Initial check-in of OpenShot Library

src/Cache.cpp

@@ -0,0 +1,117 @@
+/**
+ * \file
+ * \brief Source code for the Cache class
+ * \author Copyright (c) 2011 Jonathan Thomas
+ */
+
+#include "../include/Cache.h"
+
+using namespace std;
+using namespace openshot;
+
+// Default constructor, max frames to cache is 20
+Cache::Cache() : max_frames(20) { };
+
+// Constructor that sets the max frames to cache
+Cache::Cache(int max_frames) : max_frames(max_frames) { };
+
+// Add a Frame to the cache
+void Cache::Add(int frame_number, Frame frame)
+{
+	// Only add frame if it does not exist in the cache
+	if (!frames.count(frame_number))
+	{
+		// Add frame to queue and map
+		frames[frame_number] = frame;
+		frame_numbers.push(frame_number);
+
+		// Clean up older frames (that exceed the max frames)
+		CleanUp();
+	}
+	else
+	{
+		// Frame already exists... so just update the cache
+		frames.erase(frame_number);
+		frames[frame_number] = frame;
+	}
+}
+
+// Check for the existance of a frame in the cache
+bool Cache::Exists(int frame_number)
+{
+	// Is frame number cached
+	if (frames.count(frame_number))
+		return true;
+	else
+		return false;
+}
+
+// Get a frame from the cache
+Frame Cache::GetFrame(int frame_number)
+{
+	// Does frame exists in cache?
+	if (Exists(frame_number))
+	{
+		// return the Frame object
+		return frames[frame_number];
+	}
+	else
+		// throw an exception for the missing frame
+		throw OutOfBoundsFrame("Frame not found in the cache", frame_number, -1);
+}
+
+// Clear the cache of all frames
+void Cache::Clear()
+{
+	// clear map
+	frames.clear();
+
+	// pop each of the frames from the queue... which emptys the queue
+	while(!frame_numbers.empty()) frame_numbers.pop();
+}
+
+// Count the frames in the queue
+int Cache::Count()
+{
+	// Return the number of frames in the cache
+	return frames.size();
+}
+
+// Clean up cached frames that exceed the number in our max_frames variable
+void Cache::CleanUp()
+{
+	// check against max size
+	if (frame_numbers.size() > max_frames)
+	{
+		// Remove the oldest frame
+		int frame_to_remove = frame_numbers.front();
+
+		// Remove frame_number and frame
+		frame_numbers.pop();
+		frames.erase(frame_to_remove);
+	}
+}
+
+// Display the list of cache and clear the cache (mainly for debugging reasons)
+void Cache::DisplayAndClear()
+{
+	cout << "----- Cache List (" << frames.size() << ") ------" << endl;
+	int i = 1;
+	while(!frame_numbers.empty())
+	{
+		// Print the frame number
+		int frame_number = frame_numbers.front();
+		cout << " " << i << ") --- Frame " << frame_number << endl;
+
+		// Remove this frame
+		frame_numbers.pop();
+		frames.erase(frame_number);
+
+		// increment counter
+		i++;
+	}
+}
+
+
+
+