Hash table in action

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Hash table in action
//Compile with:
//gcc -g eina_hash_01.c -o eina_hash_01 `pkg-config --cflags --libs eina`
#include <stdio.h>
#include <string.h>
#include <Eina.h>
/*
* Eina Hash - phonebook
*
* This example demonstrate the use of Eina Hash by implementing a phonebook
* that stores its contact data into the hash.
*
* It indexes the phone numbers by Contact Full Name, so it's a hash with
* string keys.
*/
struct _Phone_Entry {
const char *name; // Full name.
const char *number; // Phone number.
};
typedef struct _Phone_Entry Phone_Entry;
static Phone_Entry _start_entries[] = {
{ "Wolfgang Amadeus Mozart", "+01 23 456-78910" },
{ "Ludwig van Beethoven", "+12 34 567-89101" },
{ "Richard Georg Strauss", "+23 45 678-91012" },
{ "Heitor Villa-Lobos", "+34 56 789-10123" },
{ NULL, NULL }
}; // _start_entries
static void
_phone_entry_free_cb(void *data)
{
free(data);
}
static Eina_Bool
_phone_book_foreach_cb(const Eina_Hash *phone_book EINA_UNUSED, const void *key,
void *data, void *fdata EINA_UNUSED)
{
const char *name = key;
const char *number = data;
printf("%s: %s\n", name, number);
// Return EINA_FALSE to stop this callback from being called
return EINA_TRUE;
}
int
main(int argc, const char *argv[])
{
(void) argc;
(void) argv;
Eina_Hash *phone_book = NULL;
int i;
const char *entry_name = "Heitor Villa-Lobos";
char *phone = NULL;
Eina_Bool r;
Eina_Iterator *it;
void *data;
eina_init();
phone_book = eina_hash_string_superfast_new(_phone_entry_free_cb);
// Add initial entries to our hash
for (i = 0; _start_entries[i].name != NULL; i++)
{
eina_hash_add(phone_book, _start_entries[i].name,
strdup(_start_entries[i].number));
}
// Look for a specific entry and get its phone number
phone = eina_hash_find(phone_book, entry_name);
if (phone)
{
printf("Printing entry.\n");
printf("Name: %s\n", entry_name);
printf("Number: %s\n\n", phone);
}
// Delete this entry
r = eina_hash_del(phone_book, entry_name, NULL);
printf("Hash entry successfully deleted? %d\n\n", r);
// Modify the pointer data of an entry and free the old one
phone = eina_hash_modify(phone_book, "Richard Georg Strauss",
strdup("+23 45 111-11111"));
free(phone);
// Modify or add an entry to the hash with eina_hash_set
// Let's first add a new entry
phone = eina_hash_set(phone_book, "Raul Seixas",
strdup("+55 01 234-56789"));
if (!phone)
{
printf("No previous phone found for Raul Seixas. ");
printf("Creating new entry.\n");
}
else
{
printf("Old phone for Raul Seixas was %s\n", phone);
free(phone);
}
printf("\n");
// Now change the phone number
phone = eina_hash_set(phone_book, "Raul Seixas",
strdup("+55 02 222-22222"));
if (phone)
{
printf("Changing phone for Raul Seixas to +55 02 222-22222. ");
printf("Old phone was %s\n", phone);
free(phone);
}
else
{
printf("No previous phone found for Raul Seixas. ");
printf("Creating new entry.\n");
}
// There are many ways to iterate over our Phone book.
// First, iterate showing the names and associated numbers.
printf("List of phones:\n");
eina_hash_foreach(phone_book, _phone_book_foreach_cb, NULL);
printf("\n");
// Now iterate using an iterator
printf("List of phones:\n");
it = eina_hash_iterator_tuple_new(phone_book);
while (eina_iterator_next(it, &data))
{
Eina_Hash_Tuple *t = data;
const char *name = t->key;
const char *number = t->data;
printf("%s: %s\n", name, number);
}
eina_iterator_free(it); // Always free the iterator after its use
printf("\n");
// Just iterate over the keys (names)
printf("List of names in the phone book:\n");
it = eina_hash_iterator_key_new(phone_book);
while (eina_iterator_next(it, &data))
{
const char *name = data;
printf("%s\n", name);
}
eina_iterator_free(it);
printf("\n");
// Just iterate over the data (numbers)
printf("List of numbers in the phone book:\n");
it = eina_hash_iterator_data_new(phone_book);
while (eina_iterator_next(it, &data))
{
const char *number = data;
printf("%s\n", number);
}
eina_iterator_free(it);
printf("\n");
// Check how many items are in the phone book
printf("There are %d items in the hash.\n\n",
eina_hash_population(phone_book));
// Change the name (key) on an entry
eina_hash_move(phone_book, "Raul Seixas", "Alceu Valenca");
printf("List of phones after change:\n");
eina_hash_foreach(phone_book, _phone_book_foreach_cb, NULL);
printf("\n");
// Empty the phone book, but don't destroy it
eina_hash_free_buckets(phone_book);
printf("There are %d items in the hash.\n\n",
eina_hash_population(phone_book));
// Phone book could still be used, but we are freeing it since we are
// done for now
eina_hash_free(phone_book);
eina_shutdown();
}