src/cx/list.h

Sun, 21 May 2023 14:03:21 +0200

author
Mike Becker <universe@uap-core.de>
date
Sun, 21 May 2023 14:03:21 +0200
changeset 704
35f06c5eeb0e
parent 699
35b2b99ee523
child 708
1caed6c9ba68
permissions
-rw-r--r--

add empty list implementation - fixes #258

     1 /*
     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
     3  *
     4  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
     5  *
     6  * Redistribution and use in source and binary forms, with or without
     7  * modification, are permitted provided that the following conditions are met:
     8  *
     9  *   1. Redistributions of source code must retain the above copyright
    10  *      notice, this list of conditions and the following disclaimer.
    11  *
    12  *   2. Redistributions in binary form must reproduce the above copyright
    13  *      notice, this list of conditions and the following disclaimer in the
    14  *      documentation and/or other materials provided with the distribution.
    15  *
    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    26  * POSSIBILITY OF SUCH DAMAGE.
    27  */
    28 /**
    29  * \file list.h
    30  * \brief Interface for list implementations.
    31  * \author Mike Becker
    32  * \author Olaf Wintermann
    33  * \version 3.0
    34  * \copyright 2-Clause BSD License
    35  */
    37 #ifndef UCX_LIST_H
    38 #define UCX_LIST_H
    40 #include "common.h"
    41 #include "collection.h"
    43 #ifdef __cplusplus
    44 extern "C" {
    45 #endif
    47 /**
    48  * List class type.
    49  */
    50 typedef struct cx_list_class_s cx_list_class;
    52 /**
    53  * Structure for holding the base data of a list.
    54  */
    55 struct cx_list_s {
    56     CX_COLLECTION_MEMBERS
    57     /**
    58      * The list class definition.
    59      */
    60     cx_list_class const *cl;
    61     /**
    62      * The actual implementation in case the list class is delegating.
    63      */
    64     cx_list_class const *climpl;
    65 };
    67 /**
    68  * The class definition for arbitrary lists.
    69  */
    70 struct cx_list_class_s {
    71     /**
    72      * Destructor function.
    73      */
    74     void (*destructor)(struct cx_list_s *list);
    76     /**
    77      * Member function for inserting a single elements.
    78      * Implementors SHOULD see to performant implementations for corner cases.
    79      */
    80     int (*insert_element)(
    81             struct cx_list_s *list,
    82             size_t index,
    83             void const *data
    84     );
    86     /**
    87      * Member function for inserting multiple elements.
    88      * Implementors SHOULD see to performant implementations for corner cases.
    89      */
    90     size_t (*insert_array)(
    91             struct cx_list_s *list,
    92             size_t index,
    93             void const *data,
    94             size_t n
    95     );
    97     /**
    98      * Member function for inserting an element relative to an iterator position.
    99      */
   100     int (*insert_iter)(
   101             struct cx_mut_iterator_s *iter,
   102             void const *elem,
   103             int prepend
   104     );
   106     /**
   107      * Member function for removing an element.
   108      */
   109     int (*remove)(
   110             struct cx_list_s *list,
   111             size_t index
   112     );
   114     /**
   115      * Member function for removing all elements.
   116      */
   117     void (*clear)(struct cx_list_s *list);
   119     /**
   120      * Member function for swapping two elements.
   121      */
   122     int (*swap)(
   123             struct cx_list_s *list,
   124             size_t i,
   125             size_t j
   126     );
   128     /**
   129      * Member function for element lookup.
   130      */
   131     void *(*at)(
   132             struct cx_list_s const *list,
   133             size_t index
   134     );
   136     /**
   137      * Member function for finding an element.
   138      */
   139     ssize_t (*find)(
   140             struct cx_list_s const *list,
   141             void const *elem
   142     );
   144     /**
   145      * Member function for sorting the list in place.
   146      */
   147     void (*sort)(struct cx_list_s *list);
   149     /**
   150      * Member function for comparing this list to another list of the same type.
   151      */
   152     int (*compare)(
   153             struct cx_list_s const *list,
   154             struct cx_list_s const *other
   155     );
   157     /**
   158      * Member function for reversing the order of the items.
   159      */
   160     void (*reverse)(struct cx_list_s *list);
   162     /**
   163      * Member function for returning an iterator pointing to the specified index.
   164      */
   165     struct cx_iterator_s (*iterator)(
   166             struct cx_list_s const *list,
   167             size_t index,
   168             bool backward
   169     );
   170 };
   172 /**
   173  * Common type for all list implementations.
   174  */
   175 typedef struct cx_list_s CxList;
   177 /**
   178  * Advises the list to store copies of the objects (default mode of operation).
   179  *
   180  * Retrieving objects from this list will yield pointers to the copies stored
   181  * within this list.
   182  *
   183  * @param list the list
   184  * @see cxListStorePointers()
   185  */
   186 __attribute__((__nonnull__))
   187 void cxListStoreObjects(CxList *list);
   189 /**
   190  * Advises the list to only store pointers to the objects.
   191  *
   192  * Retrieving objects from this list will yield the original pointers stored.
   193  *
   194  * @note This function forcibly sets the element size to the size of a pointer.
   195  * Invoking this function on a non-empty list that already stores copies of
   196  * objects is undefined.
   197  *
   198  * @param list the list
   199  * @see cxListStoreObjects()
   200  */
   201 __attribute__((__nonnull__))
   202 void cxListStorePointers(CxList *list);
   204 /**
   205  * Returns true, if this list is storing pointers instead of the actual data.
   206  *
   207  * @param list
   208  * @return true, if this list is storing pointers
   209  * @see cxListStorePointers()
   210  */
   211 __attribute__((__nonnull__))
   212 static inline bool cxListIsStoringPointers(CxList const *list) {
   213     return list->store_pointer;
   214 }
   216 /**
   217  * Returns the number of elements currently stored in the list.
   218  *
   219  * @param list the list
   220  * @return the number of currently stored elements
   221  */
   222 __attribute__((__nonnull__))
   223 static inline size_t cxListSize(CxList const *list) {
   224     return list->size;
   225 }
   227 /**
   228  * Adds an item to the end of the list.
   229  *
   230  * @param list the list
   231  * @param elem a pointer to the element to add
   232  * @return zero on success, non-zero on memory allocation failure
   233  * @see cxListAddArray()
   234  */
   235 __attribute__((__nonnull__))
   236 static inline int cxListAdd(
   237         CxList *list,
   238         void const *elem
   239 ) {
   240     return list->cl->insert_element(list, list->size, elem);
   241 }
   243 /**
   244  * Adds multiple items to the end of the list.
   245  *
   246  * This method is more efficient than invoking cxListAdd() multiple times.
   247  *
   248  * If there is not enough memory to add all elements, the returned value is
   249  * less than \p n.
   250  *
   251  * If this list is storing pointers instead of objects \p array is expected to
   252  * be an array of pointers.
   253  *
   254  * @param list the list
   255  * @param array a pointer to the elements to add
   256  * @param n the number of elements to add
   257  * @return the number of added elements
   258  */
   259 __attribute__((__nonnull__))
   260 static inline size_t cxListAddArray(
   261         CxList *list,
   262         void const *array,
   263         size_t n
   264 ) {
   265     return list->cl->insert_array(list, list->size, array, n);
   266 }
   268 /**
   269  * Inserts an item at the specified index.
   270  *
   271  * If \p index equals the list \c size, this is effectively cxListAdd().
   272  *
   273  * @param list the list
   274  * @param index the index the element shall have
   275  * @param elem a pointer to the element to add
   276  * @return zero on success, non-zero on memory allocation failure
   277  * or when the index is out of bounds
   278  * @see cxListInsertAfter()
   279  * @see cxListInsertBefore()
   280  */
   281 __attribute__((__nonnull__))
   282 static inline int cxListInsert(
   283         CxList *list,
   284         size_t index,
   285         void const *elem
   286 ) {
   287     return list->cl->insert_element(list, index, elem);
   288 }
   290 /**
   291  * Inserts multiple items to the list at the specified index.
   292  * If \p index equals the list size, this is effectively cxListAddArray().
   293  *
   294  * This method is usually more efficient than invoking cxListInsert()
   295  * multiple times.
   296  *
   297  * If there is not enough memory to add all elements, the returned value is
   298  * less than \p n.
   299  *
   300  * If this list is storing pointers instead of objects \p array is expected to
   301  * be an array of pointers.
   302  *
   303  * @param list the list
   304  * @param index the index where to add the elements
   305  * @param array a pointer to the elements to add
   306  * @param n the number of elements to add
   307  * @return the number of added elements
   308  */
   309 __attribute__((__nonnull__))
   310 static inline size_t cxListInsertArray(
   311         CxList *list,
   312         size_t index,
   313         void const *array,
   314         size_t n
   315 ) {
   316     return list->cl->insert_array(list, index, array, n);
   317 }
   319 /**
   320  * Inserts an element after the current location of the specified iterator.
   321  *
   322  * The used iterator remains operational, but all other active iterators should
   323  * be considered invalidated.
   324  *
   325  * If \p iter is not a list iterator, the behavior is undefined.
   326  * If \p iter is a past-the-end iterator, the new element gets appended to the list.
   327  *
   328  * @param iter an iterator
   329  * @param elem the element to insert
   330  * @return zero on success, non-zero on memory allocation failure
   331  * @see cxListInsert()
   332  * @see cxListInsertBefore()
   333  */
   334 __attribute__((__nonnull__))
   335 static inline int cxListInsertAfter(
   336         CxMutIterator *iter,
   337         void const *elem
   338 ) {
   339     return ((struct cx_list_s *) iter->src_handle)->cl->insert_iter(iter, elem, 0);
   340 }
   342 /**
   343  * Inserts an element before the current location of the specified iterator.
   344  *
   345  * The used iterator remains operational, but all other active iterators should
   346  * be considered invalidated.
   347  *
   348  * If \p iter is not a list iterator, the behavior is undefined.
   349  * If \p iter is a past-the-end iterator, the new element gets appended to the list.
   350  *
   351  * @param iter an iterator
   352  * @param elem the element to insert
   353  * @return zero on success, non-zero on memory allocation failure
   354  * @see cxListInsert()
   355  * @see cxListInsertAfter()
   356  */
   357 __attribute__((__nonnull__))
   358 static inline int cxListInsertBefore(
   359         CxMutIterator *iter,
   360         void const *elem
   361 ) {
   362     return ((struct cx_list_s *) iter->src_handle)->cl->insert_iter(iter, elem, 1);
   363 }
   365 /**
   366  * Removes the element at the specified index.
   367  *
   368  * If an element destructor function is specified, it is called before
   369  * removing the element.
   370  *
   371  * @param list the list
   372  * @param index the index of the element
   373  * @return zero on success, non-zero if the index is out of bounds
   374  */
   375 __attribute__((__nonnull__))
   376 static inline int cxListRemove(
   377         CxList *list,
   378         size_t index
   379 ) {
   380     return list->cl->remove(list, index);
   381 }
   383 /**
   384  * Removes all elements from this list.
   385  *
   386  * If an element destructor function is specified, it is called for each
   387  * element before removing them.
   388  *
   389  * @param list the list
   390  */
   391 __attribute__((__nonnull__))
   392 static inline void cxListClear(CxList *list) {
   393     list->cl->clear(list);
   394 }
   396 /**
   397  * Swaps two items in the list.
   398  *
   399  * Implementations should only allocate temporary memory for the swap, if
   400  * it is necessary.
   401  *
   402  * @param list the list
   403  * @param i the index of the first element
   404  * @param j the index of the second element
   405  * @return zero on success, non-zero if one of the indices is out of bounds
   406  */
   407 __attribute__((__nonnull__))
   408 static inline int cxListSwap(
   409         CxList *list,
   410         size_t i,
   411         size_t j
   412 ) {
   413     return list->cl->swap(list, i, j);
   414 }
   416 /**
   417  * Returns a pointer to the element at the specified index.
   418  *
   419  * @param list the list
   420  * @param index the index of the element
   421  * @return a pointer to the element or \c NULL if the index is out of bounds
   422  */
   423 __attribute__((__nonnull__))
   424 static inline void *cxListAt(
   425         CxList *list,
   426         size_t index
   427 ) {
   428     return list->cl->at(list, index);
   429 }
   431 /**
   432  * Returns an iterator pointing to the item at the specified index.
   433  *
   434  * The returned iterator is position-aware.
   435  *
   436  * If the index is out of range, a past-the-end iterator will be returned.
   437  *
   438  * @param list the list
   439  * @param index the index where the iterator shall point at
   440  * @return a new iterator
   441  */
   442 __attribute__((__nonnull__, __warn_unused_result__))
   443 static inline CxIterator cxListIteratorAt(
   444         CxList const *list,
   445         size_t index
   446 ) {
   447     return list->cl->iterator(list, index, false);
   448 }
   450 /**
   451  * Returns a backwards iterator pointing to the item at the specified index.
   452  *
   453  * The returned iterator is position-aware.
   454  *
   455  * If the index is out of range, a past-the-end iterator will be returned.
   456  *
   457  * @param list the list
   458  * @param index the index where the iterator shall point at
   459  * @return a new iterator
   460  */
   461 __attribute__((__nonnull__, __warn_unused_result__))
   462 static inline CxIterator cxListBackwardsIteratorAt(
   463         CxList const *list,
   464         size_t index
   465 ) {
   466     return list->cl->iterator(list, index, true);
   467 }
   469 /**
   470  * Returns a mutating iterator pointing to the item at the specified index.
   471  *
   472  * The returned iterator is position-aware.
   473  *
   474  * If the index is out of range, a past-the-end iterator will be returned.
   475  *
   476  * @param list the list
   477  * @param index the index where the iterator shall point at
   478  * @return a new iterator
   479  */
   480 __attribute__((__nonnull__, __warn_unused_result__))
   481 CxMutIterator cxListMutIteratorAt(
   482         CxList *list,
   483         size_t index
   484 );
   486 /**
   487  * Returns a mutating backwards iterator pointing to the item at the
   488  * specified index.
   489  *
   490  * The returned iterator is position-aware.
   491  *
   492  * If the index is out of range, a past-the-end iterator will be returned.
   493  *
   494  * @param list the list
   495  * @param index the index where the iterator shall point at
   496  * @return a new iterator
   497  */
   498 __attribute__((__nonnull__, __warn_unused_result__))
   499 CxMutIterator cxListMutBackwardsIteratorAt(
   500         CxList *list,
   501         size_t index
   502 );
   504 /**
   505  * Returns an iterator pointing to the first item of the list.
   506  *
   507  * The returned iterator is position-aware.
   508  *
   509  * If the list is empty, a past-the-end iterator will be returned.
   510  *
   511  * @param list the list
   512  * @return a new iterator
   513  */
   514 __attribute__((__nonnull__, __warn_unused_result__))
   515 static inline CxIterator cxListIterator(CxList const *list) {
   516     return list->cl->iterator(list, 0, false);
   517 }
   519 /**
   520  * Returns a mutating iterator pointing to the first item of the list.
   521  *
   522  * The returned iterator is position-aware.
   523  *
   524  * If the list is empty, a past-the-end iterator will be returned.
   525  *
   526  * @param list the list
   527  * @return a new iterator
   528  */
   529 __attribute__((__nonnull__, __warn_unused_result__))
   530 static inline CxMutIterator cxListMutIterator(CxList *list) {
   531     return cxListMutIteratorAt(list, 0);
   532 }
   535 /**
   536  * Returns a backwards iterator pointing to the last item of the list.
   537  *
   538  * The returned iterator is position-aware.
   539  *
   540  * If the list is empty, a past-the-end iterator will be returned.
   541  *
   542  * @param list the list
   543  * @return a new iterator
   544  */
   545 __attribute__((__nonnull__, __warn_unused_result__))
   546 static inline CxIterator cxListBackwardsIterator(CxList const *list) {
   547     return list->cl->iterator(list, list->size - 1, true);
   548 }
   550 /**
   551  * Returns a mutating backwards iterator pointing to the last item of the list.
   552  *
   553  * The returned iterator is position-aware.
   554  *
   555  * If the list is empty, a past-the-end iterator will be returned.
   556  *
   557  * @param list the list
   558  * @return a new iterator
   559  */
   560 __attribute__((__nonnull__, __warn_unused_result__))
   561 static inline CxMutIterator cxListMutBackwardsIterator(CxList *list) {
   562     return cxListMutBackwardsIteratorAt(list, list->size - 1);
   563 }
   565 /**
   566  * Returns the index of the first element that equals \p elem.
   567  *
   568  * Determining equality is performed by the list's comparator function.
   569  *
   570  * @param list the list
   571  * @param elem the element to find
   572  * @return the index of the element or a negative
   573  * value when the element is not found
   574  */
   575 __attribute__((__nonnull__))
   576 static inline ssize_t cxListFind(
   577         CxList const *list,
   578         void const *elem
   579 ) {
   580     return list->cl->find(list, elem);
   581 }
   583 /**
   584  * Sorts the list in place.
   585  *
   586  * \remark The underlying sort algorithm is implementation defined.
   587  *
   588  * @param list the list
   589  */
   590 __attribute__((__nonnull__))
   591 static inline void cxListSort(CxList *list) {
   592     list->cl->sort(list);
   593 }
   595 /**
   596  * Reverses the order of the items.
   597  *
   598  * @param list the list
   599  */
   600 __attribute__((__nonnull__))
   601 static inline void cxListReverse(CxList *list) {
   602     list->cl->reverse(list);
   603 }
   605 /**
   606  * Compares a list to another list of the same type.
   607  *
   608  * First, the list sizes are compared.
   609  * If they match, the lists are compared element-wise.
   610  *
   611  * @param list the list
   612  * @param other the list to compare to
   613  * @return zero, if both lists are equal element wise,
   614  * negative if the first list is smaller, positive if the first list is larger
   615  */
   616 __attribute__((__nonnull__))
   617 int cxListCompare(
   618         CxList const *list,
   619         CxList const *other
   620 );
   622 /**
   623  * Deallocates the memory of the specified list structure.
   624  *
   625  * Also calls content a destructor function, depending on the configuration
   626  * in CxList.content_destructor_type.
   627  *
   628  * This function itself is a destructor function for the CxList.
   629  *
   630  * @param list the list which shall be destroyed
   631  */
   632 __attribute__((__nonnull__))
   633 void cxListDestroy(CxList *list);
   635 /**
   636  * A shared instance of an empty list.
   637  *
   638  * Writing to that list is undefined.
   639  */
   640 extern CxList * const cxEmptyList;
   643 #ifdef __cplusplus
   644 } // extern "C"
   645 #endif
   647 #endif // UCX_LIST_H

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