/* PSPP - a program for statistical analysis.
Copyright (C) 2007, 2009, 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 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.
You should have received a copy of the GNU General Public License
along with this program. If not, see . */
/* Bitmap, implemented as a balanced binary tree.
Each operation has O(lg N) cost, where N is the number of
contiguous regions of 1-bits in the bitmap. Also, a cache
reduces the second and subsequent containment tests within a
single contiguous region to O(1). */
#ifndef LIBPSPP_RANGE_SET_H
#define LIBPSPP_RANGE_SET_H
#include
#include "libpspp/bt.h"
#include "libpspp/cast.h"
/* A set of ranges. */
struct range_set
{
struct pool *pool; /* Pool for freeing range_set. */
struct bt bt; /* Tree of range_set_nodes. */
/* Cache. */
unsigned long int cache_start; /* Start of region. */
unsigned long int cache_end; /* One past end of region. */
bool cache_value; /* Is the region in the set? */
};
/* A node in the range set. */
struct range_set_node
{
struct bt_node bt_node; /* Binary tree node. */
unsigned long int start; /* Start of region. */
unsigned long int end; /* One past end of region. */
};
struct range_set *range_set_create (void);
struct range_set *range_set_create_pool (struct pool *);
struct range_set *range_set_clone (const struct range_set *, struct pool *);
void range_set_destroy (struct range_set *);
void range_set_set1 (struct range_set *,
unsigned long int start, unsigned long int width);
void range_set_set0 (struct range_set *,
unsigned long int start, unsigned long int width);
bool range_set_allocate (struct range_set *, unsigned long int request,
unsigned long int *start, unsigned long int *width);
bool range_set_allocate_fully (struct range_set *, unsigned long int request,
unsigned long int *start);
bool range_set_contains (const struct range_set *, unsigned long int position);
unsigned long int range_set_scan (const struct range_set *,
unsigned long int start);
static inline bool range_set_is_empty (const struct range_set *);
#define RANGE_SET_FOR_EACH(NODE, RANGE_SET) \
for ((NODE) = range_set_first (RANGE_SET); \
(NODE) != NULL; \
(NODE) = range_set_next (RANGE_SET, NODE))
static inline const struct range_set_node *range_set_first (
const struct range_set *);
static inline const struct range_set_node *range_set_next (
const struct range_set *, const struct range_set_node *);
static inline const struct range_set_node *range_set_last (
const struct range_set *);
static inline const struct range_set_node *range_set_prev (
const struct range_set *, const struct range_set_node *);
static inline unsigned long int range_set_node_get_start (
const struct range_set_node *);
static inline unsigned long int range_set_node_get_end (
const struct range_set_node *);
static inline unsigned long int range_set_node_get_width (
const struct range_set_node *);
/* Inline functions. */
static inline struct range_set_node *range_set_node_from_bt__ (
const struct bt_node *);
static inline struct range_set_node *range_set_next__ (
const struct range_set *, const struct range_set_node *);
static inline struct range_set_node *range_set_first__ (
const struct range_set *);
static inline struct range_set_node *range_set_prev__ (
const struct range_set *, const struct range_set_node *);
static inline struct range_set_node *range_set_last__ (
const struct range_set *);
/* Returns true if RS contains no 1-bits, false otherwise. */
static inline bool
range_set_is_empty (const struct range_set *rs)
{
return bt_count (&rs->bt) == 0;
}
/* Returns the node representing the first contiguous region of
1-bits in RS, or a null pointer if RS is empty.
Any call to range_set_set1, range_set_set0, or
range_set_allocate invalidates the returned node. */
static inline const struct range_set_node *
range_set_first (const struct range_set *rs)
{
return range_set_first__ (rs);
}
/* If NODE is nonnull, returns the node representing the next
contiguous region of 1-bits in RS following NODE, or a null
pointer if NODE is the last region in RS.
If NODE is null, returns the first region in RS, as for
range_set_first.
Any call to range_set_set1, range_set_set0, or
range_set_allocate invalidates the returned node. */
static inline const struct range_set_node *
range_set_next (const struct range_set *rs, const struct range_set_node *node)
{
return (node != NULL
? range_set_next__ (rs, CONST_CAST (struct range_set_node *, node))
: range_set_first__ (rs));
}
/* Returns the node representing the last contiguous region of
1-bits in RS, or a null pointer if RS is empty.
Any call to range_set_set1, range_set_set0, or
range_set_allocate invalidates the returned node. */
static inline const struct range_set_node *
range_set_last (const struct range_set *rs)
{
return range_set_last__ (rs);
}
/* If NODE is nonnull, returns the node representing the previous
contiguous region of 1-bits in RS following NODE, or a null
pointer if NODE is the first region in RS.
If NODE is null, returns the last region in RS, as for
range_set_last.
Any call to range_set_set1, range_set_set0, or
range_set_allocate invalidates the returned node. */
static inline const struct range_set_node *
range_set_prev (const struct range_set *rs, const struct range_set_node *node)
{
return (node != NULL
? range_set_prev__ (rs, CONST_CAST (struct range_set_node *, node))
: range_set_last__ (rs));
}
/* Returns the position of the first 1-bit in NODE. */
static inline unsigned long int
range_set_node_get_start (const struct range_set_node *node)
{
return node->start;
}
/* Returns one past the position of the last 1-bit in NODE. */
static inline unsigned long int
range_set_node_get_end (const struct range_set_node *node)
{
return node->end;
}
/* Returns the number of contiguous 1-bits in NODE. */
static inline unsigned long int
range_set_node_get_width (const struct range_set_node *node)
{
return node->end - node->start;
}
/* Internal helper functions. */
/* Returns the range_set_node corresponding to the given
BT_NODE. Returns a null pointer if BT_NODE is null. */
static inline struct range_set_node *
range_set_node_from_bt__ (const struct bt_node *bt_node)
{
return bt_node ? BT_DATA (bt_node, struct range_set_node, bt_node) : NULL;
}
/* Returns the next range_set_node in RS after NODE,
or a null pointer if NODE is the last node in RS. */
static inline struct range_set_node *
range_set_next__ (const struct range_set *rs,
const struct range_set_node *node)
{
return range_set_node_from_bt__ (bt_next (&rs->bt, &node->bt_node));
}
/* Returns the first range_set_node in RS,
or a null pointer if RS is empty. */
static inline struct range_set_node *
range_set_first__ (const struct range_set *rs)
{
return range_set_node_from_bt__ (bt_first (&rs->bt));
}
/* Returns the previous range_set_node in RS after NODE,
or a null pointer if NODE is the first node in RS. */
static inline struct range_set_node *
range_set_prev__ (const struct range_set *rs,
const struct range_set_node *node)
{
return range_set_node_from_bt__ (bt_prev (&rs->bt, &node->bt_node));
}
/* Returns the last range_set_node in RS,
or a null pointer if RS is empty. */
static inline struct range_set_node *
range_set_last__ (const struct range_set *rs)
{
return range_set_node_from_bt__ (bt_last (&rs->bt));
}
#endif /* libpspp/range-set.h */