186 lines
6.8 KiB
C
Executable File
186 lines
6.8 KiB
C
Executable File
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@file dictionary.h
|
|
@author N. Devillard
|
|
@brief Implements a dictionary for string variables.
|
|
|
|
This module implements a simple dictionary object, i.e. a list
|
|
of string/string associations. This object is useful to store e.g.
|
|
informations retrieved from a configuration file (ini files).
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
|
|
#ifndef _DICTIONARY_H_
|
|
#define _DICTIONARY_H_
|
|
|
|
/*---------------------------------------------------------------------------
|
|
* Includes
|
|
---------------------------------------------------------------------------*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/*---------------------------------------------------------------------------
|
|
* New types
|
|
---------------------------------------------------------------------------*/
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Dictionary object
|
|
|
|
This object contains a list of string/string associations. Each
|
|
association is identified by a unique string key. Looking up values
|
|
in the dictionary is speeded up by the use of a (hopefully collision-free)
|
|
hash function.
|
|
*/
|
|
/*-------------------------------------------------------------------------*/
|
|
typedef struct _dictionary_ {
|
|
int n; /** Number of entries in dictionary */
|
|
int size; /** Storage size */
|
|
char **val; /** List of string values */
|
|
char **key; /** List of string keys */
|
|
unsigned *hash; /** List of hash values for keys */
|
|
}dictionary;
|
|
|
|
|
|
/*---------------------------------------------------------------------------
|
|
* Function prototypes
|
|
---------------------------------------------------------------------------*/
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Compute the hash key for a string.
|
|
@param key Character string to use for key.
|
|
@return 1 unsigned int on at least 32 bits.
|
|
|
|
This hash function has been taken from an Article in Dr Dobbs Journal.
|
|
This is normally a collision-free function, distributing keys evenly.
|
|
The key is stored anyway in the struct so that collision can be avoided
|
|
by comparing the key itself in last resort.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
unsigned dictionary_hash(const char *key);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Create a new dictionary object.
|
|
@param size Optional initial size of the dictionary.
|
|
@return 1 newly allocated dictionary objet.
|
|
|
|
This function allocates a new dictionary object of given size and returns
|
|
it. If you do not know in advance (roughly) the number of entries in the
|
|
dictionary, give size=0.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
dictionary *dictionary_new(size_t size);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Delete a dictionary object
|
|
@param d dictionary object to deallocate.
|
|
@return void
|
|
|
|
Deallocate a dictionary object and all memory associated to it.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
void dictionary_del(dictionary *vd);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Get a value from a dictionary.
|
|
@param d dictionary object to search.
|
|
@param key Key to look for in the dictionary.
|
|
@param def Default value to return if key not found.
|
|
@return 1 pointer to internally allocated character string.
|
|
|
|
This function locates a key in a dictionary and returns a pointer to its
|
|
value, or the passed 'def' pointer if no such key can be found in
|
|
dictionary. The returned character pointer points to data internal to the
|
|
dictionary object, you should not try to free it or modify it.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
char *dictionary_get(dictionary *d, const char *key, char *def);
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Set a value in a dictionary.
|
|
@param d dictionary object to modify.
|
|
@param key Key to modify or add.
|
|
@param val Value to add.
|
|
@return int 0 if Ok, anything else otherwise
|
|
|
|
If the given key is found in the dictionary, the associated value is
|
|
replaced by the provided one. If the key cannot be found in the
|
|
dictionary, it is added to it.
|
|
|
|
It is Ok to provide a NULL value for val, but NULL values for the dictionary
|
|
or the key are considered as errors: the function will return immediately
|
|
in such a case.
|
|
|
|
Notice that if you dictionary_set a variable to NULL, a call to
|
|
dictionary_get will return a NULL value: the variable will be found, and
|
|
its value (NULL) is returned. In other words, setting the variable
|
|
content to NULL is equivalent to deleting the variable from the
|
|
dictionary. It is not possible (in this implementation) to have a key in
|
|
the dictionary without value.
|
|
|
|
This function returns non-zero in case of failure.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
int dictionary_set(dictionary *vd, const char *key, const char *val);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Delete a key in a dictionary
|
|
@param d dictionary object to modify.
|
|
@param key Key to remove.
|
|
@return void
|
|
|
|
This function deletes a key in a dictionary. Nothing is done if the
|
|
key cannot be found.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
void dictionary_unset(dictionary *d, const char *key);
|
|
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Dump a dictionary to an opened file pointer.
|
|
@param d Dictionary to dump
|
|
@param f Opened file pointer.
|
|
@return void
|
|
|
|
Dumps a dictionary onto an opened file pointer. Key pairs are printed out
|
|
as @c [Key]=[Value], one per line. It is Ok to provide stdout or stderr as
|
|
output file pointers.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
void dictionary_dump(dictionary *d, FILE *out);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
/**
|
|
@brief Duplicate a string
|
|
@param s String to duplicate
|
|
@return Pointer to a newly allocated string, to be freed with free()
|
|
|
|
This is a replacement for strdup(). This implementation is provided
|
|
for systems that do not have it.
|
|
*/
|
|
/*--------------------------------------------------------------------------*/
|
|
char *aw_strdup(const char *s);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|