strongswan/src/libstrongswan/collections/array.h

230 lines
7.0 KiB
C

/*
* Copyright (C) 2014 Tobias Brunner
* Hochschule fuer Technik Rapperswil
*
* Copyright (C) 2013 Martin Willi
* Copyright (C) 2013 revosec AG
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
/**
* @defgroup array array
* @{ @ingroup collections
*/
#ifndef ARRAY_H_
#define ARRAY_H_
#include <collections/enumerator.h>
/**
* Variable sized array with fixed size elements.
*
* An array is a primitive object with associated functions to avoid the
* overhead of an object with methods. It is efficient in memory usage, but
* less efficient than a linked list in manipulating elements.
*/
typedef struct array_t array_t;
typedef enum array_idx_t array_idx_t;
/**
* Special array index values for insert/remove.
*/
enum array_idx_t {
ARRAY_HEAD = 0,
ARRAY_TAIL = -1,
};
/**
* Callback function invoked for each array element.
*
* Data is a pointer to the array element. If this is a pointer based array,
* (esize is zero), data is the pointer itself.
*
* @param data pointer to array data, or the pointer itself
* @param idx array index
* @param user user data passed with callback
*/
typedef void (*array_callback_t)(void *data, int idx, void *user);
/**
* Create a array instance.
*
* Elements get tight packed to each other. If any alignment is required, pass
* appropriate padding to each element. The reserved space does not affect
* array_count(), but just preallocates buffer space.
*
* @param esize element size for this array, use 0 for a pointer array
* @param reserve number of items to allocate space for
* @return array instance
*/
array_t *array_create(u_int esize, u_int8_t reserve);
/**
* Get the number of elements currently in the array.
*
* @return number of elements
*/
int array_count(array_t *array);
/**
* Compress an array, remove unused head/tail space.
*
* @param array array to compress, or NULL
*/
void array_compress(array_t *array);
/**
* Create an enumerator over an array.
*
* The enumerater enumerates directly over the array element (pass a pointer to
* element types), unless the array is pointer based. If zero is passed as
* element size during construction, the enumerator enumerates over the
* dereferenced pointer values.
*
* @param array array to create enumerator for, or NULL
* @return enumerator, over elements or pointers
*/
enumerator_t* array_create_enumerator(array_t *array);
/**
* Remove an element at enumerator position.
*
* @param array array to remove element in
* @param enumerator enumerator position, from array_create_enumerator()
*/
void array_remove_at(array_t *array, enumerator_t *enumerator);
/**
* Insert an element to an array.
*
* If the array is pointer based (esize = 0), the pointer itself is appended.
* Otherwise the element gets copied from the pointer.
* The idx must be either within array_count() or one above to append the item.
* Passing -1 has the same effect as passing array_count(), i.e. appends the
* item. It is always valid to pass idx 0 to prepend the item.
*
* @param array array to append element to
* @param idx index to insert item at
* @param data pointer to array element to copy
*/
void array_insert(array_t *array, int idx, void *data);
/**
* Create an pointer based array if it does not exist, insert pointer.
*
* This is a convenience function for insert a pointer and implicitly
* create a pointer based array if array is NULL. Array is set the the newly
* created array, if any.
*
* @param array pointer to array reference, potentially NULL
* @param idx index to insert item at
* @param ptr pointer to append
*/
void array_insert_create(array_t **array, int idx, void *ptr);
/**
* Insert all items from an enumerator to an array.
*
* @param array array to add items to
* @param idx index to insert each item with
* @param enumerator enumerator over void*, gets destroyed
*/
void array_insert_enumerator(array_t *array, int idx, enumerator_t *enumerator);
/**
* Get an element from the array.
*
* If data is given, the element is copied to that position.
*
* @param array array to get element from, or NULL
* @param idx index of the item to get
* @param data data to copy element to, or NULL
* @return TRUE if idx valid and item returned
*/
bool array_get(array_t *array, int idx, void *data);
/**
* Remove an element from the array.
*
* If data is given, the element is copied to that position.
*
* @param array array to remove element from, or NULL
* @param idx index of the item to remove
* @param data data to copy element to, or NULL
* @return TRUE if idx existed and item removed
*/
bool array_remove(array_t *array, int idx, void *data);
/**
* Sort the array.
*
* The comparison function must return an integer less than, equal to, or
* greater than zero if the first argument is considered to be respectively less
* than, equal to, or greater than the second. If two elements compare as
* equal, their order in the sorted array is undefined.
*
* The comparison function receives pointers to the array elements (esize != 0)
* or the actual pointers (esize = 0). The third argument is the user data
* supplied to this function.
*
* @param array array to sort, or NULL
* @param cmp comparison function
* @param user user data to pass to comparison function
*/
void array_sort(array_t *array, int (*cmp)(const void*,const void*,void*),
void *user);
/**
* Invoke a callback for all array members.
*
* @param array array to traverse, or NULL
* @param cb callback function to invoke each element with
* @param user user data to pass to callback
*/
void array_invoke(array_t *array, array_callback_t cb, void *user);
/**
* Invoke a method of each element defined with offset.
*
* @param array array to traverse, or NULL
* @param offset offset of element method, use offsetof()
*/
void array_invoke_offset(array_t *array, size_t offset);
/**
* Destroy an array.
*
* @param array array to destroy, or NULL
*/
void array_destroy(array_t *array);
/**
* Destroy an array, call a function to clean up all elements.
*
* @param array array to destroy, or NULL
* @param cb callback function to free element data
* @param user user data to pass to callback
*/
void array_destroy_function(array_t *array, array_callback_t cb, void *user);
/**
* Destroy an array, call element method defined with offset.
*
* @param array array to destroy, or NULL
* @param offset offset of element method, use offsetof()
*/
void array_destroy_offset(array_t *array, size_t offset);
#endif /** ARRAY_H_ @}*/