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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include "dhash.h"
struct my_data_t {
int foo;
char bar[128];
};
void delete_callback(hash_entry_t *entry)
{
if (entry->value.type == HASH_VALUE_PTR) free(entry->value.ptr);
}
bool visit_callback(hash_entry_t *entry, void *user_data)
{
unsigned long *count = (unsigned long *)user_data;
struct my_data_t *my_data = (struct my_data_t *) entry->value.ptr;
(*count)++;
printf("%s = [foo=%d bar=%s]\n", entry->key.str, my_data->foo, my_data->bar);
return true;
}
struct my_data_t *new_data(int foo, const char *bar)
{
struct my_data_t *my_data = malloc(sizeof(struct my_data_t));
my_data->foo = foo;
strncpy(my_data->bar, bar, sizeof(my_data->bar));
return my_data;
}
int main(int argc, char **argv)
{
static hash_table_t *table = NULL;
hash_key_t key, *keys;
hash_value_t value;
struct hash_iter_context_t *iter;
hash_entry_t *entry;
unsigned long i, n_entries;
int error;
struct my_data_t *my_data = new_data(1024, "Hello World!");
unsigned long count;
/* Create a hash table */
if ((error = hash_create(10, &table, delete_callback)) != HASH_SUCCESS) {
fprintf(stderr, "cannot create hash table (%s)\n", hash_error_string(error));
return error;
}
/* Enter a key named "My Data" and specify it's value as a pointer to my_data */
key.type = HASH_KEY_STRING;
key.str = strdup("My Data");
value.type = HASH_VALUE_PTR;
value.ptr = my_data;
if ((error = hash_enter(table, &key, &value)) != HASH_SUCCESS) {
fprintf(stderr, "cannot add to table \"%s\" (%s)\n", key.str, hash_error_string(error));
return error;
}
/* Get a list of keys and print them out, free the list when we're done */
if ((error = hash_keys(table, &count, &keys)) != HASH_SUCCESS) {
fprintf(stderr, "cannot get key list (%s)\n", hash_error_string(error));
return error;
}
for (i = 0; i < count; i++)
printf("key: %s\n", keys[i].str);
free(keys);
/* Lookup the key named "My Data" */
key.type = HASH_KEY_STRING;
key.str = strdup("My Data");
if ((error = hash_lookup(table, &key, &value)) != HASH_SUCCESS) {
fprintf(stderr, "cannot find key \"%s\" (%s)\n", key.str, hash_error_string(error));
}
/* Visit each entry in the table, callback will increment count on each visit */
printf("Iterate using callback\n");
count = 0;
hash_iterate(table, visit_callback, &count);
/* Assure number of visits equal the table size */
assert(count == hash_count(table));
/* Visit each entry using iterator object */
printf("Iterate using iterator\n");
n_entries = 0;
iter = new_hash_iter_context(table);
while ((entry = iter->next(iter)) != NULL) {
struct my_data_t *data = (struct my_data_t *) entry->value.ptr;
printf("%s = [foo=%d bar=%s]\n", entry->key.str, data->foo, data->bar);
n_entries++;
}
free(iter);
/* Assure number of visits equal the table size */
assert(n_entries == hash_count(table));
/* Remove the entry, deletion callback will be invoked */
key.type = HASH_KEY_STRING;
key.str = strdup("My Data");
if ((error = hash_delete(table, &key)) != HASH_SUCCESS) {
fprintf(stderr, "cannot delete from table (%s)\n", hash_error_string(error));
}
/* Assure key is no longer in table */
assert (!hash_has_key(table, &key));
/* Free the table */
hash_destroy(table);
return 0;
}
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