+/* PSPP - computes sample statistics.
+ Copyright (C) 2007 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ 02110-1301, USA. */
+
+/* This is a test program for the bt_* routines defined in bt.c.
+ This test program aims to be as comprehensive as possible.
+ "gcov -b" should report 100% coverage of lines and branches in
+ bt.c. "valgrind --leak-check=yes --show-reachable=yes" should
+ give a clean report. */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <libpspp/bt.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <libpspp/compiler.h>
+\f
+/* Currently running test. */
+static const char *test_name;
+
+/* Exit with a failure code.
+ (Place a breakpoint on this function while debugging.) */
+static void
+check_die (void)
+{
+ exit (EXIT_FAILURE);
+}
+
+/* If OK is not true, prints a message about failure on the
+ current source file and the given LINE and terminates. */
+static void
+check_func (bool ok, int line)
+{
+ if (!ok)
+ {
+ printf ("Check failed in %s test at %s, line %d\n",
+ test_name, __FILE__, line);
+ check_die ();
+ }
+}
+
+/* Verifies that EXPR evaluates to true.
+ If not, prints a message citing the calling line number and
+ terminates. */
+#define check(EXPR) check_func ((EXPR), __LINE__)
+
+/* Prints a message about memory exhaustion and exits with a
+ failure code. */
+static void
+xalloc_die (void)
+{
+ printf ("virtual memory exhausted\n");
+ exit (EXIT_FAILURE);
+}
+
+/* Allocates and returns N bytes of memory. */
+static void *
+xmalloc (size_t n)
+{
+ if (n != 0)
+ {
+ void *p = malloc (n);
+ if (p == NULL)
+ xalloc_die ();
+
+ return p;
+ }
+ else
+ return NULL;
+}
+
+static void *
+xmemdup (const void *p, size_t n)
+{
+ void *q = xmalloc (n);
+ memcpy (q, p, n);
+ return q;
+}
+
+/* Allocates and returns N * M bytes of memory. */
+static void *
+xnmalloc (size_t n, size_t m)
+{
+ if ((size_t) -1 / m <= n)
+ xalloc_die ();
+ return xmalloc (n * m);
+}
+\f
+/* Node type and support routines. */
+
+/* Test data element. */
+struct element
+ {
+ struct bt_node node; /* Embedded binary tree element. */
+ int data; /* Primary value. */
+ };
+
+static int aux_data;
+
+/* Returns the `struct element' that NODE is embedded within. */
+static struct element *
+bt_node_to_element (const struct bt_node *node)
+{
+ return bt_data (node, struct element, node);
+}
+
+/* Compares the `x' values in A and B and returns a strcmp-type
+ return value. Verifies that AUX points to aux_data. */
+static int
+compare_elements (const struct bt_node *a_, const struct bt_node *b_,
+ const void *aux)
+{
+ const struct element *a = bt_node_to_element (a_);
+ const struct element *b = bt_node_to_element (b_);
+
+ check (aux == &aux_data);
+ return a->data < b->data ? -1 : a->data > b->data;
+}
+
+/* Compares A and B and returns a strcmp-type return value. */
+static int
+compare_ints_noaux (const void *a_, const void *b_)
+{
+ const int *a = a_;
+ const int *b = b_;
+
+ return *a < *b ? -1 : *a > *b;
+}
+
+/* Swaps *A and *B. */
+static void
+swap (int *a, int *b)
+{
+ int t = *a;
+ *a = *b;
+ *b = t;
+}
+
+/* Reverses the order of the CNT integers starting at VALUES. */
+static void
+reverse (int *values, size_t cnt)
+{
+ size_t i = 0;
+ size_t j = cnt;
+
+ while (j > i)
+ swap (&values[i++], &values[--j]);
+}
+
+/* Arranges the CNT elements in VALUES into the lexicographically
+ next greater permutation. Returns true if successful.
+ If VALUES is already the lexicographically greatest
+ permutation of its elements (i.e. ordered from greatest to
+ smallest), arranges them into the lexicographically least
+ permutation (i.e. ordered from smallest to largest) and
+ returns false. */
+static bool
+next_permutation (int *values, size_t cnt)
+{
+ if (cnt > 0)
+ {
+ size_t i = cnt - 1;
+ while (i != 0)
+ {
+ i--;
+ if (values[i] < values[i + 1])
+ {
+ size_t j;
+ for (j = cnt - 1; values[i] >= values[j]; j--)
+ continue;
+ swap (values + i, values + j);
+ reverse (values + (i + 1), cnt - (i + 1));
+ return true;
+ }
+ }
+
+ reverse (values, cnt);
+ }
+
+ return false;
+}
+
+/* Returns N!. */
+static unsigned int
+factorial (unsigned int n)
+{
+ unsigned int value = 1;
+ while (n > 1)
+ value *= n--;
+ return value;
+}
+
+/* Randomly shuffles the CNT elements in ARRAY, each of which is
+ SIZE bytes in size. */
+static void
+random_shuffle (void *array_, size_t cnt, size_t size)
+{
+ char *array = array_;
+ char *tmp = xmalloc (size);
+ size_t i;
+
+ for (i = 0; i < cnt; i++)
+ {
+ size_t j = rand () % (cnt - i) + i;
+ if (i != j)
+ {
+ memcpy (tmp, array + j * size, size);
+ memcpy (array + j * size, array + i * size, size);
+ memcpy (array + i * size, tmp, size);
+ }
+ }
+
+ free (tmp);
+}
+
+/* Calculates floor(log(n)/log(sqrt(2))). */
+static int
+calculate_h_alpha (size_t n)
+{
+ size_t thresholds[] =
+ {
+ 0, 2, 2, 3, 4, 6, 8, 12, 16, 23, 32, 46, 64, 91, 128, 182, 256, 363,
+ 512, 725, 1024, 1449, 2048, 2897, 4096, 5793, 8192, 11586, 16384,
+ 23171, 32768, 46341, 65536, 92682, 131072, 185364, 262144, 370728,
+ 524288, 741456, 1048576, 1482911, 2097152, 2965821, 4194304, 5931642,
+ 8388608, 11863284, 16777216, 23726567, 33554432, 47453133, 67108864,
+ 94906266, 134217728, 189812532, 268435456, 379625063, 536870912,
+ 759250125, 1073741824, 1518500250, 2147483648, 3037000500,
+ };
+ size_t threshold_cnt = sizeof thresholds / sizeof *thresholds;
+ size_t i;
+
+ for (i = 0; i < threshold_cnt; i++)
+ if (thresholds[i] > n)
+ break;
+ return i - 1;
+}
+
+/* Returns the height of the tree rooted at NODE. */
+static int
+get_height (struct bt_node *node)
+{
+ if (node == NULL)
+ return 0;
+ else
+ {
+ int left = get_height (node->down[0]);
+ int right = get_height (node->down[1]);
+ return 1 + (left > right ? left : right);
+ }
+}
+
+/* Checks that BT is loosely alpha-height balanced, that is, that
+ its height is no more than h_alpha(count) + 1, where
+ h_alpha(n) = floor(log(n)/log(1/alpha)). */
+static void
+check_balance (struct bt *bt)
+{
+ /* In the notation of the Galperin and Rivest paper (and of
+ CLR), the height of a tree is the number of edges in the
+ longest path from the root to a leaf, so we have to subtract
+ 1 from our measured height. */
+ int height = get_height (bt->root) - 1;
+ int max_height = calculate_h_alpha (bt_count (bt)) + 1;
+ check (height <= max_height);
+}
+
+/* Checks that BT contains the CNT ints in DATA, that its
+ structure is correct, and that certain operations on BT
+ produce the expected results. */
+static void
+check_bt (struct bt *bt, const int data[], size_t cnt)
+{
+ struct element e;
+ size_t i;
+ int *order;
+
+ order = xmemdup (data, cnt * sizeof *data);
+ qsort (order, cnt, sizeof *order, compare_ints_noaux);
+
+ for (i = 0; i < cnt; i++)
+ {
+ struct bt_node *p;
+
+ e.data = data[i];
+ if (rand () % 2)
+ p = bt_find (bt, &e.node);
+ else
+ p = bt_insert (bt, &e.node);
+ check (p != NULL);
+ check (p != &e.node);
+ check (bt_node_to_element (p)->data == data[i]);
+ }
+
+ e.data = -1;
+ check (bt_find (bt, &e.node) == NULL);
+
+ check_balance (bt);
+
+ if (cnt == 0)
+ {
+ check (bt_first (bt) == NULL);
+ check (bt_last (bt) == NULL);
+ check (bt_next (bt, NULL) == NULL);
+ check (bt_prev (bt, NULL) == NULL);
+ }
+ else
+ {
+ struct bt_node *p;
+
+ for (p = bt_first (bt), i = 0; i < cnt; p = bt_next (bt, p), i++)
+ check (bt_node_to_element (p)->data == order[i]);
+ check (p == NULL);
+
+ for (p = bt_last (bt), i = 0; i < cnt; p = bt_prev (bt, p), i++)
+ check (bt_node_to_element (p)->data == order[cnt - i - 1]);
+ check (p == NULL);
+ }
+
+ free (order);
+}
+
+/* Inserts the CNT values from 0 to CNT - 1 (inclusive) into an
+ BT in the order specified by INSERTIONS, then deletes them in
+ the order specified by DELETIONS, checking the BT's contents
+ for correctness after each operation. */
+static void
+test_insert_delete (const int insertions[],
+ const int deletions[],
+ size_t cnt)
+{
+ struct element *elements;
+ struct bt bt;
+ size_t i;
+
+ elements = xnmalloc (cnt, sizeof *elements);
+ for (i = 0; i < cnt; i++)
+ elements[i].data = i;
+
+ bt_init (&bt, compare_elements, &aux_data);
+ check_bt (&bt, NULL, 0);
+ for (i = 0; i < cnt; i++)
+ {
+ check (bt_insert (&bt, &elements[insertions[i]].node) == NULL);
+ check_bt (&bt, insertions, i + 1);
+ }
+ for (i = 0; i < cnt; i++)
+ {
+ bt_delete (&bt, &elements[deletions[i]].node);
+ check_bt (&bt, deletions + i + 1, cnt - i - 1);
+ }
+
+ free (elements);
+}
+\f
+/* Inserts values into an BT in each possible order, then
+ removes them in each possible order, up to a specified maximum
+ size. */
+static void
+test_insert_any_remove_any (void)
+{
+ const int max_elems = 5;
+ int cnt;
+
+ for (cnt = 0; cnt <= max_elems; cnt++)
+ {
+ int *insertions, *deletions;
+ unsigned int ins_perm_cnt;
+ int i;
+
+ insertions = xnmalloc (cnt, sizeof *insertions);
+ deletions = xnmalloc (cnt, sizeof *deletions);
+ for (i = 0; i < cnt; i++)
+ insertions[i] = i;
+
+ for (ins_perm_cnt = 0;
+ ins_perm_cnt == 0 || next_permutation (insertions, cnt);
+ ins_perm_cnt++)
+ {
+ unsigned int del_perm_cnt;
+ int i;
+
+ for (i = 0; i < cnt; i++)
+ deletions[i] = i;
+
+ for (del_perm_cnt = 0;
+ del_perm_cnt == 0 || next_permutation (deletions, cnt);
+ del_perm_cnt++)
+ test_insert_delete (insertions, deletions, cnt);
+
+ check (del_perm_cnt == factorial (cnt));
+ }
+ check (ins_perm_cnt == factorial (cnt));
+
+ free (insertions);
+ free (deletions);
+ }
+}
+
+/* Inserts values into an BT in each possible order, then
+ removes them in the same order, up to a specified maximum
+ size. */
+static void
+test_insert_any_remove_same (void)
+{
+ const int max_elems = 7;
+ int cnt;
+
+ for (cnt = 0; cnt <= max_elems; cnt++)
+ {
+ int *values;
+ unsigned int permutation_cnt;
+ int i;
+
+ values = xnmalloc (cnt, sizeof *values);
+ for (i = 0; i < cnt; i++)
+ values[i] = i;
+
+ for (permutation_cnt = 0;
+ permutation_cnt == 0 || next_permutation (values, cnt);
+ permutation_cnt++)
+ test_insert_delete (values, values, cnt);
+ check (permutation_cnt == factorial (cnt));
+
+ free (values);
+ }
+}
+
+/* Inserts values into an BT in each possible order, then
+ removes them in reverse order, up to a specified maximum
+ size. */
+static void
+test_insert_any_remove_reverse (void)
+{
+ const int max_elems = 7;
+ int cnt;
+
+ for (cnt = 0; cnt <= max_elems; cnt++)
+ {
+ int *insertions, *deletions;
+ unsigned int permutation_cnt;
+ int i;
+
+ insertions = xnmalloc (cnt, sizeof *insertions);
+ deletions = xnmalloc (cnt, sizeof *deletions);
+ for (i = 0; i < cnt; i++)
+ insertions[i] = i;
+
+ for (permutation_cnt = 0;
+ permutation_cnt == 0 || next_permutation (insertions, cnt);
+ permutation_cnt++)
+ {
+ memcpy (deletions, insertions, sizeof *insertions * cnt);
+ reverse (deletions, cnt);
+
+ test_insert_delete (insertions, deletions, cnt);
+ }
+ check (permutation_cnt == factorial (cnt));
+
+ free (insertions);
+ free (deletions);
+ }
+}
+
+/* Inserts and removes values in an BT in random orders. */
+static void
+test_random_sequence (void)
+{
+ const int max_elems = 128;
+ const int max_trials = 8;
+ int cnt;
+
+ for (cnt = 0; cnt <= max_elems; cnt += 2)
+ {
+ int *insertions, *deletions;
+ int trial;
+ int i;
+
+ insertions = xnmalloc (cnt, sizeof *insertions);
+ deletions = xnmalloc (cnt, sizeof *deletions);
+ for (i = 0; i < cnt; i++)
+ insertions[i] = i;
+ for (i = 0; i < cnt; i++)
+ deletions[i] = i;
+
+ for (trial = 0; trial < max_trials; trial++)
+ {
+ random_shuffle (insertions, cnt, sizeof *insertions);
+ random_shuffle (deletions, cnt, sizeof *deletions);
+
+ test_insert_delete (insertions, deletions, cnt);
+ }
+
+ free (insertions);
+ free (deletions);
+ }
+}
+
+/* Inserts elements into an BT in ascending order. */
+static void
+test_insert_ordered (void)
+{
+ const int max_elems = 1024;
+ struct element *elements;
+ int *values;
+ struct bt bt;
+ int i;
+
+ bt_init (&bt, compare_elements, &aux_data);
+ elements = xnmalloc (max_elems, sizeof *elements);
+ values = xnmalloc (max_elems, sizeof *values);
+ for (i = 0; i < max_elems; i++)
+ {
+ values[i] = elements[i].data = i;
+ check (bt_insert (&bt, &elements[i].node) == NULL);
+ check_bt (&bt, values, i + 1);
+ }
+ free (elements);
+ free (values);
+}
+
+/* Tests bt_find_ge and bt_find_le. */
+static void
+test_find_ge_le (void)
+{
+ const int max_elems = 10;
+ struct element *elements;
+ int *values;
+ unsigned int inc_pat;
+
+ elements = xnmalloc (max_elems, sizeof *elements);
+ values = xnmalloc (max_elems, sizeof *values);
+ for (inc_pat = 0; inc_pat < (1u << max_elems); inc_pat++)
+ {
+ struct bt bt;
+ int elem_cnt = 0;
+ int i;
+
+ /* Insert the values in the pattern into BT. */
+ bt_init (&bt, compare_elements, &aux_data);
+ for (i = 0; i < max_elems; i++)
+ if (inc_pat & (1u << i))
+ {
+ values[elem_cnt] = elements[elem_cnt].data = i;
+ check (bt_insert (&bt, &elements[elem_cnt].node) == NULL);
+ elem_cnt++;
+ }
+ check_bt (&bt, values, elem_cnt);
+
+ /* Try find_ge and find_le for each possible element value. */
+ for (i = -1; i <= max_elems; i++)
+ {
+ struct element tmp;
+ struct bt_node *ge, *le;
+ int j;
+
+ ge = le = NULL;
+ for (j = 0; j < elem_cnt; j++)
+ {
+ if (ge == NULL && values[j] >= i)
+ ge = &elements[j].node;
+ if (values[j] <= i)
+ le = &elements[j].node;
+ }
+
+ tmp.data = i;
+ check (bt_find_ge (&bt, &tmp.node) == ge);
+ check (bt_find_le (&bt, &tmp.node) == le);
+ }
+ }
+ free (elements);
+ free (values);
+}
+
+/* Inserts elements into an BT, then moves the nodes around in
+ memory. */
+static void
+test_moved (void)
+{
+ const int max_elems = 128;
+ struct element *e[2];
+ int cur;
+ int *values;
+ struct bt bt;
+ int i, j;
+
+ bt_init (&bt, compare_elements, &aux_data);
+ e[0] = xnmalloc (max_elems, sizeof *e[0]);
+ e[1] = xnmalloc (max_elems, sizeof *e[1]);
+ values = xnmalloc (max_elems, sizeof *values);
+ cur = 0;
+ for (i = 0; i < max_elems; i++)
+ {
+ values[i] = e[cur][i].data = i;
+ check (bt_insert (&bt, &e[cur][i].node) == NULL);
+ check_bt (&bt, values, i + 1);
+
+ for (j = 0; j <= i; j++)
+ {
+ e[!cur][j] = e[cur][j];
+ bt_moved (&bt, &e[!cur][j].node);
+ check_bt (&bt, values, i + 1);
+ }
+ cur = !cur;
+ }
+ free (e[0]);
+ free (e[1]);
+ free (values);
+}
+
+/* Inserts values into an BT, then changes their values. */
+static void
+test_changed (void)
+{
+ const int max_elems = 6;
+ int cnt;
+
+ for (cnt = 0; cnt <= max_elems; cnt++)
+ {
+ int *values, *changed_values;
+ struct element *elements;
+ unsigned int permutation_cnt;
+ int i;
+
+ values = xnmalloc (cnt, sizeof *values);
+ changed_values = xnmalloc (cnt, sizeof *changed_values);
+ elements = xnmalloc (cnt, sizeof *elements);
+ for (i = 0; i < cnt; i++)
+ values[i] = i;
+
+ for (permutation_cnt = 0;
+ permutation_cnt == 0 || next_permutation (values, cnt);
+ permutation_cnt++)
+ {
+ for (i = 0; i < cnt; i++)
+ {
+ int j, k;
+ for (j = 0; j <= cnt; j++)
+ {
+ struct bt bt;
+ struct bt_node *changed_retval;
+
+ bt_init (&bt, compare_elements, &aux_data);
+
+ /* Add to BT in order. */
+ for (k = 0; k < cnt; k++)
+ {
+ int n = values[k];
+ elements[n].data = n;
+ check (bt_insert (&bt, &elements[n].node) == NULL);
+ }
+ check_bt (&bt, values, cnt);
+
+ /* Change value i to j. */
+ elements[i].data = j;
+ for (k = 0; k < cnt; k++)
+ changed_values[k] = k;
+ changed_retval = bt_changed (&bt, &elements[i].node);
+ if (i != j && j < cnt)
+ {
+ /* Will cause duplicate. */
+ check (changed_retval == &elements[j].node);
+ changed_values[i] = changed_values[cnt - 1];
+ check_bt (&bt, changed_values, cnt - 1);
+ }
+ else
+ {
+ /* Succeeds. */
+ check (changed_retval == NULL);
+ changed_values[i] = j;
+ check_bt (&bt, changed_values, cnt);
+ }
+ }
+ }
+ }
+ check (permutation_cnt == factorial (cnt));
+
+ free (values);
+ free (changed_values);
+ free (elements);
+ }
+}
+\f
+/* Main program. */
+
+/* Runs TEST_FUNCTION and prints a message about NAME. */
+static void
+run_test (void (*test_function) (void), const char *name)
+{
+ test_name = name;
+ putchar ('.');
+ fflush (stdout);
+ test_function ();
+}
+
+int
+main (void)
+{
+ run_test (test_insert_any_remove_any,
+ "insert any order, delete any order");
+ run_test (test_insert_any_remove_same,
+ "insert any order, delete same order");
+ run_test (test_insert_any_remove_reverse,
+ "insert any order, delete reverse order");
+ run_test (test_random_sequence,
+ "insert and delete in random sequence");
+ run_test (test_insert_ordered,
+ "insert in ascending order");
+ run_test (test_find_ge_le, "find_ge and find_le");
+ run_test (test_moved, "move elements around in memory");
+ run_test (test_changed, "change key data in nodes");
+ putchar ('\n');
+
+ return 0;
+}