49 lines
1.0 KiB
C
49 lines
1.0 KiB
C
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/*
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functions common to all hash table instantiations
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <assert.h>
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#include <limits.h>
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#include "dtypes.h"
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#include "htable.h"
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#include "hashing.h"
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htable_t *htable_new(htable_t *h, size_t size)
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{
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size = nextipow2(size);
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size *= 2; // 2 pointers per key/value pair
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size *= 2; // aim for 50% occupancy
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h->size = size;
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h->table = (void**)malloc(size*sizeof(void*));
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if (h->table == NULL) return NULL;
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size_t i;
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for(i=0; i < size; i++)
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h->table[i] = HT_NOTFOUND;
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return h;
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}
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void htable_free(htable_t *h)
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{
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free(h->table);
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}
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// empty and reduce size
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void htable_reset(htable_t *h, size_t sz)
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{
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if (h->size > sz*4) {
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size_t newsz = sz*4;
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void **newtab = (void**)realloc(h->table, newsz*sizeof(void*));
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if (newtab == NULL)
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return;
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h->size = newsz;
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h->table = newtab;
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}
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size_t i, hsz=h->size;
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for(i=0; i < hsz; i++)
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h->table[i] = HT_NOTFOUND;
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}
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