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24
25#ifndef SHARE_LIBADT_SET_HPP
26#define SHARE_LIBADT_SET_HPP
27
28#include "memory/allocation.hpp"
29
30// Sets - An Abstract Data Type
31
32class SparseSet;
33class VectorSet;
34class ListSet;
35class CoSet;
36
37class ostream;
38class SetI_;
39
40// These sets can grow or shrink, based on the initial size and the largest
41// element currently in them. Basically, they allow a bunch of bits to be
42// grouped together, tested, set & cleared, intersected, etc. The basic
43// Set class is an abstract class, and cannot be constructed. Instead,
44// one of VectorSet, SparseSet, or ListSet is created. Each variation has
45// different asymptotic running times for different operations, and different
46// constants of proportionality as well.
47// {n = number of elements, N = largest element}
48
49// VectorSet SparseSet ListSet
50// Create O(N) O(1) O(1)
51// Clear O(N) O(1) O(1)
52// Insert O(1) O(1) O(log n)
53// Delete O(1) O(1) O(log n)
54// Member O(1) O(1) O(log n)
55// Size O(N) O(1) O(1)
56// Copy O(N) O(n) O(n)
57// Union O(N) O(n) O(n log n)
58// Intersect O(N) O(n) O(n log n)
59// Difference O(N) O(n) O(n log n)
60// Equal O(N) O(n) O(n log n)
61// ChooseMember O(N) O(1) O(1)
62// Sort O(1) O(n log n) O(1)
63// Forall O(N) O(n) O(n)
64// Complement O(1) O(1) O(1)
65
66// TIME: N/32 n 8*n Accesses
67// SPACE: N/8 4*N+4*n 8*n Bytes
68
69// Create: Make an empty set
70// Clear: Remove all the elements of a Set
71// Insert: Insert an element into a Set; duplicates are ignored
72// Delete: Removes an element from a Set
73// Member: Tests for membership in a Set
74// Size: Returns the number of members of a Set
75// Copy: Copy or assign one Set to another
76// Union: Union 2 sets together
77// Intersect: Intersect 2 sets together
78// Difference: Compute A & !B; remove from set A those elements in set B
79// Equal: Test for equality between 2 sets
80// ChooseMember Pick a random member
81// Sort: If no other operation changes the set membership, a following
82// Forall will iterate the members in ascending order.
83// Forall: Iterate over the elements of a Set. Operations that modify
84// the set membership during iteration work, but the iterator may
85// skip any member or duplicate any member.
86// Complement: Only supported in the Co-Set variations. It adds a small
87// constant-time test to every Set operation.
88//
89// PERFORMANCE ISSUES:
90// If you "cast away" the specific set variation you are using, and then do
91// operations on the basic "Set" object you will pay a virtual function call
92// to get back the specific set variation. On the other hand, using the
93// generic Set means you can change underlying implementations by just
94// changing the initial declaration. Examples:
95// void foo(VectorSet vs1, VectorSet vs2) { vs1 |= vs2; }
96// "foo" must be called with a VectorSet. The vector set union operation
97// is called directly.
98// void foo(Set vs1, Set vs2) { vs1 |= vs2; }
99// "foo" may be called with *any* kind of sets; suppose it is called with
100// VectorSets. Two virtual function calls are used to figure out the that vs1
101// and vs2 are VectorSets. In addition, if vs2 is not a VectorSet then a
102// temporary VectorSet copy of vs2 will be made before the union proceeds.
103//
104// VectorSets have a small constant. Time and space are proportional to the
105// largest element. Fine for dense sets and largest element < 10,000.
106// SparseSets have a medium constant. Time is proportional to the number of
107// elements, space is proportional to the largest element.
108// Fine (but big) with the largest element < 100,000.
109// ListSets have a big constant. Time *and space* are proportional to the
110// number of elements. They work well for a few elements of *any* size
111// (i.e. sets of pointers)!
112
113//------------------------------Set--------------------------------------------
114class Set : public ResourceObj {
115 protected:
116
117 // Creates a new, empty set.
118 Set(Arena *arena) : _set_arena(arena) {};
119
120 // Creates a new set from an existing set
121 Set(const Set & s) : ResourceObj(s) {};
122
123 public:
124 // Set assignment; deep-copy guts
125 virtual Set &operator =(const Set &s)=0;
126 virtual Set &clone(void) const=0;
127
128 // Virtual destructor
129 virtual ~Set() {};
130
131 // Add member to set
132 virtual Set &operator <<=(uint elem)=0;
133 // virtual Set operator << (uint elem);
134
135 // Delete member from set
136 virtual Set &operator >>=(uint elem)=0;
137 // virtual Set operator >> (uint elem);
138
139 // Membership test. Result is Zero (absent)/ Non-Zero (present)
140 virtual int operator [](uint elem) const=0;
141
142 // Intersect sets
143 virtual Set &operator &=(const Set &s)=0;
144 // virtual Set operator & (const Set &s) const;
145
146 // Union sets
147 virtual Set &operator |=(const Set &s)=0;
148 // virtual Set operator | (const Set &s) const;
149
150 // Difference sets
151 virtual Set &operator -=(const Set &s)=0;
152 // virtual Set operator - (const Set &s) const;
153
154 // Tests for equality. Result is Zero (false)/ Non-Zero (true)
155 virtual int operator ==(const Set &s) const=0;
156 int operator !=(const Set &s) const { return !(*this == s); }
157 virtual int disjoint(const Set &s) const=0;
158
159 // Tests for strict subset. Result is Zero (false)/ Non-Zero (true)
160 virtual int operator < (const Set &s) const=0;
161 int operator > (const Set &s) const { return s < *this; }
162
163 // Tests for subset. Result is Zero (false)/ Non-Zero (true)
164 virtual int operator <=(const Set &s) const=0;
165 int operator >=(const Set &s) const { return s <= *this; }
166
167 // Clear all the elements in the Set
168 virtual void Clear(void)=0;
169
170 // Return the number of members in the Set
171 virtual uint Size(void) const=0;
172
173 // If an iterator follows a "Sort()" without any Set-modifying operations
174 // inbetween then the iterator will visit the elements in ascending order.
175 virtual void Sort(void)=0;
176
177 // Convert a set to printable string in an allocated buffer.
178 // The caller must deallocate the string.
179 virtual char *setstr(void) const;
180
181 // Print the Set on "stdout". Can be conveniently called in the debugger
182 void print() const;
183
184 // Parse text from the string into the Set. Return length parsed.
185 virtual int parse(const char *s);
186
187 // Convert a generic Set to a specific Set
188 virtual const VectorSet *asVectorSet(void) const;
189
190 // Hash the set. Sets of different types but identical elements will NOT
191 // hash the same. Same set type, same elements WILL hash the same.
192 virtual int hash() const = 0;
193
194protected:
195 friend class SetI;
196 virtual class SetI_ *iterate(uint&) const=0;
197
198 // Need storeage for the set
199 Arena *_set_arena;
200};
201
202//------------------------------Iteration--------------------------------------
203// Loop thru all elements of the set, setting "elem" to the element numbers
204// in random order. Inserted or deleted elements during this operation may
205// or may not be iterated over; untouched elements will be affected once.
206
207// Usage: for( SetI i(s); i.test(); i++ ) { body = i.elem; } ...OR...
208// for( i.reset(s); i.test(); i++ ) { body = i.elem; }
209
210class SetI_ : public ResourceObj {
211protected:
212 friend class SetI;
213 virtual ~SetI_();
214 virtual uint next(void)=0;
215 virtual int test(void)=0;
216};
217
218class SetI {
219protected:
220 SetI_ *impl;
221public:
222 uint elem; // The publically accessible element
223
224 SetI( const Set *s ) { impl = s->iterate(elem); }
225 ~SetI() { delete impl; }
226 void reset( const Set *s ) { delete impl; impl = s->iterate(elem); }
227 void operator ++(void) { elem = impl->next(); }
228 int test(void) { return impl->test(); }
229};
230
231#endif // SHARE_LIBADT_SET_HPP
232