StatementCacheKey


1   /*
2    * Distributed as part of c3p0 v.0.9.1
3    *
4    * Copyright (C) 2005 Machinery For Change, Inc.
5    *
6    * Author: Steve Waldman <swaldman@mchange.com>
7    *
8    * This library is free software; you can redistribute it and/or modify
9    * it under the terms of the GNU Lesser General Public License version 2.1, as 
10   * published by the Free Software Foundation.
11   *
12   * This software is distributed in the hope that it will be useful,
13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   * GNU Lesser General Public License for more details.
16   *
17   * You should have received a copy of the GNU Lesser General Public License
18   * along with this software; see the file LICENSE.  If not, write to the
19   * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
20   * Boston, MA 02111-1307, USA.
21   */
22  
23  
24  package com.mchange.v2.c3p0.stmt;
25  
26  import java.sql.Connection  ;
27  import java.sql.ResultSet  ;
28  import java.lang.reflect.Method  ;
29  import java.util.Arrays  ;
30  import com.mchange.v1.util.ArrayUtils;
31  import com.mchange.v2.lang.ObjectUtils;
32  
33  abstract class StatementCacheKey
34  {
35      static final int SIMPLE           = 0;
36      static final int MEMORY_COALESCED = 1;
37      static final int VALUE_IDENTITY   = 2;
38  
39      //NOTE: subclasses rely upon their _find logic being protected by StatementCacheKey.class' lock!
40      public synchronized static StatementCacheKey find( Connection   pcon, Method   stmtProducingMethod, Object  [] args )
41      {
42      switch ( VALUE_IDENTITY )
43          {
44          case SIMPLE:
45          return SimpleStatementCacheKey._find( pcon, stmtProducingMethod, args );
46          case MEMORY_COALESCED:
47          return MemoryCoalescedStatementCacheKey._find( pcon, stmtProducingMethod, args );
48          case VALUE_IDENTITY:
49          return ValueIdentityStatementCacheKey._find( pcon, stmtProducingMethod, args );
50          default:
51          throw new InternalError  ("StatementCacheKey.find() is misconfigured.");
52          }
53      }
54  
55      //MT: instances are treated as immutable once they 
56      //    have been initialized and handed to
57      //    a client. (Factories may reinitialize
58      //    instances that never get released to
59      //    clients -- those factories must prevent
60      //    concurrent access to these recycled, 
61      //    nascent keys.)
62      Connection       physicalConnection;
63      String           stmtText;
64      boolean        is_callable;
65      int            result_set_type;
66      int            result_set_concurrency;
67  
68      int[]          columnIndexes;          //jdbc3, null means default
69      String  []       columnNames;            //jdbc3, null means default
70  
71      Integer          autogeneratedKeys;   //jdbc3, null means driver default, which the spec does not sepcify 
72      Integer          resultSetHoldability; //jdbc3, null means driver default, which the spec does not sepcify
73  
74      StatementCacheKey()
75      {}
76  
77      StatementCacheKey( Connection   physicalConnection,
78                 String   stmtText,
79                 boolean is_callable,
80                 int result_set_type,
81                 int result_set_concurrency,
82                 int[] columnIndexes,
83                 String  [] columnNames,
84                 Integer   autogeneratedKeys,
85                 Integer   resultSetHoldability )
86      {
87      init( physicalConnection,
88            stmtText,
89            is_callable,
90            result_set_type,
91            result_set_concurrency,
92            columnIndexes,
93            columnNames,
94            autogeneratedKeys,
95            resultSetHoldability
96            );
97      }
98  
99      void init( Connection   physicalConnection,
100            String   stmtText,
101            boolean is_callable,
102            int result_set_type,
103            int result_set_concurrency,
104            int[] columnIndexes,          //jdbc3
105            String  [] columnNames,         //jdbc3
106            Integer   autogeneratedKeys,    //jdbc3
107            Integer   resultSetHoldability) //jdbc3
108     {
109     this.physicalConnection     = physicalConnection;
110     this.stmtText               = stmtText;
111     this.is_callable            = is_callable;
112     this.result_set_type        = result_set_type;
113     this.result_set_concurrency = result_set_concurrency;
114     this.columnIndexes          = columnIndexes;
115     this.columnNames            = columnNames;
116     this.autogeneratedKeys      = autogeneratedKeys;
117     this.resultSetHoldability   = resultSetHoldability;
118     }
119     
120     static boolean equals(StatementCacheKey _this, Object   o)
121     {
122     //TODO: assert( _this != null )
123 
124     if ( _this == o )
125         return true;
126     if (o instanceof StatementCacheKey)
127         {
128         StatementCacheKey sck = (StatementCacheKey) o;
129 
130 //      System.err.println( sck.physicalConnection + "   " + 
131 //                  _this.physicalConnection + "   equals? " + 
132 //                  sck.physicalConnection.equals( _this.physicalConnection ) );
133 
134         return 
135             sck.physicalConnection.equals(_this.physicalConnection) &&
136             sck.stmtText.equals(_this.stmtText) &&
137             sck.is_callable == _this.is_callable &&
138             sck.result_set_type == _this.result_set_type &&
139             sck.result_set_concurrency == _this.result_set_concurrency && 
140             Arrays.equals( sck.columnIndexes, _this.columnIndexes ) &&
141             Arrays.equals( sck.columnNames, _this.columnNames ) &&
142             ObjectUtils.eqOrBothNull( sck.autogeneratedKeys, _this.autogeneratedKeys ) &&
143             ObjectUtils.eqOrBothNull( sck.resultSetHoldability, _this.resultSetHoldability );
144         }
145     else
146         return false;
147     }
148     
149     static int hashCode(StatementCacheKey _this)
150     { 
151     return 
152         _this.physicalConnection.hashCode() ^
153         _this.stmtText.hashCode() ^
154         (_this.is_callable ? 1 : 0) ^
155         _this.result_set_type ^
156         _this.result_set_concurrency ^
157         ArrayUtils.hashOrZeroArray( _this.columnIndexes ) ^
158         ArrayUtils.hashOrZeroArray( _this.columnNames ) ^
159         ObjectUtils.hashOrZero( _this.autogeneratedKeys ) ^   //this is okay -- genuine constants are non-zer0
160         ObjectUtils.hashOrZero( _this.resultSetHoldability ); //this is okay -- genuine constants are non-zer0
161     }
162 
163     public String   toString()
164     { 
165     StringBuffer   out = new StringBuffer  (128);
166     out.append("[" + this.getClass().getName() + ": ");
167     out.append("physicalConnection->" + physicalConnection);
168     out.append(", stmtText->" + stmtText);
169     out.append(", is_callable->" + is_callable);
170     out.append(", result_set_type->" + result_set_type);
171     out.append(", result_set_concurrency->" + result_set_concurrency);
172     out.append(", columnIndexes->" + columnIndexes);
173     out.append(", columnNames->" + columnNames);
174     out.append(", autogeneratedKeys->" + autogeneratedKeys);
175     out.append(", resultSetHoldability->" + resultSetHoldability);
176     out.append(']');
177     return out.toString();
178     }
179 }
180 
181 
182
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