sd/source/ui/slidesorter/cache/SlsRequestQueue.hxx

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  19
  20 #ifndef INCLUDED_SD_SOURCE_UI_SLIDESORTER_CACHE_SLSREQUESTQUEUE_HXX
  21 #define INCLUDED_SD_SOURCE_UI_SLIDESORTER_CACHE_SLSREQUESTQUEUE_HXX
  22
  23 #include "SlsRequestPriorityClass.hxx"
  24 #include <cache/SlsCacheContext.hxx>
  25 #include <osl/mutex.hxx>
  26 #include <svx/sdrpageuser.hxx>
  27
  28 #include <memory>
  29
  30 namespace sd { namespace slidesorter { namespace cache {
  31
  32 /** The request queue stores requests that are described by the Request
  33     sorted according to priority class and then priority.
  34 */
  35 class RequestQueue : public sdr::PageUser
  36 {
  37 public:
  38     explicit RequestQueue (const SharedCacheContext& rpCacheContext);
  39     virtual ~RequestQueue();
  40
  41     /** Insert a request with highest or lowest priority in its priority
  42         class.  When the request is already present then it is first
  43         removed.  This effect is then a re-prioritization.
  44         @param aKey
  45             The request.
  46         @param eRequestClass
  47             The priority class in which to insert the request with highest
  48             or lowest priority.
  49         @param bInsertWithHighestPriority
  50             When this flag is <TRUE/> the request is inserted with highest
  51             priority in its class.  When <FALSE/> the request is inserted
  52             with lowest priority.
  53     */
  54     void AddRequest (
  55         CacheKey aKey,
  56         RequestPriorityClass eRequestClass);
  57
  58     /** Remove the specified request from the queue.
  59         @param aKey
  60             It is OK when the specified request is not a member of the
  61             queue.
  62     */
  63 #if OSL_DEBUG_LEVEL >=2
  64 bool
  65 #else
  66 void
  67 #endif
  68     RemoveRequest (CacheKey aKey);
  69
  70     /** Change the priority class of the specified request.
  71     */
  72     void ChangeClass (
  73         CacheKey aKey,
  74         RequestPriorityClass eNewRequestClass);
  75
  76     /** Get the request with the highest priority int the highest priority class.
  77     */
  78     CacheKey GetFront();
  79
  80     // For debugging.
  81     RequestPriorityClass GetFrontPriorityClass();
  82
  83     /** Really a synonym for RemoveRequest(GetFront());
  84     */
  85     void PopFront();
  86
  87     /** Returns <TRUE/> when there is no element in the queue.
  88     */
  89     bool IsEmpty();
  90
  91     /** Remove all requests from the queue.  This resets the minimum and
  92         maximum priorities to their default values.
  93     */
  94     void Clear();
  95
  96     /** Return the mutex that guards the access to the priority queue.
  97     */
  98     ::osl::Mutex& GetMutex() { return maMutex;}
  99
 100     /** Ensure we don't hand out a page deleted before anyone got a
 101         chance to process it
 102     */
 103     virtual void PageInDestruction(const SdrPage& rPage) override;
 104
 105 private:
 106     ::osl::Mutex maMutex;
 107     class Container;
 108     std::unique_ptr<Container> mpRequestQueue;
 109     SharedCacheContext mpCacheContext;
 110
 111     /** A lower bound of the lowest priority of all elements in the queues.
 112         The start value is 0.  It is assigned and then decreased every time
 113         when an element is inserted or marked as the request with lowest
 114         priority.
 115     */
 116     int mnMinimumPriority;
 117     /** An upper bound of the highest priority of all elements in the queues.
 118         The start value is 1.  It is assigned and then increased every time
 119         when an element is inserted or marked as the request with highest
 120         priority.
 121     */
 122     int mnMaximumPriority;
 123 };
 124
 125 } } } // end of namespace ::sd::slidesorter::cache
 126
 127 #endif
 128
 129 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */