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#ifndef STORM_STORAGE_DETERMINISTICMODELSTRONGBISIMULATIONDECOMPOSITION_H_
#define STORM_STORAGE_DETERMINISTICMODELSTRONGBISIMULATIONDECOMPOSITION_H_
#include <queue>
#include <deque>
#include "src/storage/sparse/StateType.h"
#include "src/storage/Decomposition.h"
#include "src/models/Dtmc.h"
#include "src/models/Ctmc.h"
#include "src/storage/Distribution.h"
#include "src/utility/ConstantsComparator.h"
#include "src/utility/OsDetection.h"
namespace storm {
namespace storage {
/*!
* This class represents the decomposition model into its (strong) bisimulation quotient.
*/
template <typename ValueType>
class DeterministicModelStrongBisimulationDecomposition : public Decomposition<StateBlock> {
public:
/*!
* Decomposes the given DTMC into equivalence classes under strong bisimulation.
*
* @param model The model to decompose.
* @param buildQuotient Sets whether or not the quotient model is to be built.
*/
DeterministicModelStrongBisimulationDecomposition(storm::models::Dtmc<ValueType> const& model, bool buildQuotient = false);
/*!
* Decomposes the given CTMC into equivalence classes under strong bisimulation.
*
* @param model The model to decompose.
* @param buildQuotient Sets whether or not the quotient model is to be built.
*/
DeterministicModelStrongBisimulationDecomposition(storm::models::Ctmc<ValueType> const& model, bool buildQuotient = false);
/*!
* Decomposes the given DTMC into equivalence classes under strong bisimulation in a way that onle safely
* preserves formulas of the form phi until psi.
*
* @param model The model to decompose.
* @param phiLabel The label that all phi states carry in the model.
* @param psiLabel The label that all psi states carry in the model.
* @param bounded If set to true, also bounded until formulas are preserved.
* @param buildQuotient Sets whether or not the quotient model is to be built.
*/
DeterministicModelStrongBisimulationDecomposition(storm::models::Dtmc<ValueType> const& model, std::string const& phiLabel, std::string const& psiLabel, bool bounded, bool buildQuotient = false);
/*!
* Decomposes the given CTMC into equivalence classes under strong bisimulation in a way that onle safely
* preserves formulas of the form phi until psi.
*
* @param model The model to decompose.
* @param phiLabel The label that all phi states carry in the model.
* @param psiLabel The label that all psi states carry in the model.
* @param bounded If set to true, also bounded until formulas are preserved.
* @param buildQuotient Sets whether or not the quotient model is to be built.
*/
DeterministicModelStrongBisimulationDecomposition(storm::models::Ctmc<ValueType> const& model, std::string const& phiLabel, std::string const& psiLabel, bool bounded, bool buildQuotient = false);
/*!
* Retrieves the quotient of the model under the previously computed bisimulation.
*
* @return The quotient model.
*/
std::shared_ptr<storm::models::AbstractDeterministicModel<ValueType>> getQuotient() const;
private:
class Partition;
class Block {
public:
typedef typename std::list<Block>::iterator iterator;
typedef typename std::list<Block>::const_iterator const_iterator;
// Creates a new block with the given begin and end.
Block(storm::storage::sparse::state_type begin, storm::storage::sparse::state_type end, Block* prev, Block* next, std::shared_ptr<std::string> const& label = nullptr);
// Prints the block.
void print(Partition const& partition) const;
// Sets the beginning index of the block.
void setBegin(storm::storage::sparse::state_type begin);
// Moves the beginning index of the block one step further.
void incrementBegin();
// Sets the end index of the block.
void setEnd(storm::storage::sparse::state_type end);
// Moves the end index of the block one step to the front.
void decrementEnd();
// Returns the beginning index of the block.
storm::storage::sparse::state_type getBegin() const;
// Returns the beginning index of the block.
storm::storage::sparse::state_type getEnd() const;
// Retrieves the original beginning index of the block in case the begin index has been moved.
storm::storage::sparse::state_type getOriginalBegin() const;
// Returns the iterator the block in the list of overall blocks.
iterator getIterator() const;
// Returns the iterator the block in the list of overall blocks.
void setIterator(iterator it);
// Returns the iterator the next block in the list of overall blocks if it exists.
iterator getNextIterator() const;
// Returns the iterator the next block in the list of overall blocks if it exists.
iterator getPreviousIterator() const;
// Gets the next block (if there is one).
Block& getNextBlock();
// Gets the next block (if there is one).
Block const& getNextBlock() const;
// Gets a pointer to the next block (if there is one).
Block* getNextBlockPointer();
// Retrieves whether the block as a successor block.
bool hasNextBlock() const;
// Gets the previous block (if there is one).
Block& getPreviousBlock();
// Gets a pointer to the previous block (if there is one).
Block* getPreviousBlockPointer();
// Gets the next block (if there is one).
Block const& getPreviousBlock() const;
// Retrieves whether the block as a successor block.
bool hasPreviousBlock() const;
// Checks consistency of the information in the block.
bool check() const;
// Retrieves the number of states in this block.
std::size_t getNumberOfStates() const;
// Checks whether the block is marked as a splitter.
bool isMarkedAsSplitter() const;
// Marks the block as being a splitter.
void markAsSplitter();
// Removes the mark.
void unmarkAsSplitter();
// Retrieves the ID of the block.
std::size_t getId() const;
// Retrieves the marked position in the block.
storm::storage::sparse::state_type getMarkedPosition() const;
// Sets the marked position to the given value..
void setMarkedPosition(storm::storage::sparse::state_type position);
// Increases the marked position by one.
void incrementMarkedPosition();
// Resets the marked position to the begin of the block.
void resetMarkedPosition();
// Retrieves whether the block is marked as a predecessor.
bool isMarkedAsPredecessor() const;
// Marks the block as being a predecessor block.
void markAsPredecessorBlock();
// Removes the marking.
void unmarkAsPredecessorBlock();
// Sets whether or not the block is to be interpreted as absorbing.
void setAbsorbing(bool absorbing);
// Retrieves whether the block is to be interpreted as absorbing.
bool isAbsorbing() const;
// Retrieves whether the block has a special label.
bool hasLabel() const;
// Retrieves the special label of the block if it has one.
std::string const& getLabel() const;
// Retrieves a pointer to the label of the block (which is the nullptr if there is none).
std::shared_ptr<std::string> const& getLabelPtr() const;
private:
// An iterator to itself. This is needed to conveniently insert elements in the overall list of blocks
// kept by the partition.
iterator selfIt;
// Pointers to the next and previous block.
Block* next;
Block* prev;
// The begin and end indices of the block in terms of the state vector of the partition.
storm::storage::sparse::state_type begin;
storm::storage::sparse::state_type end;
// A field that can be used for marking the block.
bool markedAsSplitter;
// A field that can be used for marking the block as a predecessor block.
bool markedAsPredecessorBlock;
// A position that can be used to store a certain position within the block.
storm::storage::sparse::state_type markedPosition;
// A flag indicating whether the block is to be interpreted as absorbing or not.
bool absorbing;
// The ID of the block. This is only used for debugging purposes.
std::size_t id;
// The label of the block or nullptr if it has none.
std::shared_ptr<std::string> label;
// A counter for the IDs of the blocks.
static std::size_t blockId;
};
class Partition {
public:
friend class Block;
/*!
* Creates a partition with one block consisting of all the states.
*
* @param numberOfStates The number of states the partition holds.
* @param keepSilentProbabilities A flag indicating whether or not silent probabilities are to be tracked.
*/
Partition(std::size_t numberOfStates, bool keepSilentProbabilities = false);
/*!
* Creates a partition with three blocks: one with all phi states, one with all psi states and one with
* all other states. The former two blocks are marked as being absorbing, because their outgoing
* transitions shall not be taken into account for future refinement.
*
* @param numberOfStates The number of states the partition holds.
* @param prob0States The states which have probability 0 of satisfying phi until psi.
* @param prob1States The states which have probability 1 of satisfying phi until psi.
* @param otherLabel The label that is to be attached to all other states.
* @param prob1Label The label that is to be attached to all states with probability 1.
* @param keepSilentProbabilities A flag indicating whether or not silent probabilities are to be tracked.
*/
Partition(std::size_t numberOfStates, storm::storage::BitVector const& prob0States, storm::storage::BitVector const& prob1States, std::string const& otherLabel, std::string const& prob1Label, bool keepSilentProbabilities = false);
Partition() = default;
Partition(Partition const& other) = default;
Partition& operator=(Partition const& other) = default;
#ifndef WINDOWS
Partition(Partition&& other) = default;
Partition& operator=(Partition&& other) = default;
#endif
/*!
* Splits all blocks of the partition such that afterwards all blocks contain only states with the label
* or no labeled state at all.
*/
void splitLabel(storm::storage::BitVector const& statesWithLabel);
// Retrieves the size of the partition, i.e. the number of blocks.
std::size_t size() const;
// Prints the partition to the standard output.
void print() const;
// Splits the block at the given position and inserts a new block after the current one holding the rest
// of the states.
Block& splitBlock(Block& block, storm::storage::sparse::state_type position);
// Inserts a block before the given block. The new block will cover all states between the beginning
// of the given block and the end of the previous block.
Block& insertBlock(Block& block);
// Retrieves the blocks of the partition.
std::list<Block> const& getBlocks() const;
// Retrieves the blocks of the partition.
std::list<Block>& getBlocks();
// Checks the partition for internal consistency.
bool check() const;
// Returns an iterator to the beginning of the states of the given block.
typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::iterator getBegin(Block const& block);
// Returns an iterator to the beginning of the states of the given block.
typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::iterator getEnd(Block const& block);
// Returns an iterator to the beginning of the states of the given block.
typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::const_iterator getBegin(Block const& block) const;
// Returns an iterator to the beginning of the states of the given block.
typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::const_iterator getEnd(Block const& block) const;
// Swaps the positions of the two given states.
void swapStates(storm::storage::sparse::state_type state1, storm::storage::sparse::state_type state2);
// Swaps the positions of the two states given by their positions.
void swapStatesAtPositions(storm::storage::sparse::state_type position1, storm::storage::sparse::state_type position2);
// Retrieves the block of the given state.
Block& getBlock(storm::storage::sparse::state_type state);
// Retrieves the block of the given state.
Block const& getBlock(storm::storage::sparse::state_type state) const;
// Retrieves the position of the given state.
storm::storage::sparse::state_type const& getPosition(storm::storage::sparse::state_type state) const;
// Retrieves the position of the given state.
void setPosition(storm::storage::sparse::state_type state, storm::storage::sparse::state_type position);
// Sets the position of the state to the given position.
storm::storage::sparse::state_type const& getState(storm::storage::sparse::state_type position) const;
// Retrieves the value for the given state.
ValueType const& getValue(storm::storage::sparse::state_type state) const;
// Retrieves the value at the given position.
ValueType const& getValueAtPosition(storm::storage::sparse::state_type position) const;
// Sets the given value for the given state.
void setValue(storm::storage::sparse::state_type state, ValueType value);
// Retrieves the vector with the probabilities going into the current splitter.
std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>& getStatesAndValues();
// Increases the value for the given state by the specified amount.
void increaseValue(storm::storage::sparse::state_type state, ValueType value);
// Updates the block mapping for the given range of states to the specified block.
void updateBlockMapping(Block& block, typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::iterator first, typename std::vector<std::pair<storm::storage::sparse::state_type, ValueType>>::iterator end);
// Retrieves the first block of the partition.
Block& getFirstBlock();
private:
// The list of blocks in the partition.
std::list<Block> blocks;
// A mapping of states to their blocks.
std::vector<Block*> stateToBlockMapping;
// A vector containing all the states and their values. It is ordered in a special way such that the
// blocks only need to define their start/end indices.
std::vector<std::pair<storm::storage::sparse::state_type, ValueType>> statesAndValues;
// This vector keeps track of the position of each state in the state vector.
std::vector<storm::storage::sparse::state_type> positions;
// A flag that indicates whether or not the vector with silent probabilities exists.
bool keepSilentProbabilities;
// This vector keeps track of the silent probabilities (i.e. the probabilities going into the very own
// equivalence class) of each state. This means that a state is silent iff its entry is non-zero.
std::vector<ValueType> silentProbabilities;
};
/*!
* Performs the partition refinement on the model and thereby computes the equivalence classes under strong
* bisimulation equivalence. If required, the quotient model is built and may be retrieved using
* getQuotient().
*
* @param model The model on whose state space to compute the coarses strong bisimulation relation.
* @param backwardTransitions The backward transitions of the model.
* @param The initial partition.
* @param buildQuotient If set, the quotient model is built and may be retrieved using the getQuotient()
* method.
*/
template<typename ModelType>
void partitionRefinement(ModelType const& model, storm::storage::SparseMatrix<ValueType> const& backwardTransitions, Partition& partition, bool buildQuotient);
/*!
* Refines the partition based on the provided splitter. After calling this method all blocks are stable
* with respect to the splitter.
*
* @param backwardTransitions A matrix that can be used to retrieve the predecessors (and their
* probabilities).
* @param splitter The splitter to use.
* @param partition The partition to split.
* @param splitterQueue A queue into which all blocks that were split are inserted so they can be treated
* as splitters in the future.
*/
void refinePartition(storm::storage::SparseMatrix<ValueType> const& backwardTransitions, Block& splitter, Partition& partition, std::deque<Block*>& splitterQueue);
/*!
* Refines the block based on their probability values (leading into the splitter).
*
* @param block The block to refine.
* @param partition The partition that contains the block.
* @param splitterQueue A queue into which all blocks that were split are inserted so they can be treated
* as splitters in the future.
*/
void refineBlockProbabilities(Block& block, Partition& partition, std::deque<Block*>& splitterQueue);
/*!
* Builds the quotient model based on the previously computed equivalence classes (stored in the blocks
* of the decomposition.
*
* @param model The model whose state space was used for computing the equivalence classes. This is used for
* determining the transitions of each equivalence class.
* @param partition The previously computed partition. This is used for quickly retrieving the block of a
* state.
*/
template<typename ModelType>
void buildQuotient(ModelType const& model, Partition const& partition);
/*!
* Creates the measure-driven initial partition for reaching psi states from phi states.
*
* @param model The model whose state space is partitioned based on reachability of psi states from phi
* states.
* @param backwardTransitions The backward transitions of the model.
* @param phiLabel The label that all phi states carry in the model.
* @param psiLabel The label that all psi states carry in the model.
* @param bounded If set to true, the initial partition will be chosen in such a way that preserves bounded
* reachability queries.
* @return The resulting partition.
*/
template<typename ModelType>
Partition getMeasureDrivenInitialPartition(ModelType const& model, storm::storage::SparseMatrix<ValueType> const& backwardTransitions, std::string const& phiLabel, std::string const& psiLabel, bool bounded = false);
/*!
* Creates the initial partition based on all the labels in the given model.
*
* @param model The model whose state space is partitioned based on its labels.
* @return The resulting partition.
*/
template<typename ModelType>
Partition getLabelBasedInitialPartition(ModelType const& model);
// If required, a quotient model is built and stored in this member.
std::shared_ptr<storm::models::AbstractDeterministicModel<ValueType>> quotient;
// A comparator that is used for determining whether two probabilities are considered to be equal.
storm::utility::ConstantsComparator<ValueType> comparator;
};
}
}
#endif /* STORM_STORAGE_DETERMINISTICMODELSTRONGBISIMULATIONDECOMPOSITION_H_ */