ucx: src/array_list.c@55cc3b373c5e

     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>

    32 #include <stdint.h>

    34 // LOW LEVEL ARRAY LIST FUNCTIONS

    36 enum cx_array_copy_result cx_array_copy(

    37         void **target,

    38         size_t *size,

    39         size_t *capacity,

    40         size_t index,

    41         void const *src,

    42         size_t elem_size,

    43         size_t elem_count,

    44         struct cx_array_reallocator_s *reallocator

    45 ) {

    46     // assert pointers

    47     assert(target != NULL);

    48     assert(size != NULL);

    49     assert(src != NULL);

    51     // determine capacity

    52     size_t cap = capacity == NULL ? *size : *capacity;

    54     // check if resize is required

    55     size_t minsize = index + elem_count;

    56     size_t newsize = *size < minsize ? minsize : *size;

    57     bool needrealloc = newsize > cap;

    59     // reallocate if possible

    60     if (needrealloc) {

    61         // a reallocator and a capacity variable must be available

    62         if (reallocator == NULL || capacity == NULL) {

    63             return CX_ARRAY_COPY_REALLOC_NOT_SUPPORTED;

    64         }

    66         // check, if we need to repair the src pointer

    67         uintptr_t targetaddr = (uintptr_t) *target;

    68         uintptr_t srcaddr = (uintptr_t) src;

    69         bool repairsrc = targetaddr <= srcaddr

    70                          && srcaddr < targetaddr + cap * elem_size;

    72         // calculate new capacity (next number divisible by 16)

    73         cap = newsize - (newsize % 16) + 16;

    74         assert(cap > newsize);

    76         // perform reallocation

    77         void *newmem = reallocator->realloc(

    78                 *target, cap, elem_size, reallocator

    79         );

    80         if (newmem == NULL) {

    81             return CX_ARRAY_COPY_REALLOC_FAILED;

    82         }

    84         // repair src pointer, if necessary

    85         if (repairsrc) {

    86             src = ((char *) newmem) + (srcaddr - targetaddr);

    87         }

    89         // store new pointer and capacity

    90         *target = newmem;

    91         *capacity = cap;

    92     }

    94     // determine target pointer

    95     char *start = *target;

    96     start += index * elem_size;

    98     // copy elements and set new size

    99     memmove(start, src, elem_count * elem_size);

   100     *size = newsize;

   102     // return successfully

   103     return CX_ARRAY_COPY_SUCCESS;

   104 }

   106 #define CX_ARRAY_SWAP_SBO_SIZE 512

   108 void cx_array_swap(

   109         void *arr,

   110         size_t elem_size,

   111         size_t idx1,

   112         size_t idx2

   113 ) {

   114     // short circuit

   115     if (idx1 == idx2) return;

   117     char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];

   118     void *tmp;

   120     // decide if we can use the local buffer

   121     if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {

   122         tmp = malloc(elem_size);

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

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

   125     } else {

   126         tmp = sbo_mem;

   127     }

   129     // calculate memory locations

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

   131     left += idx1 * elem_size;

   132     right += idx2 * elem_size;

   134     // three-way swap

   135     memcpy(tmp, left, elem_size);

   136     memcpy(left, right, elem_size);

   137     memcpy(right, tmp, elem_size);

   139     // free dynamic memory, if it was needed

   140     if (tmp != sbo_mem) {

   141         free(tmp);

   142     }

   143 }

   145 // HIGH LEVEL ARRAY LIST FUNCTIONS

   147 typedef struct {

   148     struct cx_list_s base;

   149     void *data;

   150     struct cx_array_reallocator_s reallocator;

   151 } cx_array_list;

   153 static void *cx_arl_realloc(

   154         void *array,

   155         size_t capacity,

   156         size_t elem_size,

   157         struct cx_array_reallocator_s *alloc

   158 ) {

   159     // retrieve the pointer to the list allocator

   160     CxAllocator const *al = alloc->ptr1;

   162     // use the list allocator to reallocate the memory

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

   164 }

   166 static void cx_arl_destructor(struct cx_list_s *list) {

   167     cx_array_list *arl = (cx_array_list *) list;

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

   169 }

   171 static size_t cx_arl_insert_array(

   172         struct cx_list_s *list,

   173         size_t index,

   174         void const *array,

   175         size_t n

   176 ) {

   177     // out of bounds and special case check

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

   180     // get a correctly typed pointer to the list

   181     cx_array_list *arl = (cx_array_list *) list;

   183     // do we need to move some elements?

   184     if (index < list->size) {

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

   186         first_to_move += index * list->itemsize;

   187         size_t elems_to_move = list->size - index;

   188         size_t start_of_moved = index + n;

   190         if (CX_ARRAY_COPY_SUCCESS != cx_array_copy(

   191                 &arl->data,

   192                 &list->size,

   193                 &list->capacity,

   194                 start_of_moved,

   195                 first_to_move,

   196                 list->itemsize,

   197                 elems_to_move,

   198                 &arl->reallocator

   199         )) {

   200             // if moving existing elems is unsuccessful, abort

   201             return 0;

   202         }

   203     }

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

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

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

   209     // place the new elements

   210     if (CX_ARRAY_COPY_SUCCESS == cx_array_copy(

   211             &arl->data,

   212             &list->size,

   213             &list->capacity,

   214             index,

   215             array,

   216             list->itemsize,

   217             n,

   218             &arl->reallocator

   219     )) {

   220         return n;

   221     } else {

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

   223         return 0;

   224     }

   225 }

   227 static int cx_arl_insert_iter(

   228         struct cx_mut_iterator_s *iter,

   229         void const *elem,

   230         int prepend

   231 ) {

   232     struct cx_list_s *list = iter->src_handle;

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

   234         int result = 1 != cx_arl_insert_array(

   235                 list,

   236                 iter->index + 1 - prepend,

   237                 elem,

   238                 1

   239         );

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

   241             iter->index++;

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

   243         }

   244         return result;

   245     } else {

   246         int result = 1 != cx_arl_insert_array(list, list->size, elem, 1);

   247         iter->index = list->size;

   248         return result;

   249     }

   250 }

   252 static int cx_arl_remove(

   253         struct cx_list_s *list,

   254         size_t index

   255 ) {

   256     // out-of-bounds check

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

   258         return 1;

   259     }

   261     // short-circuit removal of last element

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

   263         list->size--;

   264         return 0;

   265     }

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

   268     cx_array_list *arl = (cx_array_list *) list;

   269     int result = cx_array_copy(

   270             &arl->data,

   271             &list->size,

   272             &list->capacity,

   273             index,

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

   275             list->itemsize,

   276             list->size - index - 1,

   277             &arl->reallocator

   278     );

   279     if (result == 0) {

   280         // decrease the size

   281         list->size--;

   282     }

   283     return result;

   284 }

   286 static void *cx_arl_at(

   287         struct cx_list_s const *list,

   288         size_t index

   289 ) {

   290     if (index < list->size) {

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

   292         char *space = arl->data;

   293         return space + index * list->itemsize;

   294     } else {

   295         return NULL;

   296     }

   297 }

   299 static size_t cx_arl_find(

   300         struct cx_list_s const *list,

   301         void const *elem

   302 ) {

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

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

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

   307             return i;

   308         }

   309         cur += list->itemsize;

   310     }

   312     return list->size;

   313 }

   315 static void cx_arl_sort(struct cx_list_s *list) {

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

   317           list->size,

   318           list->itemsize,

   319           list->cmpfunc

   320     );

   321 }

   323 static int cx_arl_compare(

   324         struct cx_list_s const *list,

   325         struct cx_list_s const *other

   326 ) {

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

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

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

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

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

   332             if (d != 0) {

   333                 return d;

   334             }

   335             left += list->itemsize;

   336             right += other->itemsize;

   337         }

   338         return 0;

   339     } else {

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

   341     }

   342 }

   344 static void cx_arl_reverse(struct cx_list_s *list) {

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

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

   347     size_t half = list->size / 2;

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

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

   350     }

   351 }

   353 static bool cx_arl_iter_valid(void const *it) {

   354     struct cx_iterator_s const *iter = it;

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

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

   357 }

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

   360     struct cx_iterator_s const *iter = it;

   361     return iter->elem_handle;

   362 }

   364 static void cx_arl_iter_next(void *it) {

   365     struct cx_iterator_base_s *itbase = it;

   366     if (itbase->remove) {

   367         struct cx_mut_iterator_s *iter = it;

   368         itbase->remove = false;

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

   370     } else {

   371         struct cx_iterator_s *iter = it;

   372         iter->index++;

   373         iter->elem_handle =

   374                 ((char *) iter->elem_handle)

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

   376     }

   377 }

   379 static bool cx_arl_iter_flag_rm(void *it) {

   380     struct cx_iterator_base_s *iter = it;

   381     if (iter->mutating) {

   382         iter->remove = true;

   383         return true;

   384     } else {

   385         return false;

   386     }

   387 }

   389 static struct cx_iterator_s cx_arl_iterator(

   390         struct cx_list_s const *list,

   391         size_t index

   392 ) {

   393     struct cx_iterator_s iter;

   395     iter.index = index;

   396     iter.src_handle = list;

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

   398     iter.base.valid = cx_arl_iter_valid;

   399     iter.base.current = cx_arl_iter_current;

   400     iter.base.next = cx_arl_iter_next;

   401     iter.base.flag_removal = cx_arl_iter_flag_rm;

   402     iter.base.remove = false;

   403     iter.base.mutating = false;

   405     return iter;

   406 }

   408 static cx_list_class cx_array_list_class = {

   409         cx_arl_destructor,

   410         cx_arl_insert_array,

   411         cx_arl_insert_iter,

   412         cx_arl_remove,

   413         cx_arl_at,

   414         cx_arl_find,

   415         cx_arl_sort,

   416         cx_arl_compare,

   417         cx_arl_reverse,

   418         cx_arl_iterator,

   419 };

   421 CxList *cxArrayListCreate(

   422         CxAllocator const *allocator,

   423         CxListComparator comparator,

   424         size_t item_size,

   425         size_t initial_capacity

   426 ) {

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

   428     if (list == NULL) return NULL;

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

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

   432         cxFree(allocator, list);

   433         return NULL;

   434     }

   436     list->base.cl = &cx_array_list_class;

   437     list->base.allocator = allocator;

   438     list->base.cmpfunc = comparator;

   439     list->base.itemsize = item_size;

   440     list->base.capacity = initial_capacity;

   442     // configure the reallocator

   443     list->reallocator.realloc = cx_arl_realloc;

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

   446     return (CxList *) list;

   447 }

Mercurial > hg > ucx / file revision

src/array_list.c@55cc3b373c5e

src/array_list.c