ncsa.hdf.object.Group Maven / Gradle / Ivy
/*****************************************************************************
* Copyright by The HDF Group. *
* Copyright by the Board of Trustees of the University of Illinois. *
* All rights reserved. *
* *
* This file is part of the HDF Java Products distribution. *
* The full copyright notice, including terms governing use, modification, *
* and redistribution, is contained in the files COPYING and Copyright.html. *
* COPYING can be found at the root of the source code distribution tree. *
* Or, see http://hdfgroup.org/products/hdf-java/doc/Copyright.html. *
* If you do not have access to either file, you may request a copy from *
* [email protected]. *
****************************************************************************/
package ncsa.hdf.object;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;
import javax.swing.tree.DefaultMutableTreeNode;
/**
* Group is an abstract class. Current implementing classes are the H4Group and
* H5Group. This class includes general information of a group object such as
* members of a group and common operations on groups.
*
* Members of a group may include other groups, datasets or links.
*
*
* @version 1.1 9/4/2007
* @author Peter X. Cao
*/
public abstract class Group extends HObject {
/**
*
*/
private static final long serialVersionUID = 3913174542591568052L;
/**
* The list of members (Groups and Datasets) of this group in memory.
*/
private List memberList;
/**
* The parent group where this group is located. The parent of the root
* group is null.
*/
protected Group parent;
/**
* Total number of (Groups and Datasets) of this group in file.
*/
protected int nMembersInFile;
public static final int LINK_TYPE_HARD = 0;
public static final int LINK_TYPE_SOFT = 1;
public static final int LINK_TYPE_EXTERNAL = 64;
public static final int CRT_ORDER_TRACKED = 1;
public static final int CRT_ORDER_INDEXED = 2;
/**
* Constructs an instance of the group with specific name, path and parent
* group. An HDF data object must have a name. The path is the group path
* starting from the root. The parent group is the group where this group is
* located.
*
* For example, in H5Group(h5file, "grp", "/groups/", pgroup), "grp" is the
* name of the group, "/groups/" is the group path of the group, and pgroup
* the group where "grp" is located.
*
* @param theFile
* the file which containing the group.
* @param name
* the name of this group, e.g. "grp01".
* @param path
* the full path of this group, e.g. "/groups/".
* @param parent
* the parent of this group.
*/
public Group(FileFormat theFile, String name, String path, Group parent) {
this(theFile, name, path, parent, null);
}
/**
* @deprecated Not for public use in the future.
* Using {@link #Group(FileFormat, String, String, Group)}
*/
@Deprecated
public Group(FileFormat theFile, String name, String path, Group parent,
long[] oid) {
super(theFile, name, path, oid);
this.parent = parent;
}
/**
* Clears up member list and other resources in memory for the group. Since
* the destructor will clear memory space, the function is usually not
* needed.
*/
public void clear() {
if (memberList != null) {
((Vector) memberList).setSize(0);
}
}
/**
* Adds an object to the member list of this group in memory.
*
*
* @param object
* the HObject (Group or Dataset) to be added to the member list.
*/
public void addToMemberList(HObject object) {
if (memberList == null) {
int size = Math.min(getNumberOfMembersInFile(), this
.getFileFormat().getMaxMembers());
memberList = new Vector(size + 5);
}
if ((object != null) && !memberList.contains(object)) {
memberList.add(object);
}
}
/**
* Removes an object from the member list of this group in memory.
*
*
* @param object
* the HObject (Group or Dataset) to be removed from the member
* list.
*/
public void removeFromMemberList(HObject object) {
if (memberList != null) {
memberList.remove(object);
}
}
/**
* Returns the list of members of this group. The list is an java.awt.List
* containing Groups and Datasets.
*
* @return the list of members of this group.
*/
public List getMemberList() {
FileFormat theFile = this.getFileFormat();
String thePath = this.getPath();
String theName = this.getName();
if ((memberList == null) && (theFile != null)) {
int size = Math.min(getNumberOfMembersInFile(), this
.getFileFormat().getMaxMembers());
memberList = new Vector(size + 5); // avoid infinite loop search for
// groups without member
// find the memberList from the file by check the group path and
// name
// group may be created out of the structure tree
// (H4/5File.loadTree()).
try {
theFile.open();
} // load the file structure;
catch (Exception ex) {
;
}
DefaultMutableTreeNode root = (DefaultMutableTreeNode) theFile
.getRootNode();
if (root == null) {
return memberList;
}
Enumeration emu = root.depthFirstEnumeration();
Group g = null;
Object uObj = null;
while (emu.hasMoreElements()) {
uObj = ((DefaultMutableTreeNode) emu.nextElement())
.getUserObject();
if (uObj instanceof Group) {
g = (Group) uObj;
if (g.getPath() != null) // add this check to get rid of
// null exception
{
if ((this.isRoot() && g.isRoot())
|| (thePath.equals(g.getPath()) && g.getName()
.endsWith(theName))) {
memberList = g.getMemberList();
break;
}
}
}
}
}
return memberList;
}
/**
* Sets the name of the group.
*
* setName (String newName) changes the name of the group in memory and
* file.
*
* setName() updates the path in memory for all the objects that are under
* the group with the new name.
*
* @param newName
* The new name of the group.
*/
@Override
public void setName(String newName) throws Exception {
super.setName(newName);
if (memberList != null) {
int n = memberList.size();
HObject theObj = null;
for (int i = 0; i < n; i++) {
theObj = memberList.get(i);
theObj.setPath(this.getPath() + newName + HObject.separator);
}
}
}
/** Returns the parent group. */
public final Group getParent() {
return parent;
}
/**
* Checks if it is a root group.
*
* @return true if the group is a root group; otherwise, returns false.
*/
public final boolean isRoot() {
return (parent == null);
}
/**
* Returns the total number of members of this group in file.
*
* Current Java application such as HDFView cannot handle files with large
* numbers of objects (1,000,000 or more objects) due to JVM memory
* limitation. The max_members is used so that applications such as HDFView
* will load up to max_members number of objects. If the number of
* objects in file is larger than max_members, only
* max_members are loaded in memory.
*
* getNumberOfMembersInFile() returns the number of objects in this group.
* The number of objects in memory is obtained by getMemberList().size().
*
* @return Total number of members of this group in the file.
*/
public int getNumberOfMembersInFile() {
return nMembersInFile;
}
}