├── hash_table.c
└── hash_table.h


/hash_table.c:
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 1 | #include <stdlib.h>
 2 | #include <string.h>
 3 | 
 4 | #include "hash_table.h"
 5 | 
 6 | hash_table* create_htab()
 7 | {
 8 | 	hash_table* htab;
 9 | 
10 | 	htab = (hash_table*)malloc(sizeof(hash_table));
11 | 	int i; for(i = 0; i < HTAB_SIZE; i++) htab->nodes[i] = NULL;
12 | 
13 | 	return htab;
14 | }
15 | 
16 | void destroy_htab(hash_table* htab)
17 | {
18 | 	int i; for(i = 0; i < HTAB_SIZE; i++)
19 | 	{
20 | 		if(htab->nodes[i])
21 | 		{
22 | 			free(htab->nodes[i]->key);
23 | 			free(htab->nodes[i]);
24 | 		}
25 | 	}
26 | 
27 | 	free(htab);
28 | 
29 | 	htab = NULL;
30 | }
31 | 
32 | int htab_add(hash_table* htab, char* k, int v)
33 | {
34 | 	int hash = htab_hash(k);
35 | 
36 | 	// If the node is not already occupied, allocate space, and copy the key/value pair.
37 | 	if(htab->nodes[hash] == NULL) htab->nodes[hash] = malloc(sizeof(htable_node));
38 | 	else return 1;
39 | 
40 | 	htab->nodes[hash]->key = (char*)malloc(sizeof(char) * (strlen(k) + 1));
41 | 
42 | 	strcpy(htab->nodes[hash]->key, k);
43 | 	htab->nodes[hash]->value = v;
44 | 
45 | 	return 0;
46 | }
47 | 
48 | int htab_find(hash_table* htab, char* key)
49 | {
50 | 	int hash = htab_hash(key);
51 | 
52 | 	if(htab->nodes[hash] != NULL) return htab->nodes[hash]->value;
53 | 	else return -1;
54 | }
55 | 
56 | unsigned int htab_hash(char* k)
57 | {
58 | 	unsigned int hash = 1;
59 | 
60 | 	char* c; for(c = k; *c; c++)
61 | 		hash += (hash << *c) - *c;
62 | 
63 | 	return hash % HTAB_SIZE;
64 | }
65 | 


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/hash_table.h:
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 1 | #ifndef HASH_TABLE_H_
 2 | #define HASH_TABLE_H_
 3 | 
 4 | #define KEY_LENGTH 64
 5 | #define HTAB_SIZE 4096
 6 | 
 7 | typedef struct
 8 | {
 9 | 	char* key;
10 | 	int value;
11 | } htable_node;
12 | 
13 | typedef struct
14 | {
15 | 	int num_nodes;
16 | 	htable_node* nodes[HTAB_SIZE];
17 | } hash_table;
18 | 
19 | hash_table* create_htab();
20 | void destroy_htab(hash_table* htab);
21 | 
22 | inline int htab_add(hash_table* htab, char* key, int value);
23 | inline int htab_find(hash_table* htab, char* key);
24 | 
25 | inline unsigned int htab_hash(char* key);
26 | 
27 | #endif
28 | 


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