libdebian-installer
Data Structures | Macros | Functions
Simple hash table
Hash functions

Data Structures

struct  di_hash_table
 Hash table. More...
 
struct  di_hash_node
 Node of a hash table. More...
 

Macros

#define HASH_TABLE_RESIZE(hash_table)
 
#define HASH_TABLE_MIN_SIZE   11
 
#define HASH_TABLE_MAX_SIZE   13845163
 
#define CLAMP(x, low, high)   (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
 

Functions

di_hash_tabledi_hash_table_new (di_hash_func hash_func, di_equal_func key_equal_func)
 
di_hash_tabledi_hash_table_new_full (di_hash_func hash_func, di_equal_func key_equal_func, di_destroy_notify key_destroy_func, di_destroy_notify value_destroy_func)
 
void di_hash_table_destroy (di_hash_table *hash_table)
 
void di_hash_table_insert (di_hash_table *hash_table, void *key, void *value)
 
void * di_hash_table_lookup (di_hash_table *hash_table, const void *key)
 
void di_hash_table_foreach (di_hash_table *hash_table, di_hfunc *func, void *user_data)
 
di_ksize_t di_hash_table_size (di_hash_table *hash_table)
 
static void internal_di_hash_table_resize (di_hash_table *hash_table)
 
static di_hash_node ** internal_di_hash_table_lookup_node (di_hash_table *hash_table, const void *key)
 
static di_hash_nodeinternal_di_hash_node_new (di_hash_table *hash_table, void *key, void *value)
 
static void internal_di_hash_node_destroy (di_hash_node *hash_node, di_destroy_notify key_destroy_func, di_destroy_notify value_destroy_func) __attribute__((unused))
 
static void internal_di_hash_nodes_destroy (di_hash_node *hash_node, di_destroy_notify key_destroy_func, di_destroy_notify value_destroy_func)
 

Detailed Description

Macro Definition Documentation

#define CLAMP (   x,
  low,
  high 
)    (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
Parameters
xvalue
lowlow bound
highhigh bound
Returns
a value between low and high
#define HASH_TABLE_MAX_SIZE   13845163

The maximal hash table size

#define HASH_TABLE_MIN_SIZE   11

The minimal hash table size

Referenced by di_hash_table_new_full().

#define HASH_TABLE_RESIZE (   hash_table)
Value:
if ((hash_table->size >= 3 * hash_table->nnodes && \
hash_table->size > HASH_TABLE_MIN_SIZE) || \
(3 * hash_table->size <= hash_table->nnodes && \
hash_table->size < HASH_TABLE_MAX_SIZE)) \
internal_di_hash_table_resize (hash_table);

Defines if a resize is necessary

Parameters
hash_tablea di_hash_table

Referenced by di_hash_table_insert().

Function Documentation

void di_hash_table_destroy ( di_hash_table hash_table)

Destroys the di_hash_table. If keys and/or values are dynamically allocated, you should either free them first or create the di_hash_table using di_hash_table_new_full. In the latter case the destroy functions you supplied will be called on all keys and values before destroying the di_hash_table.

Parameters
hash_tablea di_hash_table.

References di_free(), key_destroy_func, mem_chunk, nodes, size, and value_destroy_func.

Referenced by di_packages_free(), and di_release_free().

{
size_t i;
for (i = 0; i < hash_table->size; i++)
internal_di_hash_nodes_destroy (hash_table->nodes[i], hash_table->key_destroy_func, hash_table->value_destroy_func);
di_mem_chunk_destroy (hash_table->mem_chunk);
di_free (hash_table->nodes);
di_free (hash_table);
}
void di_hash_table_foreach ( di_hash_table hash_table,
di_hfunc *  func,
void *  user_data 
)

Calls the given function for each of the key/value pairs in the di_hash_table. The function is passed the key and value of each pair, and the given user_data parameter.

Postcondition
The hash table may not be modified while iterating over it (you can't add/remove items).
Parameters
hash_tablea di_hash_table.
functhe function to call for each key/value pair.
user_datauser data to pass to the function.

References di_hash_node::key, di_hash_node::next, nodes, size, and di_hash_node::value.

{
di_hash_node *node;
size_t i;
for (i = 0; i < hash_table->size; i++)
for (node = hash_table->nodes[i]; node; node = node->next)
func (node->key, node->value, user_data);
}
void di_hash_table_insert ( di_hash_table hash_table,
void *  key,
void *  value 
)

Inserts a new key and value into a di_hash_table.

If the key already exists in the di_hash_table its current value is replaced with the new value. If you supplied a value_destroy_func when creating the di_hash_table, the old value is freed using that function. If you supplied a key_destroy_func when creating the di_hash_table, the passed key is freed using that function.

Parameters
hash_tablea di_hash_table.
keya key to insert.
valuethe value to associate with the key.

References HASH_TABLE_RESIZE, key_destroy_func, nnodes, and value_destroy_func.

Referenced by di_packages_append_package(), and di_packages_get_package_new().

{
di_hash_node **node;
node = internal_di_hash_table_lookup_node (hash_table, key);
if (*node)
{
if (hash_table->key_destroy_func)
hash_table->key_destroy_func (key);
if (hash_table->value_destroy_func)
hash_table->value_destroy_func ((*node)->value);
(*node)->value = value;
}
else
{
*node = internal_di_hash_node_new (hash_table, key, value);
hash_table->nnodes++;
HASH_TABLE_RESIZE (hash_table);
}
}
void* di_hash_table_lookup ( di_hash_table hash_table,
const void *  key 
)

Looks up a key in a di_hash_table.

Parameters
hash_tablea di_hash_table,
keythe key to look up.
Returns
the associated value, or NULL if the key is not found.

References di_hash_node::value.

Referenced by di_packages_get_package(), and di_parser_rfc822_read().

{
di_hash_node *node;
node = *internal_di_hash_table_lookup_node (hash_table, key);
return node ? node->value : NULL;
}
di_hash_table* di_hash_table_new ( di_hash_func  hash_func,
di_equal_func  key_equal_func 
)

Creates a new di_hash_table.

Parameters
hash_funca function to create a hash value from a key. Hash values are used to determine where keys are stored within the di_hash_table data structure.
key_equal_funca function to check two keys for equality. This is used when looking up keys in the di_hash_table.
Returns
a new di_hash_table.

References di_hash_table_new_full().

{
return di_hash_table_new_full (hash_func, key_equal_func, NULL, NULL);
}
di_hash_table* di_hash_table_new_full ( di_hash_func  hash_func,
di_equal_func  key_equal_func,
di_destroy_notify  key_destroy_func,
di_destroy_notify  value_destroy_func 
)

Creates a new di_hash_table like di_hash_table_new and allows to specify functions to free the memory allocated for the key and value that get called when removing the entry from the di_hash_table

Parameters
hash_funca function to create a hash value from a key. Hash values are used to determine where keys are stored within the di_hash_table data structure.
key_equal_funca function to check two keys for equality. This is used when looking up keys in the di_hash_table.
key_destroy_funca function to free the memory allocated for the key used when removing the entry from the di_hash_table or NULL if you don't want to supply such a function.
value_destroy_funca function to free the memory allocated for the value used when removing the entry from the di_hash_table or NULL if you don't want to supply such a function.
Returns
a new di_hash_table.

References di_mem_chunk_new(), di_new, hash_func, HASH_TABLE_MIN_SIZE, key_destroy_func, key_equal_func, mem_chunk, nnodes, nodes, size, and value_destroy_func.

Referenced by di_hash_table_new(), di_packages_alloc(), and di_release_alloc().

{
di_hash_table *hash_table;
size_t i;
hash_table = di_new (di_hash_table, 1);
hash_table->size = HASH_TABLE_MIN_SIZE;
hash_table->nnodes = 0;
hash_table->mem_chunk = di_mem_chunk_new (sizeof (di_hash_node), 4096);
hash_table->hash_func = hash_func;
hash_table->key_equal_func = key_equal_func;
hash_table->nodes = di_new (di_hash_node*, hash_table->size);
for (i = 0; i < hash_table->size; i++)
hash_table->nodes[i] = NULL;
return hash_table;
}
di_ksize_t di_hash_table_size ( di_hash_table hash_table)

Returns the number of elements contained in the di_hash_table.

Parameters
hash_tablea di_hash_table.
Returns
the number of key/value pairs.

References nnodes.

{
return hash_table->nnodes;
}