001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 * 019 */ 020 package org.apache.directory.shared.asn1.ber.grammar; 021 022 023 import org.apache.directory.shared.asn1.ber.IAsn1Container; 024 import org.apache.directory.shared.asn1.codec.DecoderException; 025 import org.apache.directory.shared.asn1.util.Asn1StringUtils; 026 import org.apache.directory.shared.i18n.I18n; 027 028 import org.slf4j.Logger; 029 import org.slf4j.LoggerFactory; 030 031 032 /** 033 * The abstract IGrammar which is the Mother of all the grammars. It contains 034 * the transitions table. 035 * 036 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 037 * @version $Rev: 912399 $, $Date: 2010-02-21 21:52:31 +0100 (Sun, 21 Feb 2010) $ 038 */ 039 public abstract class AbstractGrammar implements IGrammar 040 { 041 // ~ Static fields/initializers 042 // ----------------------------------------------------------------- 043 044 /** The logger */ 045 private static final Logger log = LoggerFactory.getLogger( AbstractGrammar.class ); 046 047 /** Speedup for logs */ 048 private static final boolean IS_DEBUG = log.isDebugEnabled(); 049 050 // ~ Instance fields 051 // ---------------------------------------------------------------------------- 052 053 /** 054 * Table of transitions. It's a two dimension array, the first dimension 055 * indice the states, the second dimension indices the Tag value, so it is 056 * 256 wide. 057 */ 058 protected GrammarTransition[][] transitions; 059 060 /** The grammar name */ 061 protected String name; 062 063 /** The grammar's states */ 064 protected IStates statesEnum; 065 066 /** Default constructor */ 067 public AbstractGrammar() 068 { 069 } 070 071 072 // ~ Methods 073 // ------------------------------------------------------------------------------------ 074 075 /** 076 * Return the grammar's name 077 * 078 * @return The grammar name 079 */ 080 public String getName() 081 { 082 return name; 083 } 084 085 086 /** 087 * Set the grammar's name 088 * 089 * @param name The new grammar name 090 */ 091 public void setName( String name ) 092 { 093 this.name = name; 094 } 095 096 /** 097 * Get the transition associated with the state and tag 098 * 099 * @param state The current state 100 * @param tag The current tag 101 * @return A valid transition if any, or null. 102 */ 103 public GrammarTransition getTransition( int state, int tag ) 104 { 105 return transitions[state][tag & 0x00FF]; 106 } 107 108 109 /** 110 * The main function. This is where an action is executed. If the action is 111 * null, nothing is done. 112 * 113 * @param container The Asn1Container 114 * @throws DecoderException Thrown if anything went wrong 115 */ 116 public void executeAction( IAsn1Container container ) throws DecoderException 117 { 118 119 int currentState = container.getTransition(); 120 IGrammar currentGrammar = container.getGrammar(); 121 122 // We have to deal with the special case of a GRAMMAR_END state 123 if ( currentState == IStates.END_STATE ) 124 { 125 return; 126 } 127 128 byte tagByte = container.getCurrentTLV().getTag(); 129 130 // We will loop until no more actions are to be executed 131 GrammarTransition transition = ( ( AbstractGrammar ) container.getGrammar() ).getTransition( currentState, tagByte ); 132 133 if ( transition == null ) 134 { 135 136 String errorMessage = I18n.err( I18n.ERR_00001, currentGrammar.getStatesEnum().getState( currentState ), 137 Asn1StringUtils.dumpByte( tagByte ) ); 138 139 log.error( errorMessage ); 140 141 // If we have no more grammar on the stack, then this is an 142 // error 143 throw new DecoderException( I18n.err( I18n.ERR_00002 ) ); 144 } 145 146 if ( IS_DEBUG ) 147 { 148 log.debug( transition.toString( currentGrammar.getStatesEnum() ) ); 149 } 150 151 if ( transition.hasAction() ) 152 { 153 transition.getAction().action( container ); 154 } 155 156 container.setTransition( transition.getCurrentState() ); 157 } 158 159 160 /** 161 * Get the states of the current grammar 162 * 163 * @return Returns the statesEnum. 164 */ 165 public IStates getStatesEnum() 166 { 167 return statesEnum; 168 } 169 170 171 /** 172 * Set the states for this grammar 173 * 174 * @param statesEnum The statesEnum to set. 175 */ 176 public void setStatesEnum( IStates statesEnum ) 177 { 178 this.statesEnum = statesEnum; 179 } 180 }