parallel/spmd/MultiDataObject.java

package appl.parallel.spmd;

import java.rmi.RemoteException;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;

import schmitzm.data.WritableGrid;

import edu.bonn.xulu.plugin.data.grid.MultiGrid;

import appl.parallel.client.DataServer;
import appl.parallel.server.PartitionDataServer;
import appl.parallel.spmd.split.DataPartition;

/**
 * A multi data object stores multiple elements of the same type.
 * While the related {@link MultiDataInfo} stores only Information about 
 * multi-data and is used by Xulu / V for transfer of metadata, this class
 * is a actual user object. The user can retrieve a multidata object e.g. via the
 * {@link SPMDServerController} and work with it (e.g. add elements)
 * 
 * @see SPMDServerInterface#getMultiData(String)
 * @see MultiDataInfo
 * 
 * @author Dominik Appl
 **/

public class MultiDataObject {

        private final Logger LOG = LogManager.getLogger(this.getClass().getName());

        private final MultiDataInfo multiDataInfo;

        private final DataServer dataServer;

        private MultiGrid managedGrid = null;

        /**
         * Construct a new Multidata object
         * 
         * @param info a {@link MultiDataInfo} object with the identification of the objects
         * @param dataServer a dataServer which is responsible for the actual loading of the data
         */
        public MultiDataObject(MultiDataInfo info, DataServer dataServer) {
                this.multiDataInfo = info;
                this.dataServer = dataServer;
        }

        /**
         * @param idx the position of the element
         * @return the element at the indicated position
         */
        public Object getElement(int idx) {
                try {
                        checkIndex(idx);
                        return dataServer.getData(multiDataInfo.getMultiID(idx));
                } catch (RemoteException e) {
                        LOG.error("RemoteExeception while retrieving data with ID "
                                        + multiDataInfo.getMultiID(idx)
                                        + " from PartitionDataServer");
                }
                return null;
        }

        /**
         * checks whether the indicated index is valid
         * @throws ArrayIndexOutOfBoundsException if idx is below zero or higher than number of elements 
         */
        private void checkIndex(int idx) {
                if ((idx > multiDataInfo.getCount() - 1) || idx <0 )
                        throw new ArrayIndexOutOfBoundsException("The Element with index "
                                        + idx + " was requested, but the MultiDataObject has only "
                                        + multiDataInfo.getCount() + " elements.");

        }

        /**
         * @return the number of elements in the multidataobject
         */
        public int getCount() {
                return multiDataInfo.getCount();
        }

        /**
         * Adds an element to MultiDataObjects. Method should be thread safe.
         * 
         * @return the index of the new element
         */
        public synchronized int addElement() {
                //the new ID of the MultiDataObject is generated by making
                //the first id negative and than subtracting the index from 
                //the ID
                int idx = multiDataInfo.getCount() - 1;
                try {
                        if (idx == -1)
                                throw new UnsupportedOperationException(
                                                "The MultiDataInfo must have at least one element!");
                        //simply get the first element and create a empty one.
                        int firstElementID = multiDataInfo.getMultiID(0);
                        DataPartition firstElement = dataServer.getData(firstElementID);
                        //generate a new id by making the first ID negative and subtracting the index value
                        int newID = multiDataInfo.getNewIDForIndex(idx + 1);
                        //there is a rare chance of colliding with existing ids:
                        while (dataServer.getData(newID) != null) {
                                newID--;
                        }
                        //create new element 
                        DataPartition newElement = firstElement.getEmpty(newID);
                        multiDataInfo.addElement(newID);
                        //add the element to the dataServer and to the managed MultiGrid (if any)
                        dataServer.addData(newElement);
                        if (managedGrid != null)
                                managedGrid.addGrid((WritableGrid) newElement);
                        return idx + 1;
                } catch (RemoteException e) {
                        LOG
                                        .error("RemoteExeception while trying to add a new element with idx "
                                                        + idx + " to MultiData");
                }
                return 0;
        }

        /**
         * Adds an element with the specified ID.
         * 
         * @param id the id of the element to add
         * @return the index of the new element or 0 if an error occurred
         */
        public int addElement(int id) {
                //actual maxIndex
                int idx = multiDataInfo.getCount() - 1;
                try {
                        if (idx == -1)
                                throw new UnsupportedOperationException(
                                                "The MultiDataInfo must have at least one element!");
                        //simply get the first element and create a empty one.
                        int firstElementID = multiDataInfo.getMultiID(0);
                        DataPartition firstElement = dataServer.getData(firstElementID);

                        //create new element 
                        DataPartition newElement = firstElement.getEmpty(id);
                        multiDataInfo.addElement(id);
                        //add the element to the dataServer and to the managed MultiGrid (if any)
                        dataServer.addData(newElement);
                        if (managedGrid != null)
                                managedGrid.addGrid((WritableGrid) newElement);
                        return idx + 1;
                } catch (RemoteException e) {
                        LOG
                                        .error("RemoteExeception while trying to add a new element with idx "
                                                        + idx + " to MultiData");
                }
                return 0;
        }

        /**
         * Manages a multigrid, which means that when a new element is added 
         * to the multiObject, then the same element is also added to 
         * the managed multiGrid.
         * 
         * @param toManageMultiGrid the grid to be managed. Only one grid will be 
         * managed at a time.
         *  
         */
        public void setManagedGrid(MultiGrid toManageMultiGrid) {
                this.managedGrid = toManageMultiGrid;
        }

        /**
         * @return the encapsulted {@link MultiDataInfo}
         */
        public MultiDataInfo getMultiInfo() {
                return this.multiDataInfo;
        }

        public String getName() {
                return multiDataInfo.getName();
        }

        /**
         * removes the element with the specified index from the dataServer
         * 
         * @param idx the element
         */
        public void deleteElement(int idx) {
                checkIndex(idx);
                try {
                        dataServer.removeData(multiDataInfo.getMultiID(idx));
                } catch (RemoteException e) {
                        LOG.error("Could not reach DataServer" , e);
                        e.printStackTrace();
                }       
        }
}
1	package appl.parallel.spmd;
2
3	import java.rmi.RemoteException;
4
5	import org.apache.log4j.LogManager;
6	import org.apache.log4j.Logger;
7
8	import schmitzm.data.WritableGrid;
9
10	import edu.bonn.xulu.plugin.data.grid.MultiGrid;
11
12	import appl.parallel.client.DataServer;
13	import appl.parallel.server.PartitionDataServer;
14	import appl.parallel.spmd.split.DataPartition;
15
16	/**
17	* A multi data object stores multiple elements of the same type.
18	* While the related {@link MultiDataInfo} stores only Information about
19	* multi-data and is used by Xulu / V for transfer of metadata, this class
20	* is a actual user object. The user can retrieve a multidata object e.g. via the
21	* {@link SPMDServerController} and work with it (e.g. add elements)
22	*
23	* @see SPMDServerInterface#getMultiData(String)
24	* @see MultiDataInfo
25	*
26	* @author Dominik Appl
27	**/
28
29	public class MultiDataObject {
30
31	private final Logger LOG = LogManager.getLogger(this.getClass().getName());
32
33	private final MultiDataInfo multiDataInfo;
34
35	private final DataServer dataServer;
36
37	private MultiGrid managedGrid = null;
38
39	/**
40	* Construct a new Multidata object
41	*
42	* @param info a {@link MultiDataInfo} object with the identification of the objects
43	* @param dataServer a dataServer which is responsible for the actual loading of the data
44	*/
45	public MultiDataObject(MultiDataInfo info, DataServer dataServer) {
46	this.multiDataInfo = info;
47	this.dataServer = dataServer;
48	}
49
50	/**
51	* @param idx the position of the element
52	* @return the element at the indicated position
53	*/
54	public Object getElement(int idx) {
55	try {
56	checkIndex(idx);
57	return dataServer.getData(multiDataInfo.getMultiID(idx));
58	} catch (RemoteException e) {
59	LOG.error("RemoteExeception while retrieving data with ID "
60	+ multiDataInfo.getMultiID(idx)
61	+ " from PartitionDataServer");
62	}
63	return null;
64	}
65
66	/**
67	* checks whether the indicated index is valid
68	* @throws ArrayIndexOutOfBoundsException if idx is below zero or higher than number of elements
69	*/
70	private void checkIndex(int idx) {
71	if ((idx > multiDataInfo.getCount() - 1) \|\| idx <0 )
72	throw new ArrayIndexOutOfBoundsException("The Element with index "
73	+ idx + " was requested, but the MultiDataObject has only "
74	+ multiDataInfo.getCount() + " elements.");
75
76	}
77
78	/**
79	* @return the number of elements in the multidataobject
80	*/
81	public int getCount() {
82	return multiDataInfo.getCount();
83	}
84
85	/**
86	* Adds an element to MultiDataObjects. Method should be thread safe.
87	*
88	* @return the index of the new element
89	*/
90	public synchronized int addElement() {
91	//the new ID of the MultiDataObject is generated by making
92	//the first id negative and than subtracting the index from
93	//the ID
94	int idx = multiDataInfo.getCount() - 1;
95	try {
96	if (idx == -1)
97	throw new UnsupportedOperationException(
98	"The MultiDataInfo must have at least one element!");
99	//simply get the first element and create a empty one.
100	int firstElementID = multiDataInfo.getMultiID(0);
101	DataPartition firstElement = dataServer.getData(firstElementID);
102	//generate a new id by making the first ID negative and subtracting the index value
103	int newID = multiDataInfo.getNewIDForIndex(idx + 1);
104	//there is a rare chance of colliding with existing ids:
105	while (dataServer.getData(newID) != null) {
106	newID--;
107	}
108	//create new element
109	DataPartition newElement = firstElement.getEmpty(newID);
110	multiDataInfo.addElement(newID);
111	//add the element to the dataServer and to the managed MultiGrid (if any)
112	dataServer.addData(newElement);
113	if (managedGrid != null)
114	managedGrid.addGrid((WritableGrid) newElement);
115	return idx + 1;
116	} catch (RemoteException e) {
117	LOG
118	.error("RemoteExeception while trying to add a new element with idx "
119	+ idx + " to MultiData");
120	}
121	return 0;
122	}
123
124	/**
125	* Adds an element with the specified ID.
126	*
127	* @param id the id of the element to add
128	* @return the index of the new element or 0 if an error occurred
129	*/
130	public int addElement(int id) {
131	//actual maxIndex
132	int idx = multiDataInfo.getCount() - 1;
133	try {
134	if (idx == -1)
135	throw new UnsupportedOperationException(
136	"The MultiDataInfo must have at least one element!");
137	//simply get the first element and create a empty one.
138	int firstElementID = multiDataInfo.getMultiID(0);
139	DataPartition firstElement = dataServer.getData(firstElementID);
140
141	//create new element
142	DataPartition newElement = firstElement.getEmpty(id);
143	multiDataInfo.addElement(id);
144	//add the element to the dataServer and to the managed MultiGrid (if any)
145	dataServer.addData(newElement);
146	if (managedGrid != null)
147	managedGrid.addGrid((WritableGrid) newElement);
148	return idx + 1;
149	} catch (RemoteException e) {
150	LOG
151	.error("RemoteExeception while trying to add a new element with idx "
152	+ idx + " to MultiData");
153	}
154	return 0;
155	}
156
157	/**
158	* Manages a multigrid, which means that when a new element is added
159	* to the multiObject, then the same element is also added to
160	* the managed multiGrid.
161	*
162	* @param toManageMultiGrid the grid to be managed. Only one grid will be
163	* managed at a time.
164	*
165	*/
166	public void setManagedGrid(MultiGrid toManageMultiGrid) {
167	this.managedGrid = toManageMultiGrid;
168	}
169
170	/**
171	* @return the encapsulted {@link MultiDataInfo}
172	*/
173	public MultiDataInfo getMultiInfo() {
174	return this.multiDataInfo;
175	}
176
177	public String getName() {
178	return multiDataInfo.getName();
179	}
180
181	/**
182	* removes the element with the specified index from the dataServer
183	*
184	* @param idx the element
185	*/
186	public void deleteElement(int idx) {
187	checkIndex(idx);
188	try {
189	dataServer.removeData(multiDataInfo.getMultiID(idx));
190	} catch (RemoteException e) {
191	LOG.error("Could not reach DataServer" , e);
192	e.printStackTrace();
193	}
194	}
195	}