1 a.dunfey 1.10.2.1 //%2006////////////////////////////////////////////////////////////////////////
|
2 mike 1.2 //
|
3 karl 1.7 // Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
4 // Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
5 // Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
|
6 karl 1.6 // IBM Corp.; EMC Corporation, The Open Group.
|
7 karl 1.7 // Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
8 // IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
|
9 karl 1.9 // Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
10 // EMC Corporation; VERITAS Software Corporation; The Open Group.
|
11 a.dunfey 1.10.2.1 // Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
12 // EMC Corporation; Symantec Corporation; The Open Group.
|
13 mike 1.2 //
14 // Permission is hereby granted, free of charge, to any person obtaining a copy
|
15 kumpf 1.4 // of this software and associated documentation files (the "Software"), to
16 // deal in the Software without restriction, including without limitation the
17 // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
|
18 mike 1.2 // sell copies of the Software, and to permit persons to whom the Software is
19 // furnished to do so, subject to the following conditions:
20 //
|
21 kumpf 1.4 // THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
|
22 mike 1.2 // ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
23 // "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
|
24 kumpf 1.4 // LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
25 // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
26 // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
27 mike 1.2 // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
29 //
30 //==============================================================================
31 //
32 // Author: Mike Brasher (mbrasher@bmc.com)
33 //
|
34 david.dillard 1.8 // Modified By: David Dillard, VERITAS Software Corp.
35 // (david.dillard@veritas.com)
|
36 mike 1.2 //
37 //%/////////////////////////////////////////////////////////////////////////////
38
39 #ifndef Pegasus_WQLParser_h
40 #define Pegasus_WQLParser_h
41
42 #include <Pegasus/Common/Config.h>
|
43 kumpf 1.5 #include <Pegasus/Common/ArrayInternal.h>
|
44 mike 1.2 #include <Pegasus/WQL/Linkage.h>
45 #include <Pegasus/WQL/WQLSelectStatement.h>
|
46 mike 1.10 #include <Pegasus/Common/Buffer.h>
|
47 mike 1.2
48 PEGASUS_NAMESPACE_BEGIN
49
50 /** This class is the main interface to the WQL parser used for parsing WQL1
51 compliant SQL statements.
52
53 Here's an example which parses a SELECT statement:
54
55 <pre>
56 const char TEXT[] = "SELECT X,Y FROM MyClass WHERE X > 10 AND Y < 3";
57
58 // Note that this array must be null-terminated (sizeof(TEXT) includes
59 // the null-terminator in the count).
60
|
61 mike 1.10 Buffer text(TEXT, sizeof(TEXT));
|
62 mike 1.2
63 WQLSelectStatement selectStatement;
64
65 WQLParser parser;
66
67 try
68 {
69 parser.parse(text, selectStatement);
70 }
71 catch (ParseError&)
72 {
73 ...
74 }
75 catch (MissingNullTerminator&)
76 {
77 ...
78 }
79 </pre>
80
81 Note that the text must be NULL terminated or else the MissingNullTerminator
82 exception is thrown.
83 mike 1.2
84 The text is read and the result is left in the selectStatement output
85 argument.
86
87 At this point you might wish to peek at the contents of the selectStatement.
88 This may be done by calling WQLSelectStatement::print() like this:
89
90 <pre>
91 WQLSelectStatement selectStatement;
92 ...
93 selectStatement.print();
94 </pre>
95
96 For the above query text, the following is printed:
97
98 <pre>
99 WQLSelectStatement
100 {
101 _className: "MyClass"
102
103 _propertyNames[0]: "X"
104 mike 1.2 _propertyNames[1]: "Y"
105
106 _operations[0]: "WQL_GT"
107 _operations[1]: "WQL_LT"
108 _operations[2]: "WQL_AND"
109
110 _operands[0]: "PROPERTY_NAME: X"
111 _operands[1]: "INTEGER_VALUE: 10"
112 _operands[2]: "PROPERTY_NAME: Y"
113 _operands[3]: "INTEGER_VALUE: 3"
114 }
115 </pre>
116
117 The WQLSelectStatement::evaluateWhereClause() method may be called to
118 determine whether a particular instance (whose properties are made
119 available to he evaluateWhereClause() by a user implementation of the
120 WQLPropertySource class). This method returns true, if the where clause
121 matches this instance. Here is an example:
122
123 <pre>
124 WQLSelectStatement selectStatement;
125 mike 1.2 ...
126 WQLPropertySource* propertySource = new MyPropertySource(...);
127
128 if (selectStatement.evaluateWhereClause(propertySource))
129 {
130 // It's a match!
131 }
132 </pre>
133
134 The evaluateWhereClause() method calls propertySource->getValue() to
135 obtain values for each of the properties referred to in where clause (X
136 and Y in the above query example).
137
138 The implementer of the WQLPropertySource interface must provide the
139 implementation of getValue() to produce values for the target data
140 types. The WQL library makes no assumptions about the nature of the
141 target data representation. This was done so that this libary could be
142 adapted to multiple data representations.
143
144 For use with Pegasus CIMInstance objects, a CIMInstancePropertySource
145 class could be developed whose getValue() method fetches values from
146 mike 1.2 a CIMInstance. Here is an example of how it might be used.
147
148 <pre>
149 CIMInstancePropertySource* propertySource
150 = new CIMInstancePropertySource(...);
151
152 CIMInstance instance;
153
154 while (instance = GetNextInstance(...))
155 {
156 propertySource->setInstance(currentInstance);
157
158 if (selectStatement.evaluateWhereClause(propertySource))
159 {
160 // It's a match!
161 }
162 }
163 </pre>
164
165 Of course the numeration of instances is left to the user of WQL.
166 */
167 mike 1.2 class PEGASUS_WQL_LINKAGE WQLParser
168 {
169 public:
170
171 /** Parse the SELECT statement given by the text parameter and initialize
172 the statement parameter accordingly.
173
174 Please note that this method is not thread safe. It must be guarded
175 with mutexes by the caller.
176
|
177 mike 1.3 @param text null-terminated C-string which points to SQL statement.
|
178 mike 1.2 @param statement object which holds the compiled version of the SELECT
179 statement upon return.
180 @exception ParseError if text is not a valid SELECT statement.
181 @exception MissingNullTerminator if text argument is not
182 terminated with a null.
183 */
184 static void parse(
|
185 mike 1.3 const char* text,
186 WQLSelectStatement& statement);
187
188 /** Version of parse() taking an array of characters.
189 */
190 static void parse(
|
191 mike 1.10 const Buffer& text,
|
192 mike 1.3 WQLSelectStatement& statement);
193
194 /** Version of parse() taking a string.
195 */
196 static void parse(
197 const String& text,
|
198 mike 1.2 WQLSelectStatement& statement);
199
200 private:
201
202 /** This method cleans up all the strings which were created by LEX and
203 passed to YACC. These strings cannot be cleaned up by YACC actions
204 since the actions that clean up certain strings are not always reached
205 when errors occur.
206 */
207 static void cleanup();
208
209 /** Private constructor to avoid user from creating instance of this class.
210 */
211 WQLParser() { }
212 };
213
214 PEGASUS_NAMESPACE_END
215
216 #endif /* Pegasus_WQLParser_h */
|
Return to
WQLParser.h
CVS log
Up to [Pegasus] / pegasus / src / Pegasus / WQL