ucx: src/iterator.c@b2bc48c2b251 (annotated)

src/iterator.c@b2bc48c2b251 (annotated)

src/iterator.c

Thu, 23 May 2024 15:05:24 +0200

author: Mike Becker <universe@uap-core.de>
date: Thu, 23 May 2024 15:05:24 +0200
changeset 850: b2bc48c2b251
child 851: adb4e0737c33
permissions: -rw-r--r--

add iterator over raw C arrays - closes #389

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2024 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/iterator.h"
 #include <string.h>
 static bool cx_iter_valid(void const *it) {
     struct cx_iterator_s const *iter = it;
     return iter->index < iter->elem_count;
 }
 static void *cx_iter_current(void const *it) {
     struct cx_iterator_s const *iter = it;
     return iter->elem_handle;
 }
 static void cx_iter_next_fast(void *it) {
     struct cx_iterator_base_s *itbase = it;
     if (itbase->remove) {
         struct cx_mut_iterator_s *iter = it;
         itbase->remove = false;
         iter->elem_count--;
         // only move the last element when we are not currently aiming
         // at the last element already
         if (iter->index < iter->elem_count) {
             void *last = ((char *) iter->src_handle)
                          + iter->elem_count * iter->elem_size;
             memcpy(iter->elem_handle, last, iter->elem_size);
         }
     } else {
         struct cx_iterator_s *iter = it;
         iter->index++;
         iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
     }
 }
 static void cx_iter_next_slow(void *it) {
     struct cx_iterator_base_s *itbase = it;
     if (itbase->remove) {
         struct cx_mut_iterator_s *iter = it;
         itbase->remove = false;
         iter->elem_count--;
         // number of elements to move
         size_t remaining = iter->elem_count - iter->index;
         if (remaining > 0) {
             memmove(
                     iter->elem_handle,
                     ((char *) iter->elem_handle) + iter->elem_size,
                     remaining * iter->elem_size
             );
         }
     } else {
         struct cx_iterator_s *iter = it;
         iter->index++;
         iter->elem_handle = ((char *) iter->elem_handle) + iter->elem_size;
     }
 }
 CxMutIterator cxIterator(
         void *array,
         size_t elem_size,
         size_t elem_count,
         bool remove_keeps_order
 ) {
     CxMutIterator iter;
     iter.index = 0;
     iter.src_handle = array;
     iter.elem_handle = array;
     iter.elem_size = elem_size;
     iter.elem_count = array == NULL ? 0 : elem_count;
     iter.base.valid = cx_iter_valid;
     iter.base.current = cx_iter_current;
     iter.base.next = remove_keeps_order ? cx_iter_next_slow : cx_iter_next_fast;
     iter.base.remove = false;
     iter.base.mutating = true;
     return iter;
 }

Mercurial > hg > ucx / annotate

src/iterator.c@b2bc48c2b251 (annotated)

src/iterator.c