ratelim-internal.h

/*
 * 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_INCLUDED_
#define RATELIM_INTERNAL_H_INCLUDED_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include "event2/util.h"
 
struct ev_token_bucket {
    ev_ssize_t read_limit, write_limit;
    ev_uint32_t last_updated;
};
 
struct ev_token_bucket_cfg {
    size_t read_rate;
    size_t read_maximum;
    size_t write_rate;
    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;
};
 
int ev_token_bucket_update_(struct ev_token_bucket *bucket,
    const struct ev_token_bucket_cfg *cfg,
    ev_uint32_t current_tick);
 
ev_uint32_t ev_token_bucket_get_tick_(const struct timeval *tv,
    const struct ev_token_bucket_cfg *cfg);
 
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);
 
#define ev_token_bucket_decrement_read(b,n) \
    do {                    \
        (b)->read_limit -= (n);     \
    } while (0)
#define ev_token_bucket_decrement_write(b,n)    \
    do {                    \
        (b)->write_limit -= (n);    \
    } while (0)
 
#ifdef __cplusplus
}
#endif
 
#endif