AppRequester


1   /*
2   
3      Derby - Class org.apache.derby.impl.drda.AppRequester
4   
5      Licensed to the Apache Software Foundation (ASF) under one or more
6      contributor license agreements.  See the NOTICE file distributed with
7      this work for additional information regarding copyright ownership.
8      The ASF licenses this file to You under the Apache License, Version 2.0
9      (the "License"); you may not use this file except in compliance with
10     the License.  You may obtain a copy of the License at
11  
12        http://www.apache.org/licenses/LICENSE-2.0
13  
14     Unless required by applicable law or agreed to in writing, software
15     distributed under the License is distributed on an "AS IS" BASIS,
16     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17     See the License for the specific language governing permissions and
18     limitations under the License.
19  
20   */
21  
22  package org.apache.derby.impl.drda;
23  import org.apache.derby.iapi.services.sanity.SanityManager;
24  import org.apache.derby.iapi.reference.DRDAConstants;
25  import org.apache.derby.iapi.reference.Limits;
26  
27  /**
28      AppRequester stores information about the application requester.
29      It is used so that multiple sessions can share information when they are
30      started from the same version of the application requester.
31  */
32  class AppRequester
33  {
34  
35      protected static final int MGR_LEVEL_UNKNOWN = -1;
36  
37      protected static final int UNKNOWN_CLIENT = 0;
38      protected static final int JCC_CLIENT = 1;
39      protected static final int CCC_CLIENT = 2;      // not yet supported.
40      protected static final int DNC_CLIENT = 3;      // derby net client 
41  
42      private static final int [] MIN_MGR_LEVELS = {
43                                              3, // AGENT - JCC comes in at 3
44                                              4, // CCSIDMGR  
45                                              3, // CMNAPPC, 
46                                              4, // CMNSYNCPT
47                                              5, // CMNTCPIP
48                                              1, // DICTIONARY
49                                              3, // RDB
50                                              4, // RSYNCMGR
51                                              1, // SECMGR    
52                                              6, // SQLAM
53                                              1, // SUPERVISOR    
54                                              5, // SYNCPTMGR
55                                              0  // XAMGR
56                                              };
57      
58      // Application requester information
59      protected String      extnam;         // External Name - EXCSAT
60      protected String      srvnam;         // Server Name - EXCSAT
61      protected String      srvrlslv;       // Server Product Release Level - EXCSAT
62      protected String      srvclsnm;       // Server Class Name - EXCSAT
63      protected String      spvnam;         // Supervisor Name - EXCSAT
64      protected String      prdid;          // Product specific identifier - ACCRDB protected
65      private int[]       managerLevels = new int[CodePoint.MGR_CODEPOINTS.length];
66      private int         clientType;
67      protected int       versionLevel;
68      protected int       releaseLevel;
69      protected int       modifyLevel;
70      
71  
72      // constructor 
73      /** 
74       * AppRequester constructor
75       * 
76       * @exception throws IOException
77       */
78      AppRequester () 
79      {
80          for (int i = 0; i < CodePoint.MGR_CODEPOINTS.length; i++)
81              managerLevels[i] = MGR_LEVEL_UNKNOWN;
82      }
83  
84      /**
85       * get the Application requester manager level
86       *
87       * @param manager   codepoint for manager we are looking for
88       *
89       * @return manager level for that manager
90       */
91      protected int getManagerLevel(int manager)
92      {
93          int mindex = CodePoint.getManagerIndex(manager);
94          if (SanityManager.DEBUG)
95          {
96              if (mindex < 0 || mindex > managerLevels.length)
97                  SanityManager.THROWASSERT("Unknown manager "+ manager + " mindex = "+
98                      mindex);
99          }
100         return managerLevels[mindex];
101     }
102 
103     protected void setClientVersion(String   productId)
104     {
105         prdid = productId;
106 
107         versionLevel = Integer.parseInt(prdid.substring (3, 5));
108         releaseLevel = Integer.parseInt(prdid.substring (5, 7));
109         modifyLevel = Integer.parseInt(prdid.substring (7, 8));
110         if (srvrlslv == null)
111         { clientType = UNKNOWN_CLIENT; }
112         else if (srvrlslv.indexOf("JCC") != -1)
113         { clientType = JCC_CLIENT; }
114         else if
115             (
116                 (srvrlslv.indexOf(DRDAConstants.DERBY_DRDA_CLIENT_ID) != -1)
117             )
118         { clientType = DNC_CLIENT; }
119         else
120         { clientType = UNKNOWN_CLIENT; }
121     }
122 
123     /**
124      * Returns true if Derby's client driver supports SECMEC_USRSSBPWD 
125      * DRDA security mechanism.
126      */
127     protected boolean supportsSecMecUSRSSBPWD()
128     {
129         return
130             (
131                 ( clientType == DNC_CLIENT ) &&
132                 ( greaterThanOrEqualTo( 10, 2, 0 ) )
133             );
134     }
135 
136     /**
137      * Check if the client expects QRYCLSIMP to be supported when the
138      * protocol is LMTBLKPRC.
139      *
140      * @return <code>true</code> if QRYCLSIMP is supported for
141      * LMTBLKPRC
142      */
143     protected final boolean supportsQryclsimpForLmtblkprc() {
144         return clientType == DNC_CLIENT;
145     }
146 
147     /**
148      * Check if provided JCC version level is greaterThanOrEqualTo current level
149      *
150      * @param vLevel    Version level
151      * @param rLevel    Release level
152      * @param mLevel    Modification level
153      */
154      
155     protected boolean greaterThanOrEqualTo(int vLevel, int rLevel, int mLevel)
156     {
157         if (versionLevel > vLevel)
158                 return true;
159         else if (versionLevel == vLevel) {
160                 if (releaseLevel > rLevel)
161                         return true;
162                 else if (releaseLevel == rLevel)
163                         if (modifyLevel >= mLevel)
164                                 return true;
165         }
166         return false;
167     }
168 
169     /** 
170      * set Application requester manager level
171      * if the manager level is less than the minimum manager level,
172      * set the manager level to zero (saying we can't handle this
173      * level), this will be returned
174      * to the application requester and he can decide whether or not to
175      * proceed
176      * For CCSIDMGR, if the target server supports the CCSID manager but
177      * not the CCSID requested, the value returned is FFFF
178      * For now, we won't support the CCSIDMGR since JCC doesn't request it.
179      *
180      * @param manager   codepoint of the manager
181      * @param managerLevel  level for that manager
182      *
183      */
184     protected void setManagerLevel(int manager, int managerLevel)
185     {
186         int i = CodePoint.getManagerIndex(manager);
187         if (SanityManager.DEBUG)
188         {
189             if (i < 0 || i > managerLevels.length)
190                 SanityManager.THROWASSERT("Unknown manager "+ manager + " i = " + i);
191         }
192         if (managerLevel >= MIN_MGR_LEVELS[i])
193             managerLevels[i] = managerLevel;    
194         else
195             managerLevels[i] = 0;
196     }
197     
198     /**
199      * Check if the application requester is the same as this one
200      *
201      * @param a application requester to compare to
202      * @return true if same false otherwise
203      */
204     protected boolean equals(AppRequester a)
205     {
206         // check prdid - this should be different if they are different
207         if (!prdid.equals(a.prdid))
208             return false;
209 
210         // check server product release level
211         if (notEquals(srvrlslv, a.srvrlslv))
212             return false;
213 
214         // check server names
215         if (notEquals(extnam, a.extnam))
216             return false;
217 
218         if (notEquals(srvnam, a.srvnam))
219             return false;
220 
221         if (notEquals(srvclsnm, a.srvclsnm))
222             return false;
223 
224         if (notEquals(spvnam, a.spvnam))
225             return false;
226 
227         // check manager levels
228         for (int i = 0; i < managerLevels.length; i++)
229             if (managerLevels[i] != a.managerLevels[i])
230                 return false;
231 
232         // O.K. looks good
233         return true;
234     }
235     /**
236      * Check whether two objects are not equal when 1 of the objects could
237      * be null
238      *
239      * @param a first object
240      * @param b second object
241      * @return true if not equals false otherwise
242      */
243     private boolean notEquals(Object   a, Object   b)
244     {
245         if (a != null && b == null)
246             return true;
247         if (a == null && b != null)
248             return true;
249         if (a != null && !a.equals(b))
250             return true;
251         return false;
252     }
253 
254     /**
255      * Get the maximum length supported for an exception's message
256      * parameter string.
257      */
258 
259     protected int supportedMessageParamLength() {
260 
261         switch (clientType) {
262 
263             case JCC_CLIENT:
264             case DNC_CLIENT:
265                 return Limits.DB2_JCC_MAX_EXCEPTION_PARAM_LENGTH;
266             default:
267             // Default is the max for C clients, since that is more
268             // restricted than for JCC clients.  Note, though, that
269             // JCC clients are the only ones supported right now.
270                 return Limits.DB2_CCC_MAX_EXCEPTION_PARAM_LENGTH;
271 
272         }
273 
274     }
275 
276     /**
277      * Get the type of the client.
278      */
279 
280     protected int getClientType() {
281 
282         return clientType;
283 
284     }
285 
286     /**
287      * Is this an AppRequester that supports XA 
288      *
289      * return true if XAMGR >= 7, false otherwise
290      **/
291 
292     protected  boolean isXARequester()
293     {
294         return (getManagerLevel(CodePoint.XAMGR) >= 7);
295         
296     }
297 
298 }
299
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