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-rw-r--r--iniparser/src/dictionary.c374
1 files changed, 374 insertions, 0 deletions
diff --git a/iniparser/src/dictionary.c b/iniparser/src/dictionary.c
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+/*-------------------------------------------------------------------------*/
+/**
+ @file dictionary.c
+ @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).
+*/
+/*--------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------
+ Includes
+ ---------------------------------------------------------------------------*/
+#include "dictionary.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/** Maximum value size for integers and doubles. */
+#define MAXVALSZ 1024
+
+/** Minimal allocated number of entries in a dictionary */
+#define DICTMINSZ 128
+
+/** Invalid key token */
+#define DICT_INVALID_KEY ((char *)-1)
+
+/*---------------------------------------------------------------------------
+ Private functions
+ ---------------------------------------------------------------------------*/
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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.
+ */
+/*--------------------------------------------------------------------------*/
+static char *xstrdup(const char *s) {
+ char *t;
+ size_t len;
+ if (!s)
+ return NULL;
+
+ len = strlen(s) + 1;
+ t = (char *)malloc(len);
+ if (t) {
+ memcpy(t, s, len);
+ }
+ return t;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @brief Double the size of the dictionary
+ @param d Dictionary to grow
+ @return This function returns non-zero in case of failure
+ */
+/*--------------------------------------------------------------------------*/
+static int dictionary_grow(dictionary *d) {
+ char **new_val;
+ char **new_key;
+ unsigned *new_hash;
+
+ new_val = (char **)calloc(d->size * 2, sizeof *d->val);
+ new_key = (char **)calloc(d->size * 2, sizeof *d->key);
+ new_hash = (unsigned *)calloc(d->size * 2, sizeof *d->hash);
+ if (!new_val || !new_key || !new_hash) {
+ /* An allocation failed, leave the dictionary unchanged */
+ if (new_val)
+ free(new_val);
+ if (new_key)
+ free(new_key);
+ if (new_hash)
+ free(new_hash);
+ return -1;
+ }
+ /* Initialize the newly allocated space */
+ memcpy(new_val, d->val, d->size * sizeof(char *));
+ memcpy(new_key, d->key, d->size * sizeof(char *));
+ memcpy(new_hash, d->hash, d->size * sizeof(unsigned));
+ /* Delete previous data */
+ free(d->val);
+ free(d->key);
+ free(d->hash);
+ /* Actually update the dictionary */
+ d->size *= 2;
+ d->val = new_val;
+ d->key = new_key;
+ d->hash = new_hash;
+ return 0;
+}
+
+/*---------------------------------------------------------------------------
+ Function codes
+ ---------------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------*/
+/**
+ @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) {
+ size_t len;
+ unsigned hash;
+ size_t i;
+
+ if (!key)
+ return 0;
+
+ len = strlen(key);
+ for (hash = 0, i = 0; i < len; i++) {
+ hash += (unsigned)key[i];
+ hash += (hash << 10);
+ hash ^= (hash >> 6);
+ }
+ hash += (hash << 3);
+ hash ^= (hash >> 11);
+ hash += (hash << 15);
+ return hash;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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) {
+ dictionary *d;
+
+ /* If no size was specified, allocate space for DICTMINSZ */
+ if (size < DICTMINSZ)
+ size = DICTMINSZ;
+
+ d = (dictionary *)calloc(1, sizeof *d);
+
+ if (d) {
+ d->size = size;
+ d->val = (char **)calloc(size, sizeof *d->val);
+ d->key = (char **)calloc(size, sizeof *d->key);
+ d->hash = (unsigned *)calloc(size, sizeof *d->hash);
+ }
+ return d;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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 *d) {
+ ssize_t i;
+
+ if (d == NULL)
+ return;
+ for (i = 0; i < d->size; i++) {
+ if (d->key[i] != NULL)
+ free(d->key[i]);
+ if (d->val[i] != NULL)
+ free(d->val[i]);
+ }
+ free(d->val);
+ free(d->key);
+ free(d->hash);
+ free(d);
+ return;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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.
+ */
+/*--------------------------------------------------------------------------*/
+const char *dictionary_get(const dictionary *d, const char *key, const char *def) {
+ unsigned hash;
+ ssize_t i;
+
+ hash = dictionary_hash(key);
+ for (i = 0; i < d->size; i++) {
+ if (d->key[i] == NULL)
+ continue;
+ /* Compare hash */
+ if (hash == d->hash[i]) {
+ /* Compare string, to avoid hash collisions */
+ if (!strcmp(key, d->key[i])) {
+ return d->val[i];
+ }
+ }
+ }
+ return 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 *d, const char *key, const char *val) {
+ ssize_t i;
+ unsigned hash;
+
+ if (d == NULL || key == NULL)
+ return -1;
+
+ /* Compute hash for this key */
+ hash = dictionary_hash(key);
+ /* Find if value is already in dictionary */
+ if (d->n > 0) {
+ for (i = 0; i < d->size; i++) {
+ if (d->key[i] == NULL)
+ continue;
+ if (hash == d->hash[i]) { /* Same hash value */
+ if (!strcmp(key, d->key[i])) { /* Same key */
+ /* Found a value: modify and return */
+ if (d->val[i] != NULL)
+ free(d->val[i]);
+ d->val[i] = (val ? xstrdup(val) : NULL);
+ /* Value has been modified: return */
+ return 0;
+ }
+ }
+ }
+ }
+ /* Add a new value */
+ /* See if dictionary needs to grow */
+ if (d->n == d->size) {
+ /* Reached maximum size: reallocate dictionary */
+ if (dictionary_grow(d) != 0)
+ return -1;
+ }
+
+ /* Insert key in the first empty slot. Start at d->n and wrap at
+ d->size. Because d->n < d->size this will necessarily
+ terminate. */
+ for (i = d->n; d->key[i];) {
+ if (++i == d->size)
+ i = 0;
+ }
+ /* Copy key */
+ d->key[i] = xstrdup(key);
+ d->val[i] = (val ? xstrdup(val) : NULL);
+ d->hash[i] = hash;
+ d->n++;
+ return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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) {
+ unsigned hash;
+ ssize_t i;
+
+ if (key == NULL || d == NULL) {
+ return;
+ }
+
+ hash = dictionary_hash(key);
+ for (i = 0; i < d->size; i++) {
+ if (d->key[i] == NULL)
+ continue;
+ /* Compare hash */
+ if (hash == d->hash[i]) {
+ /* Compare string, to avoid hash collisions */
+ if (!strcmp(key, d->key[i])) {
+ /* Found key */
+ break;
+ }
+ }
+ }
+ if (i >= d->size)
+ /* Key not found */
+ return;
+
+ free(d->key[i]);
+ d->key[i] = NULL;
+ if (d->val[i] != NULL) {
+ free(d->val[i]);
+ d->val[i] = NULL;
+ }
+ d->hash[i] = 0;
+ d->n--;
+ return;
+}
+
+/*-------------------------------------------------------------------------*/
+/**
+ @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(const dictionary *d, FILE *out) {
+ ssize_t i;
+
+ if (d == NULL || out == NULL)
+ return;
+ if (d->n < 1) {
+ fprintf(out, "empty dictionary\n");
+ return;
+ }
+ for (i = 0; i < d->size; i++) {
+ if (d->key[i]) {
+ fprintf(out, "%20s\t[%s]\n", d->key[i], d->val[i] ? d->val[i] : "UNDEF");
+ }
+ }
+ return;
+}
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