haproxy/ebtree/ebpttree.h
Willy Tarreau 2b5702030d MINOR: ebtree: add new eb_next_dup/eb_prev_dup() functions to visit duplicates
Sometimes it's very useful to visit duplicates of a same node, but doing
so from the application is not convenient because keys have to be compared,
while all the information is available during the next/prev steps.

Let's introduce a couple of new eb_next_dup/eb_prev_dup functions to visit
only duplicates of the current node and return NULL once it's done. Now we
have all 3 combinations :
  - next        : returns next node in the tree
  - next_dup    : returns next dup in the sub-tree
  - next_unique : returns next value after skipping dups

(cherry picked from commit 3327b8ae6866f3878322a1a29e70b450226d216d)
2013-05-07 16:10:02 +02:00

178 lines
5.8 KiB
C

/*
* Elastic Binary Trees - macros and structures for operations on pointer nodes.
* Version 6.0.6
* (C) 2002-2011 - Willy Tarreau <w@1wt.eu>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation, version 2.1
* exclusively.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _EBPTTREE_H
#define _EBPTTREE_H
#include "ebtree.h"
#include "eb32tree.h"
#include "eb64tree.h"
/* Return the structure of type <type> whose member <member> points to <ptr> */
#define ebpt_entry(ptr, type, member) container_of(ptr, type, member)
#define EBPT_ROOT EB_ROOT
#define EBPT_TREE_HEAD EB_TREE_HEAD
/* on *almost* all platforms, a pointer can be cast into a size_t which is unsigned */
#ifndef PTR_INT_TYPE
#define PTR_INT_TYPE size_t
#endif
typedef PTR_INT_TYPE ptr_t;
/* This structure carries a node, a leaf, and a key. It must start with the
* eb_node so that it can be cast into an eb_node. We could also have put some
* sort of transparent union here to reduce the indirection level, but the fact
* is, the end user is not meant to manipulate internals, so this is pointless.
* Internally, it is automatically cast as an eb32_node or eb64_node.
*/
struct ebpt_node {
struct eb_node node; /* the tree node, must be at the beginning */
void *key;
};
/*
* Exported functions and macros.
* Many of them are always inlined because they are extremely small, and
* are generally called at most once or twice in a program.
*/
/* Return leftmost node in the tree, or NULL if none */
static forceinline struct ebpt_node *ebpt_first(struct eb_root *root)
{
return ebpt_entry(eb_first(root), struct ebpt_node, node);
}
/* Return rightmost node in the tree, or NULL if none */
static forceinline struct ebpt_node *ebpt_last(struct eb_root *root)
{
return ebpt_entry(eb_last(root), struct ebpt_node, node);
}
/* Return next node in the tree, or NULL if none */
static forceinline struct ebpt_node *ebpt_next(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_next(&ebpt->node), struct ebpt_node, node);
}
/* Return previous node in the tree, or NULL if none */
static forceinline struct ebpt_node *ebpt_prev(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_prev(&ebpt->node), struct ebpt_node, node);
}
/* Return next leaf node within a duplicate sub-tree, or NULL if none. */
static inline struct ebpt_node *ebpt_next_dup(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_next_dup(&ebpt->node), struct ebpt_node, node);
}
/* Return previous leaf node within a duplicate sub-tree, or NULL if none. */
static inline struct ebpt_node *ebpt_prev_dup(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_prev_dup(&ebpt->node), struct ebpt_node, node);
}
/* Return next node in the tree, skipping duplicates, or NULL if none */
static forceinline struct ebpt_node *ebpt_next_unique(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_next_unique(&ebpt->node), struct ebpt_node, node);
}
/* Return previous node in the tree, skipping duplicates, or NULL if none */
static forceinline struct ebpt_node *ebpt_prev_unique(struct ebpt_node *ebpt)
{
return ebpt_entry(eb_prev_unique(&ebpt->node), struct ebpt_node, node);
}
/* Delete node from the tree if it was linked in. Mark the node unused. Note
* that this function relies on a non-inlined generic function: eb_delete.
*/
static forceinline void ebpt_delete(struct ebpt_node *ebpt)
{
eb_delete(&ebpt->node);
}
/*
* The following functions are inlined but derived from the integer versions.
*/
static forceinline struct ebpt_node *ebpt_lookup(struct eb_root *root, void *x)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)eb32_lookup(root, (u32)(PTR_INT_TYPE)x);
else
return (struct ebpt_node *)eb64_lookup(root, (u64)(PTR_INT_TYPE)x);
}
static forceinline struct ebpt_node *ebpt_lookup_le(struct eb_root *root, void *x)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)eb32_lookup_le(root, (u32)(PTR_INT_TYPE)x);
else
return (struct ebpt_node *)eb64_lookup_le(root, (u64)(PTR_INT_TYPE)x);
}
static forceinline struct ebpt_node *ebpt_lookup_ge(struct eb_root *root, void *x)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)eb32_lookup_ge(root, (u32)(PTR_INT_TYPE)x);
else
return (struct ebpt_node *)eb64_lookup_ge(root, (u64)(PTR_INT_TYPE)x);
}
static forceinline struct ebpt_node *ebpt_insert(struct eb_root *root, struct ebpt_node *new)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)eb32_insert(root, (struct eb32_node *)new);
else
return (struct ebpt_node *)eb64_insert(root, (struct eb64_node *)new);
}
/*
* The following functions are less likely to be used directly, because
* their code is larger. The non-inlined version is preferred.
*/
/* Delete node from the tree if it was linked in. Mark the node unused. */
static forceinline void __ebpt_delete(struct ebpt_node *ebpt)
{
__eb_delete(&ebpt->node);
}
static forceinline struct ebpt_node *__ebpt_lookup(struct eb_root *root, void *x)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)__eb32_lookup(root, (u32)(PTR_INT_TYPE)x);
else
return (struct ebpt_node *)__eb64_lookup(root, (u64)(PTR_INT_TYPE)x);
}
static forceinline struct ebpt_node *__ebpt_insert(struct eb_root *root, struct ebpt_node *new)
{
if (sizeof(void *) == 4)
return (struct ebpt_node *)__eb32_insert(root, (struct eb32_node *)new);
else
return (struct ebpt_node *)__eb64_insert(root, (struct eb64_node *)new);
}
#endif /* _EBPT_TREE_H */