src/array_list.c

Fri, 07 Apr 2023 11:30:28 +0200

author
Mike Becker <universe@uap-core.de>
date
Fri, 07 Apr 2023 11:30:28 +0200
changeset 676
d0680a23d850
parent 670
4ad8ea3aee49
child 677
b09aae58bba4
permissions
-rw-r--r--

fix initial storage allocation for array lists created with CX_STORE_POINTERS

     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  */
    29 #include "cx/array_list.h"
    30 #include <assert.h>
    31 #include <string.h>
    33 // LOW LEVEL ARRAY LIST FUNCTIONS
    35 enum cx_array_copy_result cx_array_copy(
    36         void **target,
    37         size_t *size,
    38         size_t *capacity,
    39         size_t index,
    40         void const *src,
    41         size_t elem_size,
    42         size_t elem_count,
    43         struct cx_array_reallocator_s *reallocator
    44 ) {
    45     // assert pointers
    46     assert(target != NULL);
    47     assert(size != NULL);
    48     assert(src != NULL);
    50     // determine capacity
    51     size_t cap = capacity == NULL ? *size : *capacity;
    53     // check if resize is required
    54     size_t minsize = index + elem_count;
    55     size_t newsize = *size < minsize ? minsize : *size;
    56     bool needrealloc = newsize > cap;
    58     // reallocate if possible
    59     if (needrealloc) {
    60         // a reallocator and a capacity variable must be available
    61         if (reallocator == NULL || capacity == NULL) {
    62             return CX_ARRAY_COPY_REALLOC_NOT_SUPPORTED;
    63         }
    65         // check, if we need to repair the src pointer
    66         uintptr_t targetaddr = (uintptr_t) *target;
    67         uintptr_t srcaddr = (uintptr_t) src;
    68         bool repairsrc = targetaddr <= srcaddr
    69                          && srcaddr < targetaddr + cap * elem_size;
    71         // calculate new capacity (next number divisible by 16)
    72         cap = newsize - (newsize % 16) + 16;
    73         assert(cap > newsize);
    75         // perform reallocation
    76         void *newmem = reallocator->realloc(
    77                 *target, cap, elem_size, reallocator
    78         );
    79         if (newmem == NULL) {
    80             return CX_ARRAY_COPY_REALLOC_FAILED;
    81         }
    83         // repair src pointer, if necessary
    84         if (repairsrc) {
    85             src = ((char *) newmem) + (srcaddr - targetaddr);
    86         }
    88         // store new pointer and capacity
    89         *target = newmem;
    90         *capacity = cap;
    91     }
    93     // determine target pointer
    94     char *start = *target;
    95     start += index * elem_size;
    97     // copy elements and set new size
    98     memmove(start, src, elem_count * elem_size);
    99     *size = newsize;
   101     // return successfully
   102     return CX_ARRAY_COPY_SUCCESS;
   103 }
   105 #ifndef CX_ARRAY_SWAP_SBO_SIZE
   106 #define CX_ARRAY_SWAP_SBO_SIZE 512
   107 #endif
   109 void cx_array_swap(
   110         void *arr,
   111         size_t elem_size,
   112         size_t idx1,
   113         size_t idx2
   114 ) {
   115     assert(arr != NULL);
   117     // short circuit
   118     if (idx1 == idx2) return;
   120     char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
   121     void *tmp;
   123     // decide if we can use the local buffer
   124     if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
   125         tmp = malloc(elem_size);
   126         // we don't want to enforce error handling
   127         if (tmp == NULL) abort();
   128     } else {
   129         tmp = sbo_mem;
   130     }
   132     // calculate memory locations
   133     char *left = arr, *right = arr;
   134     left += idx1 * elem_size;
   135     right += idx2 * elem_size;
   137     // three-way swap
   138     memcpy(tmp, left, elem_size);
   139     memcpy(left, right, elem_size);
   140     memcpy(right, tmp, elem_size);
   142     // free dynamic memory, if it was needed
   143     if (tmp != sbo_mem) {
   144         free(tmp);
   145     }
   146 }
   148 // HIGH LEVEL ARRAY LIST FUNCTIONS
   150 typedef struct {
   151     struct cx_list_s base;
   152     void *data;
   153     struct cx_array_reallocator_s reallocator;
   154 } cx_array_list;
   156 static void *cx_arl_realloc(
   157         void *array,
   158         size_t capacity,
   159         size_t elem_size,
   160         struct cx_array_reallocator_s *alloc
   161 ) {
   162     // retrieve the pointer to the list allocator
   163     CxAllocator const *al = alloc->ptr1;
   165     // use the list allocator to reallocate the memory
   166     return cxRealloc(al, array, capacity * elem_size);
   167 }
   169 static void cx_arl_destructor(struct cx_list_s *list) {
   170     cx_array_list *arl = (cx_array_list *) list;
   171     cxFree(list->allocator, arl->data);
   172 }
   174 static size_t cx_arl_insert_array(
   175         struct cx_list_s *list,
   176         size_t index,
   177         void const *array,
   178         size_t n
   179 ) {
   180     // out of bounds and special case check
   181     if (index > list->size || n == 0) return 0;
   183     // get a correctly typed pointer to the list
   184     cx_array_list *arl = (cx_array_list *) list;
   186     // do we need to move some elements?
   187     if (index < list->size) {
   188         char const *first_to_move = (char const *) arl->data;
   189         first_to_move += index * list->itemsize;
   190         size_t elems_to_move = list->size - index;
   191         size_t start_of_moved = index + n;
   193         if (CX_ARRAY_COPY_SUCCESS != cx_array_copy(
   194                 &arl->data,
   195                 &list->size,
   196                 &list->capacity,
   197                 start_of_moved,
   198                 first_to_move,
   199                 list->itemsize,
   200                 elems_to_move,
   201                 &arl->reallocator
   202         )) {
   203             // if moving existing elems is unsuccessful, abort
   204             return 0;
   205         }
   206     }
   208     // note that if we had to move the elements, the following operation
   209     // is guaranteed to succeed, because we have the memory already allocated
   210     // therefore, it is impossible to leave this function with an invalid array
   212     // place the new elements
   213     if (CX_ARRAY_COPY_SUCCESS == cx_array_copy(
   214             &arl->data,
   215             &list->size,
   216             &list->capacity,
   217             index,
   218             array,
   219             list->itemsize,
   220             n,
   221             &arl->reallocator
   222     )) {
   223         return n;
   224     } else {
   225         // array list implementation is "all or nothing"
   226         return 0;
   227     }
   228 }
   230 static int cx_arl_insert_element(
   231         struct cx_list_s *list,
   232         size_t index,
   233         void const *element
   234 ) {
   235     return 1 != cx_arl_insert_array(list, index, element, 1);
   236 }
   238 static int cx_arl_insert_iter(
   239         struct cx_mut_iterator_s *iter,
   240         void const *elem,
   241         int prepend
   242 ) {
   243     struct cx_list_s *list = iter->src_handle;
   244     if (iter->index < list->size) {
   245         int result = cx_arl_insert_element(
   246                 list,
   247                 iter->index + 1 - prepend,
   248                 elem
   249         );
   250         if (result == 0 && prepend != 0) {
   251             iter->index++;
   252             iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;
   253         }
   254         return result;
   255     } else {
   256         int result = cx_arl_insert_element(list, list->size, elem);
   257         iter->index = list->size;
   258         return result;
   259     }
   260 }
   262 static int cx_arl_remove(
   263         struct cx_list_s *list,
   264         size_t index
   265 ) {
   266     cx_array_list *arl = (cx_array_list *) list;
   268     // out-of-bounds check
   269     if (index >= list->size) {
   270         return 1;
   271     }
   273     // content destruction
   274     if (list->content_destructor_type != CX_DESTRUCTOR_NONE) {
   275         char *ptr = arl->data;
   276         ptr += index * list->itemsize;
   277         cx_list_invoke_destructor(list, ptr);
   278     }
   280     // short-circuit removal of last element
   281     if (index == list->size - 1) {
   282         list->size--;
   283         return 0;
   284     }
   286     // just move the elements starting at index to the left
   287     int result = cx_array_copy(
   288             &arl->data,
   289             &list->size,
   290             &list->capacity,
   291             index,
   292             ((char *) arl->data) + (index + 1) * list->itemsize,
   293             list->itemsize,
   294             list->size - index - 1,
   295             &arl->reallocator
   296     );
   297     if (result == 0) {
   298         // decrease the size
   299         list->size--;
   300     }
   301     return result;
   302 }
   304 static void cx_arl_clear(struct cx_list_s *list) {
   305     if (list->size == 0) return;
   307     cx_array_list *arl = (cx_array_list *) list;
   308     char *ptr = arl->data;
   310     switch (list->content_destructor_type) {
   311         case CX_DESTRUCTOR_SIMPLE: {
   312             for (size_t i = 0; i < list->size; i++) {
   313                 cx_list_invoke_simple_destructor(list, ptr);
   314                 ptr += list->itemsize;
   315             }
   316             break;
   317         }
   318         case CX_DESTRUCTOR_ADVANCED: {
   319             for (size_t i = 0; i < list->size; i++) {
   320                 cx_list_invoke_advanced_destructor(list, ptr);
   321                 ptr += list->itemsize;
   322             }
   323             break;
   324         }
   325         case CX_DESTRUCTOR_NONE:
   326             break; // nothing
   327     }
   329     memset(arl->data, 0, list->size * list->itemsize);
   330     list->size = 0;
   331 }
   333 static int cx_arl_swap(
   334         struct cx_list_s *list,
   335         size_t i,
   336         size_t j
   337 ) {
   338     if (i >= list->size || j >= list->size) return 1;
   339     cx_array_list *arl = (cx_array_list *) list;
   340     cx_array_swap(arl->data, list->itemsize, i, j);
   341     return 0;
   342 }
   344 static void *cx_arl_at(
   345         struct cx_list_s const *list,
   346         size_t index
   347 ) {
   348     if (index < list->size) {
   349         cx_array_list const *arl = (cx_array_list const *) list;
   350         char *space = arl->data;
   351         return space + index * list->itemsize;
   352     } else {
   353         return NULL;
   354     }
   355 }
   357 static size_t cx_arl_find(
   358         struct cx_list_s const *list,
   359         void const *elem
   360 ) {
   361     assert(list->cmpfunc != NULL);
   362     char *cur = ((cx_array_list const *) list)->data;
   364     for (size_t i = 0; i < list->size; i++) {
   365         if (0 == list->cmpfunc(elem, cur)) {
   366             return i;
   367         }
   368         cur += list->itemsize;
   369     }
   371     return list->size;
   372 }
   374 static void cx_arl_sort(struct cx_list_s *list) {
   375     assert(list->cmpfunc != NULL);
   376     qsort(((cx_array_list *) list)->data,
   377           list->size,
   378           list->itemsize,
   379           list->cmpfunc
   380     );
   381 }
   383 static int cx_arl_compare(
   384         struct cx_list_s const *list,
   385         struct cx_list_s const *other
   386 ) {
   387     assert(list->cmpfunc != NULL);
   388     if (list->size == other->size) {
   389         char const *left = ((cx_array_list const *) list)->data;
   390         char const *right = ((cx_array_list const *) other)->data;
   391         for (size_t i = 0; i < list->size; i++) {
   392             int d = list->cmpfunc(left, right);
   393             if (d != 0) {
   394                 return d;
   395             }
   396             left += list->itemsize;
   397             right += other->itemsize;
   398         }
   399         return 0;
   400     } else {
   401         return list->size < other->size ? -1 : 1;
   402     }
   403 }
   405 static void cx_arl_reverse(struct cx_list_s *list) {
   406     if (list->size < 2) return;
   407     void *data = ((cx_array_list const *) list)->data;
   408     size_t half = list->size / 2;
   409     for (size_t i = 0; i < half; i++) {
   410         cx_array_swap(data, list->itemsize, i, list->size - 1 - i);
   411     }
   412 }
   414 static bool cx_arl_iter_valid(void const *it) {
   415     struct cx_iterator_s const *iter = it;
   416     struct cx_list_s const *list = iter->src_handle;
   417     return iter->index < list->size;
   418 }
   420 static void *cx_arl_iter_current(void const *it) {
   421     struct cx_iterator_s const *iter = it;
   422     return iter->elem_handle;
   423 }
   425 static void cx_arl_iter_next(void *it) {
   426     struct cx_iterator_base_s *itbase = it;
   427     if (itbase->remove) {
   428         struct cx_mut_iterator_s *iter = it;
   429         itbase->remove = false;
   430         cx_arl_remove(iter->src_handle, iter->index);
   431     } else {
   432         struct cx_iterator_s *iter = it;
   433         iter->index++;
   434         iter->elem_handle =
   435                 ((char *) iter->elem_handle)
   436                 + ((struct cx_list_s const *) iter->src_handle)->itemsize;
   437     }
   438 }
   440 static void cx_arl_iter_prev(void *it) {
   441     struct cx_iterator_base_s *itbase = it;
   442     struct cx_mut_iterator_s *iter = it;
   443     cx_array_list *const list = iter->src_handle;
   444     if (itbase->remove) {
   445         itbase->remove = false;
   446         cx_arl_remove(iter->src_handle, iter->index);
   447     }
   448     iter->index--;
   449     if (iter->index < list->base.size) {
   450         iter->elem_handle = ((char *) list->data)
   451                             + iter->index * list->base.itemsize;
   452     }
   453 }
   455 static bool cx_arl_iter_flag_rm(void *it) {
   456     struct cx_iterator_base_s *iter = it;
   457     if (iter->mutating) {
   458         iter->remove = true;
   459         return true;
   460     } else {
   461         return false;
   462     }
   463 }
   465 static struct cx_iterator_s cx_arl_iterator(
   466         struct cx_list_s const *list,
   467         size_t index,
   468         bool backwards
   469 ) {
   470     struct cx_iterator_s iter;
   472     iter.index = index;
   473     iter.src_handle = list;
   474     iter.elem_handle = cx_arl_at(list, index);
   475     iter.base.valid = cx_arl_iter_valid;
   476     iter.base.current = cx_arl_iter_current;
   477     iter.base.next = backwards ? cx_arl_iter_prev : cx_arl_iter_next;
   478     iter.base.flag_removal = cx_arl_iter_flag_rm;
   479     iter.base.remove = false;
   480     iter.base.mutating = false;
   482     return iter;
   483 }
   485 static cx_list_class cx_array_list_class = {
   486         cx_arl_destructor,
   487         cx_arl_insert_element,
   488         cx_arl_insert_array,
   489         cx_arl_insert_iter,
   490         cx_arl_remove,
   491         cx_arl_clear,
   492         cx_arl_swap,
   493         cx_arl_at,
   494         cx_arl_find,
   495         cx_arl_sort,
   496         cx_arl_compare,
   497         cx_arl_reverse,
   498         cx_arl_iterator,
   499 };
   501 CxList *cxArrayListCreate(
   502         CxAllocator const *allocator,
   503         CxListComparator comparator,
   504         size_t item_size,
   505         size_t initial_capacity
   506 ) {
   507     if (allocator == NULL) {
   508         allocator = cxDefaultAllocator;
   509     }
   511     cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
   512     if (list == NULL) return NULL;
   514     list->base.cl = &cx_array_list_class;
   515     list->base.allocator = allocator;
   516     list->base.cmpfunc = comparator;
   517     list->base.capacity = initial_capacity;
   519     if (item_size > 0) {
   520         list->base.itemsize = item_size;
   521     } else {
   522         item_size = sizeof(void*);
   523         cxListStorePointers((CxList *) list);
   524     }
   526     // allocate the array after the real item_size is known
   527     list->data = cxCalloc(allocator, initial_capacity, item_size);
   528     if (list->data == NULL) {
   529         cxFree(allocator, list);
   530         return NULL;
   531     }
   533     // configure the reallocator
   534     list->reallocator.realloc = cx_arl_realloc;
   535     list->reallocator.ptr1 = (void *) allocator;
   537     return (CxList *) list;
   538 }

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