add implementation for priority download queue

git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@1432 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/ft/ftdwlqueue.h

@@ -0,0 +1,106 @@
+/*
+ * ftdwlqueue.h
+ *
+ *  Created on: Jul 22, 2009
+ *      Author: alexandrut
+ */
+
+#ifndef FTDWLQUEUE_H_
+#define FTDWLQUEUE_H_
+
+#include "util/rsthreads.h"
+#include "ftcontroller.h"
+
+#include <list>
+#include <string>
+
+enum DwlPriority { Low = 0, Normal, High, Auto };
+
+/* class which encapsulates download details */
+class DwlDetails {
+public:
+	DwlDetails() { return; }
+	DwlDetails(std::string fname, std::string hash, int count, std::string dest,
+			uint32_t flags, std::list<std::string> srcIds, DwlPriority priority)
+	: fname(fname), hash(hash), count(count), dest(dest), flags(flags),
+	srcIds(srcIds), retries(0), priority(priority), paused(false) {
+		return;
+	}
+
+	/* download details */
+	std::string fname;
+	std::string hash;
+	int count;
+	std::string dest;
+	uint32_t flags;
+	std::list<std::string> srcIds;
+	unsigned int retries;
+
+	/* internally used in download queue */
+	DwlPriority priority;
+	bool paused;
+};
+
+/* comparator class used when sorting list */
+class PriorityCompare {
+public:
+	PriorityCompare(bool reverse = false)
+	: reverse(reverse) { return; }
+	bool operator()(const DwlDetails & l, const DwlDetails & r) {
+		if (reverse) {return (l.priority < r.priority);}
+		else return (l.priority > r.priority);
+	}
+
+private:
+	bool reverse;
+};
+
+/* base class for a download queue with
+ * default actions for a priority queue */
+class DwlQueue {
+public:
+	/* specific actions for a priority queue */
+	virtual void insertDownload(const DwlDetails & details) = 0;
+	virtual bool getNext(DwlDetails & details) = 0;
+	virtual bool peekAtNext(DwlDetails & details) = 0;
+
+	/* administrative actions */
+	virtual bool changePriority(const std::string hash, DwlPriority priority) = 0;
+	virtual bool getPriority(const std::string hash, DwlPriority & priority) = 0;
+	virtual bool clearDownload(const std::string hash) = 0;
+	virtual void clearQueue() = 0;
+};
+
+/* general class for download queue which
+ * contains the a download priority list */
+class ftDwlQueue : public DwlQueue, public RsThread {
+public:
+	ftDwlQueue(ftController *ftc, unsigned int downloadLimit = 7, unsigned int retryLimit = 10);
+	virtual ~ftDwlQueue();
+
+	/* from thread interface */
+	virtual void run();
+
+	/* from download queue interface */
+	virtual void insertDownload(const DwlDetails & details);
+	virtual bool getNext(DwlDetails & details);
+	virtual bool peekAtNext(DwlDetails & details);
+	virtual bool changePriority(const std::string hash, DwlPriority priority);
+	virtual bool getPriority(const std::string hash, DwlPriority & priority);
+	virtual bool clearDownload(const std::string hash);
+	virtual void clearQueue();
+
+private:
+	unsigned int downloadLimit;
+	unsigned int retryLimit;
+
+	ftController *mFtController;
+
+	RsMutex prmtx;
+	std::list<DwlDetails> priorities;
+
+	unsigned int totalQueuedDwl();
+	unsigned int totalSystemDwl();
+};
+
+#endif /* FTDWLQUEUE_H_ */