| commit | author | age | ||
| d6b4a7 | 1 | |
| G | 2 | /*-------------------------------------------------------------------------*/ |
| 3 | /** | |
| 4 | @file dictionary.h | |
| 5 | @author N. Devillard | |
| 6 | @brief Implements a dictionary for string variables. | |
| 7 | @url https://github.com/ndevilla/iniparser | |
| 8 | ||
| 9 | This module implements a simple dictionary object, i.e. a list | |
| 10 | of string/string associations. This object is useful to store e.g. | |
| 11 | informations retrieved from a configuration file (ini files). | |
| 12 | */ | |
| 13 | /*--------------------------------------------------------------------------*/ | |
| 14 | ||
| 15 | #ifndef _DICTIONARY_H_ | |
| 16 | #define _DICTIONARY_H_ | |
| 17 | ||
| 18 | /*--------------------------------------------------------------------------- | |
| 19 | Includes | |
| 20 | ---------------------------------------------------------------------------*/ | |
| 21 | ||
| 22 | #include <stdio.h> | |
| 23 | #include <stdlib.h> | |
| 24 | #include <string.h> | |
| 25 | #include <unistd.h> | |
| 26 | ||
| 27 | #ifdef __cplusplus | |
| 28 | extern "C" { | |
| 29 | #endif | |
| 30 | ||
| 31 | /*--------------------------------------------------------------------------- | |
| 32 | New types | |
| 33 | ---------------------------------------------------------------------------*/ | |
| 34 | ||
| 35 | ||
| 36 | /*-------------------------------------------------------------------------*/ | |
| 37 | /** | |
| 38 | @brief Dictionary object | |
| 39 | ||
| 40 | This object contains a list of string/string associations. Each | |
| 41 | association is identified by a unique string key. Looking up values | |
| 42 | in the dictionary is speeded up by the use of a (hopefully collision-free) | |
| 43 | hash function. | |
| 44 | */ | |
| 45 | /*-------------------------------------------------------------------------*/ | |
| 46 | typedef struct _dictionary_ { | |
| 47 | int n ; /** Number of entries in dictionary */ | |
| 48 | ssize_t size ; /** Storage size */ | |
| 49 | char ** val ; /** List of string values */ | |
| 50 | char ** key ; /** List of string keys */ | |
| 51 | unsigned * hash ; /** List of hash values for keys */ | |
| 52 | } dictionary ; | |
| 53 | ||
| 54 | ||
| 55 | /*--------------------------------------------------------------------------- | |
| 56 | Function prototypes | |
| 57 | ---------------------------------------------------------------------------*/ | |
| 58 | ||
| 59 | /*-------------------------------------------------------------------------*/ | |
| 60 | /** | |
| 61 | @brief Compute the hash key for a string. | |
| 62 | @param key Character string to use for key. | |
| 63 | @return 1 unsigned int on at least 32 bits. | |
| 64 | ||
| 65 | This hash function has been taken from an Article in Dr Dobbs Journal. | |
| 66 | This is normally a collision-free function, distributing keys evenly. | |
| 67 | The key is stored anyway in the struct so that collision can be avoided | |
| 68 | by comparing the key itself in last resort. | |
| 69 | */ | |
| 70 | /*--------------------------------------------------------------------------*/ | |
| 71 | unsigned dictionary_hash(const char * key); | |
| 72 | ||
| 73 | /*-------------------------------------------------------------------------*/ | |
| 74 | /** | |
| 75 | @brief Create a new dictionary object. | |
| 76 | @param size Optional initial size of the dictionary. | |
| 77 | @return 1 newly allocated dictionary object. | |
| 78 | ||
| 79 | This function allocates a new dictionary object of given size and returns | |
| 80 | it. If you do not know in advance (roughly) the number of entries in the | |
| 81 | dictionary, give size=0. | |
| 82 | */ | |
| 83 | /*--------------------------------------------------------------------------*/ | |
| 84 | dictionary * dictionary_new(size_t size); | |
| 85 | ||
| 86 | /*-------------------------------------------------------------------------*/ | |
| 87 | /** | |
| 88 | @brief Delete a dictionary object | |
| 89 | @param d dictionary object to deallocate. | |
| 90 | @return void | |
| 91 | ||
| 92 | Deallocate a dictionary object and all memory associated to it. | |
| 93 | */ | |
| 94 | /*--------------------------------------------------------------------------*/ | |
| 95 | void dictionary_del(dictionary * vd); | |
| 96 | ||
| 97 | /*-------------------------------------------------------------------------*/ | |
| 98 | /** | |
| 99 | @brief Get a value from a dictionary. | |
| 100 | @param d dictionary object to search. | |
| 101 | @param key Key to look for in the dictionary. | |
| 102 | @param def Default value to return if key not found. | |
| 103 | @return 1 pointer to internally allocated character string. | |
| 104 | ||
| 105 | This function locates a key in a dictionary and returns a pointer to its | |
| 106 | value, or the passed 'def' pointer if no such key can be found in | |
| 107 | dictionary. The returned character pointer points to data internal to the | |
| 108 | dictionary object, you should not try to free it or modify it. | |
| 109 | */ | |
| 110 | /*--------------------------------------------------------------------------*/ | |
| 111 | const char * dictionary_get(const dictionary * d, const char * key, const char * def); | |
| 112 | ||
| 113 | ||
| 114 | /*-------------------------------------------------------------------------*/ | |
| 115 | /** | |
| 116 | @brief Set a value in a dictionary. | |
| 117 | @param d dictionary object to modify. | |
| 118 | @param key Key to modify or add. | |
| 119 | @param val Value to add. | |
| 120 | @return int 0 if Ok, anything else otherwise | |
| 121 | ||
| 122 | If the given key is found in the dictionary, the associated value is | |
| 123 | replaced by the provided one. If the key cannot be found in the | |
| 124 | dictionary, it is added to it. | |
| 125 | ||
| 126 | It is Ok to provide a NULL value for val, but NULL values for the dictionary | |
| 127 | or the key are considered as errors: the function will return immediately | |
| 128 | in such a case. | |
| 129 | ||
| 130 | Notice that if you dictionary_set a variable to NULL, a call to | |
| 131 | dictionary_get will return a NULL value: the variable will be found, and | |
| 132 | its value (NULL) is returned. In other words, setting the variable | |
| 133 | content to NULL is equivalent to deleting the variable from the | |
| 134 | dictionary. It is not possible (in this implementation) to have a key in | |
| 135 | the dictionary without value. | |
| 136 | ||
| 137 | This function returns non-zero in case of failure. | |
| 138 | */ | |
| 139 | /*--------------------------------------------------------------------------*/ | |
| 140 | int dictionary_set(dictionary * vd, const char * key, const char * val); | |
| 141 | ||
| 142 | /*-------------------------------------------------------------------------*/ | |
| 143 | /** | |
| 144 | @brief Delete a key in a dictionary | |
| 145 | @param d dictionary object to modify. | |
| 146 | @param key Key to remove. | |
| 147 | @return void | |
| 148 | ||
| 149 | This function deletes a key in a dictionary. Nothing is done if the | |
| 150 | key cannot be found. | |
| 151 | */ | |
| 152 | /*--------------------------------------------------------------------------*/ | |
| 153 | void dictionary_unset(dictionary * d, const char * key); | |
| 154 | ||
| 155 | ||
| 156 | /*-------------------------------------------------------------------------*/ | |
| 157 | /** | |
| 158 | @brief Dump a dictionary to an opened file pointer. | |
| 159 | @param d Dictionary to dump | |
| 160 | @param f Opened file pointer. | |
| 161 | @return void | |
| 162 | ||
| 163 | Dumps a dictionary onto an opened file pointer. Key pairs are printed out | |
| 164 | as @c [Key]=[Value], one per line. It is Ok to provide stdout or stderr as | |
| 165 | output file pointers. | |
| 166 | */ | |
| 167 | /*--------------------------------------------------------------------------*/ | |
| 168 | void dictionary_dump(const dictionary * d, FILE * out); | |
| 169 | ||
| 170 | #ifdef __cplusplus | |
| 171 | } | |
| 172 | #endif | |
| 173 | ||
| 174 | #endif | |
