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Basically, they allow a bunch of bits to be // grouped together, tested, set & cleared, intersected, etc. The basic // Set class is an abstract class, and cannot be constructed. Instead, // one of VectorSet, SparseSet, or ListSet is created. Each variation has // different asymptotic running times for different operations, and different // constants of proportionality as well. // {n = number of elements, N = largest element} // VectorSet SparseSet ListSet // Create O(N) O(1) O(1) // Clear O(N) O(1) O(1) // Insert O(1) O(1) O(log n) // Delete O(1) O(1) O(log n) // Member O(1) O(1) O(log n) // Size O(N) O(1) O(1) // Copy O(N) O(n) O(n) // Union O(N) O(n) O(n log n) // Intersect O(N) O(n) O(n log n) // Difference O(N) O(n) O(n log n) // Equal O(N) O(n) O(n log n) // ChooseMember O(N) O(1) O(1) // Sort O(1) O(n log n) O(1) // Forall O(N) O(n) O(n) // Complement O(1) O(1) O(1) // TIME: N/32 n 8*n Accesses // SPACE: N/8 4*N+4*n 8*n Bytes // Create: Make an empty set // Clear: Remove all the elements of a Set // Insert: Insert an element into a Set; duplicates are ignored // Delete: Removes an element from a Set // Member: Tests for membership in a Set // Size: Returns the number of members of a Set // Copy: Copy or assign one Set to another // Union: Union 2 sets together // Intersect: Intersect 2 sets together // Difference: Compute A & !B; remove from set A those elements in set B // Equal: Test for equality between 2 sets // ChooseMember Pick a random member // Sort: If no other operation changes the set membership, a following // Forall will iterate the members in ascending order. // Forall: Iterate over the elements of a Set. Operations that modify // the set membership during iteration work, but the iterator may // skip any member or duplicate any member. // Complement: Only supported in the Co-Set variations. It adds a small // constant-time test to every Set operation. // // PERFORMANCE ISSUES: // If you "cast away" the specific set variation you are using, and then do // operations on the basic "Set" object you will pay a virtual function call // to get back the specific set variation. On the other hand, using the // generic Set means you can change underlying implementations by just // changing the initial declaration. Examples: // void foo(VectorSet vs1, VectorSet vs2) { vs1 |= vs2; } // "foo" must be called with a VectorSet. The vector set union operation // is called directly. // void foo(Set vs1, Set vs2) { vs1 |= vs2; } // "foo" may be called with *any* kind of sets; suppose it is called with // VectorSets. Two virtual function calls are used to figure out the that vs1 // and vs2 are VectorSets. In addition, if vs2 is not a VectorSet then a // temporary VectorSet copy of vs2 will be made before the union proceeds. // // VectorSets have a small constant. Time and space are proportional to the // largest element. Fine for dense sets and largest element < 10,000. // SparseSets have a medium constant. Time is proportional to the number of // elements, space is proportional to the largest element. // Fine (but big) with the largest element < 100,000. // ListSets have a big constant. Time *and space* are proportional to the // number of elements. They work well for a few elements of *any* size // (i.e. sets of pointers)! //------------------------------Set-------------------------------------------- class Set : public ResourceObj { public: // Creates a new, empty set. // DO NOT CONSTRUCT A Set. THIS IS AN ABSTRACT CLASS, FOR INHERITENCE ONLY Set(Arena *arena) : _set_arena(arena) {}; // Creates a new set from an existing set // DO NOT CONSTRUCT A Set. THIS IS AN ABSTRACT CLASS, FOR INHERITENCE ONLY Set(const Set &) {}; // Set assignment; deep-copy guts virtual Set &operator =(const Set &s)=0; virtual Set &clone(void) const=0; // Virtual destructor virtual ~Set() {}; // Add member to set virtual Set &operator <<=(uint elem)=0; // virtual Set operator << (uint elem); // Delete member from set virtual Set &operator >>=(uint elem)=0; // virtual Set operator >> (uint elem); // Membership test. Result is Zero (absent)/ Non-Zero (present) virtual int operator [](uint elem) const=0; // Intersect sets virtual Set &operator &=(const Set &s)=0; // virtual Set operator & (const Set &s) const; // Union sets virtual Set &operator |=(const Set &s)=0; // virtual Set operator | (const Set &s) const; // Difference sets virtual Set &operator -=(const Set &s)=0; // virtual Set operator - (const Set &s) const; // Tests for equality. Result is Zero (false)/ Non-Zero (true) virtual int operator ==(const Set &s) const=0; int operator !=(const Set &s) const { return !(*this == s); } virtual int disjoint(const Set &s) const=0; // Tests for strict subset. Result is Zero (false)/ Non-Zero (true) virtual int operator < (const Set &s) const=0; int operator > (const Set &s) const { return s < *this; } // Tests for subset. Result is Zero (false)/ Non-Zero (true) virtual int operator <=(const Set &s) const=0; int operator >=(const Set &s) const { return s <= *this; } // Return any member of the Set. Undefined if the Set is empty. virtual uint getelem(void) const=0; // Clear all the elements in the Set virtual void Clear(void)=0; // Return the number of members in the Set virtual uint Size(void) const=0; // If an iterator follows a "Sort()" without any Set-modifying operations // inbetween then the iterator will visit the elements in ascending order. virtual void Sort(void)=0; // Convert a set to printable string in an allocated buffer. // The caller must deallocate the string. virtual char *setstr(void) const; // Print the Set on "stdout". Can be conveniently called in the debugger void print() const; // Parse text from the string into the Set. Return length parsed. virtual int parse(const char *s); // Convert a generic Set to a specific Set /* Removed for MCC BUG virtual operator const SparseSet* (void) const; virtual operator const VectorSet* (void) const; virtual operator const ListSet * (void) const; virtual operator const CoSet * (void) const; */ virtual const SparseSet *asSparseSet(void) const; virtual const VectorSet *asVectorSet(void) const; virtual const ListSet *asListSet (void) const; virtual const CoSet *asCoSet (void) const; // Hash the set. Sets of different types but identical elements will NOT // hash the same. Same set type, same elements WILL hash the same. virtual int hash() const = 0; protected: friend class SetI; friend class CoSet; virtual class SetI_ *iterate(uint&) const=0; // Need storeage for the set Arena *_set_arena; }; typedef Set&((*Set_Constructor)(Arena *arena)); extern Set &ListSet_Construct(Arena *arena); extern Set &VectorSet_Construct(Arena *arena); extern Set &SparseSet_Construct(Arena *arena); //------------------------------Iteration-------------------------------------- // Loop thru all elements of the set, setting "elem" to the element numbers // in random order. Inserted or deleted elements during this operation may // or may not be iterated over; untouched elements will be affected once. // Usage: for( SetI i(s); i.test(); i++ ) { body = i.elem; } ...OR... // for( i.reset(s); i.test(); i++ ) { body = i.elem; } class SetI_ : public ResourceObj { protected: friend class SetI; virtual ~SetI_(); virtual uint next(void)=0; virtual int test(void)=0; }; class SetI { protected: SetI_ *impl; public: uint elem; // The publically accessible element SetI( const Set *s ) { impl = s->iterate(elem); } ~SetI() { delete impl; } void reset( const Set *s ) { delete impl; impl = s->iterate(elem); } void operator ++(void) { elem = impl->next(); } int test(void) { return impl->test(); } }; #endif // SHARE_VM_LIBADT_SET_HPP