1 thilo.boehm 1.2 //%LICENSE////////////////////////////////////////////////////////////////
2 //
3 // Licensed to The Open Group (TOG) under one or more contributor license
4 // agreements. Refer to the OpenPegasusNOTICE.txt file distributed with
5 // this work for additional information regarding copyright ownership.
6 // Each contributor licenses this file to you under the OpenPegasus Open
7 // Source License; you may not use this file except in compliance with the
8 // License.
9 //
10 // Permission is hereby granted, free of charge, to any person obtaining a
11 // copy of this software and associated documentation files (the "Software"),
12 // to deal in the Software without restriction, including without limitation
13 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
14 // and/or sell copies of the Software, and to permit persons to whom the
15 // Software is furnished to do so, subject to the following conditions:
16 //
17 // The above copyright notice and this permission notice shall be included
18 // in all copies or substantial portions of the Software.
19 //
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
21 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 thilo.boehm 1.2 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
23 // IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
24 // CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
25 // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
26 // SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
27 //
28 //////////////////////////////////////////////////////////////////////////
29 //
30 //%/////////////////////////////////////////////////////////////////////////////
31 #ifndef _SCMOClassCache_H_
32 #define _SCMOClassCache_H_
33
34 #include <Pegasus/Common/Linkage.h>
35 #include <Pegasus/Common/Config.h>
36 #include <Pegasus/Common/CIMClass.h>
37 #include <Pegasus/Common/ReadWriteSem.h>
38 #include <Pegasus/Common/SCMOClass.h>
39
40 PEGASUS_NAMESPACE_BEGIN
41
42 typedef SCMOClass (*SCMOClassCacheCallbackPtr)(
43 thilo.boehm 1.2 const CIMNamespaceName& nameSpace,
44 const CIMName& className);
45
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47 thilo.boehm 1.2
48 struct SCMBClassCacheEntry
49 {
50 // Spin-lock to serialize the access to the entry
51 AtomicInt lock;
52 // The key to identify the entry
53 Uint64 key;
54 // Pointer to the cached SCMOClass
55 SCMOClass* data;
56 };
57
58 class PEGASUS_COMMON_LINKAGE SCMOClassCache
59 {
60
61 public:
62
63 /**
64 * This function returns the SCMOClass for the given class name and
65 * name space.
66 * @param ndName The UTF8 encoded name space. '\0' terminated
67 * @param nsNameLan The strlen of ndName ( without '\0')
68 thilo.boehm 1.2 * @param className The UTF8 encoded class name. '\0' terminated
69 * @param nsNameLan The strlen of className ( without '\0')
70 * @return A pointer to SCMOClass. If the class was not found, an empty
71 * SCMOClass is returned. This can be checked by using the
72 * SCMOClass.isEmpty() method.
73 **/
74 SCMOClass getSCMOClass(
75 const char* nsName,
76 Uint32 nsNameLen,
77 const char* className,
78 Uint32 classNameLen);
79
80 /**
81 * Removes the named SCMOClass from the cache.
82 * @param cimNameSpace The name space name of the SCMOClass to remove.
83 * @param cimClassName The class name of the SCMOClass to remove.
84 **/
85 void removeSCMOClass(CIMNamespaceName cimNameSpace,CIMName cimClassName);
86
87 /**
88 * Clears the whole cache.
89 thilo.boehm 1.2 * This should be only done at modification of a class.
90 * This may invalidate subclass definitions in the cache.
91 * Since class modification is relatively rare, we just flush the entire
92 * cache rather than specifically evicting subclass definitions.
93 **/
94 void clear();
95
96 /**
97 * Returns the pointer to an instance of SCMOClassCache.
98 */
99 static SCMOClassCache* getInstance();
100
101 /**
102 * Set the call back function for the SCMOClass to retrieve CIMClasses.
103 * @param clb The static call back function.
104 */
105 void setCallBack(SCMOClassCacheCallbackPtr clb)
106 {
107 _resolveCallBack = clb;
108 }
109
110 thilo.boehm 1.2 static void destroy();
111
112 #ifdef PEGASUS_DEBUG
113 void DisplayCacheStatistics();
114 #endif
115
116 private:
117
118 // Singleton instance pointer
119 static SCMOClassCache* _theInstance;
120
121 // The call back function pointer to get CIMClass's
122 SCMOClassCacheCallbackPtr _resolveCallBack;
123
124 // The cache array
125 SCMBClassCacheEntry _theCache[PEGASUS_SCMO_CLASS_CACHE_SIZE];
126
127 // Lock to prevent parallel modifications of the cache.
128 ReadWriteSem _modifyCacheLock;
129
130 // Last successful read index.
131 thilo.boehm 1.2 Uint32 _lastSuccessIndex;
132
133 // Last successful written cache index.
134 Uint32 _lastWrittenIndex;
135
136 // Counter of used cache entries.
137 Uint32 _fillingLevel;
138
139 // Indicator for destruction of the cache.
140 Boolean _dying;
141
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149 thilo.boehm 1.2
150 SCMOClassCache()
151 : _resolveCallBack(NULL),
152 _lastSuccessIndex(0),
153 _lastWrittenIndex(PEGASUS_SCMO_CLASS_CACHE_SIZE-1),
154 _fillingLevel(0),
155 _dying(false)
156 {
157 // intialize the the cache
158 for (Uint32 i = 0 ; i < PEGASUS_SCMO_CLASS_CACHE_SIZE; i++)
159 {
160 _theCache[i].data = 0;
161 _theCache[i].key = 0;
162 // set the lock counter to 1 to allow one next user to enter.
163 _theCache[i].lock.set(1);
164 }
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172 thilo.boehm 1.2
173 };
174
175 // clean-up cache data
176 ~SCMOClassCache();
177
178 Uint64 _generateKey(
179 const char* className,
180 Uint32 classNameLen,
181 const char* nameSpaceNameLen,
182 Uint32 nameSpaceName);
183
184 Boolean _sameSCMOClass(
185 const char* nsName,
186 Uint32 nsNameLen,
187 const char* className,
188 Uint32 classNameLen,
189 SCMOClass* theClass);
190
191 SCMOClass _addClassToCache(
192 const char* nsName,
193 thilo.boehm 1.2 Uint32 nsNameLen,
194 const char* className,
195 Uint32 classNameLen,
196 Uint64 theKey);
197
198
199 /**
200 * Get a lock on a cache entry.
201 * @return true if the lock was optained
202 * false if the lock was NOT optained, give up !!!
203 **/
204 Boolean _lockEntry(Uint32 index);
205
206 void _unlockEntry(Uint32 index)
207 {
208 // set the lock counter to 1 to allow one next user to enter
209 // the critical section.
210 _theCache[index].lock.set(1);
211
212 };
213 };
214 thilo.boehm 1.2
215 PEGASUS_NAMESPACE_END
216
217 #endif
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SCMOClassCache.h
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