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

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  31
  32 #ifndef SD_SLIDESORTER_REQUEST_QUEUE_HXX
  33 #define SD_SLIDESORTER_REQUEST_QUEUE_HXX
  34
  35 #include "SlsRequestPriorityClass.hxx"
  36 #include "cache/SlsCacheContext.hxx"
  37 #include "taskpane/SlideSorterCacheDisplay.hxx"
  38 #include <drawdoc.hxx>
  39 #include "osl/mutex.hxx"
  40
  41
  42 namespace sd { namespace slidesorter { namespace cache {
  43
  44 class RequestData;
  45
  46 /** The request queue stores requests that are described by the RequestData
  47     sorted according to priority class and then priority.
  48 */
  49 class RequestQueue
  50 {
  51 public:
  52     RequestQueue (const SharedCacheContext& rpCacheContext);
  53     ~RequestQueue (void);
  54
  55     /** Insert a request with highest or lowest priority in its priority
  56         class.  When the request is already present then it is first
  57         removed.  This effect is then a re-prioritization.
  58         @param rRequestData
  59             The request.
  60         @param eRequestClass
  61             The priority class in which to insert the request with highest
  62             or lowest priority.
  63         @param bInsertWithHighestPriority
  64             When this flag is <TRUE/> the request is inserted with highes
  65             priority in its class.  When <FALSE/> the request is inserted
  66             with lowest priority.
  67     */
  68     void AddRequest (
  69         CacheKey aKey,
  70         RequestPriorityClass eRequestClass,
  71         bool bInsertWithHighestPriority = false);
  72
  73     /** Remove the specified request from the queue.
  74         @param rRequestData
  75             It is OK when the specified request is not a member of the
  76             queue.
  77         @return
  78             Returns <TRUE/> when the request has been successfully been
  79             removed from the queue.  Otherwise, e.g. because the request was
  80             not a member of the queue, <FALSE/> is returned.
  81     */
  82     bool RemoveRequest (CacheKey aKey);
  83
  84     /** Change the priority class of the specified request.
  85     */
  86     void ChangeClass (
  87         CacheKey aKey,
  88         RequestPriorityClass eNewRequestClass);
  89
  90     /** Get the request with the highest priority int the highest priority class.
  91     */
  92     CacheKey GetFront (void);
  93
  94     // For debugging.
  95     RequestPriorityClass GetFrontPriorityClass (void);
  96
  97     /** Really a synonym for RemoveRequest(GetFront());
  98     */
  99     void PopFront (void);
 100
 101     /** Returns <TRUE/> when there is no element in the queue.
 102     */
 103     bool IsEmpty (void);
 104
 105     /** Remove all requests from the queue.  This resets the minimum and
 106         maximum priorities to their default values.
 107     */
 108     void Clear (void);
 109
 110     /** Return the mutex that guards the access to the priority queue.
 111     */
 112     ::osl::Mutex& GetMutex (void);
 113
 114 private:
 115     ::osl::Mutex maMutex;
 116     class Container;
 117     ::boost::scoped_ptr<Container> mpRequestQueue;
 118     SharedCacheContext mpCacheContext;
 119
 120     /** A lower bound of the lowest priority of all elements in the queues.
 121         The start value is 0.  It is assigned and then decreased every time
 122         when an element is inserted or marked as the request with lowest
 123         priority.
 124     */
 125     int mnMinimumPriority;
 126     /** An upper bound of the highest priority of all elements in the queues.
 127         The start value is 1.  It is assigned and then increased every time
 128         when an element is inserted or marked as the request with highest
 129         priority.
 130     */
 131     int mnMaximumPriority;
 132 };
 133
 134
 135 } } } // end of namespace ::sd::slidesorter::cache
 136
 137 #endif