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	mojays	2	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			}