeList;
import com.cloud.host.Host;
import com.cloud.host.HostVO;
import com.cloud.host.Host.Type;
import com.cloud.offering.ServiceOffering;
import com.cloud.utils.component.Adapter;
import com.cloud.vm.VirtualMachine;
import com.cloud.vm.VirtualMachineProfile;

public interface HostAllocator extends Adapter {

	/**
	 * @param UserVm vm
	 * @param ServiceOffering offering
	 **/
	boolean isVirtualMachineUpgradable(final VirtualMachine vm, final ServiceOffering offering);

	/** 
	* Determines which physical hosts are suitable to 
	* allocate the guest virtual machines on 
	* 
	* @param VirtualMachineProfile vmProfile
	* @param DeploymentPlan plan
	* @param GuestType type
	* @param ExcludeList avoid
	* @param int returnUpTo (use -1 to return all possible hosts)
	* @return List<Host> List of hosts that are suitable for VM allocation
	**/ 
	
	public List<Host> allocateTo(VirtualMachineProfile<?extends VirtualMachine> vmProfile, DeploymentPlan plan, Type type, ExcludeList avoid, int returnUpTo);
	
    /**
     * Determines which physical hosts are suitable to allocate the guest
     * virtual machines on.
     * 
     * Allocators must set any other hosts not considered for allocation in the
     * ExcludeList avoid. Thus the avoid set and the list of hosts suitable,
     * together must cover the entire host set in the cluster.
     * 
     * @param VirtualMachineProfile
     *            vmProfile
     * @param DeploymentPlan
     *            plan
     * @param GuestType
     *            type
     * @param ExcludeList
     *            avoid
     * @param int returnUpTo (use -1 to return all possible hosts)
     * @param boolean considerReservedCapacity (default should be true, set to
     *        false if host capacity calculation should not look at reserved
     *        capacity)
     * @return List<Host> List of hosts that are suitable for VM allocation
     **/ 
    
    public List<Host> allocateTo(VirtualMachineProfile<?extends VirtualMachine> vmProfile, DeploymentPlan plan, Type type, ExcludeList avoid, int returnUpTo, boolean considerReservedCapacity);

    /**
     * Determines which physical hosts are suitable to allocate the guest
     * virtual machines on.
     * 
     * Allocators must set any other hosts not considered for allocation in the
     * ExcludeList avoid. Thus the avoid set and the list of hosts suitable,
     * together must cover the entire host set in the cluster.
     * 
     * @param VirtualMachineProfile
     *            vmProfile
     * @param DeploymentPlan
     *            plan
     * @param GuestType
     *            type
     * @param ExcludeList
     *            avoid
     * @param List
     *            <HostVO> hosts
     * @param int returnUpTo (use -1 to return all possible hosts)
     * @param boolean considerReservedCapacity (default should be true, set to
     *        false if host capacity calculation should not look at reserved
     *        capacity)
     * @return List<Host> List of hosts that are suitable for VM allocation
     **/
     public List<Host> allocateTo(VirtualMachineProfile<? extends VirtualMachine> vmProfile, DeploymentPlan plan, Type type, ExcludeList avoid, List<HostVO> hosts, int returnUpTo, boolean considerReservedCapacity);

     public static int RETURN_UPTO_ALL = -1;

}
