src/cx/list.h

Wed, 15 Feb 2023 16:48:11 +0100

author
Mike Becker <universe@uap-core.de>
date
Wed, 15 Feb 2023 16:48:11 +0100
changeset 655
7340c4255f1f
parent 647
2e6e9d9f2159
child 664
af5bf4603a5d
permissions
-rw-r--r--

implement backwards iterator - fixes #238

     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 "allocator.h"
    42 #include "iterator.h"
    44 #ifdef __cplusplus
    45 extern "C" {
    46 #endif
    48 /**
    49  * A comparator function comparing two list elements.
    50  */
    51 typedef int(*CxListComparator)(
    52         void const *left,
    53         void const *right
    54 );
    56 /**
    57  * List class type.
    58  */
    59 typedef struct cx_list_class_s cx_list_class;
    61 /**
    62  * Structure for holding the base data of a list.
    63  */
    64 struct cx_list_s {
    65     /**
    66      * The list class definition.
    67      */
    68     cx_list_class const *cl;
    69     /**
    70      * The actual implementation in case the list class is delegating.
    71      */
    72     cx_list_class const *climpl;
    73     /**
    74      * The allocator to use.
    75      */
    76     CxAllocator const *allocator;
    77     /**
    78      * The comparator function for the elements.
    79      */
    80     CxListComparator cmpfunc;
    81     /**
    82      * The size of each element (payload only).
    83      */
    84     size_t itemsize;
    85     /**
    86      * The size of the list (number of currently stored elements).
    87      */
    88     size_t size;
    89     /**
    90      * The capacity of the list (maximum number of elements).
    91      */
    92     size_t capacity;
    93     union {
    94         /**
    95          * An optional simple destructor for the list contents that admits the free() interface.
    96          *
    97          * @remark Set content_destructor_type to #CX_DESTRUCTOR_SIMPLE.
    98          *
    99          * @attention Read the documentation of the particular list implementation
   100          * whether this destructor shall only destroy the contents or also free the memory.
   101          */
   102         cx_destructor_func simple_destructor;
   103         /**
   104          * An optional advanced destructor for the list contents providing additional data.
   105          *
   106          * @remark Set content_destructor_type to #CX_DESTRUCTOR_ADVANCED.
   107          *
   108          * @attention Read the documentation of the particular list implementation
   109          * whether this destructor shall only destroy the contents or also free the memory.
   110          */
   111         cx_advanced_destructor advanced_destructor;
   112     };
   113     /**
   114      * The type of destructor to use.
   115      */
   116     enum cx_destructor_type content_destructor_type;
   117 };
   119 /**
   120  * The class definition for arbitrary lists.
   121  */
   122 struct cx_list_class_s {
   123     /**
   124      * Destructor function.
   125      */
   126     void (*destructor)(struct cx_list_s *list);
   128     /**
   129      * Member function for inserting a single elements.
   130      * Implementors SHOULD see to performant implementations for corner cases.
   131      */
   132     int (*insert_element)(
   133             struct cx_list_s *list,
   134             size_t index,
   135             void const *data
   136     );
   138     /**
   139      * Member function for inserting multiple elements.
   140      * Implementors SHOULD see to performant implementations for corner cases.
   141      */
   142     size_t (*insert_array)(
   143             struct cx_list_s *list,
   144             size_t index,
   145             void const *data,
   146             size_t n
   147     );
   149     /**
   150      * Member function for inserting an element relative to an iterator position.
   151      */
   152     int (*insert_iter)(
   153             struct cx_mut_iterator_s *iter,
   154             void const *elem,
   155             int prepend
   156     );
   158     /**
   159      * Member function for removing an element.
   160      */
   161     int (*remove)(
   162             struct cx_list_s *list,
   163             size_t index
   164     );
   166     /**
   167      * Member function for swapping two elements.
   168      */
   169     int (*swap)(
   170             struct cx_list_s *list,
   171             size_t i,
   172             size_t j
   173     );
   175     /**
   176      * Member function for element lookup.
   177      */
   178     void *(*at)(
   179             struct cx_list_s const *list,
   180             size_t index
   181     );
   183     /**
   184      * Member function for finding an element.
   185      */
   186     size_t (*find)(
   187             struct cx_list_s const *list,
   188             void const *elem
   189     );
   191     /**
   192      * Member function for sorting the list in place.
   193      */
   194     void (*sort)(struct cx_list_s *list);
   196     /**
   197      * Member function for comparing this list to another list of the same type.
   198      */
   199     int (*compare)(
   200             struct cx_list_s const *list,
   201             struct cx_list_s const *other
   202     );
   204     /**
   205      * Member function for reversing the order of the items.
   206      */
   207     void (*reverse)(struct cx_list_s *list);
   209     /**
   210      * Member function for returning an iterator pointing to the specified index.
   211      */
   212     struct cx_iterator_s (*iterator)(
   213             struct cx_list_s const *list,
   214             size_t index,
   215             bool backward
   216     );
   217 };
   219 /**
   220  * Common type for all list implementations.
   221  */
   222 typedef struct cx_list_s CxList;
   224 /**
   225  * Advises the list to store copies of the objects (default mode of operation).
   226  *
   227  * Retrieving objects from this list will yield pointers to the copies stored
   228  * within this list.
   229  *
   230  * @param list the list
   231  * @see cxListStorePointers()
   232  */
   233 __attribute__((__nonnull__))
   234 void cxListStoreObjects(CxList *list);
   236 /**
   237  * Advises the list to only store pointers to the objects.
   238  *
   239  * Retrieving objects from this list will yield the original pointers stored.
   240  *
   241  * @note This function forcibly sets the element size to the size of a pointer.
   242  * Invoking this function on a non-empty list that already stores copies of
   243  * objects is undefined.
   244  *
   245  * @param list the list
   246  * @see cxListStoreObjects()
   247  */
   248 __attribute__((__nonnull__))
   249 void cxListStorePointers(CxList *list);
   251 /**
   252  * Returns true, if this list is storing pointers instead of the actual data.
   253  *
   254  * @param list
   255  * @return
   256  * @see cxListStorePointers()
   257  */
   258 __attribute__((__nonnull__))
   259 bool cxListIsStoringPointers(CxList *list);
   261 /**
   262  * Adds an item to the end of the list.
   263  *
   264  * @param list the list
   265  * @param elem a pointer to the element to add
   266  * @return zero on success, non-zero on memory allocation failure
   267  * @see cxListAddArray()
   268  */
   269 __attribute__((__nonnull__))
   270 static inline int cxListAdd(
   271         CxList *list,
   272         void const *elem
   273 ) {
   274     return list->cl->insert_element(list, list->size, elem);
   275 }
   277 /**
   278  * Adds multiple items to the end of the list.
   279  *
   280  * This method is more efficient than invoking cxListAdd() multiple times.
   281  *
   282  * If there is not enough memory to add all elements, the returned value is
   283  * less than \p n.
   284  *
   285  * If this list is storing pointers instead of objects \p array is expected to
   286  * be an array of pointers.
   287  *
   288  * @param list the list
   289  * @param array a pointer to the elements to add
   290  * @param n the number of elements to add
   291  * @return the number of added elements
   292  */
   293 __attribute__((__nonnull__))
   294 static inline size_t cxListAddArray(
   295         CxList *list,
   296         void const *array,
   297         size_t n
   298 ) {
   299     return list->cl->insert_array(list, list->size, array, n);
   300 }
   302 /**
   303  * Inserts an item at the specified index.
   304  *
   305  * If \p index equals the list \c size, this is effectively cxListAdd().
   306  *
   307  * @param list the list
   308  * @param index the index the element shall have
   309  * @param elem a pointer to the element to add
   310  * @return zero on success, non-zero on memory allocation failure
   311  * or when the index is out of bounds
   312  * @see cxListInsertAfter()
   313  * @see cxListInsertBefore()
   314  */
   315 __attribute__((__nonnull__))
   316 static inline int cxListInsert(
   317         CxList *list,
   318         size_t index,
   319         void const *elem
   320 ) {
   321     return list->cl->insert_element(list, index, elem);
   322 }
   324 /**
   325  * Inserts multiple items to the list at the specified index.
   326  * If \p index equals the list size, this is effectively cxListAddArray().
   327  *
   328  * This method is usually more efficient than invoking cxListInsert()
   329  * multiple times.
   330  *
   331  * If there is not enough memory to add all elements, the returned value is
   332  * less than \p n.
   333  *
   334  * If this list is storing pointers instead of objects \p array is expected to
   335  * be an array of pointers.
   336  *
   337  * @param list the list
   338  * @param index the index where to add the elements
   339  * @param array a pointer to the elements to add
   340  * @param n the number of elements to add
   341  * @return the number of added elements
   342  */
   343 __attribute__((__nonnull__))
   344 static inline size_t cxListInsertArray(
   345         CxList *list,
   346         size_t index,
   347         void const *array,
   348         size_t n
   349 ) {
   350     return list->cl->insert_array(list, index, array, n);
   351 }
   353 /**
   354  * Inserts an element after the current location of the specified iterator.
   355  *
   356  * The used iterator remains operational, but all other active iterators should
   357  * be considered invalidated.
   358  *
   359  * If \p iter is not a list iterator, the behavior is undefined.
   360  * If \p iter is a past-the-end iterator, the new element gets appended to the list.
   361  *
   362  * @param iter an iterator
   363  * @param elem the element to insert
   364  * @return zero on success, non-zero on memory allocation failure
   365  * @see cxListInsert()
   366  * @see cxListInsertBefore()
   367  */
   368 __attribute__((__nonnull__))
   369 static inline int cxListInsertAfter(
   370         CxMutIterator *iter,
   371         void const *elem
   372 ) {
   373     return ((struct cx_list_s *) iter->src_handle)->cl->insert_iter(iter, elem, 0);
   374 }
   376 /**
   377  * Inserts an element before the current location of the specified iterator.
   378  *
   379  * The used iterator remains operational, but all other active iterators should
   380  * be considered invalidated.
   381  *
   382  * If \p iter is not a list iterator, the behavior is undefined.
   383  * If \p iter is a past-the-end iterator, the new element gets appended to the list.
   384  *
   385  * @param iter an iterator
   386  * @param elem the element to insert
   387  * @return zero on success, non-zero on memory allocation failure
   388  * @see cxListInsert()
   389  * @see cxListInsertAfter()
   390  */
   391 __attribute__((__nonnull__))
   392 static inline int cxListInsertBefore(
   393         CxMutIterator *iter,
   394         void const *elem
   395 ) {
   396     return ((struct cx_list_s *) iter->src_handle)->cl->insert_iter(iter, elem, 1);
   397 }
   399 /**
   400  * Removes the element at the specified index.
   401  * @param list the list
   402  * @param index the index of the element
   403  * @return zero on success, non-zero if the index is out of bounds
   404  */
   405 __attribute__((__nonnull__))
   406 static inline int cxListRemove(
   407         CxList *list,
   408         size_t index
   409 ) {
   410     return list->cl->remove(list, index);
   411 }
   413 /**
   414  * Swaps two items in the list.
   415  *
   416  * Implementations should only allocate temporary memory for the swap, if
   417  * it is necessary.
   418  *
   419  * @param list the list
   420  * @param i the index of the first element
   421  * @param j the index of the second element
   422  * @return zero on success, non-zero if one of the indices is out of bounds
   423  */
   424 __attribute__((__nonnull__))
   425 static inline int cxListSwap(
   426         CxList *list,
   427         size_t i,
   428         size_t j
   429 ) {
   430     return list->cl->swap(list, i, j);
   431 }
   433 /**
   434  * Returns a pointer to the element at the specified index.
   435  *
   436  * @param list the list
   437  * @param index the index of the element
   438  * @return a pointer to the element or \c NULL if the index is out of bounds
   439  */
   440 __attribute__((__nonnull__))
   441 static inline void *cxListAt(
   442         CxList *list,
   443         size_t index
   444 ) {
   445     return list->cl->at(list, index);
   446 }
   448 /**
   449  * Returns an iterator pointing to the item at the specified index.
   450  *
   451  * The returned iterator is position-aware.
   452  *
   453  * If the index is out of range, a past-the-end iterator will be returned.
   454  *
   455  * @param list the list
   456  * @param index the index where the iterator shall point at
   457  * @return a new iterator
   458  */
   459 __attribute__((__nonnull__, __warn_unused_result__))
   460 static inline CxIterator cxListIteratorAt(
   461         CxList const *list,
   462         size_t index
   463 ) {
   464     return list->cl->iterator(list, index, false);
   465 }
   467 /**
   468  * Returns a backwards iterator pointing to the item at the specified index.
   469  *
   470  * The returned iterator is position-aware.
   471  *
   472  * If the index is out of range, a past-the-end iterator will be returned.
   473  *
   474  * @param list the list
   475  * @param index the index where the iterator shall point at
   476  * @return a new iterator
   477  */
   478 __attribute__((__nonnull__, __warn_unused_result__))
   479 static inline CxIterator cxListBackwardsIteratorAt(
   480         CxList const *list,
   481         size_t index
   482 ) {
   483     return list->cl->iterator(list, index, true);
   484 }
   486 /**
   487  * Returns a mutating iterator pointing to the item at the specified index.
   488  *
   489  * The returned iterator is position-aware.
   490  *
   491  * If the index is out of range, a past-the-end iterator will be returned.
   492  *
   493  * @param list the list
   494  * @param index the index where the iterator shall point at
   495  * @return a new iterator
   496  */
   497 __attribute__((__nonnull__, __warn_unused_result__))
   498 CxMutIterator cxListMutIteratorAt(
   499         CxList *list,
   500         size_t index
   501 );
   503 /**
   504  * Returns a mutating backwards iterator pointing to the item at the
   505  * specified index.
   506  *
   507  * The returned iterator is position-aware.
   508  *
   509  * If the index is out of range, a past-the-end iterator will be returned.
   510  *
   511  * @param list the list
   512  * @param index the index where the iterator shall point at
   513  * @return a new iterator
   514  */
   515 __attribute__((__nonnull__, __warn_unused_result__))
   516 CxMutIterator cxListMutBackwardsIteratorAt(
   517         CxList *list,
   518         size_t index
   519 );
   521 /**
   522  * Returns an iterator pointing to the first item of the list.
   523  *
   524  * The returned iterator is position-aware.
   525  *
   526  * If the list is empty, a past-the-end iterator will be returned.
   527  *
   528  * @param list the list
   529  * @return a new iterator
   530  */
   531 __attribute__((__nonnull__, __warn_unused_result__))
   532 static inline CxIterator cxListIterator(CxList const *list) {
   533     return list->cl->iterator(list, 0, false);
   534 }
   536 /**
   537  * Returns a mutating iterator pointing to the first item of the list.
   538  *
   539  * The returned iterator is position-aware.
   540  *
   541  * If the list is empty, a past-the-end iterator will be returned.
   542  *
   543  * @param list the list
   544  * @return a new iterator
   545  */
   546 __attribute__((__nonnull__, __warn_unused_result__))
   547 static inline CxMutIterator cxListMutIterator(CxList *list) {
   548     return cxListMutIteratorAt(list, 0);
   549 }
   552 /**
   553  * Returns a backwards iterator pointing to the last item of the list.
   554  *
   555  * The returned iterator is position-aware.
   556  *
   557  * If the list is empty, a past-the-end iterator will be returned.
   558  *
   559  * @param list the list
   560  * @return a new iterator
   561  */
   562 __attribute__((__nonnull__, __warn_unused_result__))
   563 static inline CxIterator cxListBackwardsIterator(CxList const *list) {
   564     return list->cl->iterator(list, list->size - 1, true);
   565 }
   567 /**
   568  * Returns a mutating backwards iterator pointing to the last item of the list.
   569  *
   570  * The returned iterator is position-aware.
   571  *
   572  * If the list is empty, a past-the-end iterator will be returned.
   573  *
   574  * @param list the list
   575  * @return a new iterator
   576  */
   577 __attribute__((__nonnull__, __warn_unused_result__))
   578 static inline CxMutIterator cxListMutBackwardsIterator(CxList *list) {
   579     return cxListMutBackwardsIteratorAt(list, list->size - 1);
   580 }
   582 /**
   583  * Returns the index of the first element that equals \p elem.
   584  *
   585  * Determining equality is performed by the list's comparator function.
   586  *
   587  * @param list the list
   588  * @param elem the element to find
   589  * @return the index of the element or \c (size+1) if the element is not found
   590  */
   591 __attribute__((__nonnull__))
   592 static inline size_t cxListFind(
   593         CxList const *list,
   594         void const *elem
   595 ) {
   596     return list->cl->find(list, elem);
   597 }
   599 /**
   600  * Sorts the list in place.
   601  *
   602  * \remark The underlying sort algorithm is implementation defined.
   603  *
   604  * @param list the list
   605  */
   606 __attribute__((__nonnull__))
   607 static inline void cxListSort(CxList *list) {
   608     list->cl->sort(list);
   609 }
   611 /**
   612  * Reverses the order of the items.
   613  *
   614  * @param list the list
   615  */
   616 __attribute__((__nonnull__))
   617 static inline void cxListReverse(CxList *list) {
   618     list->cl->reverse(list);
   619 }
   621 /**
   622  * Compares a list to another list of the same type.
   623  *
   624  * First, the list sizes are compared.
   625  * If they match, the lists are compared element-wise.
   626  *
   627  * @param list the list
   628  * @param other the list to compare to
   629  * @return zero, if both lists are equal element wise,
   630  * negative if the first list is smaller, positive if the first list is larger
   631  */
   632 __attribute__((__nonnull__))
   633 int cxListCompare(
   634         CxList const *list,
   635         CxList const *other
   636 );
   638 /**
   639  * Deallocates the memory of the specified list structure.
   640  *
   641  * Also calls content a destructor function, depending on the configuration
   642  * in CxList.content_destructor_type.
   643  *
   644  * This function itself is a destructor function for the CxList.
   645  *
   646  * @param list the list which shall be destroyed
   647  */
   648 __attribute__((__nonnull__))
   649 void cxListDestroy(CxList *list);
   651 #ifdef __cplusplus
   652 } // extern "C"
   653 #endif
   655 #endif // UCX_LIST_H

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