106 lines
4.1 KiB
C
106 lines
4.1 KiB
C
/* $NetBSD: ratelim-internal.h,v 1.2 2013/04/11 16:56:41 christos Exp $ */
|
|
/*
|
|
* Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
|
|
*
|
|
* 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.
|
|
* 3. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
|
|
*/
|
|
#ifndef _RATELIM_INTERNAL_H_
|
|
#define _RATELIM_INTERNAL_H_
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#include "event2/util.h"
|
|
|
|
/** A token bucket is an internal structure that tracks how many bytes we are
|
|
* currently willing to read or write on a given bufferevent or group of
|
|
* bufferevents */
|
|
struct ev_token_bucket {
|
|
/** How many bytes are we willing to read or write right now? These
|
|
* values are signed so that we can do "defecit spending" */
|
|
ev_ssize_t read_limit, write_limit;
|
|
/** When was this bucket last updated? Measured in abstract 'ticks'
|
|
* relative to the token bucket configuration. */
|
|
ev_uint32_t last_updated;
|
|
};
|
|
|
|
/** Configuration info for a token bucket or set of token buckets. */
|
|
struct ev_token_bucket_cfg {
|
|
/** How many bytes are we willing to read on average per tick? */
|
|
size_t read_rate;
|
|
/** How many bytes are we willing to read at most in any one tick? */
|
|
size_t read_maximum;
|
|
/** How many bytes are we willing to write on average per tick? */
|
|
size_t write_rate;
|
|
/** How many bytes are we willing to write at most in any one tick? */
|
|
size_t write_maximum;
|
|
|
|
/* How long is a tick? Note that fractions of a millisecond are
|
|
* ignored. */
|
|
struct timeval tick_timeout;
|
|
|
|
/* How long is a tick, in milliseconds? Derived from tick_timeout. */
|
|
unsigned msec_per_tick;
|
|
};
|
|
|
|
/** The current tick is 'current_tick': add bytes to 'bucket' as specified in
|
|
* 'cfg'. */
|
|
int ev_token_bucket_update(struct ev_token_bucket *bucket,
|
|
const struct ev_token_bucket_cfg *cfg,
|
|
ev_uint32_t current_tick);
|
|
|
|
/** In which tick does 'tv' fall according to 'cfg'? Note that ticks can
|
|
* overflow easily; your code needs to handle this. */
|
|
ev_uint32_t ev_token_bucket_get_tick(const struct timeval *tv,
|
|
const struct ev_token_bucket_cfg *cfg);
|
|
|
|
/** Adjust 'bucket' to respect 'cfg', and note that it was last updated in
|
|
* 'current_tick'. If 'reinitialize' is true, we are changing the
|
|
* configuration of 'bucket'; otherwise, we are setting it up for the first
|
|
* time.
|
|
*/
|
|
int ev_token_bucket_init(struct ev_token_bucket *bucket,
|
|
const struct ev_token_bucket_cfg *cfg,
|
|
ev_uint32_t current_tick,
|
|
int reinitialize);
|
|
|
|
int bufferevent_remove_from_rate_limit_group_internal(struct bufferevent *bev,
|
|
int unsuspend);
|
|
|
|
/** Decrease the read limit of 'b' by 'n' bytes */
|
|
#define ev_token_bucket_decrement_read(b,n) \
|
|
do { \
|
|
(b)->read_limit -= (n); \
|
|
} while (/*CONSTCOND*/0)
|
|
/** Decrease the write limit of 'b' by 'n' bytes */
|
|
#define ev_token_bucket_decrement_write(b,n) \
|
|
do { \
|
|
(b)->write_limit -= (n); \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|