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#ifndef __tim_filter_h__
#define __tim_filter_h__
/*-
* Copyright (c) 2016-9 Netflix, Inc.
* All rights reserved.
*
* 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.
*
* $FreeBSD$
*/
/*
* Author: Randall Stewart <rrs@netflix.com>
*/
#include <sys/types.h>
#include <machine/param.h>
/*
* Do not change the size unless you know what you are
* doing, the current size of 5 is designed around
* the cache-line size for an amd64 processor. Other processors
* may need other sizes.
*/
#define NUM_FILTER_ENTRIES 3
struct filter_entry {
uint64_t value; /* Value */
uint32_t time_up; /* Time updated */
} __packed ;
struct filter_entry_small {
uint32_t value; /* Value */
uint32_t time_up; /* Time updated */
};
struct time_filter {
uint32_t cur_time_limit;
struct filter_entry entries[NUM_FILTER_ENTRIES];
#ifdef _KERNEL
} __aligned(CACHE_LINE_SIZE);
#else
};
#endif
struct time_filter_small {
uint32_t cur_time_limit;
struct filter_entry_small entries[NUM_FILTER_ENTRIES];
};
/*
* To conserve on space there is a code duplication here (this
* is where polymophism would be nice in the kernel). Everything
* is duplicated to have a filter with a value of uint32_t instead
* of a uint64_t. This saves 20 bytes and the structure size
* drops to 44 from 64. The bad part about this is you end
* up with two sets of functions. The xxx_small() access
* the uint32_t value's where the xxx() the uint64_t values.
* This forces the user to keep straight which type of structure
* they allocated and which call they need to make. crossing
* over calls will create either invalid memory references or
* very bad results :)
*/
#define FILTER_TYPE_MIN 1
#define FILTER_TYPE_MAX 2
#ifdef _KERNEL
int setup_time_filter(struct time_filter *tf, int fil_type, uint32_t time_len);
void reset_time(struct time_filter *tf, uint32_t time_len);
void forward_filter_clock(struct time_filter *tf, uint32_t ticks_forward);
void tick_filter_clock(struct time_filter *tf, uint32_t now);
uint32_t apply_filter_min(struct time_filter *tf, uint64_t value, uint32_t now);
uint32_t apply_filter_max(struct time_filter *tf, uint64_t value, uint32_t now);
void filter_reduce_by(struct time_filter *tf, uint64_t reduce_by, uint32_t now);
void filter_increase_by(struct time_filter *tf, uint64_t incr_by, uint32_t now);
static uint64_t inline
get_filter_value(struct time_filter *tf)
{
return(tf->entries[0].value);
}
static uint32_t inline
get_cur_timelim(struct time_filter *tf)
{
return(tf->cur_time_limit);
}
int setup_time_filter_small(struct time_filter_small *tf,
int fil_type, uint32_t time_len);
void reset_time_small(struct time_filter_small *tf, uint32_t time_len);
void forward_filter_clock_small(struct time_filter_small *tf,
uint32_t ticks_forward);
void tick_filter_clock_small(struct time_filter_small *tf, uint32_t now);
uint32_t apply_filter_min_small(struct time_filter_small *tf,
uint32_t value, uint32_t now);
uint32_t apply_filter_max_small(struct time_filter_small *tf,
uint32_t value, uint32_t now);
void filter_reduce_by_small(struct time_filter_small *tf,
uint32_t reduce_by, uint32_t now);
void filter_increase_by_small(struct time_filter_small *tf,
uint32_t incr_by, uint32_t now);
static uint64_t inline
get_filter_value_small(struct time_filter_small *tf)
{
return(tf->entries[0].value);
}
static uint32_t inline
get_cur_timelim_small(struct time_filter_small *tf)
{
return(tf->cur_time_limit);
}
#endif
#endif
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