/*
* Copyright 1999-2006 University of Chicago
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.globus.rsl;
import java.util.*;
/**
* This class provides convieniene methods for
* accessing and manipulatig simple rsl expressions.
* The class provides methods for retreiving and setting
* values of specified attributes.
*/
public class RslAttributes {
protected RslNode rslTree;
/**
* Creates an empty RslAttributes object.
*/
public RslAttributes() {
rslTree = new RslNode();
}
/**
* Creates a new RslAttributes object with
* specified rsl parse tree.
*
* @param rslTree the rsl parse tree.
*/
public RslAttributes(RslNode rslTree) {
this.rslTree = rslTree;
}
/**
* Creates a new RslAttributes object from
* specified RSL string.
*
* @param rsl the rsl string.
* @exception ParseException if the rsl cannot be parsed.
*/
public RslAttributes(String rsl)
throws ParseException {
rslTree = RSLParser.parse(rsl);
}
/**
* Returns the rsl parse tree.
*
* @return the rsl parse tree.
*/
public RslNode getRslNode() {
return rslTree;
}
/**
* Returns a string value of the specified attribute.
* If the attribute contains multiple values the
* first one is returned.
*
* @param attribute the rsl attribute to return the value of.
* @return value of the relation. Null is returned if there is
* no such attribute of the attribute/value relation is
* not an equality relation.
*/
public String getSingle(String attribute) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null || nv.getOperator() != NameOpValue.EQ) return null;
Object obj = nv.getFirstValue();
if (obj != null && obj instanceof Value) {
return ((Value)obj).getCompleteValue();
} else {
return null;
}
}
/**
* Returns a list of strings for a specified attribute.
* For example for 'arguments' attribute.
*
* @param attribute the rsl attribute to return the values of.
* @return the list of values of the relation. Each value is
* a string. Null is returned if there is no such
* attribute or the attribute/values relation is not
* an equality relation.
*/
public List getMulti(String attribute) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null || nv.getOperator() != NameOpValue.EQ) return null;
List values = nv.getValues();
List list = new LinkedList();
Iterator iter = values.iterator();
Object obj;
while( iter.hasNext() ) {
obj = iter.next();
if (obj instanceof Value) {
list.add( ((Value)obj).getCompleteValue() );
}
}
return list;
}
/**
* Returns a key/value pair map for a specified attribute.
* For example for 'environment' attribute.
* Note: <I>Use getVariables() for rsl_substitution attribute.</I>
*
* @param attribute the rsl attribute to return the key/value pair map of.
* @return a key/value pair map. Null is returned if there is no such
* attribute defined or if the attribute/value relation is not
* an equality relation.
*/
public Map getMap(String attribute) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null || nv.getOperator() != NameOpValue.EQ) return null;
List values = nv.getValues();
Map map = new HashMap();
Iterator iter = values.iterator();
Object obj;
while( iter.hasNext() ) {
obj = iter.next();
if (obj instanceof List) {
String key, value;
List list = (List)obj;
if (list.size() != 2) continue; // must have 2 values!
obj = list.get(0);
if (obj instanceof Value) {
key = ((Value)obj).getCompleteValue();
} else {
continue;
}
obj = list.get(1);
if (obj instanceof Value) {
value = ((Value)obj).getCompleteValue();
} else {
continue;
}
map.put(key, value);
}
}
return map;
}
/**
* Returns a variable name/value pair map of variable definitions.
* Currently specified by the 'rsl_substitution' attribute.
*
* @param attribute the attribute that defines variables. Currently,
* only 'rsl_substitution' is supported.
* @return a variable name/value pair map. Null, if there is no
* definitions for a specified attribute.
*
*/
public Map getVariables(String attribute) {
Bindings binds = rslTree.getBindings(attribute);
if (binds == null) return null;
List values = binds.getValues();
Map map = new HashMap();
Iterator iter = values.iterator();
Binding binding;
while( iter.hasNext() ) {
binding = (Binding)iter.next();
map.put(binding.getName(),
binding.getValue().getCompleteValue());
}
return map;
}
/**
* Adds a new variable definition to the specified variable definitions
* attribute.
*
* @param attribute the variable definitions attribute - rsl_subsititution.
* @param varName the variable name to add.
* @param value the value of the variable to add.
*/
public void addVariable(String attribute, String varName, String value) {
Bindings binds = rslTree.getBindings(attribute);
if (binds == null) {
binds = new Bindings(attribute);
rslTree.put(binds);
}
binds.add(new Binding(varName, value));
}
/**
* Removes a specific variable definition given a variable name.
*
* @param attribute the attribute that defines variable definitions.
* @param varName the name of the variable to remove.
* @return true if the variable was successfully removed. Otherwise,
* returns false,
*/
public boolean removeVariable(String attribute, String varName) {
Bindings binds = rslTree.getBindings(attribute);
if (binds == null) return false;
return binds.removeVariable(varName);
}
/**
* Removes a specific attribute from attribute/value relations.
*
* @param attribute the attribute name to remove.
*/
public void remove(String attribute) {
rslTree.removeParam(attribute);
}
/**
* Removes a specific value from a list of values of the specified
* attribute.
*
* @param attribute the attribute from which to remote the value from.
* @param value the specific value to remove.
* @return true if the value was successfully removed. Otherwise,
* returns false,
*/
public boolean remove(String attribute, String value) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null || nv.getOperator() != NameOpValue.EQ) return false;
return nv.remove(new Value(value));
}
/**
* Removes a specific key from a list of values of the specified
* attribute. The attribute values must be in the right form. See
* the 'environment' rsl attribute.
*
* @param attribute the attribute to remove the key from.
* @param key the key to remove.
* @return true if the key was successfully removed. Otherwise,
* returns false.
*/
public boolean removeMap(String attribute, String key) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null || nv.getOperator() != NameOpValue.EQ) return false;
List values = nv.getValues();
Iterator iter = values.iterator();
Object obj;
int i=0;
int found = -1;
while( iter.hasNext() ) {
obj = iter.next();
if (obj instanceof List) {
List vr = (List)obj;
if (vr.size() > 0) {
Object var = vr.get(0);
if (var instanceof Value &&
((Value)var).getValue().equals(key)) {
found = i;
break;
}
}
}
i++;
}
if (found != -1) {
values.remove(found);
return true;
} else {
return false;
}
}
protected NameOpValue getRelation(String attribute) {
NameOpValue nv = rslTree.getParam(attribute);
if (nv == null) {
nv = new NameOpValue(attribute, NameOpValue.EQ);
rslTree.put(nv);
}
return nv;
}
/**
* Sets the attribute value to the given value.
* All previous values are removed first.
*
* @param attribute the attribute to set the value of.
* @param value the value to add.
*/
public void set(String attribute, String value) {
NameOpValue nv = getRelation(attribute);
nv.clear();
nv.add(new Value(value));
}
/**
* Adds a simple value to the list of values of a given
* attribute.
*
* @param attribute the attribute to add the value to.
* @param value the value to add.
*/
public void add(String attribute, String value) {
NameOpValue nv = getRelation(attribute);
nv.add(new Value(value));
}
/**
* Sets the attribute value to the given list of values.
* The list of values is added as a single value.
*
* @param attribute the attribute to set the value of.
* @param values the list of values to add.
*/
public void setMulti(String attribute, String [] values) {
NameOpValue nv = getRelation(attribute);
nv.clear();
List list = new LinkedList();
for (int i=0;i<values.length;i++) {
list.add(new Value(values[i]));
}
nv.add(list);
}
/**
* Adds a list of values as a single value to the specified
* attribute.
*
* @param attribute the attribute to add the list of values to.
* @param values the values to add.
*/
public void addMulti(String attribute, String [] values) {
NameOpValue nv = getRelation(attribute);
List list = new LinkedList();
for (int i=0;i<values.length;i++) {
list.add(new Value(values[i]));
}
nv.add(list);
}
// --- Compatibility API with old RslAttributes class ---
/**
* Returns the first value of a specified attribute.
*
* @return the first value of the attribute.
* @deprecated use getSingle() instead.
*/
public String getFirstValue(String attribute) {
return getSingle(attribute);
}
/**
* Returns the values for a specified attribute.
*
* @return the list of values.
* @deprecated use getMulti() instead.
*/
public List get(String attribute) {
return getMulti(attribute);
}
/**
* Returns the rsl.
*
* @return the rsl.
*/
public String toRSL() {
return rslTree.toRSL(true);
}
}