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7 <title>Hash Random Int Subscript Insert Timing Test
</title>
8 <meta http-equiv=
"Content-Type" content=
"text/html; charset=us-ascii" />
12 <h1>Hash-Based Random-Integer
<tt><b>operator
</b>[]
</tt> Insert
14 <h2><a name=
"description" id=
"description">Description
</a></h2>
15 <p>This test inserts a number of values with uniform i.i.d.
16 integer keys into a container, using
17 <tt><b>operator
</b>[]
</tt>. It measures the average time for
18 <tt><b>operator
</b>[]
</tt> as a function of the number of
20 <p>(The test was executed with
<a href=
"../../../../testsuite/performance/ext/pb_ds/random_int_subscript_insert_timing.cc"><tt>hash_random_int_subscript_insert_timing_test
</tt></a>
22 <h2><a name=
"purpose" id=
"purpose">Purpose
</a></h2>
23 <p>The test primarily checks the effect of different underlying
24 hash-tables (see
<a href=
"hash_based_containers.html">Design::Associative
25 Containers::Associative Containers::Hash-Based
27 <h2><a name=
"results" id=
"results">Results
</a></h2>
28 <p>Figures
<a href=
"#NCCG">NCCG
</a>,
<a href=
"#NCCM">NCCM
</a>,
29 and
<a href=
"#NCCL">NCCL
</a> show the results for the native
30 and collision-chaining types in
<a href=
"assoc_performance_tests.html#gcc"><u>g++
</u></a>,
<a href=
"assoc_performance_tests.html#msvc"><u>MSVC++
</u></a>, and
31 <a href=
"assoc_performance_tests.html#local"><u>local
</u></a>,
32 respectively; Figures
<a href=
"#NGPG">NGPG
</a>,
<a href=
"#NGPM">NGPM
</a>, and
<a href=
"#NGPL">NGPL
</a> show the results
33 for the native and probing types in
<a href=
"assoc_performance_tests.html#gcc"><u>g++
</u></a>,
<a href=
"assoc_performance_tests.html#msvc"><u>msvc++
</u></a>, and
34 <a href=
"assoc_performance_tests.html#local"><u>local
</u></a>
35 respectively; Figures
<a href=
"#CCGPG">CCGPG
</a>,
<a href=
"#CCGPM">CCGPM
</a>, and
<a href=
"#CCGPL">CCGPL
</a> compare the
36 results for the collision-chaining and probing types of
37 <tt>pb_ds
</tt> only, in
<a href=
"assoc_performance_tests.html#gcc"><u>g++
</u></a>,
<a href=
"assoc_performance_tests.html#msvc"><u>MSVC++
</u></a>, and
38 <a href=
"assoc_performance_tests.html#local"><u>local
</u></a>
40 <div id=
"NCCG_res_div">
42 <div id=
"NCCG_cc_hash_random_int_subscript_timing_test_insert">
44 <div id=
"NCCG_Native_and_collision-chaining_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NCCG" id=
"NCCG"><img src=
"cc_hash_random_int_subscript_timing_test_insert_gcc.png" alt=
"no image" /></a></h6>NCCG: Native and collision-chaining hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#gcc">g++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
47 cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
48 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
49 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
50 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
51 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
52 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
53 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
56 <tt>std::tr1::unordered_map
</tt> with
<tt>cache_hash_code
</tt> =
<tt><b>false
</b></tt></li>
58 cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
59 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
60 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
61 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
62 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
63 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
64 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
66 cc_hash_mod_prime_nea_lc_1div8_1div1_nsth_map-
67 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
68 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
69 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
70 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
71 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
72 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
1</i></li>
74 cc_hash_mask_exp_nea_lc_1div8_1div1_nsth_map-
75 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
76 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
77 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
78 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
79 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
80 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
1</i></li>
82 </div><div style=
"width: 100%; height: 20px"></div></div>
87 <div id=
"NCCM_res_div">
89 <div id=
"NCCM_cc_hash_random_int_subscript_timing_test_insert">
91 <div id=
"NCCM_Native_and_collision-chaining_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NCCM" id=
"NCCM"><img src=
"cc_hash_random_int_subscript_timing_test_insert_msvc.png" alt=
"no image" /></a></h6>NCCM: Native and collision-chaining hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#msvc">msvc++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
95 <tt>stdext::hash_map
</tt></li>
97 cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
98 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
99 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
100 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
101 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
102 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
103 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
105 cc_hash_mod_prime_nea_lc_1div8_1div1_nsth_map-
106 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
107 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
108 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
109 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
110 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
111 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
1</i></li>
113 cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
114 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
115 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
116 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
117 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
118 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
119 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
121 cc_hash_mask_exp_nea_lc_1div8_1div1_nsth_map-
122 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
123 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
124 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
125 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
126 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
127 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
1</i></li>
129 </div><div style=
"width: 100%; height: 20px"></div></div>
134 <div id=
"NCCL_res_div">
135 <div id=
"NCCL_local">
136 <div id=
"NCCL_cc_hash_random_int_subscript_timing_test_insert">
137 <div id=
"NCCL_assoc">
138 <div id=
"NCCL_Native_and_collision-chaining_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style =
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NCCL" id=
"NCCL"><img src=
"cc_hash_random_int_subscript_timing_test_insert_local.png" alt=
"no image" /></a></h6>NCCL: Native and collision-chaining hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href =
"assoc_performance_tests.html#local">local
</a></div><div style =
"width: 100%; height: 20px"></div></div>
143 <div id=
"NGPG_res_div">
145 <div id=
"NGPG_gp_hash_random_int_subscript_timing_test_insert">
146 <div id=
"NGPG_assoc">
147 <div id=
"NGPG_Native_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NGPG" id=
"NGPG"><img src=
"gp_hash_random_int_subscript_timing_test_insert_gcc.png" alt=
"no image" /></a></h6>NGPG: Native and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#gcc">g++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
150 gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
151 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
152 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
153 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
154 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
155 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
156 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"quadratic_probe_fn.html"><tt>quadratic_probe_fn
</tt></a>
160 <tt>std::tr1::unordered_map
</tt> with
<tt>cache_hash_code
</tt> =
<tt><b>false
</b></tt></li>
162 gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
163 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
164 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
165 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
166 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
167 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
168 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"linear_probe_fn.html"><tt>linear_probe_fn
</tt></a>
171 </div><div style=
"width: 100%; height: 20px"></div></div>
176 <div id=
"NGPM_res_div">
178 <div id=
"NGPM_gp_hash_random_int_subscript_timing_test_insert">
179 <div id=
"NGPM_assoc">
180 <div id=
"NGPM_Native_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NGPM" id=
"NGPM"><img src=
"gp_hash_random_int_subscript_timing_test_insert_msvc.png" alt=
"no image" /></a></h6>NGPM: Native and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#msvc">msvc++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
184 <tt>stdext::hash_map
</tt></li>
186 gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
187 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
188 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
189 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
190 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
191 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
192 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"quadratic_probe_fn.html"><tt>quadratic_probe_fn
</tt></a>
195 gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
196 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
197 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
198 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
199 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
200 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
201 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"linear_probe_fn.html"><tt>linear_probe_fn
</tt></a>
204 </div><div style=
"width: 100%; height: 20px"></div></div>
209 <div id=
"NGPL_res_div">
210 <div id=
"NGPL_local">
211 <div id=
"NGPL_gp_hash_random_int_subscript_timing_test_insert">
212 <div id=
"NGPL_assoc">
213 <div id=
"NGPL_Native_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style =
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"NGPL" id=
"NGPL"><img src=
"gp_hash_random_int_subscript_timing_test_insert_local.png" alt=
"no image" /></a></h6>NGPL: Native and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href =
"assoc_performance_tests.html#local">local
</a></div><div style =
"width: 100%; height: 20px"></div></div>
218 <div id=
"CCGPG_res_div">
220 <div id=
"CCGPG_ccgp_hash_random_int_subscript_timing_test_insert">
221 <div id=
"CCGPG_assoc">
222 <div id=
"CCGPG_Collision-chaining_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"CCGPG" id=
"CCGPG"><img src=
"ccgp_hash_random_int_subscript_timing_test_insert_gcc.png" alt=
"no image" /></a></h6>CCGPG: Collision-chaining and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#gcc">g++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
225 gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
226 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
227 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
228 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
229 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
230 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
231 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"quadratic_probe_fn.html"><tt>quadratic_probe_fn
</tt></a>
234 cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
235 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
236 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
237 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
238 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
239 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
240 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
242 cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
243 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
244 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
245 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
246 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
247 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
248 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
250 gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
251 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
252 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
253 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
254 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
255 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
256 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"linear_probe_fn.html"><tt>linear_probe_fn
</tt></a>
259 </div><div style=
"width: 100%; height: 20px"></div></div>
264 <div id=
"CCGPM_res_div">
265 <div id=
"CCGPM_msvc">
266 <div id=
"CCGPM_ccgp_hash_random_int_subscript_timing_test_insert">
267 <div id=
"CCGPM_assoc">
268 <div id=
"CCGPM_Collision-chaining_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style=
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"CCGPM" id=
"CCGPM"><img src=
"ccgp_hash_random_int_subscript_timing_test_insert_msvc.png" alt=
"no image" /></a></h6>CCGPM: Collision-chaining and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href=
"assoc_performance_tests.html#msvc">msvc++
</a><p>In the above figure, the names in the legends have the following meaning:
</p>
271 cc_hash_mod_prime_nea_lc_1div8_1div2_nsth_map-
272 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
273 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
274 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
275 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
276 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
277 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
279 cc_hash_mask_exp_nea_lc_1div8_1div2_nsth_map-
280 <a href=
"cc_hash_table.html"><tt>cc_hash_table
</tt></a>
281 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
282 , and
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
283 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
284 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
285 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i></li>
287 gp_hash_mod_quadp_prime_nea_lc_1div8_1div2_nsth_map-
288 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
289 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mod_range_hashing.html"><tt>direct_mod_range_hashing
</tt></a>
290 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
291 with
<tt>Size_Policy
</tt> =
<a href=
"hash_prime_size_policy.html"><tt>hash_prime_size_policy
</tt></a>
292 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
293 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"quadratic_probe_fn.html"><tt>quadratic_probe_fn
</tt></a>
296 gp_hash_mask_linp_exp_nea_lc_1div8_1div2_nsth_map-
297 <a href=
"gp_hash_table.html"><tt>gp_hash_table
</tt></a>
298 with
<tt>Comb_Hash_Fn
</tt> =
<a href=
"direct_mask_range_hashing.html"><tt>direct_mask_range_hashing
</tt></a>
299 ,
<tt>Resize_Policy
</tt> =
<a href=
"hash_standard_resize_policy.html"><tt>hash_standard_resize_policy
</tt></a>
300 with
<tt>Size_Policy
</tt> =
<a href=
"hash_exponential_size_policy.html"><tt>hash_exponential_size_policy
</tt></a>
301 , and
<tt>Trigger_Policy
</tt> =
<a href=
"hash_load_check_resize_trigger.html"><tt>hash_load_check_resize_trigger
</tt></a>
302 with
<i>α<sub>min
</sub></i> =
<i>1/
8</i> and
<i>α<sub>max
</sub></i> =
<i>1/
2</i>, and
<tt>Probe_Fn
</tt> =
<a href=
"linear_probe_fn.html"><tt>linear_probe_fn
</tt></a>
305 </div><div style=
"width: 100%; height: 20px"></div></div>
310 <div id=
"CCGPL_res_div">
311 <div id=
"CCGPL_local">
312 <div id=
"CCGPL_ccgp_hash_random_int_subscript_timing_test_insert">
313 <div id=
"CCGPL_assoc">
314 <div id=
"CCGPL_Collision-chaining_and_probing_hash_random_int_insert_timing_test_using__tt__b_operator_455b__455tt_"><div style =
"border-style: dotted; border-width: 1px; border-color: lightgray"><h6 class=
"c1"><a name=
"CCGPL" id=
"CCGPL"><img src=
"ccgp_hash_random_int_subscript_timing_test_insert_local.png" alt=
"no image" /></a></h6>CCGPL: Collision-chaining and probing hash random int insert timing test using
<tt><b>operator
</b></tt> -
<a href =
"assoc_performance_tests.html#local">local
</a></div><div style =
"width: 100%; height: 20px"></div></div>
319 <h2><a name=
"observations" id=
"observations">Observations
</a></h2>
320 <p>In this setting, as in
<a href=
"hash_text_find_find_timing_test.html">Hash-Based Text
321 <tt>find
</tt> Find Timing Test
</a> and
<a href=
"hash_random_int_find_find_timing_test.html">Hash-Based
322 Random-Integer
<tt>find
</tt> Find Timing Test
</a> , the choice
323 of underlying hash-table underlying hash-table (see
<a href=
"hash_based_containers.html">Design::Associative
324 Containers::Hash-Based Containers
</a> ) affects performance
325 most, then the range-hashing scheme (See
<a href=
"hash_based_containers.html#hash_policies">Design::Associative
326 Containers::Hash-Based Containers::Hash Policies
</a> ), and,
327 only finally, other policies.
</p>
328 <p>There are some differences, however:
</p>
330 <li>In this setting, probing tables function sometimes more
331 efficiently than collision-chaining tables (see Figures
332 <a href=
"#CCGPG">CCGPG
</a> and
<a href=
"#CCGPM">CCGPM
</a> ).
333 This is explained shortly.
</li>
334 <li>The performance graphs have a
"saw-tooth" shape. The
335 average insert time rises and falls. As values are inserted
336 into the container, the load factor grows larger. Eventually,
337 a resize occurs. The reallocations and rehashing are
338 relatively expensive. After this, the load factor is smaller
341 <p>Collision-chaining containers use indirection for greater
342 flexibility; probing containers store values contiguously, in
343 an array (see Figure
<a href=
"motivation.html#different_underlying_data_structures">Motivation::Different
344 underlying data structures
</a> A and B, respectively). It
345 follows that for simple data types, probing containers access
346 their allocator less frequently than collision-chaining
347 containers, (although they still have less efficient probing
348 sequences). This explains why some probing containers fare
349 better than collision-chaining containers in this case.
</p>
350 <p>Within each type of hash-table, the range-hashing scheme
351 affects performance more than other policies. This is similar
352 to the situation in
<a href=
"hash_text_find_find_timing_test.html">Hash-Based Text
353 <tt>find
</tt> Find Timing Test
</a> and
<a href=
"hash_random_int_find_find_timing_test.html">Hash-Based
354 Random-Integer
<tt>find
</tt> Find Timing Test
</a>.
355 Unsurprisingly, however, containers with
<u>lower
</u>
356 <i>alpha
<sub>max
</sub></i> perform
<u>worse
</u> in this case,
357 since more re-hashes are performed.
</p>
358 <p><a href=
"assoc_performance_tests.html#hash_based_types">Observations::Hash-Based
359 Container Types
</a> summarizes some observations on hash-based
360 containers;
<a href=
"assoc_performance_tests.html#hash_based_policies">Observations::Hash-Based
361 Containers' Policies
</a> summarizes some observations on
362 hash-based containers' policies.
</p>