/*
Query.java
The query class is used to do database lookups and listings.
The Query class is serializable, in order to be passed over
an RMI link.
Created: 21 October 1996
Module By: Jonathan Abbey, jonabbey@arlut.utexas.edu
-----------------------------------------------------------------------
Ganymede Directory Management System
Copyright (C) 1996-2013
The University of Texas at Austin
Ganymede is a registered trademark of The University of Texas at Austin
Contact information
Author Email: ganymede_author@arlut.utexas.edu
Email mailing list: ganymede@arlut.utexas.edu
US Mail:
Computer Science Division
Applied Research Laboratories
The University of Texas at Austin
PO Box 8029, Austin TX 78713-8029
Telephone: (512) 835-3200
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package arlut.csd.ganymede.common;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Set;
import java.util.Vector;
/*------------------------------------------------------------------------------
class
Query
------------------------------------------------------------------------------*/
/**
* <p>The Query class is used to submit query requests to the GANYMEDE server,
* both for complex database searches and for simple object listings. A
* Query class can fully specify a boolean search expression on any field
* of any object type in the GANYMEDE database. Each Query, however, can
* only search one object type at a time.</p>
*
* <p>While providing support for arbitrarily complex queries, the Query
* class also includes constructors for the simple "list object" case.</p>
*/
public class Query implements java.io.Serializable {
static final long serialVersionUID = 7921652227732781133L;
// ---
/**
* <p>The id of the object type that the queryNodes are looking
* to match on.</p>
*
* <p>If this value is left at -1, objectName will be consulted
* instead.</p>
*/
public short objectType = -1;
/**
* <p>The name of the object type that the queryNodes are looking
* to match on.</p>
*
* <p>This value is consulted only if objectType is left at -1.</p>
*/
public String objectName = null;
/**
* <p>We want to be able to save a query on the server and re-issue it
* on behalf of the user. If we are saved, the name to save under
* will be here. We may or may not want it here.</p>
*
* <p>I don't believe anything in the server actually uses this yet.</p>
*/
public String saveName = null;
/**
* <p>The root of a graph of QueryNodes that encodes the desired
* search criteria.</p>
*/
public QueryNode root;
/**
* <p>If true, this query will only be matched against objects in the
* database that the user has permission to edit.</p>
*/
public boolean editableOnly;
/**
* <p>If true, this query will only be matched against the subset of
* objects in the database that the user has requested via
* the Session filter mechanism.</p>
*/
public boolean filtered = false;
/**
* <p>A Set of field id's in Short form that the server will take into
* account when returning a data dump. If null, all default fields
* should be returned.</p>
*/
private Set<Short> permitSet = null;
/**
* <p>If we are on the server, we'll have a generic reference to a
* GanymedeSession so that we can look up the description of the
* object type.</p>
*/
transient QueryDescriber describer = null;
/* -- */
/**
* <p>Constructor for fully specified query (base by id)</p>
*
* @param objectType numeric object type code to search over
* @param root root node of a boolean logic tree to be processed in an in-order traversal
* @param editableOnly if true, the server will only return objects that the user's session
* currently has permission to edit
*/
public Query(short objectType, QueryNode root, boolean editableOnly)
{
this.objectType = objectType;
this.root = root;
this.editableOnly = editableOnly;
objectName = null;
}
/**
* <p>Constructor for fully specified query (base by name)</p>
*
* @param objectName name of object type to query
* @param root root node of a boolean logic tree to be processed in an in-order traversal
* @param editableOnly if true, the server will only return objects that
* the user's session currently has permission to edit
*/
public Query(String objectName, QueryNode root, boolean editableOnly)
{
this.objectName = objectName;
this.root = root;
this.editableOnly = editableOnly;
objectType = -1;
}
/**
* <p>Constructor to create a query returning only editable objects (base by id)</p>
*
* @param objectType numeric object type code to search over
* @param root root node of a boolean logic tree to be processed in an in-order traversal
*/
public Query(short objectType, QueryNode root)
{
this.objectType = objectType;
this.root = root;
editableOnly = true;
objectName = null;
}
/**
* <p>Constructor to create a query returning only editable objects (base by name)</p>
*
* @param objectName name of object type to query
* @param root root node of a boolean logic tree to be processed in an in-order traversal
*/
public Query(String objectName, QueryNode root)
{
this.objectName = objectName;
this.root = root;
objectType = -1;
editableOnly = true;
}
/**
* <p>Constructor for a query to list all editable objects of the specified type.</p>
*
* @param objectType numeric object type code to search over
*/
public Query(short objectType)
{
this.objectType = objectType;
objectName = null;
root = null;
editableOnly = true;
}
/**
* <p>Constructor for a query to list all editable objects of the specified type.</p>
*
* @param objectName name of object type to query
*/
public Query(String objectName)
{
this.objectName = objectName;
objectType = -1;
root = null;
editableOnly = true;
}
/**
* <p>Sets a reference to a GanymedeSession on the server only, for
* use in providing more descriptive toString() results.</p>
*/
public void setDescriber(QueryDescriber describer)
{
this.describer = describer;
}
/**
* <p>This method determines whether the query engine will filter
* the query according to the current list of visible owner groups.
* Queries by default are filtered.</p>
*
* @param filtered If true, the query will be masked by ownership
*
* @see arlut.csd.ganymede.rmi.Session#filterQueries(java.util.Vector)
*/
public void setFiltered(boolean filtered)
{
this.filtered = filtered;
}
/**
* <p>This method resets the permitSet, allowing
* all fields to be returned by default.</p>
*/
public synchronized void resetPermitSet()
{
permitSet = null;
}
/**
* <p>This method returns true if this Query is requesting a restricted
* set of fields.</p>
*/
public boolean hasPermitSet()
{
return this.permitSet != null;
}
/**
* <p>This method adds a field identifier to the list of fields that
* may be returned. Once this method is called with a field
* identifier, the query will only return fields that have been
* explicitly added.</p>
*
* <p>resetPermitSet() may be called to reset the list to the
* initial allow-all state.</p>
*/
public synchronized void addField(short id)
{
if (permitSet == null)
{
permitSet = new HashSet<Short>();
}
permitSet.add(Short.valueOf(id));
}
/**
* <p>This method adds a field identifier to the list of fields that
* may be returned. Once this method is called with a field
* identifier, the query will only return fields that have been
* explicitly added.</p>
*
* <p>resetPermitSet() may be called to reset the
* list to the initial allow-all state.</p>
*/
public synchronized void removeField(short id)
{
if (permitSet == null)
{
return;
}
permitSet.remove(Short.valueOf(id));
}
/**
* <p>This method returns true if the field with the given id number
* should be returned.</p>
*/
public synchronized boolean returnField(short id)
{
if (permitSet == null)
{
return true;
}
return permitSet.contains(Short.valueOf(id));
}
/**
* <p>This method returns true if the field with the given id number
* should be returned.</p>
*/
public synchronized boolean returnField(Short value)
{
if (permitSet == null)
{
return true;
}
return permitSet.contains(value);
}
/**
* <p>Returns a copy of the restricted list of fields that this Query
* wants to have returned.</p>
*/
public synchronized Set<Short> getFieldSet()
{
if (permitSet == null)
{
return new HashSet<Short>();
}
else
{
return new HashSet<Short>(permitSet);
}
}
public String toString()
{
StringBuilder result = new StringBuilder();
if (objectType != -1)
{
result.append("objectType = ");
if (describer != null)
{
result.append(describer.describeType(objectType));
}
else
{
result.append(String.valueOf(objectType));
}
}
else
{
result.append("objectName = ");
result.append(objectName);
}
if (editableOnly)
{
result.append(",");
result.append("editable");
}
if (root != null)
{
result.append(",");
result.append(root.toString());
}
return result.toString();
}
public String describeField(short fieldId)
{
if (describer == null)
{
return "<" + String.valueOf(fieldId) + ">";
}
if (objectType != -1)
{
return describer.describeField(objectType, fieldId);
}
else
{
return describer.describeField(objectName, fieldId);
}
}
}