CloudSim源代码学习之虚拟机分配策略.doc

package org.cloudbus.cloudsim;import java.util.List;/An ordered collection (also known as a sequence)import java.util.Map;/【补充：针对java.util.Map的Value做排序 来源：360doc】针对java.util.Map的Value做排序：/Map的特性：/Map内涵数据是Key - Value的架构集合体，而Key是属于Set的架构集合体，也就是说Key的值是唯一的，而Value的值可以重复。一般常用的对象是HashMap或TreeMap，如果考虑效能的话，建议使用HashMap，如果希望Key值有顺序性，就使用TreeMap吧！所以Map的集合体，数据的摆放方式是没有顺序性的，我们需要借助有顺序性的集合体List来帮忙。/范例数据如下定义：/Map map_Data = new HashMap();/map_Data.put(A, 98);/map_Data.put(B, 50);/map_Data.put(C, 76);/map_Data.put(D, 23);/map_Data.put(E, 85);/System.out.println(map_Data);现在将Map集合体转换成List集合体，而List对象使用ArrayList来实做如下：/将map_Data由Map型态转成List型态的list_Data，以便进行排序/ListMap.Entry list_Data = new ArrayListMap.Entry(map_Data.entrySet();/透过Collections.sort(List l, Comparator c)方法来做排序的动作，由传入参数可以了解List l就是要排序的数据结构体，另外还需要一个Comparator c对象，此对象是用来评估List l中的任两对象的大小值，实做如下：/排序/Collections.sort(list_Data, new ComparatorMap.Entry()/ /public int compare(Map.Entry o1, Map.Entry o2)/ /return (o2.getValue() - o1.getValue();/);/上方的Comparator c参数是使用匿名类别的方式来实做的。所以排序完成的数据内容在list_Data这个对象中，将其印出来看结果：/System.out.println(list_Data); /*【VmAllocationPolicy 抽象类 代表数据中心主机到虚拟机的供应协议】 * VmAllocationPolicy is an abstract class that represents the provisioning * policy of hosts to virtual machines in a Datacentre. It supports【 two-stage * commit of reservation of hosts】: first, we reserve the host and, once * commited by the user, it is effectivelly allocated to he/she * * authorRodrigo N. Calheiros * authorAnton Beloglazov * sinceCloudSim Toolkit 1.0 */public abstract class VmAllocationPolicy /* The host list. 主机列表*/private List hostList;/限制泛型/*分配一新的VmAllocationPolicy对象 * Allocates a new VmAllocationPolicy object. * * param list Machines available in this Datacentre * * pre $none * post $none */public VmAllocationPolicy(List list) setHostList(list);/*分配主机给一特定虚拟机 * Allocates a host for a given VM. The host to be allocated is the one * that was already reserved. * * param vm virtual machine which the host is reserved to * * return $true if the host could be allocated; $false otherwise * * pre $none * post $none */public abstract boolean allocateHostForVm(Vm vm);/*分配一特定主机给指定虚拟机 * Allocates a specified host for a given VM. * * param vm virtual machine which the host is reserved to * * return $true if the host could be allocated; $false otherwise * * pre $none * post $none */public abstract boolean allocateHostForVm(Vm vm, Host host);/*【根据当前利用率最优虚拟机分配】 * Optimize allocation of the VMs according to current utilization. * * param vmList the vm list * param utilizationBound the utilization bound * param time the time * * return the array list hash map */public abstract ListMap optimizeAllocation(List vmList);/*释放主机 * Releases the host used by a VM. * * param vm the vm * * pre $none * post $none */public abstract void deallocateHostForVm(Vm vm);/*指定用户指定虚拟机上的主机 * Get the host that is executing the given VM belonging to the * given user. * * param vm the vm * * return the Host with the given vmID and userID; $null if not found * * pre $none * post $none */public abstract Host getHost(Vm vm);/* 与上面同样的功能 ？ * Get the host that is executing the given VM belonging to the * given user. * * param vmId the vm id * param userId the user id * * return the Host with the given vmID and userID; $null if not found * * pre $none * post $none */public abstract Host getHost(int vmId, int userId);/*设置主机列表 * Sets the host list. * * param hostList the new host list */protected void setH