Hash table. More...

#include "mercury_util_config.h"

Include dependency graph for mercury_hash_table.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	hg_hash_table_iter
	Definition of a hg_hash_table_iter. More...

Macros
#define	HG_HASH_TABLE_NULL ((void *) 0)
	A null HashTableValue. More...

Typedefs
typedef struct hg_hash_table	hg_hash_table_t
	A hash table structure. More...

typedef struct hg_hash_table_iter	hg_hash_table_iter_t
	Structure used to iterate over a hash table. More...

typedef struct hg_hash_table_entry	hg_hash_table_entry_t
	Internal structure representing an entry in a hash table. More...

typedef void *	hg_hash_table_key_t
	A key to look up a value in a hg_hash_table_t. More...

typedef void *	hg_hash_table_value_t
	A value stored in a hg_hash_table_t. More...

typedef unsigned int(*	hg_hash_table_hash_func_t )(hg_hash_table_key_t value)
	Hash function used to generate hash values for keys used in a hash table. More...

typedef int(*	hg_hash_table_equal_func_t )(hg_hash_table_key_t value1, hg_hash_table_key_t value2)
	Function used to compare two keys for equality. More...

typedef void(*	hg_hash_table_key_free_func_t )(hg_hash_table_key_t value)
	Type of function used to free keys when entries are removed from a hash table. More...

typedef void(*	hg_hash_table_value_free_func_t )(hg_hash_table_value_t value)
	Type of function used to free values when entries are removed from a hash table. More...

Functions
HG_UTIL_EXPORT hg_hash_table_t *	hg_hash_table_new (hg_hash_table_hash_func_t hash_func, hg_hash_table_equal_func_t equal_func)
	Create a new hash table. More...

HG_UTIL_EXPORT void	hg_hash_table_free (hg_hash_table_t *hash_table)
	Destroy a hash table. More...

HG_UTIL_EXPORT void	hg_hash_table_register_free_functions (hg_hash_table_t *hash_table, hg_hash_table_key_free_func_t key_free_func, hg_hash_table_value_free_func_t value_free_func)
	Register functions used to free the key and value when an entry is removed from a hash table. More...

HG_UTIL_EXPORT int	hg_hash_table_insert (hg_hash_table_t *hash_table, hg_hash_table_key_t key, hg_hash_table_value_t value)
	Insert a value into a hash table, overwriting any existing entry using the same key. More...

HG_UTIL_EXPORT hg_hash_table_value_t	hg_hash_table_lookup (hg_hash_table_t *hash_table, hg_hash_table_key_t key)
	Look up a value in a hash table by key. More...

HG_UTIL_EXPORT int	hg_hash_table_remove (hg_hash_table_t *hash_table, hg_hash_table_key_t key)
	Remove a value from a hash table. More...

HG_UTIL_EXPORT unsigned int	hg_hash_table_num_entries (hg_hash_table_t *hash_table)
	Retrieve the number of entries in a hash table. More...

HG_UTIL_EXPORT void	hg_hash_table_iterate (hg_hash_table_t hash_table, hg_hash_table_iter_t iter)
	Initialise a HashTableIterator to iterate over a hash table. More...

HG_UTIL_EXPORT int	hg_hash_table_iter_has_more (hg_hash_table_iter_t *iterator)
	Determine if there are more keys in the hash table to iterate over. More...

HG_UTIL_EXPORT hg_hash_table_value_t	hg_hash_table_iter_next (hg_hash_table_iter_t *iterator)
	Using a hash table iterator, retrieve the next key. More...

Detailed Description

Hash table.

A hash table stores a set of values which can be addressed by a key. Given the key, the corresponding value can be looked up quickly.

To create a hash table, use hg_hash_table_new. To destroy a hash table, use hg_hash_table_free.

To insert a value into a hash table, use hg_hash_table_insert.

To remove a value from a hash table, use hg_hash_table_remove.

To look up a value by its key, use hg_hash_table_lookup.

To iterate over all values in a hash table, use hg_hash_table_iterate to initialize a hg_hash_table_iter structure. Each value can then be read in turn using hg_hash_table_iter_next and hg_hash_table_iter_has_more.

Definition in file mercury_hash_table.h.

Macro Definition Documentation

#define HG_HASH_TABLE_NULL ((void *) 0)

A null HashTableValue.

Definition at line 99 of file mercury_hash_table.h.

Typedef Documentation

typedef struct hg_hash_table hg_hash_table_t

A hash table structure.

Definition at line 59 of file mercury_hash_table.h.

typedef struct hg_hash_table_iter hg_hash_table_iter_t

Structure used to iterate over a hash table.

Definition at line 65 of file mercury_hash_table.h.

typedef struct hg_hash_table_entry hg_hash_table_entry_t

Internal structure representing an entry in a hash table.

Definition at line 71 of file mercury_hash_table.h.

typedef void* hg_hash_table_key_t

A key to look up a value in a hg_hash_table_t.

Definition at line 77 of file mercury_hash_table.h.

typedef void* hg_hash_table_value_t

A value stored in a hg_hash_table_t.

Definition at line 83 of file mercury_hash_table.h.

typedef unsigned int(* hg_hash_table_hash_func_t)(hg_hash_table_key_t value)

Hash function used to generate hash values for keys used in a hash table.

Parameters

value The value to generate a hash value for.

Returns: The hash value.

Definition at line 109 of file mercury_hash_table.h.

typedef int(* hg_hash_table_equal_func_t)(hg_hash_table_key_t value1, hg_hash_table_key_t value2)

Function used to compare two keys for equality.

Returns: Non-zero if the two keys are equal, zero if the keys are not equal.

Definition at line 118 of file mercury_hash_table.h.

typedef void(* hg_hash_table_key_free_func_t)(hg_hash_table_key_t value)

Type of function used to free keys when entries are removed from a hash table.

Definition at line 125 of file mercury_hash_table.h.

typedef void(* hg_hash_table_value_free_func_t)(hg_hash_table_value_t value)

Type of function used to free values when entries are removed from a hash table.

Definition at line 132 of file mercury_hash_table.h.

Function Documentation

HG_UTIL_EXPORT hg_hash_table_t* hg_hash_table_new	(	hg_hash_table_hash_func_t	hash_func,
		hg_hash_table_equal_func_t	equal_func
	)

Create a new hash table.

Parameters

hash_func	Function used to generate hash keys for the keys used in the table.
equal_func	Function used to test keys used in the table for equality.

Returns: A new hash table structure, or NULL if it was not possible to allocate the new hash table.

HG_UTIL_EXPORT void hg_hash_table_free ( hg_hash_table_t * hash_table )

Destroy a hash table.

Parameters

hash_table The hash table to destroy.

HG_UTIL_EXPORT void hg_hash_table_register_free_functions	(	hg_hash_table_t *	hash_table,
		hg_hash_table_key_free_func_t	key_free_func,
		hg_hash_table_value_free_func_t	value_free_func
	)

Register functions used to free the key and value when an entry is removed from a hash table.

Parameters

hash_table	The hash table.
key_free_func	Function used to free keys.
value_free_func	Function used to free values.

HG_UTIL_EXPORT int hg_hash_table_insert	(	hg_hash_table_t *	hash_table,
		hg_hash_table_key_t	key,
		hg_hash_table_value_t	value
	)

Insert a value into a hash table, overwriting any existing entry using the same key.

Parameters

hash_table	The hash table.
key	The key for the new value.
value	The value to insert.

Returns: Non-zero if the value was added successfully, or zero if it was not possible to allocate memory for the new entry.

HG_UTIL_EXPORT hg_hash_table_value_t hg_hash_table_lookup	(	hg_hash_table_t *	hash_table,
		hg_hash_table_key_t	key
	)

Look up a value in a hash table by key.

Parameters

hash_table	The hash table.
key	The key of the value to look up.

Returns: The value, or HASH_TABLE_NULL if there is no value with that key in the hash table.

HG_UTIL_EXPORT int hg_hash_table_remove	(	hg_hash_table_t *	hash_table,
		hg_hash_table_key_t	key
	)

Remove a value from a hash table.

Parameters

hash_table	The hash table.
key	The key of the value to remove.

Returns: Non-zero if a key was removed, or zero if the specified key was not found in the hash table.

HG_UTIL_EXPORT unsigned int hg_hash_table_num_entries ( hg_hash_table_t * hash_table )

Retrieve the number of entries in a hash table.

Parameters

hash_table The hash table.

Returns: The number of entries in the hash table.

HG_UTIL_EXPORT void hg_hash_table_iterate	(	hg_hash_table_t *	hash_table,
		hg_hash_table_iter_t *	iter
	)

Initialise a HashTableIterator to iterate over a hash table.

Parameters

hash_table	The hash table.
iter	Pointer to an iterator structure to initialise.

HG_UTIL_EXPORT int hg_hash_table_iter_has_more ( hg_hash_table_iter_t * iterator )

Determine if there are more keys in the hash table to iterate over.

Parameters

iterator The hash table iterator.

Returns: Zero if there are no more values to iterate over, non-zero if there are more values to iterate over.

HG_UTIL_EXPORT hg_hash_table_value_t hg_hash_table_iter_next ( hg_hash_table_iter_t * iterator )

Using a hash table iterator, retrieve the next key.

Parameters

iterator The hash table iterator.

Returns: The next key from the hash table, or HG_HASH_TABLE_NULL if there are no more keys to iterate over.

Classes

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation