-/* PSPP - computes sample statistics.
- Copyright (C) 2007 Free Software Foundation, Inc.
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2007, 2011 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 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 3 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.
+ 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. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
-#include <libpspp/heap.h>
-#include <libpspp/pool.h>
-#include <libpspp/assertion.h>
+#include "libpspp/heap.h"
+#include "libpspp/pool.h"
+#include "libpspp/assertion.h"
-#include "xalloc.h"
+#include "gl/xalloc.h"
/* A heap. */
-struct heap
+struct heap
{
/* Comparison function and auxiliary data. */
heap_compare_func *compare;
const void *aux;
/* Contents. */
- struct heap_node **nodes; /* Element 0 unused, 1...CNT are the heap. */
- size_t cnt; /* Number of elements in heap. */
- size_t cap; /* Max CNT without allocating more memory. */
+ struct heap_node **nodes; /* Element 0 unused, 1...N are the heap. */
+ size_t n; /* Number of elements in heap. */
+ size_t allocated; /* Max N without allocating more memory. */
};
static inline void set_node (struct heap *, size_t idx, struct heap_node *);
To obtain a max-heap, negate the return value of the
comparison function. */
struct heap *
-heap_create (heap_compare_func *compare, const void *aux)
+heap_create (heap_compare_func *compare, const void *aux)
{
struct heap *h = xmalloc (sizeof *h);
h->compare = compare;
h->aux = aux;
h->nodes = NULL;
- h->cap = 0;
- h->cnt = 0;
+ h->allocated = 0;
+ h->n = 0;
return h;
}
/* Destroys H (callback for pool). */
static void
-destroy_callback (void *h)
+destroy_callback (void *h)
{
heap_destroy (h);
}
comparison function. */
struct heap *
heap_create_pool (struct pool *pool,
- heap_compare_func *compare, const void *aux)
+ heap_compare_func *compare, const void *aux)
{
struct heap *h = heap_create (compare, aux);
pool_register (pool, destroy_callback, h);
/* Destroys heap H. */
void
-heap_destroy (struct heap *h)
+heap_destroy (struct heap *h)
{
- if (h != NULL)
+ if (h != NULL)
{
free (h->nodes);
free (h);
/* Returns true if H is empty, false if it contains at least one
element. */
bool
-heap_is_empty (const struct heap *h)
+heap_is_empty (const struct heap *h)
{
- return h->cnt == 0;
+ return h->n == 0;
}
/* Returns the number of elements in H. */
size_t
-heap_count (const struct heap *h)
+heap_count (const struct heap *h)
{
- return h->cnt;
+ return h->n;
}
/* Heap nodes may be moved around in memory as necessary, e.g. as
NODE that was moved and its heap H before attempting any other
operation on H. */
void
-heap_moved (struct heap *h, struct heap_node *node)
+heap_moved (struct heap *h, struct heap_node *node)
{
- assert (node->idx <= h->cnt);
+ assert (node->idx <= h->n);
h->nodes[node->idx] = node;
}
/* Returns the node with the minimum value in H, which must not
be empty. */
struct heap_node *
-heap_minimum (const struct heap *h)
+heap_minimum (const struct heap *h)
{
assert (!heap_is_empty (h));
return h->nodes[1];
void
heap_insert (struct heap *h, struct heap_node *node)
{
- if (h->cnt >= h->cap)
+ if (h->n >= h->allocated)
{
- h->cap = 2 * (h->cap + 8);
- h->nodes = xnrealloc (h->nodes, h->cap + 1, sizeof *h->nodes);
+ h->allocated = 2 * (h->allocated + 8);
+ h->nodes = xnrealloc (h->nodes, h->allocated + 1, sizeof *h->nodes);
}
- h->cnt++;
- set_node (h, h->cnt, node);
- propagate_up (h, h->cnt);
+ h->n++;
+ set_node (h, h->n, node);
+ propagate_up (h, h->n);
expensive_assert (is_heap (h));
}
void
heap_delete (struct heap *h, struct heap_node *node)
{
- assert (node->idx <= h->cnt);
+ assert (node->idx <= h->n);
assert (h->nodes[node->idx] == node);
- if (node->idx < h->cnt)
+ if (node->idx < h->n)
{
- set_node (h, node->idx, h->nodes[h->cnt--]);
+ set_node (h, node->idx, h->nodes[h->n--]);
heap_changed (h, h->nodes[node->idx]);
}
- else
- h->cnt--;
+ else
+ h->n--;
}
/* After client code changes the value represented by a heap
the nodes from the heap, update their values, then re-insert
all of them. */
void
-heap_changed (struct heap *h, struct heap_node *node)
+heap_changed (struct heap *h, struct heap_node *node)
{
- assert (node->idx <= h->cnt);
+ assert (node->idx <= h->n);
assert (h->nodes[node->idx] == node);
if (!propagate_up (h, node->idx))
/* Sets h->nodes[IDX] and updates NODE's 'idx' field
accordingly. */
static void
-set_node (struct heap *h, size_t idx, struct heap_node *node)
+set_node (struct heap *h, size_t idx, struct heap_node *node)
{
h->nodes[idx] = node;
h->nodes[idx]->idx = idx;
/* Moves the node with the given IDX down the heap as necessary
to restore the heap property. */
static void
-propagate_down (struct heap *h, size_t idx)
+propagate_down (struct heap *h, size_t idx)
{
- for (;;)
+ for (;;)
{
size_t least;
least = lesser_node (h, idx, 2 * idx);
to restore the heap property. Returns true if the node was
moved, false otherwise.*/
static bool
-propagate_up (struct heap *h, size_t idx)
+propagate_up (struct heap *h, size_t idx)
{
bool moved = false;
- for (; idx > 1 && less (h, idx, idx / 2); idx /= 2)
+ for (; idx > 1 && less (h, idx, idx / 2); idx /= 2)
{
swap_nodes (h, idx, idx / 2);
- moved = true;
+ moved = true;
}
return moved;
}
/* Returns true if, in H, the node with index A has value less
than the node with index B. */
static bool
-less (const struct heap *h, size_t a, size_t b)
+less (const struct heap *h, size_t a, size_t b)
{
return h->compare (h->nodes[a], h->nodes[b], h->aux) < 0;
}
with the lesser value. B is allowed to be out of the range of
valid node indexes, in which case A is returned. */
static size_t
-lesser_node (const struct heap *h, size_t a, size_t b)
+lesser_node (const struct heap *h, size_t a, size_t b)
{
- assert (a <= h->cnt);
- return b > h->cnt || less (h, a, b) ? a : b;
+ assert (a <= h->n);
+ return b > h->n || less (h, a, b) ? a : b;
}
/* Swaps, in H, the nodes with indexes A and B. */
static void
-swap_nodes (struct heap *h, size_t a, size_t b)
+swap_nodes (struct heap *h, size_t a, size_t b)
{
struct heap_node *t;
-
- assert (a <= h->cnt);
- assert (b <= h->cnt);
+
+ assert (a <= h->n);
+ assert (b <= h->n);
t = h->nodes[a];
set_node (h, a, h->nodes[b]);
/* Returns true if H is a valid heap,
false otherwise. */
static bool UNUSED
-is_heap (const struct heap *h)
+is_heap (const struct heap *h)
{
size_t i;
-
- for (i = 2; i <= h->cnt; i++)
- if (less (h, i, i / 2))
+
+ for (i = 2; i <= h->n; i++)
+ if (less (h, i, i / 2))
return false;
- for (i = 1; i <= h->cnt; i++)
+ for (i = 1; i <= h->n; i++)
if (h->nodes[i]->idx != i)
return false;
projects / pspp / blobdiff