libstdc++
cc_hash_max_collision_check_resize_trigger_imp.hpp
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1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2022 Free Software Foundation, Inc.
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16 // Under Section 7 of GPL version 3, you are granted additional
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18 // 3.1, as published by the Free Software Foundation.
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25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
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35 
36 /**
37  * @file cc_hash_max_collision_check_resize_trigger_imp.hpp
38  * Contains a resize trigger implementation.
39  */
40 
41 #ifdef PB_DS_CLASS_C_DEC
42 
43 PB_DS_CLASS_T_DEC
44 PB_DS_CLASS_C_DEC::
45 cc_hash_max_collision_check_resize_trigger(float load) :
46  m_load(load),
47  m_size(0),
48  m_num_col(0),
49  m_max_col(0),
50  m_resize_needed(false)
51 { }
52 
53 PB_DS_CLASS_T_DEC
54 inline void
55 PB_DS_CLASS_C_DEC::
56 notify_find_search_start()
57 { }
58 
59 PB_DS_CLASS_T_DEC
60 inline void
61 PB_DS_CLASS_C_DEC::
62 notify_find_search_collision()
63 { }
64 
65 PB_DS_CLASS_T_DEC
66 inline void
67 PB_DS_CLASS_C_DEC::
68 notify_find_search_end()
69 { }
70 
71 PB_DS_CLASS_T_DEC
72 inline void
73 PB_DS_CLASS_C_DEC::
74 notify_insert_search_start()
75 { m_num_col = 0; }
76 
77 PB_DS_CLASS_T_DEC
78 inline void
79 PB_DS_CLASS_C_DEC::
80 notify_insert_search_collision()
81 { ++m_num_col; }
82 
83 PB_DS_CLASS_T_DEC
84 inline void
85 PB_DS_CLASS_C_DEC::
86 notify_insert_search_end()
87 { calc_resize_needed(); }
88 
89 PB_DS_CLASS_T_DEC
90 inline void
91 PB_DS_CLASS_C_DEC::
92 notify_erase_search_start()
93 { }
94 
95 PB_DS_CLASS_T_DEC
96 inline void
97 PB_DS_CLASS_C_DEC::
98 notify_erase_search_collision()
99 { }
100 
101 PB_DS_CLASS_T_DEC
102 inline void
103 PB_DS_CLASS_C_DEC::
104 notify_erase_search_end()
105 { }
106 
107 PB_DS_CLASS_T_DEC
108 inline void
109 PB_DS_CLASS_C_DEC::
110 notify_inserted(size_type)
111 { }
112 
113 PB_DS_CLASS_T_DEC
114 inline void
115 PB_DS_CLASS_C_DEC::
116 notify_erased(size_type)
117 { m_resize_needed = true; }
118 
119 PB_DS_CLASS_T_DEC
120 void
121 PB_DS_CLASS_C_DEC::
122 notify_cleared()
123 { m_resize_needed = false; }
124 
125 PB_DS_CLASS_T_DEC
126 inline bool
127 PB_DS_CLASS_C_DEC::
128 is_resize_needed() const
129 { return m_resize_needed; }
130 
131 PB_DS_CLASS_T_DEC
132 inline bool
133 PB_DS_CLASS_C_DEC::
134 is_grow_needed(size_type /*size*/, size_type /*num_used_e*/) const
135 { return m_num_col >= m_max_col; }
136 
137 PB_DS_CLASS_T_DEC
138 void
139 PB_DS_CLASS_C_DEC::
140 notify_resized(size_type new_size)
141 {
142  m_size = new_size;
143 
144 #ifdef PB_DS_HT_MAP_RESIZE_TRACE_
145  std::cerr << "chmccrt::notify_resized "
146  << static_cast<unsigned long>(new_size) << std::endl;
147 #endif
148 
149  calc_max_num_coll();
150  calc_resize_needed();
151  m_num_col = 0;
152 }
153 
154 PB_DS_CLASS_T_DEC
155 void
156 PB_DS_CLASS_C_DEC::
157 calc_max_num_coll()
158 {
159  // max_col <-- \sqrt{2 load \ln( 2 m \ln( m ) ) }
160  const double ln_arg = 2 * m_size * std::log(double(m_size));
161  m_max_col = size_type(std::ceil(std::sqrt(2 * m_load * std::log(ln_arg))));
162 
163 #ifdef PB_DS_HT_MAP_RESIZE_TRACE_
164  std::cerr << "chmccrt::calc_max_num_coll "
165  << static_cast<unsigned long>(m_size) << " "
166  << static_cast<unsigned long>(m_max_col) << std::endl;
167 #endif
168 }
169 
170 PB_DS_CLASS_T_DEC
171 void
172 PB_DS_CLASS_C_DEC::
173 notify_externally_resized(size_type new_size)
174 { notify_resized(new_size); }
175 
176 PB_DS_CLASS_T_DEC
177 void
178 PB_DS_CLASS_C_DEC::
179 swap(PB_DS_CLASS_C_DEC& other)
180 {
181  std::swap(m_load, other.m_load);
182  std::swap(m_size, other.m_size);
183  std::swap(m_num_col, other.m_num_col);
184  std::swap(m_max_col, other.m_max_col);
185  std::swap(m_resize_needed, other.m_resize_needed);
186 }
187 
188 PB_DS_CLASS_T_DEC
189 inline float
190 PB_DS_CLASS_C_DEC::
191 get_load() const
192 {
193  PB_DS_STATIC_ASSERT(access, external_load_access);
194  return m_load;
195 }
196 
197 PB_DS_CLASS_T_DEC
198 inline void
199 PB_DS_CLASS_C_DEC::
200 calc_resize_needed()
201 { m_resize_needed = m_resize_needed || m_num_col >= m_max_col; }
202 
203 PB_DS_CLASS_T_DEC
204 void
205 PB_DS_CLASS_C_DEC::
206 set_load(float load)
207 {
208  PB_DS_STATIC_ASSERT(access, external_load_access);
209  m_load = load;
210  calc_max_num_coll();
211  calc_resize_needed();
212 }
213 
214 #endif
complex< _Tp > log(const complex< _Tp > &)
Return complex natural logarithm of z.
Definition: complex:824
complex< _Tp > sqrt(const complex< _Tp > &)
Return complex square root of z.
Definition: complex:933
void swap(any &__x, any &__y) noexcept
Exchange the states of two any objects.
Definition: any:429
ostream cerr
Linked to standard output.
basic_ostream< _CharT, _Traits > & endl(basic_ostream< _CharT, _Traits > &__os)
Write a newline and flush the stream.
Definition: ostream:688