ucx: src/array_list.c@77021e06b1a8

     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     // short circuit

   116     if (idx1 == idx2) return;

   118     char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];

   119     void *tmp;

   121     // decide if we can use the local buffer

   122     if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {

   123         tmp = malloc(elem_size);

   124         // we don't want to enforce error handling

   125         if (tmp == NULL) abort();

   126     } else {

   127         tmp = sbo_mem;

   128     }

   130     // calculate memory locations

   131     char *left = arr, *right = arr;

   132     left += idx1 * elem_size;

   133     right += idx2 * elem_size;

   135     // three-way swap

   136     memcpy(tmp, left, elem_size);

   137     memcpy(left, right, elem_size);

   138     memcpy(right, tmp, elem_size);

   140     // free dynamic memory, if it was needed

   141     if (tmp != sbo_mem) {

   142         free(tmp);

   143     }

   144 }

   146 // HIGH LEVEL ARRAY LIST FUNCTIONS

   148 typedef struct {

   149     struct cx_list_s base;

   150     void *data;

   151     struct cx_array_reallocator_s reallocator;

   152 } cx_array_list;

   154 static void *cx_arl_realloc(

   155         void *array,

   156         size_t capacity,

   157         size_t elem_size,

   158         struct cx_array_reallocator_s *alloc

   159 ) {

   160     // retrieve the pointer to the list allocator

   161     CxAllocator const *al = alloc->ptr1;

   163     // use the list allocator to reallocate the memory

   164     return cxRealloc(al, array, capacity * elem_size);

   165 }

   167 static void cx_arl_destructor(struct cx_list_s *list) {

   168     cx_array_list *arl = (cx_array_list *) list;

   169     cxFree(list->allocator, arl->data);

   170 }

   172 static size_t cx_arl_insert_array(

   173         struct cx_list_s *list,

   174         size_t index,

   175         void const *array,

   176         size_t n

   177 ) {

   178     // out of bounds and special case check

   179     if (index > list->size || n == 0) return 0;

   181     // get a correctly typed pointer to the list

   182     cx_array_list *arl = (cx_array_list *) list;

   184     // do we need to move some elements?

   185     if (index < list->size) {

   186         char const *first_to_move = (char const *) arl->data;

   187         first_to_move += index * list->itemsize;

   188         size_t elems_to_move = list->size - index;

   189         size_t start_of_moved = index + n;

   191         if (CX_ARRAY_COPY_SUCCESS != cx_array_copy(

   192                 &arl->data,

   193                 &list->size,

   194                 &list->capacity,

   195                 start_of_moved,

   196                 first_to_move,

   197                 list->itemsize,

   198                 elems_to_move,

   199                 &arl->reallocator

   200         )) {

   201             // if moving existing elems is unsuccessful, abort

   202             return 0;

   203         }

   204     }

   206     // note that if we had to move the elements, the following operation

   207     // is guaranteed to succeed, because we have the memory already allocated

   208     // therefore, it is impossible to leave this function with an invalid array

   210     // place the new elements

   211     if (CX_ARRAY_COPY_SUCCESS == cx_array_copy(

   212             &arl->data,

   213             &list->size,

   214             &list->capacity,

   215             index,

   216             array,

   217             list->itemsize,

   218             n,

   219             &arl->reallocator

   220     )) {

   221         return n;

   222     } else {

   223         // array list implementation is "all or nothing"

   224         return 0;

   225     }

   226 }

   228 static int cx_arl_insert_element(

   229         struct cx_list_s *list,

   230         size_t index,

   231         void const *element

   232 ) {

   233     return 1 != cx_arl_insert_array(list, index, element, 1);

   234 }

   236 static int cx_arl_insert_iter(

   237         struct cx_mut_iterator_s *iter,

   238         void const *elem,

   239         int prepend

   240 ) {

   241     struct cx_list_s *list = iter->src_handle;

   242     if (iter->index < list->size) {

   243         int result = cx_arl_insert_element(

   244                 list,

   245                 iter->index + 1 - prepend,

   246                 elem

   247         );

   248         if (result == 0 && prepend != 0) {

   249             iter->index++;

   250             iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;

   251         }

   252         return result;

   253     } else {

   254         int result = cx_arl_insert_element(list, list->size, elem);

   255         iter->index = list->size;

   256         return result;

   257     }

   258 }

   260 static int cx_arl_remove(

   261         struct cx_list_s *list,

   262         size_t index

   263 ) {

   264     // out-of-bounds check

   265     if (index >= list->size) {

   266         return 1;

   267     }

   269     // short-circuit removal of last element

   270     if (index == list->size - 1) {

   271         list->size--;

   272         return 0;

   273     }

   275     // just move the elements starting at index to the left

   276     cx_array_list *arl = (cx_array_list *) list;

   277     int result = cx_array_copy(

   278             &arl->data,

   279             &list->size,

   280             &list->capacity,

   281             index,

   282             ((char *) arl->data) + (index + 1) * list->itemsize,

   283             list->itemsize,

   284             list->size - index - 1,

   285             &arl->reallocator

   286     );

   287     if (result == 0) {

   288         // decrease the size

   289         list->size--;

   290     }

   291     return result;

   292 }

   294 static void *cx_arl_at(

   295         struct cx_list_s const *list,

   296         size_t index

   297 ) {

   298     if (index < list->size) {

   299         cx_array_list const *arl = (cx_array_list const *) list;

   300         char *space = arl->data;

   301         return space + index * list->itemsize;

   302     } else {

   303         return NULL;

   304     }

   305 }

   307 static size_t cx_arl_find(

   308         struct cx_list_s const *list,

   309         void const *elem

   310 ) {

   311     char *cur = ((cx_array_list const *) list)->data;

   313     for (size_t i = 0; i < list->size; i++) {

   314         if (0 == list->cmpfunc(elem, cur)) {

   315             return i;

   316         }

   317         cur += list->itemsize;

   318     }

   320     return list->size;

   321 }

   323 static void cx_arl_sort(struct cx_list_s *list) {

   324     qsort(((cx_array_list *) list)->data,

   325           list->size,

   326           list->itemsize,

   327           list->cmpfunc

   328     );

   329 }

   331 static int cx_arl_compare(

   332         struct cx_list_s const *list,

   333         struct cx_list_s const *other

   334 ) {

   335     if (list->size == other->size) {

   336         char const *left = ((cx_array_list const *) list)->data;

   337         char const *right = ((cx_array_list const *) other)->data;

   338         for (size_t i = 0; i < list->size; i++) {

   339             int d = list->cmpfunc(left, right);

   340             if (d != 0) {

   341                 return d;

   342             }

   343             left += list->itemsize;

   344             right += other->itemsize;

   345         }

   346         return 0;

   347     } else {

   348         return list->size < other->size ? -1 : 1;

   349     }

   350 }

   352 static void cx_arl_reverse(struct cx_list_s *list) {

   353     if (list->size < 2) return;

   354     void *data = ((cx_array_list const *) list)->data;

   355     size_t half = list->size / 2;

   356     for (size_t i = 0; i < half; i++) {

   357         cx_array_swap(data, list->itemsize, i, list->size - 1 - i);

   358     }

   359 }

   361 static bool cx_arl_iter_valid(void const *it) {

   362     struct cx_iterator_s const *iter = it;

   363     struct cx_list_s const *list = iter->src_handle;

   364     return iter->index < list->size;

   365 }

   367 static void *cx_arl_iter_current(void const *it) {

   368     struct cx_iterator_s const *iter = it;

   369     return iter->elem_handle;

   370 }

   372 static void cx_arl_iter_next(void *it) {

   373     struct cx_iterator_base_s *itbase = it;

   374     if (itbase->remove) {

   375         struct cx_mut_iterator_s *iter = it;

   376         itbase->remove = false;

   377         cx_arl_remove(iter->src_handle, iter->index);

   378     } else {

   379         struct cx_iterator_s *iter = it;

   380         iter->index++;

   381         iter->elem_handle =

   382                 ((char *) iter->elem_handle)

   383                 + ((struct cx_list_s const *) iter->src_handle)->itemsize;

   384     }

   385 }

   387 static bool cx_arl_iter_flag_rm(void *it) {

   388     struct cx_iterator_base_s *iter = it;

   389     if (iter->mutating) {

   390         iter->remove = true;

   391         return true;

   392     } else {

   393         return false;

   394     }

   395 }

   397 static struct cx_iterator_s cx_arl_iterator(

   398         struct cx_list_s const *list,

   399         size_t index

   400 ) {

   401     struct cx_iterator_s iter;

   403     iter.index = index;

   404     iter.src_handle = list;

   405     iter.elem_handle = cx_arl_at(list, index);

   406     iter.base.valid = cx_arl_iter_valid;

   407     iter.base.current = cx_arl_iter_current;

   408     iter.base.next = cx_arl_iter_next;

   409     iter.base.flag_removal = cx_arl_iter_flag_rm;

   410     iter.base.remove = false;

   411     iter.base.mutating = false;

   413     return iter;

   414 }

   416 static cx_list_class cx_array_list_class = {

   417         cx_arl_destructor,

   418         cx_arl_insert_element,

   419         cx_arl_insert_array,

   420         cx_arl_insert_iter,

   421         cx_arl_remove,

   422         cx_arl_at,

   423         cx_arl_find,

   424         cx_arl_sort,

   425         cx_arl_compare,

   426         cx_arl_reverse,

   427         cx_arl_iterator,

   428 };

   430 CxList *cxArrayListCreate(

   431         CxAllocator const *allocator,

   432         CxListComparator comparator,

   433         size_t item_size,

   434         size_t initial_capacity

   435 ) {

   436     cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));

   437     if (list == NULL) return NULL;

   439     list->data = cxCalloc(allocator, initial_capacity, item_size);

   440     if (list->data == NULL) {

   441         cxFree(allocator, list);

   442         return NULL;

   443     }

   445     list->base.cl = &cx_array_list_class;

   446     list->base.allocator = allocator;

   447     list->base.cmpfunc = comparator;

   448     list->base.itemsize = item_size;

   449     list->base.capacity = initial_capacity;

   451     // configure the reallocator

   452     list->reallocator.realloc = cx_arl_realloc;

   453     list->reallocator.ptr1 = (void *) allocator;

   455     return (CxList *) list;

   456 }

Mercurial > hg > ucx / file revision

src/array_list.c@77021e06b1a8

src/array_list.c