Start coding proof of work logic.

src/cpp/ripple/ProofOfWork.h

@@ -0,0 +1,66 @@
+#ifndef PROOF_OF_WORK__H
+#define PROOF_OF_WORK__H
+
+#include <string>
+
+#include <boost/thread/mutex.hpp>
+#include <boost/bimap.hpp>
+#include <boost/bimap/set_of.hpp>
+#include <boost/bimap/multiset_of.hpp>
+
+#include "uint256.h"
+
+class ProofOfWork
+{
+protected:
+
+	std::string		mToken;
+	uint256			mChallenge;
+	uint256			mTarget;
+	int				mIterations;
+
+	static const uint256 sMinTarget;
+	static const int sMaxIterations;
+
+public:
+	ProofOfWork(const std::string& token, int iterations, const uint256& challenge, const uint256& target) :
+		mToken(token), mChallenge(challenge), mTarget(target), mIterations(iterations)
+	{ ; }
+
+	bool isValid() const;
+
+	uint256 solve(int maxIterations) const;
+	bool checkSolution(const uint256& solution) const;
+
+	// approximate number of hashes needed to solve
+	static uint64 getDifficulty(const uint256& target, int iterations);
+	uint64 getDifficulty() const { return getDifficulty(mTarget, mIterations); }
+};
+
+class ProofOfWorkGenerator
+{
+public:
+	typedef boost::bimap< boost::bimaps::multiset_of<time_t>, boost::bimaps::set_of<uint256> > powMap_t;
+	typedef powMap_t::value_type	powMap_vt;
+
+protected:
+	uint256							mSecret;
+	int								mIterations;
+	uint256							mTarget;
+	time_t							mLastDifficultyChange;
+
+	powMap_t						mSolvedChallenges;
+	boost::mutex					mLock;
+
+public:
+	ProofOfWorkGenerator(const uint256& secret);
+
+	ProofOfWork getProof();
+	bool checkProof(const std::string& token, const uint256& solution);
+
+	void loadHigh();
+	void loadLow();
+	uint64 getDifficulty()	{ return ProofOfWork::getDifficulty(mTarget, mIterations); }
+};
+
+#endif