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 appl.parallel.client.DataServer;
import appl.parallel.spmd.split.DataPartition;
import edu.bonn.xulu.plugin.data.grid.MultiGrid;

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