88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
#include "./dictres.h"
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#include <assert.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "util/chaos/abchash.h"
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static void dictres_calculate_hash_(dictres_item_t* items, size_t length) {
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assert(items != NULL || length == 0);
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for (size_t i = 0; i < length; ++i) {
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dictres_item_t* item = &items[i];
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const size_t len = strlen(item->key);
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if (!chaos_abchash_validate(item->key, len)) {
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fprintf(stderr, "dictress: invalid key, '%s'\n", item->key);
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abort();
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}
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item->hash = chaos_abchash(item->key, len);
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}
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}
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static void dictres_sort_(dictres_item_t* items, size_t length) {
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assert(items != NULL || length == 0);
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for (size_t i = 0; i < length; ++i) {
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for (size_t j = 1; j < length-i; ++j) {
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if (items[j-1].hash > items[j].hash) {
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/* Speed of swapping can be improved but simple is best. :) */
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const dictres_item_t temp = items[j-1];
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items[j-1] = items[j];
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items[j] = temp;
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}
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}
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}
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}
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static void dictres_validate_(dictres_item_t* items, size_t length) {
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assert(items != NULL || length == 0);
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for (size_t i = 1; i < length; ++i) {
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if (items[i-1].hash == items[i].hash) {
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fprintf(stderr,
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"dictres: detected hash collision between '%s' and '%s'\n",
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items[i-1].key, items[i].key);
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}
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}
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}
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void dictres_optimize_(dictres_item_t* items, size_t length) {
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assert(items != NULL || length == 0);
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dictres_calculate_hash_(items, length);
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dictres_sort_(items, length);
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dictres_validate_(items, length);
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}
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const char* dictres_find_(
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const dictres_item_t* items, size_t length, const char* key) {
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assert(items != NULL || length == 0);
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const size_t keylen = strlen(key);
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assert(chaos_abchash_validate(key, keylen));
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const uint64_t hash = chaos_abchash(key, keylen);
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size_t l = 0, r = length-1;
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while (l <= r && r < length) {
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const size_t i = (l+r)/2;
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if (items[i].hash == hash) {
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return items[i].value;
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}
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if (items[i].hash < hash) {
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l = i+1;
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} else {
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if (i == 0) break;
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r = i-1;
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}
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}
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fprintf(stderr, "dictres: cannot find key, '%s'\n", key);
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abort();
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}
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