1 /* a generic DYNamic ARray implementation. */
3 /* Copyright (c) 2004-2022. The SimGrid Team.
4 * All rights reserved. */
6 /* This program is free software; you can redistribute it and/or modify it
7 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #include "simgrid/Exception.hpp"
14 #include "xbt/string.hpp"
15 #include "xbt/sysdep.h"
16 #include <sys/types.h>
18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_dyn, xbt, "Dynamic arrays");
20 static inline void _sanity_check_dynar(const_xbt_dynar_t dynar)
22 xbt_assert(dynar, "dynar is nullptr");
25 static inline void _sanity_check_idx(int idx)
27 xbt_assert(idx >= 0, "dynar idx(=%d) < 0", idx);
30 static inline void _check_inbound_idx(const_xbt_dynar_t dynar, int idx)
32 xbt_assert(idx >= 0 && idx < static_cast<int>(dynar->used),
33 "dynar is not that long. You asked %d, but it's only %lu long", idx, dynar->used);
36 static inline void _check_populated_dynar(const_xbt_dynar_t dynar)
38 xbt_assert(dynar->used > 0, "dynar %p is empty", dynar);
41 static inline void _xbt_dynar_resize(xbt_dynar_t dynar, unsigned long new_size)
43 if (new_size != dynar->size) {
44 dynar->size = new_size;
45 dynar->data = xbt_realloc(dynar->data, new_size * dynar->elmsize);
49 static inline void _xbt_dynar_expand(xbt_dynar_t dynar, unsigned long nb)
51 const unsigned long old_size = dynar->size;
54 const unsigned long expand = 2 * (old_size + 1);
55 _xbt_dynar_resize(dynar, (nb > expand ? nb : expand));
56 XBT_DEBUG("expand %p from %lu to %lu elements", dynar, old_size, dynar->size);
60 static inline void* _xbt_dynar_elm(const_xbt_dynar_t dynar, unsigned long idx)
62 auto* const data = static_cast<char*>(dynar->data);
63 const unsigned long elmsize = dynar->elmsize;
65 return data + idx * elmsize;
68 static inline void _xbt_dynar_get_elm(void* dst, const_xbt_dynar_t dynar, unsigned long idx)
70 const void* const elm = _xbt_dynar_elm(dynar, idx);
71 memcpy(dst, elm, dynar->elmsize);
75 * Creates a new dynar. If a @c free_f is provided, the elements have to be pointer of pointer. That is to say that
76 * dynars can contain either base types (int, char, double, etc) or pointer of pointers (struct **).
78 * @param elmsize size of each element in the dynar
79 * @param free_f function to call each time we want to get rid of an element (or nullptr if nothing to do).
81 xbt_dynar_t xbt_dynar_new(const unsigned long elmsize, void_f_pvoid_t free_f)
83 auto* dynar = xbt_new0(s_xbt_dynar_t, 1);
87 dynar->elmsize = elmsize;
88 dynar->data = nullptr;
89 dynar->free_f = free_f;
94 /** Destructor of the structure leaving the content unmodified. Ie, the array is freed, but the content is not touched
95 * (the @a free_f function is not used).
97 * @param dynar poor victim
99 void xbt_dynar_free_container(xbt_dynar_t* dynar)
101 if (dynar && *dynar) {
102 xbt_dynar_t d = *dynar;
109 /** @brief Frees the content and set the size to 0 */
110 void xbt_dynar_reset(xbt_dynar_t dynar)
112 _sanity_check_dynar(dynar);
114 XBT_CDEBUG(xbt_dyn, "Reset the dynar %p", (void *) dynar);
116 xbt_dynar_map(dynar, dynar->free_f);
122 * Shrinks (reduces) the dynar by removing empty slots in the internal storage to save memory.
123 * If @c empty_slots_wanted is not zero, this operation preserves that amount of empty slot, for fast future additions.
124 * Note that if @c empty_slots_wanted is large enough, the internal array is expanded instead of shrunk.
126 * @param dynar a dynar
127 * @param empty_slots_wanted number of empty slots elements that can be inserted the internal storage without resizing it
129 void xbt_dynar_shrink(xbt_dynar_t dynar, int empty_slots_wanted)
131 _xbt_dynar_resize(dynar, dynar->used + empty_slots_wanted);
134 /** @brief Destructor: kilkil a dynar and its content. */
135 void xbt_dynar_free(xbt_dynar_t* dynar)
137 if (dynar && *dynar) {
138 xbt_dynar_reset(*dynar);
139 xbt_dynar_free_container(dynar);
143 /** @brief Count of dynar's elements */
144 unsigned long xbt_dynar_length(const_xbt_dynar_t dynar)
146 return (dynar ? dynar->used : 0UL);
149 /**@brief check if a dynar is empty */
150 int xbt_dynar_is_empty(const_xbt_dynar_t dynar)
152 return (xbt_dynar_length(dynar) == 0);
155 /** @brief Retrieve a copy of the Nth element of a dynar.
157 * @param dynar information dealer
158 * @param idx index of the slot we want to retrieve
159 * @param[out] dst where to put the result to.
161 void xbt_dynar_get_cpy(const_xbt_dynar_t dynar, unsigned long idx, void* dst)
163 _sanity_check_dynar(dynar);
164 _check_inbound_idx(dynar, idx);
166 _xbt_dynar_get_elm(dst, dynar, idx);
169 /** @brief Retrieve a pointer to the Nth element of a dynar.
171 * Note that the returned value is the actual content of the dynar.
172 * Make a copy before fooling with it.
174 void* xbt_dynar_get_ptr(const_xbt_dynar_t dynar, unsigned long idx)
177 _sanity_check_dynar(dynar);
178 _check_inbound_idx(dynar, idx);
180 res = _xbt_dynar_elm(dynar, idx);
184 void* xbt_dynar_set_at_ptr(const xbt_dynar_t dynar, unsigned long idx)
186 _sanity_check_dynar(dynar);
188 if (idx >= dynar->used) {
189 _xbt_dynar_expand(dynar, idx + 1);
190 if (idx > dynar->used) {
191 memset(_xbt_dynar_elm(dynar, dynar->used), 0, (idx - dynar->used) * dynar->elmsize);
193 dynar->used = idx + 1;
195 return _xbt_dynar_elm(dynar, idx);
198 /** @brief Make room for a new element, and return a pointer to it
200 * You can then use regular affectation to set its value instead of relying on the slow memcpy. This is what
201 * xbt_dynar_insert_at_as() does.
203 void* xbt_dynar_insert_at_ptr(xbt_dynar_t dynar, int idx)
206 unsigned long old_used;
207 unsigned long new_used;
210 _sanity_check_dynar(dynar);
211 _sanity_check_idx(idx);
213 old_used = dynar->used;
214 new_used = old_used + 1;
216 _xbt_dynar_expand(dynar, new_used);
218 nb_shift = old_used - idx;
221 memmove(_xbt_dynar_elm(dynar, idx + 1), _xbt_dynar_elm(dynar, idx), nb_shift * dynar->elmsize);
224 dynar->used = new_used;
225 res = _xbt_dynar_elm(dynar, idx);
229 /** @brief Set the Nth dynar's element, expanding the dynar and sliding the previous values to the right
231 * Set the Nth element of a dynar, expanding the dynar if needed, and moving the previously existing value and all
232 * subsequent ones to one position right in the dynar.
234 void xbt_dynar_insert_at(xbt_dynar_t dynar, int idx, const void* src)
236 /* checks done in xbt_dynar_insert_at_ptr */
237 memcpy(xbt_dynar_insert_at_ptr(dynar, idx), src, dynar->elmsize);
240 /** @brief Remove the Nth element, sliding other values to the left
242 * Get the Nth element of a dynar, removing it from the dynar and moving all subsequent values to one position left in
245 * If the object argument of this function is a non-null pointer, the removed element is copied to this address. If not,
246 * the element is freed using the free_f function passed at dynar creation.
248 void xbt_dynar_remove_at(xbt_dynar_t dynar, int idx, void* object)
250 _sanity_check_dynar(dynar);
251 _check_inbound_idx(dynar, idx);
254 _xbt_dynar_get_elm(object, dynar, idx);
255 } else if (dynar->free_f) {
256 dynar->free_f(_xbt_dynar_elm(dynar, idx));
259 unsigned long nb_shift = dynar->used - 1 - idx;
262 unsigned long offset = nb_shift * dynar->elmsize;
263 memmove(_xbt_dynar_elm(dynar, idx), _xbt_dynar_elm(dynar, idx + 1), offset);
269 /** @brief Returns a boolean indicating whether the element is part of the dynar
271 * Beware that if your dynar contains pointed values (such as strings) instead of scalar, this function is probably not
272 * what you want. It would compare the pointer values, not the pointed elements.
274 int xbt_dynar_member(const_xbt_dynar_t dynar, const void* elem)
276 for (unsigned long it = 0; it < dynar->used; it++)
277 if (not memcmp(_xbt_dynar_elm(dynar, it), elem, dynar->elmsize)) {
284 /** @brief Make room at the end of the dynar for a new element, and return a pointer to it.
286 * You can then use regular affectation to set its value instead of relying on the slow memcpy. This is what
287 * xbt_dynar_push_as() does.
289 void* xbt_dynar_push_ptr(xbt_dynar_t dynar)
291 return xbt_dynar_insert_at_ptr(dynar, dynar->used);
294 /** @brief Add an element at the end of the dynar */
295 void xbt_dynar_push(xbt_dynar_t dynar, const void* src)
297 /* checks done in xbt_dynar_insert_at_ptr */
298 memcpy(xbt_dynar_insert_at_ptr(dynar, dynar->used), src, dynar->elmsize);
301 /** @brief Mark the last dynar's element as unused and return a pointer to it.
303 * You can then use regular affectation to set its value instead of relying on the slow memcpy. This is what
304 * xbt_dynar_pop_as() does.
306 void* xbt_dynar_pop_ptr(xbt_dynar_t dynar)
308 _check_populated_dynar(dynar);
309 XBT_CDEBUG(xbt_dyn, "Pop %p", (void *) dynar);
311 return _xbt_dynar_elm(dynar, dynar->used);
314 /** @brief Get and remove the last element of the dynar */
315 void xbt_dynar_pop(xbt_dynar_t dynar, void* dst)
317 /* sanity checks done by remove_at */
318 XBT_CDEBUG(xbt_dyn, "Pop %p", (void *) dynar);
319 xbt_dynar_remove_at(dynar, dynar->used - 1, dst);
322 /** @brief Add an element at the beginning of the dynar.
324 * This is less efficient than xbt_dynar_push()
326 void xbt_dynar_unshift(xbt_dynar_t dynar, const void* src)
328 /* sanity checks done by insert_at */
329 xbt_dynar_insert_at(dynar, 0, src);
332 /** @brief Get and remove the first element of the dynar.
334 * This is less efficient than xbt_dynar_pop()
336 void xbt_dynar_shift(xbt_dynar_t dynar, void* dst)
338 /* sanity checks done by remove_at */
339 xbt_dynar_remove_at(dynar, 0, dst);
342 /** @brief Apply a function to each member of a dynar
344 * The mapped function may change the value of the element itself, but should not mess with the structure of the dynar.
346 void xbt_dynar_map(const_xbt_dynar_t dynar, void_f_pvoid_t op)
348 auto* const data = static_cast<char*>(dynar->data);
349 const unsigned long elmsize = dynar->elmsize;
350 const unsigned long used = dynar->used;
352 _sanity_check_dynar(dynar);
354 for (unsigned long i = 0; i < used; i++) {
355 char* elm = data + i * elmsize;
360 /** @brief Sorts a dynar according to the function <tt>compar_fn</tt>
362 * This function simply apply the classical qsort(3) function to the data stored in the dynar.
363 * You should thus refer to the libc documentation, or to some online tutorial on how to write
364 * a comparison function. Here is a quick example if you have integers in your dynar:
367 int cmpfunc (const void * a, const void * b) {
374 * And now, a function to sort a dynar of MSG hosts depending on their speed:
376 int cmpfunc(const MSG_host_t a, const MSG_host_t b) {
377 MSG_host_t hostA = *(MSG_host_t*)a;
378 MSG_host_t hostB = *(MSG_host_t*)b;
379 return MSG_host_get_speed(hostA) - MSG_host_get_speed(hostB);
383 * @param dynar the dynar to sort
384 * @param compar_fn comparison function of type (int (compar_fn*) (const void*) (const void*)).
386 void xbt_dynar_sort(const_xbt_dynar_t dynar, int_f_cpvoid_cpvoid_t compar_fn)
388 if (dynar->data != nullptr)
389 qsort(dynar->data, dynar->used, dynar->elmsize, compar_fn);