org.apache.xerces.util.XMLGrammarPoolImpl Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.xerces.util;
import org.apache.xerces.xni.grammars.Grammar;
import org.apache.xerces.xni.grammars.XMLGrammarDescription;
import org.apache.xerces.xni.grammars.XMLGrammarPool;
/**
* Stores grammars in a pool associated to a specific key. This grammar pool
* implementation stores two types of grammars: those keyed by the root element
* name, and those keyed by the grammar's target namespace.
*
* This is the default implementation of the GrammarPool interface.
* As we move forward, this will become more function-rich and robust.
*
* @author Jeffrey Rodriguez, IBM
* @author Andy Clark, IBM
* @author Neil Graham, IBM
* @author Pavani Mukthipudi, Sun Microsystems
* @author Neeraj Bajaj, SUN Microsystems
*
* @version $Id: XMLGrammarPoolImpl.java 447241 2006-09-18 05:12:57Z mrglavas $
*/
public class XMLGrammarPoolImpl implements XMLGrammarPool {
//
// Constants
//
/** Default size. */
protected static final int TABLE_SIZE = 11;
//
// Data
//
/** Grammars. */
protected Entry[] fGrammars = null;
// whether this pool is locked
protected boolean fPoolIsLocked;
// the number of grammars in the pool
protected int fGrammarCount = 0;
private static final boolean DEBUG = false ;
//
// Constructors
//
/** Constructs a grammar pool with a default number of buckets. */
public XMLGrammarPoolImpl() {
fGrammars = new Entry[TABLE_SIZE];
fPoolIsLocked = false;
} // ()
/** Constructs a grammar pool with a specified number of buckets. */
public XMLGrammarPoolImpl(int initialCapacity) {
fGrammars = new Entry[initialCapacity];
fPoolIsLocked = false;
}
//
// XMLGrammarPool methods
//
/* Retrieve the initial known set of grammars. This method is
* called by a validator before the validation starts. The application
* can provide an initial set of grammars available to the current
* validation attempt.
*
* @param grammarType The type of the grammar, from the
* org.apache.xerces.xni.grammars.XMLGrammarDescription
* interface.
* @return The set of grammars the validator may put in its "bucket"
*/
public Grammar [] retrieveInitialGrammarSet (String grammarType) {
synchronized (fGrammars) {
int grammarSize = fGrammars.length ;
Grammar [] tempGrammars = new Grammar[fGrammarCount];
int pos = 0;
for (int i = 0; i < grammarSize; i++) {
for (Entry e = fGrammars[i]; e != null; e = e.next) {
if (e.desc.getGrammarType().equals(grammarType)) {
tempGrammars[pos++] = e.grammar;
}
}
}
Grammar[] toReturn = new Grammar[pos];
System.arraycopy(tempGrammars, 0, toReturn, 0, pos);
return toReturn;
}
} // retrieveInitialGrammarSet (String): Grammar[]
/* Return the final set of grammars that the validator ended up
* with. This method is called after the validation finishes. The
* application may then choose to cache some of the returned grammars.
* In this implementation, we make our choice based on whether this object
* is "locked"--that is, whether the application has instructed
* us not to accept any new grammars.
*
* @param grammarType The type of the grammars being returned;
* @param grammars An array containing the set of grammars being
* returned; order is not significant.
*/
public void cacheGrammars(String grammarType, Grammar[] grammars) {
if(!fPoolIsLocked) {
for (int i = 0; i < grammars.length; i++) {
if(DEBUG) {
System.out.println("CACHED GRAMMAR " + (i+1) ) ;
Grammar temp = grammars[i] ;
//print(temp.getGrammarDescription());
}
putGrammar(grammars[i]);
}
}
} // cacheGrammars(String, Grammar[]);
/* This method requests that the application retrieve a grammar
* corresponding to the given GrammarIdentifier from its cache.
* If it cannot do so it must return null; the parser will then
* call the EntityResolver.
* An application must not call its EntityResolver itself
* from this method; this may result in infinite recursions.
*
* This implementation chooses to use the root element name to identify a DTD grammar
* and the target namespace to identify a Schema grammar.
*
* @param desc The description of the Grammar being requested.
* @return The Grammar corresponding to this description or null if
* no such Grammar is known.
*/
public Grammar retrieveGrammar(XMLGrammarDescription desc) {
if(DEBUG){
System.out.println("RETRIEVING GRAMMAR FROM THE APPLICATION WITH FOLLOWING DESCRIPTION :");
//print(desc);
}
return getGrammar(desc);
} // retrieveGrammar(XMLGrammarDescription): Grammar
//
// Public methods
//
/**
* Puts the specified grammar into the grammar pool and associates it to
* its root element name or its target namespace.
*
* @param grammar The Grammar.
*/
public void putGrammar(Grammar grammar) {
if(!fPoolIsLocked) {
synchronized (fGrammars) {
XMLGrammarDescription desc = grammar.getGrammarDescription();
int hash = hashCode(desc);
int index = (hash & 0x7FFFFFFF) % fGrammars.length;
for (Entry entry = fGrammars[index]; entry != null; entry = entry.next) {
if (entry.hash == hash && equals(entry.desc, desc)) {
entry.grammar = grammar;
return;
}
}
// create a new entry
Entry entry = new Entry(hash, desc, grammar, fGrammars[index]);
fGrammars[index] = entry;
fGrammarCount++;
}
}
} // putGrammar(Grammar)
/**
* Returns the grammar associated to the specified grammar description.
* Currently, the root element name is used as the key for DTD grammars
* and the target namespace is used as the key for Schema grammars.
*
* @param desc The Grammar Description.
*/
public Grammar getGrammar(XMLGrammarDescription desc) {
synchronized (fGrammars) {
int hash = hashCode(desc);
int index = (hash & 0x7FFFFFFF) % fGrammars.length;
for (Entry entry = fGrammars[index] ; entry != null ; entry = entry.next) {
if ((entry.hash == hash) && equals(entry.desc, desc)) {
return entry.grammar;
}
}
return null;
}
} // getGrammar(XMLGrammarDescription):Grammar
/**
* Removes the grammar associated to the specified grammar description from the
* grammar pool and returns the removed grammar. Currently, the root element name
* is used as the key for DTD grammars and the target namespace is used
* as the key for Schema grammars.
*
* @param desc The Grammar Description.
* @return The removed grammar.
*/
public Grammar removeGrammar(XMLGrammarDescription desc) {
synchronized (fGrammars) {
int hash = hashCode(desc);
int index = (hash & 0x7FFFFFFF) % fGrammars.length;
for (Entry entry = fGrammars[index], prev = null ; entry != null ; prev = entry, entry = entry.next) {
if ((entry.hash == hash) && equals(entry.desc, desc)) {
if (prev != null) {
prev.next = entry.next;
}
else {
fGrammars[index] = entry.next;
}
Grammar tempGrammar = entry.grammar;
entry.grammar = null;
fGrammarCount--;
return tempGrammar;
}
}
return null;
}
} // removeGrammar(XMLGrammarDescription):Grammar
/**
* Returns true if the grammar pool contains a grammar associated
* to the specified grammar description. Currently, the root element name
* is used as the key for DTD grammars and the target namespace is used
* as the key for Schema grammars.
*
* @param desc The Grammar Description.
*/
public boolean containsGrammar(XMLGrammarDescription desc) {
synchronized (fGrammars) {
int hash = hashCode(desc);
int index = (hash & 0x7FFFFFFF) % fGrammars.length;
for (Entry entry = fGrammars[index] ; entry != null ; entry = entry.next) {
if ((entry.hash == hash) && equals(entry.desc, desc)) {
return true;
}
}
return false;
}
} // containsGrammar(XMLGrammarDescription):boolean
/* Sets this grammar pool to a "locked" state--i.e.,
* no new grammars will be added until it is "unlocked".
*/
public void lockPool() {
fPoolIsLocked = true;
} // lockPool()
/*
Sets this grammar pool to an "unlocked" state--i.e.,
* new grammars will be added when putGrammar or cacheGrammars
* are called.
*/
public void unlockPool() {
fPoolIsLocked = false;
} // unlockPool()
/*
*
This method clears the pool-i.e., removes references
* to all the grammars in it.
*/
public void clear() {
for (int i=0; i-->