1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements.  See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License.  You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22package com.sun.org.apache.xerces.internal.impl.dtd;
23
24import com.sun.org.apache.xerces.internal.util.SymbolTable;
25import com.sun.org.apache.xerces.internal.xni.Augmentations;
26import com.sun.org.apache.xerces.internal.xni.XMLDTDContentModelHandler;
27import com.sun.org.apache.xerces.internal.xni.XNIException;
28
29/**
30 * <p>A DTD grammar that produces balanced syntax trees.</p>
31 *
32 * @xerces.internal
33 *
34 * @author Michael Glavassevich, IBM
35 */
36final class BalancedDTDGrammar extends DTDGrammar {
37
38    //
39    // Data
40    //
41
42    /** Mixed. */
43    private boolean fMixed;
44
45    /** Stack depth */
46    private int fDepth = 0;
47
48    /** Children content model operation stack. */
49    private short [] fOpStack = null;
50
51    /** Holder for choice/sequence/leaf groups at each depth. */
52    private int [][] fGroupIndexStack;
53
54    /** Sizes of the allocated portions of each int[] in fGroupIndexStack. */
55    private int [] fGroupIndexStackSizes;
56
57    //
58    // Constructors
59    //
60
61    /** Default constructor. */
62    public BalancedDTDGrammar(SymbolTable symbolTable, XMLDTDDescription desc) {
63        super(symbolTable, desc);
64    } // BalancedDTDGrammar(SymbolTable,XMLDTDDescription)
65
66    //
67    // Public methods
68    //
69
70    /**
71     * The start of a content model. Depending on the type of the content
72     * model, specific methods may be called between the call to the
73     * startContentModel method and the call to the endContentModel method.
74     *
75     * @param elementName The name of the element.
76     * @param augs Additional information that may include infoset
77     *                      augmentations.
78     * @throws XNIException Thrown by handler to signal an error.
79     */
80    public final void startContentModel(String elementName, Augmentations augs)
81        throws XNIException {
82        fDepth = 0;
83        initializeContentModelStacks();
84        super.startContentModel(elementName, augs);
85    } // startContentModel(String)
86
87    /**
88     * A start of either a mixed or children content model. A mixed
89     * content model will immediately be followed by a call to the
90     * <code>pcdata()</code> method. A children content model will
91     * contain additional groups and/or elements.
92     *
93     * @param augs Additional information that may include infoset
94     *                      augmentations.
95     * @throws XNIException Thrown by handler to signal an error.
96     *
97     * @see #any
98     * @see #empty
99     */
100    public final void startGroup(Augmentations augs) throws XNIException {
101        ++fDepth;
102        initializeContentModelStacks();
103        fMixed = false;
104    } // startGroup()
105
106    /**
107     * The appearance of "#PCDATA" within a group signifying a
108     * mixed content model. This method will be the first called
109     * following the content model's <code>startGroup()</code>.
110     *
111     *@param augs Additional information that may include infoset
112     *                      augmentations.
113     *
114     * @throws XNIException Thrown by handler to signal an error.
115     *
116     * @see #startGroup
117     */
118    public final void pcdata(Augmentations augs) throws XNIException {
119        fMixed = true;
120    } // pcdata()
121
122    /**
123     * A referenced element in a mixed or children content model.
124     *
125     * @param elementName The name of the referenced element.
126     * @param augs Additional information that may include infoset
127     *                      augmentations.
128     *
129     * @throws XNIException Thrown by handler to signal an error.
130     */
131    public final void element(String elementName, Augmentations augs) throws XNIException {
132        addToCurrentGroup(addUniqueLeafNode(elementName));
133    } // element(String)
134
135    /**
136     * The separator between choices or sequences of a mixed or children
137     * content model.
138     *
139     * @param separator The type of children separator.
140     * @param augs Additional information that may include infoset
141     *                      augmentations.
142     * @throws XNIException Thrown by handler to signal an error.
143     *
144     * @see org.apache.xerces.xni.XMLDTDContentModelHandler#SEPARATOR_CHOICE
145     * @see org.apache.xerces.xni.XMLDTDContentModelHandler#SEPARATOR_SEQUENCE
146     */
147    public final void separator(short separator, Augmentations augs) throws XNIException {
148        if (separator == XMLDTDContentModelHandler.SEPARATOR_CHOICE) {
149            fOpStack[fDepth] = XMLContentSpec.CONTENTSPECNODE_CHOICE;
150        }
151        else if (separator == XMLDTDContentModelHandler.SEPARATOR_SEQUENCE) {
152            fOpStack[fDepth] = XMLContentSpec.CONTENTSPECNODE_SEQ;
153        }
154    } // separator(short)
155
156    /**
157     * The occurrence count for a child in a children content model or
158     * for the mixed content model group.
159     *
160     * @param occurrence The occurrence count for the last element
161     *                   or group.
162     * @param augs Additional information that may include infoset
163     *                      augmentations.
164     * @throws XNIException Thrown by handler to signal an error.
165     *
166     * @see org.apache.xerces.xni.XMLDTDContentModelHandler#OCCURS_ZERO_OR_ONE
167     * @see org.apache.xerces.xni.XMLDTDContentModelHandler#OCCURS_ZERO_OR_MORE
168     * @see org.apache.xerces.xni.XMLDTDContentModelHandler#OCCURS_ONE_OR_MORE
169     */
170    public final void occurrence(short occurrence, Augmentations augs) throws XNIException {
171        if (!fMixed) {
172            int currentIndex = fGroupIndexStackSizes[fDepth] - 1;
173            if (occurrence == XMLDTDContentModelHandler.OCCURS_ZERO_OR_ONE) {
174                fGroupIndexStack[fDepth][currentIndex] = addContentSpecNode(XMLContentSpec.CONTENTSPECNODE_ZERO_OR_ONE, fGroupIndexStack[fDepth][currentIndex], -1);
175            }
176            else if ( occurrence == XMLDTDContentModelHandler.OCCURS_ZERO_OR_MORE) {
177                fGroupIndexStack[fDepth][currentIndex] = addContentSpecNode(XMLContentSpec.CONTENTSPECNODE_ZERO_OR_MORE, fGroupIndexStack[fDepth][currentIndex], -1);
178            }
179            else if ( occurrence == XMLDTDContentModelHandler.OCCURS_ONE_OR_MORE) {
180                fGroupIndexStack[fDepth][currentIndex] = addContentSpecNode(XMLContentSpec.CONTENTSPECNODE_ONE_OR_MORE, fGroupIndexStack[fDepth][currentIndex], -1);
181            }
182        }
183    } // occurrence(short)
184
185    /**
186     * The end of a group for mixed or children content models.
187     *
188     * @param augs Additional information that may include infoset
189     *                      augmentations.
190     * @throws XNIException Thrown by handler to signal an error.
191     */
192    public final void endGroup(Augmentations augs) throws XNIException {
193        final int length = fGroupIndexStackSizes[fDepth];
194        final int group = length > 0 ? addContentSpecNodes(0, length - 1) : addUniqueLeafNode(null);
195        --fDepth;
196        addToCurrentGroup(group);
197    } // endGroup()
198
199    /**
200     * The end of the DTD.
201     *
202     * @param augs Additional information that may include infoset
203     *                      augmentations.
204     * @throws XNIException Thrown by handler to signal an error.
205     */
206    public final void endDTD(Augmentations augs) throws XNIException {
207        super.endDTD(augs);
208        fOpStack = null;
209        fGroupIndexStack = null;
210        fGroupIndexStackSizes = null;
211    } // endDTD()
212
213    //
214    // Protected methods
215    //
216
217    /**
218     * Adds the content spec to the given element declaration.
219     */
220    protected final void addContentSpecToElement(XMLElementDecl elementDecl) {
221        int contentSpec = fGroupIndexStackSizes[0] > 0 ? fGroupIndexStack[0][0] : -1;
222        setContentSpecIndex(fCurrentElementIndex, contentSpec);
223    }
224
225    //
226    // Private methods
227    //
228
229    /**
230     * Creates a subtree from the leaf nodes at the current depth.
231     */
232    private int addContentSpecNodes(int begin, int end) {
233        if (begin == end) {
234            return fGroupIndexStack[fDepth][begin];
235        }
236        final int middle = (begin + end) >>> 1;
237        return addContentSpecNode(fOpStack[fDepth],
238                addContentSpecNodes(begin, middle),
239                addContentSpecNodes(middle + 1, end));
240    } // addContentSpecNodes(int,int)
241
242    /**
243     * Initialize the stacks which temporarily hold content models.
244     */
245    private void initializeContentModelStacks() {
246        if (fOpStack == null) {
247            fOpStack = new short[8];
248            fGroupIndexStack = new int [8][];
249            fGroupIndexStackSizes = new int [8];
250        }
251        else if (fDepth == fOpStack.length) {
252            short [] newOpStack = new short[fDepth * 2];
253            System.arraycopy(fOpStack, 0, newOpStack, 0, fDepth);
254            fOpStack = newOpStack;
255            int [][] newGroupIndexStack = new int[fDepth * 2][];
256            System.arraycopy(fGroupIndexStack, 0, newGroupIndexStack, 0, fDepth);
257            fGroupIndexStack = newGroupIndexStack;
258            int [] newGroupIndexStackLengths = new int[fDepth * 2];
259            System.arraycopy(fGroupIndexStackSizes, 0, newGroupIndexStackLengths, 0, fDepth);
260            fGroupIndexStackSizes = newGroupIndexStackLengths;
261        }
262        fOpStack[fDepth] = -1;
263        fGroupIndexStackSizes[fDepth] = 0;
264    } // initializeContentModelStacks()
265
266    /**
267     * Add XMLContentSpec to the current group.
268     *
269     * @param contentSpec handle to the XMLContentSpec to add to the current group
270     */
271    private void addToCurrentGroup(int contentSpec) {
272        int [] currentGroup = fGroupIndexStack[fDepth];
273        int length = fGroupIndexStackSizes[fDepth]++;
274        if (currentGroup == null) {
275            currentGroup = new int[8];
276            fGroupIndexStack[fDepth] = currentGroup;
277        }
278        else if (length == currentGroup.length) {
279            int [] newGroup = new int[currentGroup.length * 2];
280            System.arraycopy(currentGroup, 0, newGroup, 0, currentGroup.length);
281            currentGroup = newGroup;
282            fGroupIndexStack[fDepth] = currentGroup;
283        }
284        currentGroup[length] = contentSpec;
285    } // addToCurrentGroup(int)
286
287} // class BalancedDTDGrammar
288