#ifndef STORM_STORAGE_BITVECTOR_H_
#define STORM_STORAGE_BITVECTOR_H_
#include <cmath>
#include <cstdint>
#include <ostream>
#include <vector>
#include <iterator>
namespace storm {
namespace storage {
/*!
* A bit vector that is internally represented as a vector of 64-bit values.
*/
class BitVector {
public:
/*!
* A class that enables iterating over the indices of the bit vector whose corresponding bits are set to
* true. Note that this is a const iterator, which cannot alter the bit vector.
*/
class const_iterator : public std::iterator<std::input_iterator_tag, uint_fast64_t> {
// Declare the BitVector class as a friend class to access its internal storage.
friend class BitVector;
public:
/*!
* Constructs an iterator over the indices of the set bits in the given bit vector, starting and
* stopping, respectively, at the given indices.
*
* @param dataPtr A pointer to the first bucket of the underlying bit vector.
* @param startIndex The index where to begin looking for set bits.
* @param setOnFirstBit A flag that indicates whether the iterator is to be moved to the index of the
* first bit upon construction.
* @param endIndex The index at which to abort the iteration process.
*/
const_iterator(uint64_t const* dataPtr, uint_fast64_t startIndex, uint_fast64_t endIndex, bool setOnFirstBit = true);
/*!
* Constructs an iterator by copying the given iterator.
*
* @param other The iterator to copy.
*/
const_iterator(const_iterator const& other);
/*!
* Assigns the contents of the given iterator to the current one via copying the former's contents.
*
* @param other The iterator from which to copy-assign.
*/
const_iterator& operator=(const_iterator const& other);
/*!
* Increases the position of the iterator to the position of the next bit that is set to true in the
* underlying bit vector.
*
* @return A reference to this iterator.
*/
const_iterator& operator++();
/*!
* Returns the index of the current bit to which this iterator points.
*
* @return The index of the current bit to which this iterator points.
*/
uint_fast64_t operator*() const;
/*!
* Compares the iterator with another iterator for inequality.
*
* @param other The iterator with respect to which inequality is checked.
* @return True if the two iterators are unequal.
*/
bool operator!=(const_iterator const& other) const;
/*!
* Compares the iterator with another iterator for equality.
*
* @param other The iterator with respect to which equality is checked.
* @return True if the two iterators are equal.
*/
bool operator==(const_iterator const& other) const;
private:
// The underlying bit vector of this iterator.
uint64_t const* dataPtr;
// The index of the bit this iterator currently points to.
uint_fast64_t currentIndex;
// The index of the bit that is past the end of the range of this iterator.
uint_fast64_t endIndex;
};
/*
* Constructs an empty bit vector of length 0.
*/
BitVector();
/*!
* Constructs a bit vector which can hold the given number of bits and initializes all bits with the
* provided truth value.
*
* @param length The number of bits the bit vector should be able to hold.
* @param init The initial value of the first |length| bits.
*/
BitVector(uint_fast64_t length, bool init = false);
/*!
* Creates a bit vector that has exactly the bits set that are given by the provided input iterator range
* [first, last).
*
* @param The length of the bit vector.
* @param first The begin of the iterator range.
* @param last The end of the iterator range.
*/
template<typename InputIterator>
BitVector(uint_fast64_t length, InputIterator first, InputIterator last);
/*!
* Performs a deep copy of the given bit vector.
*
* @param other A reference to the bit vector to be copied.
*/
BitVector(BitVector const& other);
/*!
* Move constructs the bit vector from the given bit vector.
*
* @param other The bit vector from which to move-construct.
*/
BitVector(BitVector&& other);
/*!
* Compares the given bit vector with the current one.
*
* @param other The bitvector with which to compare the current one.
* @return True iff the other bit vector is semantically the same as the current one.
*/
bool operator==(BitVector const& other);
/*!
* Compares the given bit vector with the current one.
*
* @param other The bitvector with which to compare the current one.
* @return True iff the other bit vector is semantically not the same as the current one.
*/
bool operator!=(BitVector const& other);
/*!
* Assigns the contents of the given bit vector to the current bit vector via a deep copy.
*
* @param other The bit vector to assign to the current bit vector.
* @return A reference to this bit vector after it has been assigned the given bit vector by means of a
* deep copy.
*/
BitVector& operator=(BitVector const& other);
/*!
* Move assigns the given bit vector to the current bit vector.
*
* @param other The bit vector whose content is moved to the current bit vector.
* @return A reference to this bit vector after the contents of the given bit vector have been moved
* into it.
*/
BitVector& operator=(BitVector&& other);
/*!
* Retrieves whether the current bit vector is (in some order) smaller than the given one.
*
* @param other The other bit vector.
* @return True iff the current bit vector is smaller than the given one.
*/
bool operator<(BitVector const& other) const;
/*!
* Sets the given truth value at the given index.
*
* @param index The index where to set the truth value.
* @param value The truth value to set.
*/
void set(const uint_fast64_t index, bool value = true);
/*!
* Sets all bits in the given iterator range [first, last).
*
* @param first The begin of the iterator range.
* @param last The element past the last element of the iterator range.
*/
template<typename InputIterator>
void set(InputIterator first, InputIterator last);
/*!
* Retrieves the truth value of the bit at the given index. Note: this does not check whether the given
* index is within bounds.
*
* @param index The index of the bit to access.
* @return True iff the bit at the given index is set.
*/
bool operator[](uint_fast64_t index) const;
/*!
* Retrieves the truth value of the bit at the given index and performs a bound check. If the access is
* out-of-bounds an OutOfBoundsException is thrown.
*
* @param index The index of the bit to access.
* @return True iff the bit at the given index is set.
*/
bool get(const uint_fast64_t index) const;
/*!
* Resizes the bit vector to hold the given new number of bits. If the bit vector becomes smaller this way,
* the bits are truncated. Otherwise, the new bits are initialized to the given value.
*
* @param newLength The new number of bits the bit vector can hold.
* @param init The truth value to which to initialize newly created bits.
*/
void resize(uint_fast64_t newLength, bool init = false);
/*!
* Performs a logical "and" with the given bit vector. In case the sizes of the bit vectors do not match,
* only the matching portion is considered and the overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A bit vector corresponding to the logical "and" of the two bit vectors.
*/
BitVector operator&(BitVector const& other) const;
/*!
* Performs a logical "and" with the given bit vector and assigns the result to the current bit vector.
* In case the sizes of the bit vectors do not match, only the matching portion is considered and the
* overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A reference to the current bit vector corresponding to the logical "and"
* of the two bit vectors.
*/
BitVector& operator&=(BitVector const& other);
/*!
* Performs a logical "or" with the given bit vector. In case the sizes of the bit vectors do not match,
* only the matching portion is considered and the overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A bit vector corresponding to the logical "or" of the two bit vectors.
*/
BitVector operator|(BitVector const& other) const;
/*!
* Performs a logical "or" with the given bit vector and assigns the result to the current bit vector.
* In case the sizes of the bit vectors do not match, only the matching portion is considered and the
* overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A reference to the current bit vector corresponding to the logical "or"
* of the two bit vectors.
*/
BitVector& operator|=(BitVector const& other);
/*!
* Performs a logical "xor" with the given bit vector. In case the sizes of the bit vectors do not match,
* only the matching portion is considered and the overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A bit vector corresponding to the logical "xor" of the two bit vectors.
*/
BitVector operator^(BitVector const& other) const;
/*!
* Computes a bit vector that is as long as the number of set bits in the given filter that has bit i is set
* iff the i-th set bit of the current bit vector is set in the filter.
*
* @param filter A reference the bit vector to use as the filter.
* @return A bit vector that is as long as the number of set bits in the given filter that has bit i is set
* iff the i-th set bit of the current bit vector is set in the filter.
*/
BitVector operator%(BitVector const& filter) const;
/*!
* Performs a logical "not" on the bit vector.
*
* @return A bit vector corresponding to the logical "not" of the bit vector.
*/
BitVector operator~() const;
/*!
* Negates all bits in the bit vector.
*/
void complement();
/*!
* Performs a logical "implies" with the given bit vector. In case the sizes of the bit vectors do not
* match, only the matching portion is considered and the overlapping bits are set to 0.
*
* @param other A reference to the bit vector to use for the operation.
* @return A bit vector corresponding to the logical "implies" of the two bit vectors.
*/
BitVector implies(BitVector const& other) const;
/*!
* Checks whether all bits that are set in the current bit vector are also set in the given bit vector.
*
* @param other A reference to the bit vector whose bits are (possibly) a superset of the bits of
* the current bit vector.
* @return True iff all bits that are set in the current bit vector are also set in the given bit
* vector.
*/
bool isSubsetOf(BitVector const& other) const;
/*!
* Checks whether none of the bits that are set in the current bit vector are also set in the given bit
* vector.
*
* @param other A reference to the bit vector whose bits are (possibly) disjoint from the bits in
* the current bit vector.
* @return True iff none of the bits that are set in the current bit vector are also set in the
* given bit vector.
*/
bool isDisjointFrom(BitVector const& other) const;
/*!
* Retrieves whether no bits are set to true in this bit vector.
*
* @return False iff there is at least one bit set in this vector.
*/
bool empty() const;
/*!
* Retrievs whether all bits are set in this bit vector.
*
* @return True iff all bits in the bit vector are set.
*/
bool full() const;
/*!
* Removes all set bits from the bit vector. Calling empty() after this operation will yield true.
*/
void clear();
/*!
* Returns the number of bits that are set to true in this bit vector.
*
* @return The number of bits that are set to true in this bit vector.
*/
uint_fast64_t getNumberOfSetBits() const;
/*!
* Retrieves the number of bits set in this bit vector with an index strictly smaller than the given one.
*
* @param index The index for which to retrieve the number of set bits with a smaller index.
* @return The number of bits set in this bit vector with an index strictly smaller than the given one.
*/
uint_fast64_t getNumberOfSetBitsBeforeIndex(uint_fast64_t index) const;
/*!
* Retrieves the number of bits this bit vector can store.
*
* @return The number of bits this bit vector can hold.
*/
size_t size() const;
/*!
* Returns the size of the bit vector in memory measured in bytes.
*
* @return The size of the bit vector in memory measured in bytes.
*/
uint_fast64_t getSizeInMemory() const;
/*!
* Returns an iterator to the indices of the set bits in the bit vector.
*/
const_iterator begin() const;
/*!
* Returns an iterator pointing at the element past the bit vector.
*/
const_iterator end() const;
/*!
* Calculates a hash value for this bit vector.
*
* @return The hash value of this bit vector.
*/
std::size_t hash() const;
/*
* Retrieves the index of the bit that is the next bit set to true in the bit vector. If there is none,
* this function returns the number of bits this vector holds in total. Put differently, if the return
* value is equal to a call to size(), then there is no bit set after the specified position.
*
* @param startingIndex The index at which to start the search for the next bit that is set. The
* bit at this index itself is already considered.
* @return The index of the next bit that is set after the given index.
*/
uint_fast64_t getNextSetIndex(uint_fast64_t startingIndex) const;
friend std::ostream& operator<<(std::ostream& out, BitVector const& bitVector);
private:
/*!
* Retrieves the index of the next bit that is set to true after (and including) the given starting index.
*
* @param dataPtr A pointer to the first bucket of the data storage.
* @param startingIndex The index where to start the search.
* @param endIndex The index at which to stop the search.
* @return The index of the bit that is set after the given starting index, but before the given end index
* in the given bit vector or endIndex in case the end index was reached.
*/
static uint_fast64_t getNextSetIndex(uint64_t const* dataPtr, uint_fast64_t startingIndex, uint_fast64_t endIndex);
/*!
* Truncate the last bucket so that no bits are set starting from bitCount.
*/
void truncateLastBucket();
// The number of bits that this bit vector can hold.
uint_fast64_t bitCount;
// The underlying storage of 64-bit buckets for all bits of this bit vector.
std::vector<uint64_t> bucketVector;
// A bit mask that can be used to reduce a modulo 64 operation to a logical "and".
static const uint_fast64_t mod64mask = (1 << 6) - 1;
};
} // namespace storage
} // namespace storm
#endif // STORM_STORAGE_BITVECTOR_H_