ASF_20_SRC_AUTO/src/deprecated/java/org/apache/cocoon/components/treeprocessor/MapStackResolver.java - cocoon - Git at Google

 /*
  * Copyright 1999-2004 The Apache Software Foundation.
  *
  * 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.apache.cocoon.components.treeprocessor;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;

 import org.apache.avalon.framework.parameters.Parameters;
 import org.apache.cocoon.sitemap.PatternException;

 /**
  * Utility class for handling {...} pattern substitutions from a List of Maps.
  *
  * @author <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
  * @version CVS $Id: MapStackResolver.java,v 1.3 2004/03/05 13:02:41 bdelacretaz Exp $
  * @deprecated use {@link org.apache.cocoon.components.treeprocessor.variables.VariableResolverFactory}
  */

 public abstract class MapStackResolver {

     public static final Map EMPTY_MAP = Collections.unmodifiableMap(new java.util.HashMap(0));

     /**
      * Resolve all {...} patterns using the values given in the list of maps.
      */
     public abstract String resolve(List mapStack) throws PatternException;

     /**
      * Does an expression need resolving (i.e. contain {...} patterns) ?
      */
     public static boolean needsResolve(String expression) {
         if (expression == null || expression.length() == 0) {
             return false;
         }

         // Is the first char a '{' ?
         if (expression.charAt(0) == '{') {
             return true;
         }

         if (expression.length() < 2) {
             return false;
         }

         // Is there any unescaped '{' ?
         int pos = 1;
         while ( (pos = expression.indexOf('{', pos)) != -1) {
             // Found a '{' : is it escaped ?
             if (expression.charAt(pos - 1) != '\\') {
                 // No : need to resolve
                 return true;
             }
             pos++;
         }
         // Nothing found...
         return false;
     }

     /**
      * Unescape an expression that doesn't need to be resolved, but may contain
      * escaped '{' characters.
      *
      * @param expression the expression to unescape.
      * @return the unescaped result, or <code>expression</code> if unescaping isn't necessary.
      */
     public static String unescape(String expression) {
         // Does it need escaping ?
         if (expression == null || expression.indexOf("\\{") == -1) {
             return expression;
         }

         StringBuffer buf = new StringBuffer();
         for (int i = 0; i < expression.length(); i++) {
             char ch = expression.charAt(i);
             if (ch != '\\' || i >= (expression.length() - 1) || expression.charAt(i+1) != '{') {
                 buf.append(ch);
             }
         }

         return buf.toString();
     }

     /**
      * Get a resolver for a given expression. Chooses the most efficient implementation
      * depending on <code>expression</code>.
      */
     public static MapStackResolver getResolver(String expression) throws PatternException {
         if (needsResolve(expression)) {
 //            return new RealResolver(expression);
             return new CompiledResolver(expression);
         } else {
             return new NullResolver(expression);
         }
     }

     /**
      * Build a <code>Parameters</code> object from a Map of named <code>ListOfMapResolver</code>s and
      * a list of Maps used for resolution.
      *
      * @return a fully resolved <code>Parameters</code>.
      */
     public static Parameters buildParameters(Map expressions, List mapStack) throws PatternException {
         if (expressions == null || expressions.size() == 0) {
             return Parameters.EMPTY_PARAMETERS;
         }

         Parameters result = new Parameters();

         Iterator iter = expressions.entrySet().iterator();
         while (iter.hasNext()) {
             Map.Entry entry = (Map.Entry)iter.next();
             result.setParameter(
                 ((MapStackResolver)entry.getKey()).resolve(mapStack),
                 ((MapStackResolver)entry.getValue()).resolve(mapStack)
             );
         }

         return result;
     }

     /**
      * Resolve all values of a <code>Map</code> from a Map of named <code>ListOfMapResolver</code>s and
      * a list of Maps used for resolution.
      *
      * @return a fully resolved <code>Map</code>.
      */
     public static Map resolveMap(Map expressions, List mapStack) throws PatternException {
         int size;
         if (expressions == null || (size = expressions.size()) == 0) {
             return EMPTY_MAP;
         }

         Map result = new HashMap(size);

         Iterator iter = expressions.entrySet().iterator();
         while (iter.hasNext()) {
             Map.Entry entry = (Map.Entry)iter.next();
             result.put(
                 ((MapStackResolver)entry.getKey()).resolve(mapStack),
                 ((MapStackResolver)entry.getValue()).resolve(mapStack)
             );
         }

         return result;
     }

     //-------------------------------------------------------------------------
     /**
      * No-op resolver for expressions that don't need to be resolved.
      */
     private static class NullResolver extends MapStackResolver {
         private String originalExpr = null;
         private String expression = null;

         public NullResolver(String expression) {
             if (expression != null) {
                 this.originalExpr = expression;
                 this.expression = unescape(expression);
             }
         }

         public String toString() {
             return this.originalExpr;
         }

         public final String resolve(List mapStack) {
             return this.expression;
         }
     }

     //-------------------------------------------------------------------------

     /**
      * Compiled form for faster substitution
      */
     private static class CompiledResolver extends MapStackResolver {
         private String originalExpr;

         private String[] strings;
         private int[] levels;

         public CompiledResolver(String expression) throws PatternException {
             this.originalExpr = expression;
             compile(expression);
         }

         public String toString() {
             return this.originalExpr;
         }

         private void compile(String expr) throws PatternException {
             // We're sure here that expr *contains* some substitutions

             List stringList = new ArrayList();
             List levelList  = new ArrayList();

             int length = expr.length();
             int prev = 0; // position after last closing brace

             comp : while(prev < length) {
                 // find next unescaped '{'
                 int pos = prev;
                 while(pos < length &&
                       (pos = expr.indexOf('{', pos)) != -1 &&
                       (pos != 0 && expr.charAt(pos - 1) == '\\')) {
                     pos++;
                 }

                 if (pos >= length || pos == -1) {
                     // no more braces
                     if (prev < length) {
                         stringList.add(unescape(expr.substring(prev)));
                         levelList.add(new Integer(-1));
                     }
                     break comp;
                 }

                 // Pass closing brace
                 pos++;

                 // Add litteral strings between closing and next opening brace
                 if (prev < pos-1) {
                     stringList.add(unescape(expr.substring(prev, pos - 1)));
                     levelList.add(new Integer(-1));
                 }

                 // Determine subst level
                 int level = 1; // Start at 1 since it will be substracted from list.size()
                 while(expr.startsWith("../", pos)) {
                     level++;
                     pos += "../".length();
                 }

                 int end = expr.indexOf('}', pos);
                 if (end == -1) {
                     throw new PatternException("Unmatched '{' in " + expr);
                 }

                 stringList.add(expr.substring(pos, end));
                 levelList.add(new Integer(level));

                 prev = end + 1;
             }

             this.strings = new String[stringList.size()];
             this.levels = new int[stringList.size()];
             for (int i = 0; i < strings.length; i++) {
                 this.strings[i] = (String)stringList.get(i);
                 this.levels[i] = ((Integer)levelList.get(i)).intValue();
             }
         }

         public final String resolve(List mapStack) throws PatternException {
             StringBuffer result = new StringBuffer();
             int stackSize = mapStack.size();

             for (int i = 0; i < this.strings.length; i++) {
                 int level = this.levels[i];
                 if (level == -1) {
                     result.append(this.strings[i]);

                 } else {
                     if (level > stackSize) {
                         throw new PatternException("Error while evaluating '" + this.originalExpr +
                             "' : not so many levels");
                     }

                     Object value = ((Map)mapStack.get(stackSize - level)).get(this.strings[i]);
                     if (value != null) {
                         result.append(value);
                     }
                 }
             }

             return result.toString();
         }

 //        public void dump() {
 //            System.out.println(this.originalExpr + " compiled in :");
 //            for (int i = 0; i < this.strings.length; i++) {
 //                System.out.print("[" + this.levels[i] + ":'" + this.strings[i] + "'] ");
 //            }
 //            System.out.println();
 //            System.out.println();
 //        }
     }

 //    public static void main(String [] args) throws Exception {
 //
 //        new CompiledResolver("&{../../blah}").dump();
 //        new CompiledResolver("{t1}tt{t2}x").dump();
 //        new CompiledResolver("\\{t1}tt{t2}xx").dump();
 //        new CompiledResolver("{t1}tt\\{t2}xx").dump();
 //        new CompiledResolver("{t1}tt{t2}xx").dump();
 //        new CompiledResolver("xx{../t1}{../../../t2}zz").dump();
 //        new CompiledResolver("xx{../t1}\\{../../../t2}zz").dump();
 //
 //    }
 }
	/*
	* Copyright 1999-2004 The Apache Software Foundation.
	*
	* 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.apache.cocoon.components.treeprocessor;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;

	import org.apache.avalon.framework.parameters.Parameters;
	import org.apache.cocoon.sitemap.PatternException;

	/**
	* Utility class for handling {...} pattern substitutions from a List of Maps.
	*
	* @author <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
	* @version CVS $Id: MapStackResolver.java,v 1.3 2004/03/05 13:02:41 bdelacretaz Exp $
	* @deprecated use {@link org.apache.cocoon.components.treeprocessor.variables.VariableResolverFactory}
	*/

	public abstract class MapStackResolver {

	public static final Map EMPTY_MAP = Collections.unmodifiableMap(new java.util.HashMap(0));

	/**
	* Resolve all {...} patterns using the values given in the list of maps.
	*/
	public abstract String resolve(List mapStack) throws PatternException;

	/**
	* Does an expression need resolving (i.e. contain {...} patterns) ?
	*/
	public static boolean needsResolve(String expression) {
	if (expression == null \|\| expression.length() == 0) {
	return false;
	}

	// Is the first char a '{' ?
	if (expression.charAt(0) == '{') {
	return true;
	}

	if (expression.length() < 2) {
	return false;
	}

	// Is there any unescaped '{' ?
	int pos = 1;
	while ( (pos = expression.indexOf('{', pos)) != -1) {
	// Found a '{' : is it escaped ?
	if (expression.charAt(pos - 1) != '\\') {
	// No : need to resolve
	return true;
	}
	pos++;
	}
	// Nothing found...
	return false;
	}

	/**
	* Unescape an expression that doesn't need to be resolved, but may contain
	* escaped '{' characters.
	*
	* @param expression the expression to unescape.
	* @return the unescaped result, or <code>expression</code> if unescaping isn't necessary.
	*/
	public static String unescape(String expression) {
	// Does it need escaping ?
	if (expression == null \|\| expression.indexOf("\\{") == -1) {
	return expression;
	}

	StringBuffer buf = new StringBuffer();
	for (int i = 0; i < expression.length(); i++) {
	char ch = expression.charAt(i);
	if (ch != '\\' \|\| i >= (expression.length() - 1) \|\| expression.charAt(i+1) != '{') {
	buf.append(ch);
	}
	}

	return buf.toString();
	}

	/**
	* Get a resolver for a given expression. Chooses the most efficient implementation
	* depending on <code>expression</code>.
	*/
	public static MapStackResolver getResolver(String expression) throws PatternException {
	if (needsResolve(expression)) {
	// return new RealResolver(expression);
	return new CompiledResolver(expression);
	} else {
	return new NullResolver(expression);
	}
	}

	/**
	* Build a <code>Parameters</code> object from a Map of named <code>ListOfMapResolver</code>s and
	* a list of Maps used for resolution.
	*
	* @return a fully resolved <code>Parameters</code>.
	*/
	public static Parameters buildParameters(Map expressions, List mapStack) throws PatternException {
	if (expressions == null \|\| expressions.size() == 0) {
	return Parameters.EMPTY_PARAMETERS;
	}

	Parameters result = new Parameters();

	Iterator iter = expressions.entrySet().iterator();
	while (iter.hasNext()) {
	Map.Entry entry = (Map.Entry)iter.next();
	result.setParameter(
	((MapStackResolver)entry.getKey()).resolve(mapStack),
	((MapStackResolver)entry.getValue()).resolve(mapStack)
	);
	}

	return result;
	}

	/**
	* Resolve all values of a <code>Map</code> from a Map of named <code>ListOfMapResolver</code>s and
	* a list of Maps used for resolution.
	*
	* @return a fully resolved <code>Map</code>.
	*/
	public static Map resolveMap(Map expressions, List mapStack) throws PatternException {
	int size;
	if (expressions == null \|\| (size = expressions.size()) == 0) {
	return EMPTY_MAP;
	}

	Map result = new HashMap(size);

	Iterator iter = expressions.entrySet().iterator();
	while (iter.hasNext()) {
	Map.Entry entry = (Map.Entry)iter.next();
	result.put(
	((MapStackResolver)entry.getKey()).resolve(mapStack),
	((MapStackResolver)entry.getValue()).resolve(mapStack)
	);
	}

	return result;
	}

	//-------------------------------------------------------------------------
	/**
	* No-op resolver for expressions that don't need to be resolved.
	*/
	private static class NullResolver extends MapStackResolver {
	private String originalExpr = null;
	private String expression = null;

	public NullResolver(String expression) {
	if (expression != null) {
	this.originalExpr = expression;
	this.expression = unescape(expression);
	}
	}

	public String toString() {
	return this.originalExpr;
	}

	public final String resolve(List mapStack) {
	return this.expression;
	}
	}

	//-------------------------------------------------------------------------

	/**
	* Compiled form for faster substitution
	*/
	private static class CompiledResolver extends MapStackResolver {
	private String originalExpr;

	private String[] strings;
	private int[] levels;

	public CompiledResolver(String expression) throws PatternException {
	this.originalExpr = expression;
	compile(expression);
	}

	public String toString() {
	return this.originalExpr;
	}

	private void compile(String expr) throws PatternException {
	// We're sure here that expr contains some substitutions

	List stringList = new ArrayList();
	List levelList = new ArrayList();

	int length = expr.length();
	int prev = 0; // position after last closing brace

	comp : while(prev < length) {
	// find next unescaped '{'
	int pos = prev;
	while(pos < length &&
	(pos = expr.indexOf('{', pos)) != -1 &&
	(pos != 0 && expr.charAt(pos - 1) == '\\')) {
	pos++;
	}

	if (pos >= length \|\| pos == -1) {
	// no more braces
	if (prev < length) {
	stringList.add(unescape(expr.substring(prev)));
	levelList.add(new Integer(-1));
	}
	break comp;
	}

	// Pass closing brace
	pos++;

	// Add litteral strings between closing and next opening brace
	if (prev < pos-1) {
	stringList.add(unescape(expr.substring(prev, pos - 1)));
	levelList.add(new Integer(-1));
	}

	// Determine subst level
	int level = 1; // Start at 1 since it will be substracted from list.size()
	while(expr.startsWith("../", pos)) {
	level++;
	pos += "../".length();
	}

	int end = expr.indexOf('}', pos);
	if (end == -1) {
	throw new PatternException("Unmatched '{' in " + expr);
	}

	stringList.add(expr.substring(pos, end));
	levelList.add(new Integer(level));

	prev = end + 1;
	}

	this.strings = new String[stringList.size()];
	this.levels = new int[stringList.size()];
	for (int i = 0; i < strings.length; i++) {
	this.strings[i] = (String)stringList.get(i);
	this.levels[i] = ((Integer)levelList.get(i)).intValue();
	}
	}

	public final String resolve(List mapStack) throws PatternException {
	StringBuffer result = new StringBuffer();
	int stackSize = mapStack.size();

	for (int i = 0; i < this.strings.length; i++) {
	int level = this.levels[i];
	if (level == -1) {
	result.append(this.strings[i]);

	} else {
	if (level > stackSize) {
	throw new PatternException("Error while evaluating '" + this.originalExpr +
	"' : not so many levels");
	}

	Object value = ((Map)mapStack.get(stackSize - level)).get(this.strings[i]);
	if (value != null) {
	result.append(value);
	}
	}
	}

	return result.toString();
	}

	// public void dump() {
	// System.out.println(this.originalExpr + " compiled in :");
	// for (int i = 0; i < this.strings.length; i++) {
	// System.out.print("[" + this.levels[i] + ":'" + this.strings[i] + "'] ");
	// }
	// System.out.println();
	// System.out.println();
	// }
	}

	// public static void main(String [] args) throws Exception {
	//
	// new CompiledResolver("&{../../blah}").dump();
	// new CompiledResolver("{t1}tt{t2}x").dump();
	// new CompiledResolver("\\{t1}tt{t2}xx").dump();
	// new CompiledResolver("{t1}tt\\{t2}xx").dump();
	// new CompiledResolver("{t1}tt{t2}xx").dump();
	// new CompiledResolver("xx{../t1}{../../../t2}zz").dump();
	// new CompiledResolver("xx{../t1}\\{../../../t2}zz").dump();
	//
	// }
	}