1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
24
25 #ifndef SHARE_VM_LIBADT_SET_HPP
26 #define SHARE_VM_LIBADT_SET_HPP
27
28 #include "libadt/port.hpp"
29 #include "memory/allocation.hpp"
30
31 // Sets - An Abstract Data Type
32
33 //INTERFACE
34
35 class SparseSet;
36 class VectorSet;
37 class ListSet;
38 class CoSet;
39
40 class ostream;
41 class SetI_;
42
43 // These sets can grow or shrink, based on the initial size and the largest
44 // element currently in them. Basically, they allow a bunch of bits to be
45 // grouped together, tested, set & cleared, intersected, etc. The basic
46 // Set class is an abstract class, and cannot be constructed. Instead,
47 // one of VectorSet, SparseSet, or ListSet is created. Each variation has
48 // different asymptotic running times for different operations, and different
49 // constants of proportionality as well.
50 // {n = number of elements, N = largest element}
51
52 // VectorSet SparseSet ListSet
53 // Create O(N) O(1) O(1)
54 // Clear O(N) O(1) O(1)
55 // Insert O(1) O(1) O(log n)
56 // Delete O(1) O(1) O(log n)
57 // Member O(1) O(1) O(log n)
58 // Size O(N) O(1) O(1)
59 // Copy O(N) O(n) O(n)
60 // Union O(N) O(n) O(n log n)
61 // Intersect O(N) O(n) O(n log n)
62 // Difference O(N) O(n) O(n log n)
63 // Equal O(N) O(n) O(n log n)
64 // ChooseMember O(N) O(1) O(1)
65 // Sort O(1) O(n log n) O(1)
66 // Forall O(N) O(n) O(n)
67 // Complement O(1) O(1) O(1)
68
69 // TIME: N/32 n 8*n Accesses
70 // SPACE: N/8 4*N+4*n 8*n Bytes
71
72 // Create: Make an empty set
73 // Clear: Remove all the elements of a Set
74 // Insert: Insert an element into a Set; duplicates are ignored
75 // Delete: Removes an element from a Set
76 // Member: Tests for membership in a Set
77 // Size: Returns the number of members of a Set
78 // Copy: Copy or assign one Set to another
79 // Union: Union 2 sets together
80 // Intersect: Intersect 2 sets together
81 // Difference: Compute A & !B; remove from set A those elements in set B
82 // Equal: Test for equality between 2 sets
83 // ChooseMember Pick a random member
84 // Sort: If no other operation changes the set membership, a following
85 // Forall will iterate the members in ascending order.
86 // Forall: Iterate over the elements of a Set. Operations that modify
87 // the set membership during iteration work, but the iterator may
88 // skip any member or duplicate any member.
89 // Complement: Only supported in the Co-Set variations. It adds a small
90 // constant-time test to every Set operation.
91 //
92 // PERFORMANCE ISSUES:
93 // If you "cast away" the specific set variation you are using, and then do
94 // operations on the basic "Set" object you will pay a virtual function call
95 // to get back the specific set variation. On the other hand, using the
96 // generic Set means you can change underlying implementations by just
97 // changing the initial declaration. Examples:
98 // void foo(VectorSet vs1, VectorSet vs2) { vs1 |= vs2; }
99 // "foo" must be called with a VectorSet. The vector set union operation
100 // is called directly.
101 // void foo(Set vs1, Set vs2) { vs1 |= vs2; }
102 // "foo" may be called with *any* kind of sets; suppose it is called with
103 // VectorSets. Two virtual function calls are used to figure out the that vs1
104 // and vs2 are VectorSets. In addition, if vs2 is not a VectorSet then a
105 // temporary VectorSet copy of vs2 will be made before the union proceeds.
106 //
107 // VectorSets have a small constant. Time and space are proportional to the
108 // largest element. Fine for dense sets and largest element < 10,000.
109 // SparseSets have a medium constant. Time is proportional to the number of
110 // elements, space is proportional to the largest element.
111 // Fine (but big) with the largest element < 100,000.
112 // ListSets have a big constant. Time *and space* are proportional to the
113 // number of elements. They work well for a few elements of *any* size
114 // (i.e. sets of pointers)!
115
116 //------------------------------Set--------------------------------------------
117 class Set : public ResourceObj {
118 public:
119
120 // Creates a new, empty set.
121 // DO NOT CONSTRUCT A Set. THIS IS AN ABSTRACT CLASS, FOR INHERITENCE ONLY
122 Set(Arena *arena) : _set_arena(arena) {};
123
124 // Creates a new set from an existing set
125 // DO NOT CONSTRUCT A Set. THIS IS AN ABSTRACT CLASS, FOR INHERITENCE ONLY
126 Set(const Set &) {};
127
128 // Set assignment; deep-copy guts
129 virtual Set &operator =(const Set &s)=0;
130 virtual Set &clone(void) const=0;
131
132 // Virtual destructor
133 virtual ~Set() {};
134
135 // Add member to set
136 virtual Set &operator <<=(uint elem)=0;
137 // virtual Set operator << (uint elem);
138
139 // Delete member from set
140 virtual Set &operator >>=(uint elem)=0;
141 // virtual Set operator >> (uint elem);
142
143 // Membership test. Result is Zero (absent)/ Non-Zero (present)
144 virtual int operator [](uint elem) const=0;
145
146 // Intersect sets
147 virtual Set &operator &=(const Set &s)=0;
148 // virtual Set operator & (const Set &s) const;
149
150 // Union sets
151 virtual Set &operator |=(const Set &s)=0;
152 // virtual Set operator | (const Set &s) const;
153
154 // Difference sets
155 virtual Set &operator -=(const Set &s)=0;
156 // virtual Set operator - (const Set &s) const;
157
158 // Tests for equality. Result is Zero (false)/ Non-Zero (true)
159 virtual int operator ==(const Set &s) const=0;
160 int operator !=(const Set &s) const { return !(*this == s); }
161 virtual int disjoint(const Set &s) const=0;
162
163 // Tests for strict 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 // Tests for subset. Result is Zero (false)/ Non-Zero (true)
168 virtual int operator <=(const Set &s) const=0;
169 int operator >=(const Set &s) const { return s <= *this; }
170
171 // Return any member of the Set. Undefined if the Set is empty.
172 virtual uint getelem(void) const=0;
173
174 // Clear all the elements in the Set
175 virtual void Clear(void)=0;
176
177 // Return the number of members in the Set
178 virtual uint Size(void) const=0;
179
180 // If an iterator follows a "Sort()" without any Set-modifying operations
181 // inbetween then the iterator will visit the elements in ascending order.
182 virtual void Sort(void)=0;
183
184 // Convert a set to printable string in an allocated buffer.
185 // The caller must deallocate the string.
186 virtual char *setstr(void) const;
187
188 // Print the Set on "stdout". Can be conveniently called in the debugger
189 void print() const;
190
191 // Parse text from the string into the Set. Return length parsed.
192 virtual int parse(const char *s);
193
194 // Convert a generic Set to a specific Set
195 /* Removed for MCC BUG
196 virtual operator const SparseSet* (void) const;
197 virtual operator const VectorSet* (void) const;
198 virtual operator const ListSet * (void) const;
199 virtual operator const CoSet * (void) const; */
200 virtual const SparseSet *asSparseSet(void) const;
201 virtual const VectorSet *asVectorSet(void) const;
202 virtual const ListSet *asListSet (void) const;
203 virtual const CoSet *asCoSet (void) const;
204
205 // Hash the set. Sets of different types but identical elements will NOT
206 // hash the same. Same set type, same elements WILL hash the same.
207 virtual int hash() const = 0;
208
209 protected:
210 friend class SetI;
211 friend class CoSet;
212 virtual class SetI_ *iterate(uint&) const=0;
213
214 // Need storeage for the set
215 Arena *_set_arena;
216 };
217 typedef Set&((*Set_Constructor)(Arena *arena));
218 extern Set &ListSet_Construct(Arena *arena);
219 extern Set &VectorSet_Construct(Arena *arena);
220 extern Set &SparseSet_Construct(Arena *arena);
221
222 //------------------------------Iteration--------------------------------------
223 // Loop thru all elements of the set, setting "elem" to the element numbers
224 // in random order. Inserted or deleted elements during this operation may
225 // or may not be iterated over; untouched elements will be affected once.
226
227 // Usage: for( SetI i(s); i.test(); i++ ) { body = i.elem; } ...OR...
228 // for( i.reset(s); i.test(); i++ ) { body = i.elem; }
229
230 class SetI_ : public ResourceObj {
231 protected:
232 friend class SetI;
233 virtual ~SetI_();
234 virtual uint next(void)=0;
235 virtual int test(void)=0;
236 };
237
238 class SetI {
239 protected:
240 SetI_ *impl;
241 public:
242 uint elem; // The publically accessible element
243
244 SetI( const Set *s ) { impl = s->iterate(elem); }
245 ~SetI() { delete impl; }
246 void reset( const Set *s ) { delete impl; impl = s->iterate(elem); }
247 void operator ++(void) { elem = impl->next(); }
248 int test(void) { return impl->test(); }
249 };
250
251 #endif // SHARE_VM_LIBADT_SET_HPP