X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fheap.c;h=c825704ea9fc80efbd278dd44bb8f3013b216d51;hb=0569b2e2c28be9bf5754297f705d82b6518e0f7d;hp=d262d042e7f71a809c10191e15cb17f0c1b49d4f;hpb=756e3feab0a2dab6be0a96164079fce2a2d8f9b4;p=pspp

diff --git a/src/libpspp/heap.c b/src/libpspp/heap.c
index d262d042e7..c825704ea9 100644
--- a/src/libpspp/heap.c
+++ b/src/libpspp/heap.c
@@ -1,42 +1,40 @@
-/* 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 *);
@@ -51,20 +49,20 @@ static inline bool propagate_up (struct heap *, size_t idx);
    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);
 }
@@ -77,7 +75,7 @@ destroy_callback (void *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);
@@ -86,9 +84,9 @@ heap_create_pool (struct pool *pool,
 
 /* 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);
@@ -98,16 +96,16 @@ heap_destroy (struct heap *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
@@ -116,16 +114,16 @@ heap_count (const struct heap *h)
    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];
@@ -135,15 +133,15 @@ heap_minimum (const struct heap *h)
 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));
 }
@@ -152,16 +150,16 @@ heap_insert (struct heap *h, struct heap_node *node)
 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
@@ -176,9 +174,9 @@ heap_delete (struct heap *h, struct heap_node *node)
    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))
@@ -193,7 +191,7 @@ static inline void swap_nodes (struct heap *, size_t a, size_t b);
 /* 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;
@@ -202,9 +200,9 @@ set_node (struct heap *h, size_t idx, struct heap_node *node)
 /* 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);
@@ -221,13 +219,13 @@ propagate_down (struct heap *h, size_t 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;
 }
@@ -235,7 +233,7 @@ propagate_up (struct heap *h, size_t idx)
 /* 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;
 }
@@ -244,20 +242,20 @@ less (const struct heap *h, size_t a, size_t b)
    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]);
@@ -267,15 +265,15 @@ swap_nodes (struct heap *h, size_t a, size_t 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;