merge LoaderQueue into Loader

[lyx.git] / src / graphics / GraphicsLoader.cpp

diff --git a/src/graphics/GraphicsLoader.cpp b/src/graphics/GraphicsLoader.cpp
index a7ac094cd2e69690deafb0c776e15504b89a1ab7..c5a6326d82460683c97e3541119e310cd151da3c 100644 (file)
--- a/src/graphics/GraphicsLoader.cpp
+++ b/src/graphics/GraphicsLoader.cpp
@@ -15,19 +15,152 @@
 #include "GraphicsCacheItem.h"
 #include "GraphicsImage.h"
 #include "GraphicsParams.h"
-#include "LoaderQueue.h"
+#include "GraphicsCache.h"
+#include "debug.h"
+
+#include "support/Timeout.h"
 
 #include <boost/bind.hpp>
 
+#include <set>
+#include <queue>
 
 using std::string;
+using std::endl;
+using std::list;
 
 
 namespace lyx {
+namespace graphics {
 
 using support::FileName;
 
-namespace graphics {
+/////////////////////////////////////////////////////////////////////
+//
+// LoaderQueue
+//
+/////////////////////////////////////////////////////////////////////
+
+class LoaderQueue {
+public:
+       /// Use this to request that the item is loaded.
+       void touch(Cache::ItemPtr const & item);
+       /// Query whether the clock is ticking.
+       bool running() const;
+       ///get the and only instance of the class
+       static LoaderQueue & get();
+private:
+       /// This class is a singleton class... use LoaderQueue::get() instead
+       LoaderQueue();
+       /// The in-progress loading queue (elements are unique here).
+       std::list<Cache::ItemPtr> cache_queue_;
+       /// Used to make the insertion of new elements faster.
+       std::set<Cache::ItemPtr> cache_set_;
+       /// Newly touched elements go here. loadNext moves them to cache_queue_
+       std::queue<Cache::ItemPtr> bucket_;
+       ///
+       Timeout timer;
+       ///
+       bool running_;
+
+       /** This is the 'threaded' method, that does the loading in the
+        *  background.
+        */
+       void loadNext();
+       ///
+       void startLoader();
+       ///
+       void stopLoader();
+};
+
+
+//static int s_numimages_ = 5;
+//static int s_millisecs_ = 500;
+
+static int s_numimages_ = 10;
+static int s_millisecs_ = 500;
+
+LoaderQueue & LoaderQueue::get()
+{
+       static LoaderQueue singleton;
+       return singleton;
+}
+
+
+void LoaderQueue::loadNext()
+{
+       LYXERR(Debug::GRAPHICS, "LoaderQueue: "
+               << cache_queue_.size() << " items in the queue");
+       int counter = s_numimages_;
+       while (cache_queue_.size() && counter--) {
+               Cache::ItemPtr ptr = cache_queue_.front();
+               cache_set_.erase(ptr);
+               cache_queue_.pop_front();
+               if (ptr->status() == WaitingToLoad)
+                       ptr->startLoading();
+       }
+       if (cache_queue_.size()) {
+               startLoader();
+       } else {
+               stopLoader();
+       }
+}
+
+
+LoaderQueue::LoaderQueue() : timer(s_millisecs_, Timeout::ONETIME),
+                            running_(false)
+{
+       timer.timeout.connect(boost::bind(&LoaderQueue::loadNext, this));
+}
+
+
+void LoaderQueue::startLoader()
+{
+       LYXERR(Debug::GRAPHICS, "LoaderQueue: waking up");
+       running_ = true ;
+       timer.setTimeout(s_millisecs_);
+       timer.start();
+}
+
+
+void LoaderQueue::stopLoader()
+{
+       timer.stop();
+       running_ = false ;
+       LYXERR(Debug::GRAPHICS, "LoaderQueue: I'm going to sleep");
+}
+
+
+bool LoaderQueue::running() const
+{
+       return running_ ;
+}
+
+
+void LoaderQueue::touch(Cache::ItemPtr const & item)
+{
+       if (! cache_set_.insert(item).second) {
+               list<Cache::ItemPtr>::iterator
+                       it = cache_queue_.begin();
+               list<Cache::ItemPtr>::iterator
+                       end = cache_queue_.end();
+
+               it = std::find(it, end, item);
+               if (it != end)
+                       cache_queue_.erase(it);
+       }
+       cache_queue_.push_front(item);
+       if (!running_)
+               startLoader();
+}
+
+
+
+/////////////////////////////////////////////////////////////////////
+//
+// GraphicsLoader
+//
+/////////////////////////////////////////////////////////////////////
 
 typedef boost::shared_ptr<Image> ImagePtr;