damus

nostr ios client
git clone git://jb55.com/damus
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stringspeed.c (6170B)


      1 /* Simple speed tests for a hash of strings. */
      2 #include <ccan/htable/htable_type.h>
      3 #include <ccan/htable/htable.c>
      4 #include <ccan/tal/str/str.h>
      5 #include <ccan/tal/grab_file/grab_file.h>
      6 #include <ccan/tal/tal.h>
      7 #include <ccan/hash/hash.h>
      8 #include <ccan/time/time.h>
      9 #include <stdio.h>
     10 #include <stdlib.h>
     11 #include <string.h>
     12 #include <time.h>
     13 #include <unistd.h>
     14 #include <sys/time.h>
     15 
     16 static size_t hashcount;
     17 
     18 static const char *strkey(const char *str)
     19 {
     20 	return str;
     21 }
     22 
     23 static size_t hash_str(const char *key)
     24 {
     25 	hashcount++;
     26 	return hash(key, strlen(key), 0);
     27 }
     28 
     29 static bool cmp(const char *obj, const char *key)
     30 {
     31 	return strcmp(obj, key) == 0;
     32 }
     33 
     34 HTABLE_DEFINE_TYPE(char, strkey, hash_str, cmp, htable_str);
     35 
     36 /* Nanoseconds per operation */
     37 static size_t normalize(const struct timeabs *start,
     38 			const struct timeabs *stop,
     39 			unsigned int num)
     40 {
     41 	return time_to_nsec(time_divide(time_between(*stop, *start), num));
     42 }
     43 
     44 int main(int argc, char *argv[])
     45 {
     46 	size_t i, j, num;
     47 	struct timeabs start, stop;
     48 	struct htable_str ht;
     49 	char **words, **misswords;
     50 
     51 	words = tal_strsplit(NULL, grab_file(NULL,
     52 					     argv[1] ? argv[1] : "/usr/share/dict/words"), "\n",
     53 			     STR_NO_EMPTY);
     54 	htable_str_init(&ht);
     55 	num = tal_count(words) - 1;
     56 	/* Note that on my system, num is just > 98304, where we double! */
     57 	printf("%zu words\n", num);
     58 
     59 	/* Append and prepend last char for miss testing. */
     60 	misswords = tal_arr(words, char *, num);
     61 	for (i = 0; i < num; i++) {
     62 		char lastc;
     63 		if (strlen(words[i]))
     64 			lastc = words[i][strlen(words[i])-1];
     65 		else
     66 			lastc = 'z';
     67 		misswords[i] = tal_fmt(misswords, "%c%s%c%c",
     68 				       lastc, words[i], lastc, lastc);
     69 	}
     70 
     71 	printf("#01: Initial insert: ");
     72 	fflush(stdout);
     73 	start = time_now();
     74 	for (i = 0; i < num; i++)
     75 		htable_str_add(&ht, words[i]);
     76 	stop = time_now();
     77 	printf(" %zu ns\n", normalize(&start, &stop, num));
     78 
     79 	printf("Bytes allocated: %zu\n",
     80 	       sizeof(ht.raw.table[0]) << ht.raw.bits);
     81 
     82 	printf("#02: Initial lookup (match): ");
     83 	fflush(stdout);
     84 	start = time_now();
     85 	for (i = 0; i < num; i++)
     86 		if (htable_str_get(&ht, words[i]) != words[i])
     87 			abort();
     88 	stop = time_now();
     89 	printf(" %zu ns\n", normalize(&start, &stop, num));
     90 
     91 	printf("#03: Initial lookup (miss): ");
     92 	fflush(stdout);
     93 	start = time_now();
     94 	for (i = 0; i < num; i++) {
     95 		if (htable_str_get(&ht, misswords[i]))
     96 			abort();
     97 	}
     98 	stop = time_now();
     99 	printf(" %zu ns\n", normalize(&start, &stop, num));
    100 
    101 	/* Lookups in order are very cache-friendly for judy; try random */
    102 	printf("#04: Initial lookup (random): ");
    103 	fflush(stdout);
    104 	start = time_now();
    105 	for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num)
    106 		if (htable_str_get(&ht, words[j]) != words[j])
    107 			abort();
    108 	stop = time_now();
    109 	printf(" %zu ns\n", normalize(&start, &stop, num));
    110 
    111 	hashcount = 0;
    112 	printf("#05: Initial delete all: ");
    113 	fflush(stdout);
    114 	start = time_now();
    115 	for (i = 0; i < num; i++)
    116 		if (!htable_str_del(&ht, words[i]))
    117 			abort();
    118 	stop = time_now();
    119 	printf(" %zu ns\n", normalize(&start, &stop, num));
    120 
    121 	printf("#06: Initial re-inserting: ");
    122 	fflush(stdout);
    123 	start = time_now();
    124 	for (i = 0; i < num; i++)
    125 		htable_str_add(&ht, words[i]);
    126 	stop = time_now();
    127 	printf(" %zu ns\n", normalize(&start, &stop, num));
    128 
    129 	hashcount = 0;
    130 	printf("#07: Deleting first half: ");
    131 	fflush(stdout);
    132 	start = time_now();
    133 	for (i = 0; i < num; i+=2)
    134 		if (!htable_str_del(&ht, words[i]))
    135 			abort();
    136 	stop = time_now();
    137 	printf(" %zu ns\n", normalize(&start, &stop, num));
    138 
    139 	printf("#08: Adding (a different) half: ");
    140 	fflush(stdout);
    141 
    142 	start = time_now();
    143 	for (i = 0; i < num; i+=2)
    144 		htable_str_add(&ht, misswords[i]);
    145 	stop = time_now();
    146 	printf(" %zu ns\n", normalize(&start, &stop, num));
    147 
    148 	printf("#09: Lookup after half-change (match): ");
    149 	fflush(stdout);
    150 	start = time_now();
    151 	for (i = 1; i < num; i+=2)
    152 		if (htable_str_get(&ht, words[i]) != words[i])
    153 			abort();
    154 	for (i = 0; i < num; i+=2) {
    155 		if (htable_str_get(&ht, misswords[i]) != misswords[i])
    156 			abort();
    157 	}
    158 	stop = time_now();
    159 	printf(" %zu ns\n", normalize(&start, &stop, num));
    160 
    161 	printf("#10: Lookup after half-change (miss): ");
    162 	fflush(stdout);
    163 	start = time_now();
    164 	for (i = 0; i < num; i+=2)
    165 		if (htable_str_get(&ht, words[i]))
    166 			abort();
    167 	for (i = 1; i < num; i+=2) {
    168 		if (htable_str_get(&ht, misswords[i]))
    169 			abort();
    170 	}
    171 	stop = time_now();
    172 	printf(" %zu ns\n", normalize(&start, &stop, num));
    173 
    174 	/* Hashtables with delete markers can fill with markers over time.
    175 	 * so do some changes to see how it operates in long-term. */
    176 	printf("#11: Churn 1: ");
    177 	start = time_now();
    178 	for (j = 0; j < num; j+=2) {
    179 		if (!htable_str_del(&ht, misswords[j]))
    180 			abort();
    181 		if (!htable_str_add(&ht, words[j]))
    182 			abort();
    183 	}
    184 	stop = time_now();
    185 	printf(" %zu ns\n", normalize(&start, &stop, num));
    186 
    187 	printf("#12: Churn 2: ");
    188 	start = time_now();
    189 	for (j = 1; j < num; j+=2) {
    190 		if (!htable_str_del(&ht, words[j]))
    191 			abort();
    192 		if (!htable_str_add(&ht, misswords[j]))
    193 			abort();
    194 	}
    195 	stop = time_now();
    196 	printf(" %zu ns\n", normalize(&start, &stop, num));
    197 
    198 	printf("#13: Churn 3: ");
    199 	start = time_now();
    200 	for (j = 1; j < num; j+=2) {
    201 		if (!htable_str_del(&ht, misswords[j]))
    202 			abort();
    203 		if (!htable_str_add(&ht, words[j]))
    204 			abort();
    205 	}
    206 	stop = time_now();
    207 	printf(" %zu ns\n", normalize(&start, &stop, num));
    208 
    209 	/* Now it's back to normal... */
    210 	printf("#14: Post-Churn lookup (match): ");
    211 	fflush(stdout);
    212 	start = time_now();
    213 	for (i = 0; i < num; i++)
    214 		if (htable_str_get(&ht, words[i]) != words[i])
    215 			abort();
    216 	stop = time_now();
    217 	printf(" %zu ns\n", normalize(&start, &stop, num));
    218 
    219 	printf("#15: Post-Churn lookup (miss): ");
    220 	fflush(stdout);
    221 	start = time_now();
    222 	for (i = 0; i < num; i++) {
    223 		if (htable_str_get(&ht, misswords[i]))
    224 			abort();
    225 	}
    226 	stop = time_now();
    227 	printf(" %zu ns\n", normalize(&start, &stop, num));
    228 
    229 	/* Lookups in order are very cache-friendly for judy; try random */
    230 	printf("#16: Post-Churn lookup (random): ");
    231 	fflush(stdout);
    232 	start = time_now();
    233 	for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num)
    234 		if (htable_str_get(&ht, words[j]) != words[j])
    235 			abort();
    236 	stop = time_now();
    237 	printf(" %zu ns\n", normalize(&start, &stop, num));
    238 
    239 	return 0;
    240 }