| /* |
| * 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. |
| */ |
| /* |
| * $Id: ExpandedNameTable.java 468653 2006-10-28 07:07:05Z minchau $ |
| */ |
| package org.apache.xml.dtm.ref; |
| |
| import org.apache.xml.dtm.DTM; |
| |
| /** |
| * This is a default implementation of a table that manages mappings from |
| * expanded names to expandedNameIDs. |
| * |
| * %OPT% The performance of the getExpandedTypeID() method is very important |
| * to DTM building. To get the best performance out of this class, we implement |
| * a simple hash algorithm directly into this class, instead of using the |
| * inefficient java.util.Hashtable. The code for the get and put operations |
| * are combined in getExpandedTypeID() method to share the same hash calculation |
| * code. We only need to implement the rehash() interface which is used to |
| * expand the hash table. |
| */ |
| public class ExpandedNameTable |
| { |
| |
| /** Array of extended types for this document */ |
| private ExtendedType[] m_extendedTypes; |
| |
| /** The initial size of the m_extendedTypes array */ |
| private static int m_initialSize = 128; |
| |
| /** Next available extended type */ |
| // %REVIEW% Since this is (should be) always equal |
| // to the length of m_extendedTypes, do we need this? |
| private int m_nextType; |
| |
| // These are all the types prerotated, for caller convenience. |
| public static final int ELEMENT = ((int)DTM.ELEMENT_NODE) ; |
| public static final int ATTRIBUTE = ((int)DTM.ATTRIBUTE_NODE) ; |
| public static final int TEXT = ((int)DTM.TEXT_NODE) ; |
| public static final int CDATA_SECTION = ((int)DTM.CDATA_SECTION_NODE) ; |
| public static final int ENTITY_REFERENCE = ((int)DTM.ENTITY_REFERENCE_NODE) ; |
| public static final int ENTITY = ((int)DTM.ENTITY_NODE) ; |
| public static final int PROCESSING_INSTRUCTION = ((int)DTM.PROCESSING_INSTRUCTION_NODE) ; |
| public static final int COMMENT = ((int)DTM.COMMENT_NODE) ; |
| public static final int DOCUMENT = ((int)DTM.DOCUMENT_NODE) ; |
| public static final int DOCUMENT_TYPE = ((int)DTM.DOCUMENT_TYPE_NODE) ; |
| public static final int DOCUMENT_FRAGMENT =((int)DTM.DOCUMENT_FRAGMENT_NODE) ; |
| public static final int NOTATION = ((int)DTM.NOTATION_NODE) ; |
| public static final int NAMESPACE = ((int)DTM.NAMESPACE_NODE) ; |
| |
| /** Workspace for lookup. NOT THREAD SAFE! |
| * */ |
| ExtendedType hashET = new ExtendedType(-1, "", ""); |
| |
| /** The array to store the default extended types. */ |
| private static ExtendedType[] m_defaultExtendedTypes; |
| |
| /** |
| * The default load factor of the Hashtable. |
| * This is used to calcualte the threshold. |
| */ |
| private static float m_loadFactor = 0.75f; |
| |
| /** |
| * The initial capacity of the hash table. Use a bigger number |
| * to avoid the cost of expanding the table. |
| */ |
| private static int m_initialCapacity = 203; |
| |
| /** |
| * The capacity of the hash table, i.e. the size of the |
| * internal HashEntry array. |
| */ |
| private int m_capacity; |
| |
| /** |
| * The threshold of the hash table, which is equal to capacity * loadFactor. |
| * If the number of entries in the hash table is bigger than the threshold, |
| * the hash table needs to be expanded. |
| */ |
| private int m_threshold; |
| |
| /** |
| * The internal array to store the hash entries. |
| * Each array member is a slot for a hash bucket. |
| */ |
| private HashEntry[] m_table; |
| |
| /** |
| * Init default values |
| */ |
| static { |
| m_defaultExtendedTypes = new ExtendedType[DTM.NTYPES]; |
| |
| for (int i = 0; i < DTM.NTYPES; i++) |
| { |
| m_defaultExtendedTypes[i] = new ExtendedType(i, "", ""); |
| } |
| } |
| |
| /** |
| * Create an expanded name table. |
| */ |
| public ExpandedNameTable() |
| { |
| m_capacity = m_initialCapacity; |
| m_threshold = (int)(m_capacity * m_loadFactor); |
| m_table = new HashEntry[m_capacity]; |
| |
| initExtendedTypes(); |
| } |
| |
| |
| /** |
| * Initialize the vector of extended types with the |
| * basic DOM node types. |
| */ |
| private void initExtendedTypes() |
| { |
| m_extendedTypes = new ExtendedType[m_initialSize]; |
| for (int i = 0; i < DTM.NTYPES; i++) { |
| m_extendedTypes[i] = m_defaultExtendedTypes[i]; |
| m_table[i] = new HashEntry(m_defaultExtendedTypes[i], i, i, null); |
| } |
| |
| m_nextType = DTM.NTYPES; |
| } |
| |
| /** |
| * Given an expanded name represented by namespace, local name and node type, |
| * return an ID. If the expanded-name does not exist in the internal tables, |
| * the entry will be created, and the ID will be returned. Any additional |
| * nodes that are created that have this expanded name will use this ID. |
| * |
| * @param namespace The namespace |
| * @param localName The local name |
| * @param type The node type |
| * |
| * @return the expanded-name id of the node. |
| */ |
| public int getExpandedTypeID(String namespace, String localName, int type) |
| { |
| return getExpandedTypeID(namespace, localName, type, false); |
| } |
| |
| /** |
| * Given an expanded name represented by namespace, local name and node type, |
| * return an ID. If the expanded-name does not exist in the internal tables, |
| * the entry will be created, and the ID will be returned. Any additional |
| * nodes that are created that have this expanded name will use this ID. |
| * <p> |
| * If searchOnly is true, we will return -1 if the name is not found in the |
| * table, otherwise the name is added to the table and the expanded name id |
| * of the new entry is returned. |
| * |
| * @param namespace The namespace |
| * @param localName The local name |
| * @param type The node type |
| * @param searchOnly If it is true, we will only search for the expanded name. |
| * -1 is return is the name is not found. |
| * |
| * @return the expanded-name id of the node. |
| */ |
| public int getExpandedTypeID(String namespace, String localName, int type, boolean searchOnly) |
| { |
| if (null == namespace) |
| namespace = ""; |
| if (null == localName) |
| localName = ""; |
| |
| // Calculate the hash code |
| int hash = type + namespace.hashCode() + localName.hashCode(); |
| |
| // Redefine the hashET object to represent the new expanded name. |
| hashET.redefine(type, namespace, localName, hash); |
| |
| // Calculate the index into the HashEntry table. |
| int index = hash % m_capacity; |
| if (index < 0) |
| index = -index; |
| |
| // Look up the expanded name in the hash table. Return the id if |
| // the expanded name is already in the hash table. |
| for (HashEntry e = m_table[index]; e != null; e = e.next) |
| { |
| if (e.hash == hash && e.key.equals(hashET)) |
| return e.value; |
| } |
| |
| if (searchOnly) |
| { |
| return DTM.NULL; |
| } |
| |
| // Expand the internal HashEntry array if necessary. |
| if (m_nextType > m_threshold) { |
| rehash(); |
| index = hash % m_capacity; |
| if (index < 0) |
| index = -index; |
| } |
| |
| // Create a new ExtendedType object |
| ExtendedType newET = new ExtendedType(type, namespace, localName, hash); |
| |
| // Expand the m_extendedTypes array if necessary. |
| if (m_extendedTypes.length == m_nextType) { |
| ExtendedType[] newArray = new ExtendedType[m_extendedTypes.length * 2]; |
| System.arraycopy(m_extendedTypes, 0, newArray, 0, |
| m_extendedTypes.length); |
| m_extendedTypes = newArray; |
| } |
| |
| m_extendedTypes[m_nextType] = newET; |
| |
| // Create a new hash entry for the new ExtendedType and put it into |
| // the table. |
| HashEntry entry = new HashEntry(newET, m_nextType, hash, m_table[index]); |
| m_table[index] = entry; |
| |
| return m_nextType++; |
| } |
| |
| /** |
| * Increases the capacity of and internally reorganizes the hashtable, |
| * in order to accommodate and access its entries more efficiently. |
| * This method is called when the number of keys in the hashtable exceeds |
| * this hashtable's capacity and load factor. |
| */ |
| private void rehash() |
| { |
| int oldCapacity = m_capacity; |
| HashEntry[] oldTable = m_table; |
| |
| int newCapacity = 2 * oldCapacity + 1; |
| m_capacity = newCapacity; |
| m_threshold = (int)(newCapacity * m_loadFactor); |
| |
| m_table = new HashEntry[newCapacity]; |
| for (int i = oldCapacity-1; i >=0 ; i--) |
| { |
| for (HashEntry old = oldTable[i]; old != null; ) |
| { |
| HashEntry e = old; |
| old = old.next; |
| |
| int newIndex = e.hash % newCapacity; |
| if (newIndex < 0) |
| newIndex = -newIndex; |
| |
| e.next = m_table[newIndex]; |
| m_table[newIndex] = e; |
| } |
| } |
| } |
| |
| /** |
| * Given a type, return an expanded name ID.Any additional nodes that are |
| * created that have this expanded name will use this ID. |
| * |
| * @return the expanded-name id of the node. |
| */ |
| public int getExpandedTypeID(int type) |
| { |
| return type; |
| } |
| |
| /** |
| * Given an expanded-name ID, return the local name part. |
| * |
| * @param ExpandedNameID an ID that represents an expanded-name. |
| * @return String Local name of this node, or null if the node has no name. |
| */ |
| public String getLocalName(int ExpandedNameID) |
| { |
| return m_extendedTypes[ExpandedNameID].getLocalName(); |
| } |
| |
| /** |
| * Given an expanded-name ID, return the local name ID. |
| * |
| * @param ExpandedNameID an ID that represents an expanded-name. |
| * @return The id of this local name. |
| */ |
| public final int getLocalNameID(int ExpandedNameID) |
| { |
| // ExtendedType etype = m_extendedTypes[ExpandedNameID]; |
| if (m_extendedTypes[ExpandedNameID].getLocalName().equals("")) |
| return 0; |
| else |
| return ExpandedNameID; |
| } |
| |
| |
| /** |
| * Given an expanded-name ID, return the namespace URI part. |
| * |
| * @param ExpandedNameID an ID that represents an expanded-name. |
| * @return String URI value of this node's namespace, or null if no |
| * namespace was resolved. |
| */ |
| public String getNamespace(int ExpandedNameID) |
| { |
| String namespace = m_extendedTypes[ExpandedNameID].getNamespace(); |
| return (namespace.equals("") ? null : namespace); |
| } |
| |
| /** |
| * Given an expanded-name ID, return the namespace URI ID. |
| * |
| * @param ExpandedNameID an ID that represents an expanded-name. |
| * @return The id of this namespace. |
| */ |
| public final int getNamespaceID(int ExpandedNameID) |
| { |
| //ExtendedType etype = m_extendedTypes[ExpandedNameID]; |
| if (m_extendedTypes[ExpandedNameID].getNamespace().equals("")) |
| return 0; |
| else |
| return ExpandedNameID; |
| } |
| |
| /** |
| * Given an expanded-name ID, return the local name ID. |
| * |
| * @param ExpandedNameID an ID that represents an expanded-name. |
| * @return The id of this local name. |
| */ |
| public final short getType(int ExpandedNameID) |
| { |
| //ExtendedType etype = m_extendedTypes[ExpandedNameID]; |
| return (short)m_extendedTypes[ExpandedNameID].getNodeType(); |
| } |
| |
| /** |
| * Return the size of the ExpandedNameTable |
| * |
| * @return The size of the ExpandedNameTable |
| */ |
| public int getSize() |
| { |
| return m_nextType; |
| } |
| |
| /** |
| * Return the array of extended types |
| * |
| * @return The array of extended types |
| */ |
| public ExtendedType[] getExtendedTypes() |
| { |
| return m_extendedTypes; |
| } |
| |
| /** |
| * Inner class which represents a hash table entry. |
| * The field next points to the next entry which is hashed into |
| * the same bucket in the case of "hash collision". |
| */ |
| private static final class HashEntry |
| { |
| ExtendedType key; |
| int value; |
| int hash; |
| HashEntry next; |
| |
| protected HashEntry(ExtendedType key, int value, int hash, HashEntry next) |
| { |
| this.key = key; |
| this.value = value; |
| this.hash = hash; |
| this.next = next; |
| } |
| } |
| |
| } |