1 /**************************************************************
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
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11 * http://www.apache.org/licenses/LICENSE-2.0
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14 * software distributed under the License is distributed on an
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20 *************************************************************/
21
22
23
24 #include "precompiled_sd.hxx"
25
26 #include "SlsRequestQueue.hxx"
27
28 #include <set>
29
30
31 #undef VERBOSE
32 //#define VERBOSE
33
34 namespace sd { namespace slidesorter { namespace cache {
35
36 /** This class extends the actual request data with additional information
37 that is used by the priority queues.
38 */
39 class Request
40 {
41 public:
Request(CacheKey aKey,sal_Int32 nPriority,RequestPriorityClass eClass)42 Request (
43 CacheKey aKey, sal_Int32 nPriority, RequestPriorityClass eClass)
44 : maKey(aKey), mnPriorityInClass(nPriority), meClass(eClass)
45 {}
46 /** Sort requests according to priority classes and then to priorities.
47 */
48 class Comparator { public:
operator ()(const Request & rRequest1,const Request & rRequest2)49 bool operator() (const Request& rRequest1, const Request& rRequest2)
50 {
51 if (rRequest1.meClass == rRequest2.meClass)
52 return (rRequest1.mnPriorityInClass > rRequest2.mnPriorityInClass);
53 else
54 return (rRequest1.meClass < rRequest2.meClass);
55 }
56 };
57 /** Request data is compared arbitrarily by their addresses in memory.
58 This just establishes an order so that the STL containers are happy.
59 The order is not semantically interpreted.
60 */
61 class DataComparator { public:
DataComparator(const Request & rRequest)62 DataComparator (const Request&rRequest):maKey(rRequest.maKey){}
DataComparator(const CacheKey aKey)63 DataComparator (const CacheKey aKey):maKey(aKey){}
operator ()(const Request & rRequest)64 bool operator() (const Request& rRequest) { return maKey == rRequest.maKey; }
65 private: const CacheKey maKey;
66 };
67
68 CacheKey maKey;
69 sal_Int32 mnPriorityInClass;
70 RequestPriorityClass meClass;
71 };
72
73
74 class RequestQueue::Container
75 : public ::std::set<
76 Request,
77 Request::Comparator>
78 {
79 };
80
81
82
83
84 //===== GenericRequestQueue =================================================
85
86
RequestQueue(const SharedCacheContext & rpCacheContext)87 RequestQueue::RequestQueue (const SharedCacheContext& rpCacheContext)
88 : maMutex(),
89 mpRequestQueue(new Container()),
90 mpCacheContext(rpCacheContext),
91 mnMinimumPriority(0),
92 mnMaximumPriority(1)
93 {
94 }
95
96
97
98
~RequestQueue(void)99 RequestQueue::~RequestQueue (void)
100 {
101 }
102
103
104
105
AddRequest(CacheKey aKey,RequestPriorityClass eRequestClass,bool)106 void RequestQueue::AddRequest (
107 CacheKey aKey,
108 RequestPriorityClass eRequestClass,
109 bool /*bInsertWithHighestPriority*/)
110 {
111 ::osl::MutexGuard aGuard (maMutex);
112
113 OSL_ASSERT(eRequestClass>=MIN__CLASS && eRequestClass<=MAX__CLASS);
114
115 // If the request is already a member of the queue then remove it so
116 // that the following insertion will use the new prioritization.
117 #ifdef VERBOSE
118 bool bRemoved =
119 #endif
120 RemoveRequest(aKey);
121
122 // The priority of the request inside its priority class is defined by
123 // the page number. This ensures a strict top-to-bottom, left-to-right
124 // order.
125 sal_Int32 nPriority (mpCacheContext->GetPriority(aKey));
126 Request aRequest (aKey, nPriority, eRequestClass);
127 mpRequestQueue->insert(aRequest);
128
129 SSCD_SET_REQUEST_CLASS(rRequestData.GetPage(),eRequestClass);
130
131 #ifdef VERBOSE
132 OSL_TRACE("%s request for page %d with priority class %d",
133 bRemoved?"replaced":"added",
134 (rRequestData.GetPage()->GetPageNum()-1)/2,
135 eRequestClass);
136 #endif
137 }
138
139
140
141
RemoveRequest(CacheKey aKey)142 bool RequestQueue::RemoveRequest (
143 CacheKey aKey)
144 {
145 bool bRequestWasRemoved (false);
146 ::osl::MutexGuard aGuard (maMutex);
147
148 while(true)
149 {
150 Container::const_iterator aRequestIterator = ::std::find_if (
151 mpRequestQueue->begin(),
152 mpRequestQueue->end(),
153 Request::DataComparator(aKey));
154 if (aRequestIterator != mpRequestQueue->end())
155 {
156 if (aRequestIterator->mnPriorityInClass == mnMinimumPriority+1)
157 mnMinimumPriority++;
158 else if (aRequestIterator->mnPriorityInClass == mnMaximumPriority-1)
159 mnMaximumPriority--;
160 mpRequestQueue->erase(aRequestIterator);
161 bRequestWasRemoved = true;
162
163 if (bRequestWasRemoved)
164 {
165 SSCD_SET_STATUS(rRequest.GetPage(),NONE);
166 }
167 }
168 else
169 break;
170 }
171
172 return bRequestWasRemoved;
173 }
174
175
176
177
ChangeClass(CacheKey aKey,RequestPriorityClass eNewRequestClass)178 void RequestQueue::ChangeClass (
179 CacheKey aKey,
180 RequestPriorityClass eNewRequestClass)
181 {
182 ::osl::MutexGuard aGuard (maMutex);
183
184 OSL_ASSERT(eNewRequestClass>=MIN__CLASS && eNewRequestClass<=MAX__CLASS);
185
186 Container::const_iterator iRequest (
187 ::std::find_if (
188 mpRequestQueue->begin(),
189 mpRequestQueue->end(),
190 Request::DataComparator(aKey)));
191 if (iRequest!=mpRequestQueue->end() && iRequest->meClass!=eNewRequestClass)
192 {
193 AddRequest(aKey, eNewRequestClass, true);
194 SSCD_SET_REQUEST_CLASS(rRequestData.GetPage(),eNewRequestClass);
195 }
196 }
197
198
199
200
GetFront(void)201 CacheKey RequestQueue::GetFront (void)
202 {
203 ::osl::MutexGuard aGuard (maMutex);
204
205 if (mpRequestQueue->empty())
206 throw ::com::sun::star::uno::RuntimeException(
207 ::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM(
208 "RequestQueue::GetFront(): queue is empty")),
209 NULL);
210
211 return mpRequestQueue->begin()->maKey;
212 }
213
214
215
216
GetFrontPriorityClass(void)217 RequestPriorityClass RequestQueue::GetFrontPriorityClass (void)
218 {
219 ::osl::MutexGuard aGuard (maMutex);
220
221 if (mpRequestQueue->empty())
222 throw ::com::sun::star::uno::RuntimeException(
223 ::rtl::OUString(RTL_CONSTASCII_USTRINGPARAM(
224 "RequestQueue::GetFrontPriorityClass(): queue is empty")),
225 NULL);
226
227 return mpRequestQueue->begin()->meClass;
228 }
229
230
231
232
PopFront(void)233 void RequestQueue::PopFront (void)
234 {
235 ::osl::MutexGuard aGuard (maMutex);
236
237 if ( ! mpRequestQueue->empty())
238 {
239 SSCD_SET_STATUS(maRequestQueue.begin()->mpData->GetPage(),NONE);
240
241 mpRequestQueue->erase(mpRequestQueue->begin());
242
243 // Reset the priority counter if possible.
244 if (mpRequestQueue->empty())
245 {
246 mnMinimumPriority = 0;
247 mnMaximumPriority = 1;
248 }
249 }
250 }
251
252
253
254
IsEmpty(void)255 bool RequestQueue::IsEmpty (void)
256 {
257 ::osl::MutexGuard aGuard (maMutex);
258 return mpRequestQueue->empty();
259 }
260
261
262
263
Clear(void)264 void RequestQueue::Clear (void)
265 {
266 ::osl::MutexGuard aGuard (maMutex);
267
268 mpRequestQueue->clear();
269 mnMinimumPriority = 0;
270 mnMaximumPriority = 1;
271 }
272
273
274
275
GetMutex(void)276 ::osl::Mutex& RequestQueue::GetMutex (void)
277 {
278 return maMutex;
279 }
280
281
282 } } } // end of namespace ::sd::slidesorter::cache
283
284
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286