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authorZbigniew Kempczyński <zbigniew.kempczynski@intel.com>2020-01-22 12:05:48 +0100
committerPetri Latvala <petri.latvala@intel.com>2020-01-23 10:49:13 +0200
commit93bc97385ae25b112c34b11748a2b55fbfb0e87b (patch)
tree3016e7e147ef8add2fe890c4b944749cd3f6a0ce /lib/igt_collection.c
parent1e6cb3e75925cf623df04f78430ae9299632ec3f (diff)
lib/igt_collection: Adding combinatorics facility
Dynamic tests gives us new method to create tests depending on the hardware/software capabilities. To check coverage some tests require verification over some set of objects/data. To make life easier with combinatorics this patch introduces igt_collection. Currently it supports iterating over set to get subsets, combinations, variations with and without repetitions. Code has some limitation (set/subset cannot be larger than 16 elements, what is enough for most cases). Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com> Cc: Petri Latvala <petri.latvala@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Acked-by: Petri Latvala <petri.latvala@intel.com>
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+/*
+ * Copyright © 2020 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "igt.h"
+#include "igt_collection.h"
+
+/**
+ * SECTION:igt_collection
+ * @short_description: Generic combinatorics library
+ * @title: Collection
+ * @include: igt.h
+ *
+ * # Generic combinatorics library.
+ *
+ * Supports:
+ * - subsets
+ * - combinations
+ * - variations with repetitions
+ * - variations without repetitions
+ *
+ * ## Subsets
+ *
+ * Let A = { 1, 2, 3 }
+ *
+ * With subset size == 2 we got subsets with number of elements <= subset size:
+ * {}
+ * { 1 }
+ * { 2 }
+ * { 3 }
+ * { 1, 2 }
+ * { 1, 3 }
+ * { 2, 3 }
+ *
+ * ## Combinations
+ *
+ * Let A = { 1, 2, 3 }
+ *
+ * With subset size == 2 we got subsets with number of elements == subset size:
+ * { 1, 2 }
+ * { 1, 3 }
+ * { 2, 3 }
+ *
+ * So it is similar to subset extraction but targeted to single subset size.
+ *
+ * ## Variations with repetitions
+ *
+ * Let A = { 0, 1 }
+ *
+ * With result size == 3 we got result tuples:
+ *
+ * ( 0, 0, 0 )
+ * ( 0, 0, 1 )
+ * ( 0, 1, 0 )
+ * ( 0, 1, 1 )
+ * ( 1, 0, 0 )
+ * ( 1, 0, 1 )
+ * ( 1, 1, 0 )
+ * ( 1, 1, 1 )
+ *
+ * ## Variations without repetitions
+ *
+ * Let A = { 1, 2, 3 }
+ *
+ * With subset size == 2 we got tuples:
+ *
+ * (1, 2)
+ * (1, 3)
+ * (2, 1)
+ * (2, 3)
+ * (3, 1)
+ * (3, 2)
+ *
+ * # Usage examples:
+ *
+ * ## iterator is manually controlled:
+ *
+ * |[<!-- language="C" -->
+ * struct igt_collection *set;
+ * struct igt_collection *subset;
+ * struct igt_collection_iter *iter;
+ *
+ * int i;
+ * set = igt_collection_create(4);
+ * iter = igt_collection_iter_init(set, 2, SUBSET);
+ * //iter = igt_collection_iter_init(set, 2, COMBINATION);
+ * //iter = igt_collection_iter_init(set, 2, VARIATION_R);
+ * //iter = igt_collection_iter_init(set, 2, VARIATION_NR);
+ *
+ * for (i = 0; i < set->size; i++) {
+ * igt_collection_set_value(set, i, i + 1);
+ * igt_collection_set_pointer(set, i, &i + i);
+ * }
+ *
+ * while ((subset = igt_collection_iter_next(iter))) {
+ * // --- do sth with subset ---
+ * // --- subset is a part of iterator, so don't free it! ---
+ * }
+ *
+ * igt_collection_iter_destroy(iter);
+ * igt_collection_destroy(set);
+ * ]|
+ *
+ * ## iterator is created and destroyed inside helper macros:
+ * |[<!-- language="C" -->
+ * struct igt_collection *set;
+ * struct igt_collection *subset, *result;
+ * struct igt_collection_data *data;
+ *
+ * for_each_subset(subset, subset_size, set)
+ * // --- do sth with subset ---
+ *
+ * for_each_combination(subset, subset_size, set)
+ * // --- do sth with subset ---
+ *
+ * for_each_variation_r(result, result_size, set)
+ * // --- do sth with result ---
+ *
+ * for_each_variation_nr(result, result_size, set)
+ * // --- do sth with result ---
+ *
+ * // macro for iteration over set data - for_each_collection_data()
+ * for_each_subset(subset, subset_size, set)
+ * for_each_collection_data(data, subset)
+ * printf("v: %d, p: %p\n", data->value, data->ptr);
+ * ]|
+ */
+
+struct igt_collection_iter {
+ const struct igt_collection *set;
+ enum igt_collection_iter_algo algorithm;
+ bool init;
+ int result_size;
+ struct igt_collection result;
+
+ /* Algorithms state */
+ struct {
+ uint32_t result_bits;
+ int current_result_size;
+ int idxs[IGT_COLLECTION_MAXSIZE];
+ } data;
+};
+
+/**
+ * igt_collection_create
+ * @size: size of the collection, must be greater than 0 and less
+ * than #IGT_COLLECTION_MAXSIZE
+ *
+ * Function creates a collection (set) containing igt_collection_data elements.
+ *
+ * Returns:
+ * pointer to #igt_collection. Asserts on memory allocation failure.
+ */
+struct igt_collection *igt_collection_create(int size)
+{
+ struct igt_collection *set;
+ int i;
+
+ igt_assert(size > 0 && size <= IGT_COLLECTION_MAXSIZE);
+
+ set = calloc(1, sizeof(*set));
+ igt_assert(set);
+
+ set->size = size;
+ for (i = 0; i < size; i++)
+ set->set[i].value = i; /* set to index as default */
+
+ return set;
+}
+
+/**
+ * igt_collection_duplicate
+ * @src: source collection
+ *
+ * Function duplicates collection. Useful to cover multithreading
+ * when different threads need to get it's own copy of the collection
+ * acquired during iteration.
+ *
+ * Returns:
+ * pointer to #igt_collection. Asserts on memory allocation failure.
+ */
+struct igt_collection *
+igt_collection_duplicate(const struct igt_collection *src)
+{
+ struct igt_collection *set = malloc(sizeof(*set));
+
+ igt_assert(set);
+ memcpy(set, src, sizeof(*set));
+
+ return set;
+}
+
+/**
+ * igt_collection_destroy
+ * @set: collection to be freed
+ *
+ * Function frees collection memory.
+ */
+void igt_collection_destroy(struct igt_collection *set)
+{
+ free(set);
+}
+
+/**
+ * igt_collection_set_value
+ * @set: collection
+ * @index: index of value data to be set in the collection
+ * @value: new value
+ *
+ * Assign new value to the collection element at @index.
+ */
+void igt_collection_set_value(struct igt_collection *set, int index, int value)
+{
+ igt_assert(index >= 0 && index < set->size);
+ set->set[index].value = value;
+}
+
+/**
+ * igt_collection_get_value
+ * @set: collection
+ * @index: index of value data to be get from the collection
+ *
+ * Returns: integer value at from the collection element at @index.
+ */
+int igt_collection_get_value(struct igt_collection *set, int index)
+{
+ igt_assert(index >= 0 && index < set->size);
+ return set->set[index].value;
+}
+
+/**
+ * igt_collection_set_pointer
+ * @set: collection
+ * @index: index of pointer data to be set in the collection
+ * @ptr: new pointer
+ */
+void igt_collection_set_pointer(struct igt_collection *set, int index, void *ptr)
+{
+ igt_assert(index >= 0 && index < set->size);
+ set->set[index].ptr = ptr;
+}
+
+/**
+ * igt_collection_get_pointer
+ * @set: collection
+ * @index: index of pointer data to be get from the collection
+ *
+ * Returns: pointer from the collection element at @index.
+ */
+void *igt_collection_get_pointer(struct igt_collection *set, int index)
+{
+ igt_assert(index >= 0 && index < set->size);
+ return set->set[index].ptr;
+}
+
+/**
+ * igt_collection_iter_create
+ * @set: base collection
+ * @result_size: result collection size
+ * @algorithm: method of iterating over base collection
+ *
+ * Function creates iterator which contains result collection changed each time
+ * igt_collection_iter_next() is called. For variations without repetitions
+ * (VARIATION_R) result collection size can be larger than size of
+ * base collection (although still less or equal #IGT_COLLECTION_MAXSIZE).
+ * As result collection is a part of the iterator to be thread-safe
+ * igt_collection_duplicate() must be called to make result collection copy
+ * before passing it to the thread.
+ *
+ * Returns:
+ * pointer to #igt_collection_iter. Asserts on memory allocation failure.
+ */
+struct igt_collection_iter *
+igt_collection_iter_create(const struct igt_collection *set, int result_size,
+ enum igt_collection_iter_algo algorithm)
+{
+ struct igt_collection_iter *iter;
+
+ igt_assert(result_size > 0 && result_size <= IGT_COLLECTION_MAXSIZE);
+ if (algorithm != VARIATION_R)
+ igt_assert(result_size <= set->size);
+
+ iter = calloc(1, sizeof(*iter));
+ igt_assert(iter);
+
+ iter->set = set;
+ iter->result_size = result_size;
+ iter->algorithm = algorithm;
+ iter->init = true;
+
+ return iter;
+}
+
+/**
+ * igt_collection_iter_destroy
+ * @iter: iterator to be freed
+ *
+ * Function frees iterator memory.
+ */
+void igt_collection_iter_destroy(struct igt_collection_iter *iter)
+{
+ free(iter);
+}
+
+static struct igt_collection *
+igt_collection_iter_subsets(struct igt_collection_iter *iter)
+{
+ const struct igt_collection *set = iter->set;
+ struct igt_collection *curr = &iter->result;
+ int i, pos = 0;
+
+ if (iter->init) {
+ iter->init = false;
+ iter->data.result_bits = 0;
+ iter->data.current_result_size = 0;
+ curr->size = 0;
+ } else {
+ iter->data.result_bits++;
+ if (iter->data.result_bits & (1 << iter->set->size)) {
+ iter->data.current_result_size++;
+ iter->data.result_bits = 0;
+ }
+ if (iter->data.current_result_size > iter->result_size)
+ return NULL;
+ }
+
+ while (igt_hweight(iter->data.result_bits) !=
+ iter->data.current_result_size) {
+ iter->data.result_bits++;
+ if (iter->data.result_bits & (1 << iter->set->size)) {
+ iter->data.current_result_size++;
+ iter->data.result_bits = 0;
+ }
+ }
+
+ if (iter->data.current_result_size > iter->result_size)
+ return NULL;
+
+ for (i = 0; i < set->size; i++) {
+ if (!(iter->data.result_bits & (1 << i)))
+ continue;
+ curr->set[pos++] = set->set[i];
+ curr->size = pos;
+ }
+
+ return curr;
+}
+
+static struct igt_collection *
+igt_collection_iter_combination(struct igt_collection_iter *iter)
+{
+ const struct igt_collection *set = iter->set;
+ struct igt_collection *curr = &iter->result;
+ int i, pos = 0;
+
+ if (iter->init) {
+ iter->init = false;
+ iter->data.result_bits = 0;
+ iter->result.size = iter->result_size;
+ } else {
+ iter->data.result_bits++;
+ }
+
+ while (igt_hweight(iter->data.result_bits) != iter->result_size)
+ iter->data.result_bits++;
+
+ if (iter->data.result_bits & (1 << set->size))
+ return NULL;
+
+ for (i = 0; i < set->size; i++) {
+ if (!(iter->data.result_bits & (1 << i)))
+ continue;
+ curr->set[pos++] = set->set[i];
+ curr->size = pos;
+ }
+
+ return curr;
+}
+
+static struct igt_collection *
+igt_collection_iter_variation_r(struct igt_collection_iter *iter)
+{
+ const struct igt_collection *set = iter->set;
+ struct igt_collection *curr = &iter->result;
+ int i;
+
+ if (iter->init) {
+ iter->init = false;
+ iter->result.size = iter->result_size;
+ for (i = 0; i < iter->result_size; i++)
+ iter->data.idxs[i] = 0;
+ }
+
+ if (iter->data.idxs[0] == iter->set->size)
+ return NULL;
+
+ for (i = 0; i < iter->result_size; i++)
+ curr->set[i] = set->set[iter->data.idxs[i]];
+
+ for (i = iter->result_size-1; i >= 0; i--) {
+ if (++iter->data.idxs[i] == iter->set->size && i > 0) {
+ iter->data.idxs[i] %= iter->set->size;
+ } else {
+ break;
+ }
+ }
+
+ return curr;
+}
+
+static struct igt_collection *
+igt_collection_iter_variation_nr(struct igt_collection_iter *iter)
+{
+ const struct igt_collection *set = iter->set;
+ struct igt_collection *curr = &iter->result;
+ bool in_use[IGT_COLLECTION_MAXSIZE];
+ bool skip;
+ int i;
+
+ if (iter->init) {
+ iter->init = false;
+ iter->result.size = iter->result_size;
+ for (i = 0; i < iter->result_size; i++)
+ iter->data.idxs[i] = 0;
+ }
+
+ /*
+ * Simple naive algorithm checking does element index is already
+ * occupied.
+ */
+retry:
+ skip = false;
+
+ if (iter->data.idxs[0] == iter->set->size)
+ return NULL;
+
+ for (i = 0; i < iter->result_size; i++)
+ curr->set[i] = set->set[iter->data.idxs[i]];
+
+ memset(in_use, 0, sizeof(in_use));
+ for (i = 0; i < iter->result_size; i++) {
+ if (in_use[iter->data.idxs[i]]) {
+ skip = true;
+ break;
+ }
+ in_use[iter->data.idxs[i]] = true;
+ }
+
+ for (i = iter->result_size-1; i >= 0; i--) {
+ if (++iter->data.idxs[i] == iter->set->size && i > 0) {
+ iter->data.idxs[i] %= iter->set->size;
+ } else {
+ break;
+ }
+ }
+
+ if (skip)
+ goto retry;
+
+ return curr;
+}
+
+/**
+ * igt_collection_iter_next
+ * @iter: collection iterator
+ *
+ * Function iterates over collection regarding to algorithm selected during
+ * iterator creation returning collection (subset or tuples (for variations)).
+ *
+ * Returns: pointer to the collection (it is a part of the iterator memory
+ * so to be thread-safe it must be duplicated by the caller when
+ * necessary) or NULL when there're no more elements. Iterator is no longer
+ * valid and must be then freed with igt_collection_iter_destroy().
+ */
+struct igt_collection *
+igt_collection_iter_next(struct igt_collection_iter *iter)
+{
+ struct igt_collection *ret_set = NULL;
+
+ switch(iter->algorithm) {
+ case SUBSET:
+ ret_set = igt_collection_iter_subsets(iter);
+ break;
+ case COMBINATION:
+ ret_set = igt_collection_iter_combination(iter);
+ break;
+ case VARIATION_R:
+ ret_set = igt_collection_iter_variation_r(iter);
+ break;
+ case VARIATION_NR:
+ ret_set = igt_collection_iter_variation_nr(iter);
+ break;
+ default:
+ igt_assert_f(false, "Unknown algorithm\n");
+ }
+
+ return ret_set;
+}
+
+/**
+ * igt_collection_iter_next_or_end
+ * @iter: collection iterator
+ *
+ * Function does the same as igt_collection_iter_next() but additionally
+ * checks when the iterator is no longer valid and frees it then.
+ * Useful for for_each_* macros to avoid necessity of manual handling
+ * the iterator.
+ */
+struct igt_collection *
+igt_collection_iter_next_or_end(struct igt_collection_iter *iter)
+{
+ struct igt_collection *ret_set =
+ igt_collection_iter_next(iter);
+
+ if (!ret_set)
+ igt_collection_iter_destroy(iter);
+
+ return ret_set;
+}