freebsd-skq/sys/sys/rangeset.h
Konstantin Belousov 1809ef7836 Implement rangesets.
The data structure implements non-intersecting intervals over the [0,
UINT64_MAX] range, and supports fast insert, predicated clearing of
subrange, and lookup of an interval containing the specified address.
Internally it is a pctrie over the interval start addresses.

Implementation provides additional guarantees over the structure state
in case of memory allocation failures.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Differential revision:	https://reviews.freebsd.org/D18893
2019-02-20 09:38:19 +00:00

89 lines
3.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2019 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Konstantin Belousov <kib@FreeBSD.org>
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_RANGESET_H
#define _SYS_RANGESET_H
#ifdef _KERNEL
#include <sys/_rangeset.h>
typedef bool (*rs_pred_t)(void *ctx, void *r);
/*
* This structure must be embedded at the start of the rangeset element.
*/
struct rs_el {
uint64_t re_start; /* pctrie key */
uint64_t re_end;
};
void rangeset_init(struct rangeset *rs, rs_dup_data_t dup_data,
rs_free_data_t free_data, void *rs_data_ctx, u_int alloc_flags);
void rangeset_fini(struct rangeset *rs);
bool rangeset_check_empty(struct rangeset *rs, uint64_t start,
uint64_t end);
/*
* r point to the app data with struct rs_el at the beginning.
*/
int rangeset_insert(struct rangeset *rs, uint64_t start, uint64_t end,
void *r);
/*
* Guarantees that on error the rangeset is not modified. Remove
* might need to split element if its start/end completely cover the
* removed range, in which case ENOMEM might be returned.
*/
void rangeset_remove_all(struct rangeset *rs);
int rangeset_remove(struct rangeset *rs, uint64_t start, uint64_t end);
int rangeset_remove_pred(struct rangeset *rs, uint64_t start,
uint64_t end, rs_pred_t pred);
/*
* Really returns the pointer to the data with struct rs_el embedded
* at the beginning.
*/
void *rangeset_lookup(struct rangeset *rs, uint64_t place);
/*
* Copies src_rs entries into dst_rs. dst_rs must be empty.
* Leaves dst_rs empty on failure.
*/
int rangeset_copy(struct rangeset *dst_rs, struct rangeset *src_rs);
#endif
#endif