/* A splay-tree datatype.
- Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 1998-2020 Free Software Foundation, Inc.
Contributed by Mark Mitchell (mark@markmitchell.com).
This file is part of GNU CC.
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
#include <stdio.h>
#include "splay-tree.h"
static void splay_tree_delete_helper (splay_tree, splay_tree_node);
+static inline void rotate_left (splay_tree_node *,
+ splay_tree_node, splay_tree_node);
+static inline void rotate_right (splay_tree_node *,
+ splay_tree_node, splay_tree_node);
static void splay_tree_splay (splay_tree, splay_tree_key);
-static splay_tree_node splay_tree_splay_helper (splay_tree,
- splay_tree_key,
- splay_tree_node*,
- splay_tree_node*,
- splay_tree_node*);
-static int splay_tree_foreach_helper (splay_tree, splay_tree_node,
+static int splay_tree_foreach_helper (splay_tree_node,
splay_tree_foreach_fn, void*);
/* Deallocate NODE (a member of SP), and all its sub-trees. */
#undef VDEL
}
-/* Help splay SP around KEY. PARENT and GRANDPARENT are the parent
- and grandparent, respectively, of NODE. */
+/* Rotate the edge joining the left child N with its parent P. PP is the
+ grandparents' pointer to P. */
-static splay_tree_node
-splay_tree_splay_helper (splay_tree sp, splay_tree_key key,
- splay_tree_node *node, splay_tree_node *parent,
- splay_tree_node *grandparent)
+static inline void
+rotate_left (splay_tree_node *pp, splay_tree_node p, splay_tree_node n)
{
- splay_tree_node *next;
- splay_tree_node n;
- int comparison;
-
- n = *node;
-
- if (!n)
- return *parent;
-
- comparison = (*sp->comp) (key, n->key);
-
- if (comparison == 0)
- /* We've found the target. */
- next = 0;
- else if (comparison < 0)
- /* The target is to the left. */
- next = &n->left;
- else
- /* The target is to the right. */
- next = &n->right;
-
- if (next)
- {
- /* Continue down the tree. */
- n = splay_tree_splay_helper (sp, key, next, node, parent);
-
- /* The recursive call will change the place to which NODE
- points. */
- if (*node != n)
- return n;
- }
-
- if (!parent)
- /* NODE is the root. We are done. */
- return n;
-
- /* First, handle the case where there is no grandparent (i.e.,
- *PARENT is the root of the tree.) */
- if (!grandparent)
- {
- if (n == (*parent)->left)
- {
- *node = n->right;
- n->right = *parent;
- }
- else
- {
- *node = n->left;
- n->left = *parent;
- }
- *parent = n;
- return n;
- }
+ splay_tree_node tmp;
+ tmp = n->right;
+ n->right = p;
+ p->left = tmp;
+ *pp = n;
+}
- /* Next handle the cases where both N and *PARENT are left children,
- or where both are right children. */
- if (n == (*parent)->left && *parent == (*grandparent)->left)
- {
- splay_tree_node p = *parent;
-
- (*grandparent)->left = p->right;
- p->right = *grandparent;
- p->left = n->right;
- n->right = p;
- *grandparent = n;
- return n;
- }
- else if (n == (*parent)->right && *parent == (*grandparent)->right)
- {
- splay_tree_node p = *parent;
-
- (*grandparent)->right = p->left;
- p->left = *grandparent;
- p->right = n->left;
- n->left = p;
- *grandparent = n;
- return n;
- }
+/* Rotate the edge joining the right child N with its parent P. PP is the
+ grandparents' pointer to P. */
- /* Finally, deal with the case where N is a left child, but *PARENT
- is a right child, or vice versa. */
- if (n == (*parent)->left)
- {
- (*parent)->left = n->right;
- n->right = *parent;
- (*grandparent)->right = n->left;
- n->left = *grandparent;
- *grandparent = n;
- return n;
- }
- else
- {
- (*parent)->right = n->left;
- n->left = *parent;
- (*grandparent)->left = n->right;
- n->right = *grandparent;
- *grandparent = n;
- return n;
- }
+static inline void
+rotate_right (splay_tree_node *pp, splay_tree_node p, splay_tree_node n)
+{
+ splay_tree_node tmp;
+ tmp = n->left;
+ n->left = p;
+ p->right = tmp;
+ *pp = n;
}
-/* Splay SP around KEY. */
+/* Bottom up splay of key. */
static void
splay_tree_splay (splay_tree sp, splay_tree_key key)
if (sp->root == 0)
return;
- splay_tree_splay_helper (sp, key, &sp->root,
- /*grandparent=*/0, /*parent=*/0);
+ do {
+ int cmp1, cmp2;
+ splay_tree_node n, c;
+
+ n = sp->root;
+ cmp1 = (*sp->comp) (key, n->key);
+
+ /* Found. */
+ if (cmp1 == 0)
+ return;
+
+ /* Left or right? If no child, then we're done. */
+ if (cmp1 < 0)
+ c = n->left;
+ else
+ c = n->right;
+ if (!c)
+ return;
+
+ /* Next one left or right? If found or no child, we're done
+ after one rotation. */
+ cmp2 = (*sp->comp) (key, c->key);
+ if (cmp2 == 0
+ || (cmp2 < 0 && !c->left)
+ || (cmp2 > 0 && !c->right))
+ {
+ if (cmp1 < 0)
+ rotate_left (&sp->root, n, c);
+ else
+ rotate_right (&sp->root, n, c);
+ return;
+ }
+
+ /* Now we have the four cases of double-rotation. */
+ if (cmp1 < 0 && cmp2 < 0)
+ {
+ rotate_left (&n->left, c, c->left);
+ rotate_left (&sp->root, n, n->left);
+ }
+ else if (cmp1 > 0 && cmp2 > 0)
+ {
+ rotate_right (&n->right, c, c->right);
+ rotate_right (&sp->root, n, n->right);
+ }
+ else if (cmp1 < 0 && cmp2 > 0)
+ {
+ rotate_right (&n->left, c, c->right);
+ rotate_left (&sp->root, n, n->left);
+ }
+ else if (cmp1 > 0 && cmp2 < 0)
+ {
+ rotate_left (&n->right, c, c->left);
+ rotate_right (&sp->root, n, n->right);
+ }
+ } while (1);
}
/* Call FN, passing it the DATA, for every node below NODE, all of
value is returned. Otherwise, this function returns 0. */
static int
-splay_tree_foreach_helper (splay_tree sp, splay_tree_node node,
+splay_tree_foreach_helper (splay_tree_node node,
splay_tree_foreach_fn fn, void *data)
{
int val;
+ splay_tree_node *stack;
+ int stack_ptr, stack_size;
- if (!node)
- return 0;
+ /* A non-recursive implementation is used to avoid filling the stack
+ for large trees. Splay trees are worst case O(n) in the depth of
+ the tree. */
- val = splay_tree_foreach_helper (sp, node->left, fn, data);
- if (val)
- return val;
+#define INITIAL_STACK_SIZE 100
+ stack_size = INITIAL_STACK_SIZE;
+ stack_ptr = 0;
+ stack = XNEWVEC (splay_tree_node, stack_size);
+ val = 0;
- val = (*fn)(node, data);
- if (val)
- return val;
+ for (;;)
+ {
+ while (node != NULL)
+ {
+ if (stack_ptr == stack_size)
+ {
+ stack_size *= 2;
+ stack = XRESIZEVEC (splay_tree_node, stack, stack_size);
+ }
+ stack[stack_ptr++] = node;
+ node = node->left;
+ }
- return splay_tree_foreach_helper (sp, node->right, fn, data);
-}
+ if (stack_ptr == 0)
+ break;
+ node = stack[--stack_ptr];
+
+ val = (*fn) (node, data);
+ if (val)
+ break;
+
+ node = node->right;
+ }
+
+ XDELETEVEC (stack);
+ return val;
+}
/* An allocator and deallocator based on xmalloc. */
static void *
splay_tree_deallocate_fn deallocate_fn,
void *allocate_data)
{
- splay_tree sp = (splay_tree) (*allocate_fn) (sizeof (struct splay_tree_s),
- allocate_data);
+ return
+ splay_tree_new_typed_alloc (compare_fn, delete_key_fn, delete_value_fn,
+ allocate_fn, allocate_fn, deallocate_fn,
+ allocate_data);
+}
+
+/*
+
+@deftypefn Supplemental splay_tree splay_tree_new_with_typed_alloc @
+(splay_tree_compare_fn @var{compare_fn}, @
+splay_tree_delete_key_fn @var{delete_key_fn}, @
+splay_tree_delete_value_fn @var{delete_value_fn}, @
+splay_tree_allocate_fn @var{tree_allocate_fn}, @
+splay_tree_allocate_fn @var{node_allocate_fn}, @
+splay_tree_deallocate_fn @var{deallocate_fn}, @
+void * @var{allocate_data})
+
+This function creates a splay tree that uses two different allocators
+@var{tree_allocate_fn} and @var{node_allocate_fn} to use for allocating the
+tree itself and its nodes respectively. This is useful when variables of
+different types need to be allocated with different allocators.
+
+The splay tree will use @var{compare_fn} to compare nodes,
+@var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to
+deallocate values. Keys and values will be deallocated when the
+tree is deleted using splay_tree_delete or when a node is removed
+using splay_tree_remove. splay_tree_insert will release the previously
+inserted key and value using @var{delete_key_fn} and @var{delete_value_fn}
+if the inserted key is already found in the tree.
+
+@end deftypefn
+
+*/
+
+splay_tree
+splay_tree_new_typed_alloc (splay_tree_compare_fn compare_fn,
+ splay_tree_delete_key_fn delete_key_fn,
+ splay_tree_delete_value_fn delete_value_fn,
+ splay_tree_allocate_fn tree_allocate_fn,
+ splay_tree_allocate_fn node_allocate_fn,
+ splay_tree_deallocate_fn deallocate_fn,
+ void * allocate_data)
+{
+ splay_tree sp = (splay_tree) (*tree_allocate_fn)
+ (sizeof (struct splay_tree_s), allocate_data);
+
sp->root = 0;
sp->comp = compare_fn;
sp->delete_key = delete_key_fn;
sp->delete_value = delete_value_fn;
- sp->allocate = allocate_fn;
+ sp->allocate = node_allocate_fn;
sp->deallocate = deallocate_fn;
sp->allocate_data = allocate_data;
if (sp->root && comparison == 0)
{
- /* If the root of the tree already has the indicated KEY, just
- replace the value with VALUE. */
+ /* If the root of the tree already has the indicated KEY, delete
+ the old key and old value, and replace them with KEY and VALUE. */
+ if (sp->delete_key)
+ (*sp->delete_key) (sp->root->key);
if (sp->delete_value)
(*sp->delete_value)(sp->root->value);
+ sp->root->key = key;
sp->root->value = value;
}
else
{
/* Create a new node, and insert it at the root. */
splay_tree_node node;
-
+
node = ((splay_tree_node)
- (*sp->allocate) (sizeof (struct splay_tree_node_s),
- sp->allocate_data));
+ (*sp->allocate) (sizeof (struct splay_tree_node_s),
+ sp->allocate_data));
node->key = key;
node->value = value;
right = sp->root->right;
/* Delete the root node itself. */
+ if (sp->delete_key)
+ (*sp->delete_key) (sp->root->key);
if (sp->delete_value)
(*sp->delete_value) (sp->root->value);
(*sp->deallocate) (sp->root, sp->allocate_data);
int
splay_tree_foreach (splay_tree sp, splay_tree_foreach_fn fn, void *data)
{
- return splay_tree_foreach_helper (sp, sp->root, fn, data);
+ return splay_tree_foreach_helper (sp->root, fn, data);
}
/* Splay-tree comparison function, treating the keys as ints. */
else
return 0;
}
+
+/* Splay-tree comparison function, treating the keys as strings. */
+
+int
+splay_tree_compare_strings (splay_tree_key k1, splay_tree_key k2)
+{
+ return strcmp ((char *) k1, (char *) k2);
+}
+
+/* Splay-tree delete function, simply using free. */
+
+void
+splay_tree_delete_pointers (splay_tree_value value)
+{
+ free ((void *) value);
+}
projects / deliverable / binutils-gdb.git / blobdiff