utilities: bsearch and qsort with additional user_data pointer argument

src/utils.h

@@ -74,4 +74,41 @@ char* obi_format_date(time_t date);
 void* obi_get_memory_aligned_on_16(int size, int* shift);
 
 
+/**
+ * @brief Version of quick sort modified to allow the user to provide an
+ *        additional pointer sent to the comparison function.
+ *
+ * @param key This is the pointer to the object that serves as key for the search, type-casted as a void*.
+ * @param base This is the pointer to the first object of the array where the search is performed, type-casted as a void*.
+ * @param num This is the number of elements in the array pointed by base.
+ * @param size This is the size in bytes of each element in the array.
+ * @param user_data This is an additional pointer passed to the comparison function.
+ * @param cmp This is the function that compares two elements, eventually with an additional pointer.
+ *
+ * @returns A pointer to an entry in the array that matches the search key.
+ * @retval NULL if key is not found.
+ *
+ * @since January 2017
+ * @author original code modified by Celine Mercier (celine.mercier@metabarcoding.org)
+ */
+void* bsearch_user_data(const void* key, const void* base, size_t num, size_t size, const void* user_data,
+              	  	  	int (*cmp)(const void *key, const void *elt, const void* user_data));
+
+
+/**
+ * @brief Version of quick sort modified to allow the user to provide an
+ *        additional pointer sent to the comparison function.
+ *
+ * @param aa This is the pointer to the first element of the array to be sorted.
+ * @param n This is the number of elements in the array pointed by base.
+ * @param es This is the size in bytes of each element in the array.
+ * @param user_data This is an additional pointer passed to the comparison function.
+ * @param cmp This is the function that compares two elements, eventually with an additional pointer.
+ *
+ * @since January 2017
+ * @author original code modified by Celine Mercier (celine.mercier@metabarcoding.org)
+ */
+void qsort_user_data(void *aa, size_t n, size_t es, const void *user_data, int (*cmp)(const void *, const void *, const void *));
+
+
 #endif /* UTILS_H_ */