ucx: src/array_list.c@2e6e9d9f2159 (annotated)

src/array_list.c@2e6e9d9f2159 (annotated)

src/array_list.c

Wed, 08 Feb 2023 20:26:09 +0100

author: Mike Becker <universe@uap-core.de>
date: Wed, 08 Feb 2023 20:26:09 +0100
changeset 647: 2e6e9d9f2159
parent 643: 5700ba9154ab
child 654: c9d008861178
permissions: -rw-r--r--

implement swap function for list elements - fixes #218

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include "cx/array_list.h"
 #include <assert.h>
 #include <string.h>
 #include <stdint.h>
 // LOW LEVEL ARRAY LIST FUNCTIONS
 enum cx_array_copy_result cx_array_copy(
         void **target,
         size_t *size,
         size_t *capacity,
         size_t index,
         void const *src,
         size_t elem_size,
         size_t elem_count,
         struct cx_array_reallocator_s *reallocator
 ) {
     // assert pointers
     assert(target != NULL);
     assert(size != NULL);
     assert(src != NULL);
     // determine capacity
     size_t cap = capacity == NULL ? *size : *capacity;
     // check if resize is required
     size_t minsize = index + elem_count;
     size_t newsize = *size < minsize ? minsize : *size;
     bool needrealloc = newsize > cap;
     // reallocate if possible
     if (needrealloc) {
         // a reallocator and a capacity variable must be available
         if (reallocator == NULL || capacity == NULL) {
             return CX_ARRAY_COPY_REALLOC_NOT_SUPPORTED;
         }
         // check, if we need to repair the src pointer
         uintptr_t targetaddr = (uintptr_t) *target;
         uintptr_t srcaddr = (uintptr_t) src;
         bool repairsrc = targetaddr <= srcaddr
                          && srcaddr < targetaddr + cap * elem_size;
         // calculate new capacity (next number divisible by 16)
         cap = newsize - (newsize % 16) + 16;
         assert(cap > newsize);
         // perform reallocation
         void *newmem = reallocator->realloc(
                 *target, cap, elem_size, reallocator
         );
         if (newmem == NULL) {
             return CX_ARRAY_COPY_REALLOC_FAILED;
         }
         // repair src pointer, if necessary
         if (repairsrc) {
             src = ((char *) newmem) + (srcaddr - targetaddr);
         }
         // store new pointer and capacity
         *target = newmem;
         *capacity = cap;
     }
     // determine target pointer
     char *start = *target;
     start += index * elem_size;
     // copy elements and set new size
     memmove(start, src, elem_count * elem_size);
     *size = newsize;
     // return successfully
     return CX_ARRAY_COPY_SUCCESS;
 }
 #ifndef CX_ARRAY_SWAP_SBO_SIZE
 #define CX_ARRAY_SWAP_SBO_SIZE 512
 #endif
 void cx_array_swap(
         void *arr,
         size_t elem_size,
         size_t idx1,
         size_t idx2
 ) {
     // short circuit
     if (idx1 == idx2) return;
     char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE];
     void *tmp;
     // decide if we can use the local buffer
     if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) {
         tmp = malloc(elem_size);
         // we don't want to enforce error handling
         if (tmp == NULL) abort();
     } else {
         tmp = sbo_mem;
     }
     // calculate memory locations
     char *left = arr, *right = arr;
     left += idx1 * elem_size;
     right += idx2 * elem_size;
     // three-way swap
     memcpy(tmp, left, elem_size);
     memcpy(left, right, elem_size);
     memcpy(right, tmp, elem_size);
     // free dynamic memory, if it was needed
     if (tmp != sbo_mem) {
         free(tmp);
     }
 }
 // HIGH LEVEL ARRAY LIST FUNCTIONS
 typedef struct {
     struct cx_list_s base;
     void *data;
     struct cx_array_reallocator_s reallocator;
 } cx_array_list;
 static void *cx_arl_realloc(
         void *array,
         size_t capacity,
         size_t elem_size,
         struct cx_array_reallocator_s *alloc
 ) {
     // retrieve the pointer to the list allocator
     CxAllocator const *al = alloc->ptr1;
     // use the list allocator to reallocate the memory
     return cxRealloc(al, array, capacity * elem_size);
 }
 static void cx_arl_destructor(struct cx_list_s *list) {
     cx_array_list *arl = (cx_array_list *) list;
     cxFree(list->allocator, arl->data);
 }
 static size_t cx_arl_insert_array(
         struct cx_list_s *list,
         size_t index,
         void const *array,
         size_t n
 ) {
     // out of bounds and special case check
     if (index > list->size || n == 0) return 0;
     // get a correctly typed pointer to the list
     cx_array_list *arl = (cx_array_list *) list;
     // do we need to move some elements?
     if (index < list->size) {
         char const *first_to_move = (char const *) arl->data;
         first_to_move += index * list->itemsize;
         size_t elems_to_move = list->size - index;
         size_t start_of_moved = index + n;
         if (CX_ARRAY_COPY_SUCCESS != cx_array_copy(
                 &arl->data,
                 &list->size,
                 &list->capacity,
                 start_of_moved,
                 first_to_move,
                 list->itemsize,
                 elems_to_move,
                 &arl->reallocator
         )) {
             // if moving existing elems is unsuccessful, abort
             return 0;
         }
     }
     // note that if we had to move the elements, the following operation
     // is guaranteed to succeed, because we have the memory already allocated
     // therefore, it is impossible to leave this function with an invalid array
     // place the new elements
     if (CX_ARRAY_COPY_SUCCESS == cx_array_copy(
             &arl->data,
             &list->size,
             &list->capacity,
             index,
             array,
             list->itemsize,
             n,
             &arl->reallocator
     )) {
         return n;
     } else {
         // array list implementation is "all or nothing"
         return 0;
     }
 }
 static int cx_arl_insert_element(
         struct cx_list_s *list,
         size_t index,
         void const *element
 ) {
     return 1 != cx_arl_insert_array(list, index, element, 1);
 }
 static int cx_arl_insert_iter(
         struct cx_mut_iterator_s *iter,
         void const *elem,
         int prepend
 ) {
     struct cx_list_s *list = iter->src_handle;
     if (iter->index < list->size) {
         int result = cx_arl_insert_element(
                 list,
                 iter->index + 1 - prepend,
                 elem
         );
         if (result == 0 && prepend != 0) {
             iter->index++;
             iter->elem_handle = ((char *) iter->elem_handle) + list->itemsize;
         }
         return result;
     } else {
         int result = cx_arl_insert_element(list, list->size, elem);
         iter->index = list->size;
         return result;
     }
 }
 static int cx_arl_remove(
         struct cx_list_s *list,
         size_t index
 ) {
     // out-of-bounds check
     if (index >= list->size) {
         return 1;
     }
     // short-circuit removal of last element
     if (index == list->size - 1) {
         list->size--;
         return 0;
     }
     // just move the elements starting at index to the left
     cx_array_list *arl = (cx_array_list *) list;
     int result = cx_array_copy(
             &arl->data,
             &list->size,
             &list->capacity,
             index,
             ((char *) arl->data) + (index + 1) * list->itemsize,
             list->itemsize,
             list->size - index - 1,
             &arl->reallocator
     );
     if (result == 0) {
         // decrease the size
         list->size--;
     }
     return result;
 }
 static int cx_arl_swap(
         struct cx_list_s *list,
         size_t i,
         size_t j
 ) {
     if (i >= list->size || j >= list->size) return 1;
     cx_array_list *arl = (cx_array_list *) list;
     cx_array_swap(arl->data, list->itemsize, i, j);
     return 0;
 }
 static void *cx_arl_at(
         struct cx_list_s const *list,
         size_t index
 ) {
     if (index < list->size) {
         cx_array_list const *arl = (cx_array_list const *) list;
         char *space = arl->data;
         return space + index * list->itemsize;
     } else {
         return NULL;
     }
 }
 static size_t cx_arl_find(
         struct cx_list_s const *list,
         void const *elem
 ) {
     char *cur = ((cx_array_list const *) list)->data;
     for (size_t i = 0; i < list->size; i++) {
         if (0 == list->cmpfunc(elem, cur)) {
             return i;
         }
         cur += list->itemsize;
     }
     return list->size;
 }
 static void cx_arl_sort(struct cx_list_s *list) {
     qsort(((cx_array_list *) list)->data,
           list->size,
           list->itemsize,
           list->cmpfunc
     );
 }
 static int cx_arl_compare(
         struct cx_list_s const *list,
         struct cx_list_s const *other
 ) {
     if (list->size == other->size) {
         char const *left = ((cx_array_list const *) list)->data;
         char const *right = ((cx_array_list const *) other)->data;
         for (size_t i = 0; i < list->size; i++) {
             int d = list->cmpfunc(left, right);
             if (d != 0) {
                 return d;
             }
             left += list->itemsize;
             right += other->itemsize;
         }
         return 0;
     } else {
         return list->size < other->size ? -1 : 1;
     }
 }
 static void cx_arl_reverse(struct cx_list_s *list) {
     if (list->size < 2) return;
     void *data = ((cx_array_list const *) list)->data;
     size_t half = list->size / 2;
     for (size_t i = 0; i < half; i++) {
         cx_array_swap(data, list->itemsize, i, list->size - 1 - i);
     }
 }
 static bool cx_arl_iter_valid(void const *it) {
     struct cx_iterator_s const *iter = it;
     struct cx_list_s const *list = iter->src_handle;
     return iter->index < list->size;
 }
 static void *cx_arl_iter_current(void const *it) {
     struct cx_iterator_s const *iter = it;
     return iter->elem_handle;
 }
 static void cx_arl_iter_next(void *it) {
     struct cx_iterator_base_s *itbase = it;
     if (itbase->remove) {
         struct cx_mut_iterator_s *iter = it;
         itbase->remove = false;
         cx_arl_remove(iter->src_handle, iter->index);
     } else {
         struct cx_iterator_s *iter = it;
         iter->index++;
         iter->elem_handle =
                 ((char *) iter->elem_handle)
                 + ((struct cx_list_s const *) iter->src_handle)->itemsize;
     }
 }
 static bool cx_arl_iter_flag_rm(void *it) {
     struct cx_iterator_base_s *iter = it;
     if (iter->mutating) {
         iter->remove = true;
         return true;
     } else {
         return false;
     }
 }
 static struct cx_iterator_s cx_arl_iterator(
         struct cx_list_s const *list,
         size_t index
 ) {
     struct cx_iterator_s iter;
     iter.index = index;
     iter.src_handle = list;
     iter.elem_handle = cx_arl_at(list, index);
     iter.base.valid = cx_arl_iter_valid;
     iter.base.current = cx_arl_iter_current;
     iter.base.next = cx_arl_iter_next;
     iter.base.flag_removal = cx_arl_iter_flag_rm;
     iter.base.remove = false;
     iter.base.mutating = false;
     return iter;
 }
 static cx_list_class cx_array_list_class = {
         cx_arl_destructor,
         cx_arl_insert_element,
         cx_arl_insert_array,
         cx_arl_insert_iter,
         cx_arl_remove,
         cx_arl_swap,
         cx_arl_at,
         cx_arl_find,
         cx_arl_sort,
         cx_arl_compare,
         cx_arl_reverse,
         cx_arl_iterator,
 };
 CxList *cxArrayListCreate(
         CxAllocator const *allocator,
         CxListComparator comparator,
         size_t item_size,
         size_t initial_capacity
 ) {
     cx_array_list *list = cxCalloc(allocator, 1, sizeof(cx_array_list));
     if (list == NULL) return NULL;
     list->data = cxCalloc(allocator, initial_capacity, item_size);
     if (list->data == NULL) {
         cxFree(allocator, list);
         return NULL;
     }
     list->base.cl = &cx_array_list_class;
     list->base.allocator = allocator;
     list->base.cmpfunc = comparator;
     list->base.itemsize = item_size;
     list->base.capacity = initial_capacity;
     // configure the reallocator
     list->reallocator.realloc = cx_arl_realloc;
     list->reallocator.ptr1 = (void *) allocator;
     return (CxList *) list;
 }

Mercurial > hg > ucx / annotate

src/array_list.c@2e6e9d9f2159 (annotated)

src/array_list.c