eina_hash_04.c

Same example as Eina_Hash in action but using a "string djb2" hash table instead of "string superfast".

//Compile with:
//gcc -g eina_hash_04.c -o eina_hash_04 `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_djb2_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();
}
Eina.h
Eina Utility library.
eina_hash_iterator_key_new
EINA_API Eina_Iterator * eina_hash_iterator_key_new(const Eina_Hash *hash)
Returns a new iterator associated with hash keys.
Definition: eina_hash.c:1272
eina_hash_iterator_data_new
EINA_API Eina_Iterator * eina_hash_iterator_data_new(const Eina_Hash *hash)
Returns a new iterator associated with a hash.
Definition: eina_hash.c:1246
eina_hash_del
EINA_API Eina_Bool eina_hash_del(Eina_Hash *hash, const void *key, const void *data)
Removes the entry identified by a key or a data from the given hash table.
Definition: eina_hash.c:1030
eina_hash_free_buckets
EINA_API void eina_hash_free_buckets(Eina_Hash *hash)
Frees the given hash table buckets resources.
Definition: eina_hash.c:886
eina_hash_move
EINA_API Eina_Bool eina_hash_move(Eina_Hash *hash, const void *old_key, const void *new_key)
Changes the key of an entry in a hash without triggering the free callback.
Definition: eina_hash.c:1191
eina_hash_population
EINA_API int eina_hash_population(const Eina_Hash *hash)
Returns the number of entries in the given hash table.
Definition: eina_hash.c:858
eina_hash_add
EINA_API Eina_Bool eina_hash_add(Eina_Hash *hash, const void *key, const void *data)
Adds an entry to the given hash table.
Definition: eina_hash.c:931
eina_hash_modify
EINA_API void * eina_hash_modify(Eina_Hash *hash, const void *key, const void *data)
Modifies the entry pointer at the specified key and returns the previous entry.
Definition: eina_hash.c:1174
eina_hash_free
EINA_API void eina_hash_free(Eina_Hash *hash)
Frees the given hash table's resources.
Definition: eina_hash.c:868
eina_hash_string_djb2_new
EINA_API Eina_Hash * eina_hash_string_djb2_new(Eina_Free_Cb data_free_cb)
Creates a new hash table using the djb2 algorithm.
Definition: eina_hash.c:780
eina_hash_foreach
EINA_API void eina_hash_foreach(const Eina_Hash *hash, Eina_Hash_Foreach func, const void *fdata)
Calls a function on every member stored in the hash table.
Definition: eina_hash.c:1223
Eina_Hash
struct _Eina_Hash Eina_Hash
Type for a generic hash table.
Definition: eina_hash.h:285
eina_hash_find
EINA_API void * eina_hash_find(const Eina_Hash *hash, const void *key)
Retrieves a specific entry in the given hash table.
Definition: eina_hash.c:1069
eina_hash_set
EINA_API void * eina_hash_set(Eina_Hash *hash, const void *key, const void *data)
Modifies the entry pointer at the specified key and returns the previous entry or adds the entry if n...
Definition: eina_hash.c:1121
eina_hash_iterator_tuple_new
EINA_API Eina_Iterator * eina_hash_iterator_tuple_new(const Eina_Hash *hash)
Returned a new iterator associated with hash keys and data.
Definition: eina_hash.c:1299
eina_iterator_free
EINA_API void eina_iterator_free(Eina_Iterator *iterator)
Frees an iterator.
Definition: eina_iterator.c:98
eina_iterator_next
EINA_API Eina_Bool eina_iterator_next(Eina_Iterator *iterator, void **data)
Returns the value of the current element and go to the next one.
Definition: eina_iterator.c:118
eina_shutdown
EINA_API int eina_shutdown(void)
Shuts down the Eina library.
Definition: eina_main.c:379
eina_init
EINA_API int eina_init(void)
Initializes the Eina library.
Definition: eina_main.c:291
EINA_TRUE
#define EINA_TRUE
boolean value TRUE (numerical value 1)
Definition: eina_types.h:539
Eina_Bool
unsigned char Eina_Bool
Type to mimic a boolean.
Definition: eina_types.h:527
EINA_UNUSED
#define EINA_UNUSED
Used to indicate that a function parameter is purposely unused.
Definition: eina_types.h:339
_Eina_Hash_Tuple
Data for a hash table of key/value pairs.
Definition: eina_hash.h:298
_Eina_Iterator
structure of an iterator
Definition: eina_iterator.h:159