hashtable.c File Reference

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Detailed Description

Hashtable implementation internals.

This file contains the full documentation of all functions, types, constants, and variables used in the hashtable implementation, including those that are intended only for internal use. For the public interface to hash tables, see hashtable.h.

Definition in file hashtable.c.

#include <stdlib.h>
#include <string.h>
#include "hashtable.h"

Go to the source code of this file.

Defines
#define	NEW(T)   (T*) malloc(sizeof(T))
	Allocate memory for some type.
#define	NEWARRAY(T, N)   (T*) calloc((N), sizeof(T))
	Allocate memory for an array.
Functions
hashtable *	copy_hashtable (struct hashtable *dest, struct hashtable *src)
	Insert all elements from one hash table into another.
void	free_hashtable (struct hashtable *table)
	Free all the memory used by a hash table.
int	hashtable_add (struct hashtable *table, char *key, void *value)
	Add an entry to a hash table.
unsigned int	hashtable_default_hash (const char *key)
	The default hash function.
void	hashtable_iter (const struct hashtable *table, void(*func)(char *key, void *value))
	Call a function for each entry in a hash table.
void *	hashtable_lookup (const struct hashtable *table, const char *key)
	Look up the value bound to a key.
hashtable *	make_hashtable (unsigned int(*hash)(const char *), unsigned int nbuckets)
	Create a hash table.

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Define Documentation

#define NEW

(

T

)

(T*) malloc(sizeof(T))

Allocate memory for some type.

Parameters:

T

The type to allocate memory for.

Returns:

A pointer to the newly allocated storage.

Definition at line 18 of file hashtable.c.

#define NEWARRAY	(	T,
		N		)	(T*) calloc((N), sizeof(T))

Allocate memory for an array.

Parameters:

	T	The type of the elements of the array.
	N	The number of elements in the array.

Returns:

A pointer to the array.

Definition at line 25 of file hashtable.c.

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Function Documentation

struct hashtable* copy_hashtable	(	struct hashtable *	dest,
		struct hashtable *	src
	)

Insert all elements from one hash table into another.

Parameters:

	dest	The hash table to insert elements into.
	src	The hash table whose elements are to be inserted.

Returns:

dest

Definition at line 73 of file hashtable.c.

References hashtable::bucket, hashtable_add(), hashtable_entry::key, hashtable::nbuckets, hashtable_entry::next, and hashtable_entry::value.

void free_hashtable

(

struct hashtable *

table

)

Free all the memory used by a hash table.

Parameters:

table

The hash table to be deallocated.

Definition at line 106 of file hashtable.c.

References hashtable::bucket, hashtable::nbuckets, and hashtable_entry::next.

int hashtable_add	(	struct hashtable *	table,
		char *	key,
		void *	value
	)

Add an entry to a hash table.

Parameters:

	table	The hash table the entry is to be added to.
	key	The key for the entry.
	value	The value for the entry.

Returns:

Nonzero on success, 0 on failure.

Definition at line 45 of file hashtable.c.

References hashtable::bucket, hashtable_entry::key, NEW, hashtable_entry::next, and hashtable_entry::value.

unsigned int hashtable_default_hash

(

const char *

key

)

The default hash function.

This function can be used as the hash parameter to make_hash_table().

Parameters:

key

The key to be hashed.

Returns:

The hash for the key.

Definition at line 91 of file hashtable.c.

void hashtable_iter	(	const struct hashtable *	table,
		void(*)(char *key, void *value)	func
	)

Call a function for each entry in a hash table.

Parameters:

	table	The hash table whose entries to iterate over.
	func	The function to call for each entry. The function receives two argument: 1. The key of the entry. 2. The value of the entry.

Definition at line 131 of file hashtable.c.

References hashtable::bucket, hashtable_entry::key, hashtable::nbuckets, hashtable_entry::next, and hashtable_entry::value.

void* hashtable_lookup	(	const struct hashtable *	table,
		const char *	key
	)

Look up the value bound to a key.

Parameters:

	table	The hash table in which to look up the key.
	key	The key to look up.

Returns:

The value belonging to the key if found, NULL if not found.

Definition at line 149 of file hashtable.c.

References hashtable::bucket, hashtable_entry::key, hashtable_entry::next, and hashtable_entry::value.

struct hashtable* make_hashtable	(	unsigned int(*)(const char *)	hash,
		unsigned int	nbuckets
	)

Create a hash table.

Parameters:

	hash	The hash function to use with this hash table. The function has to map NUL-terminated strings to unsigned ints.
	nbuckets	The number of buckets in the hash table.

Returns:

The new hash table on success, NULL on failure.

Definition at line 169 of file hashtable.c.

References hashtable::bucket, hashtable::hash, hashtable::nbuckets, NEW, and NEWARRAY.

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