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/*

 * Ratelimiting calculations

 *

 * Copyright IBM, Corp. 2011

 *

 * Authors:

 *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>

 *

 * This work is licensed under the terms of the GNU LGPL, version 2 or later.

 * See the COPYING.LIB file in the top-level directory.

 *

 */

#ifndef QEMU_RATELIMIT_H

#define QEMU_RATELIMIT_H 1

typedef struct {

    int64_t next_slice_time;

    uint64_t slice_quota;

    uint64_t slice_ns;

    uint64_t dispatched;

} RateLimit;

static inline int64_t ratelimit_calculate_delay(RateLimit *limit, uint64_t n)

{

    int64_t now = qemu_get_clock_ns(rt_clock);

    if (limit->next_slice_time < now) {

        limit->next_slice_time = now + limit->slice_ns;

        limit->dispatched = 0;

    }

    if (limit->dispatched == 0 || limit->dispatched + n <= limit->slice_quota) {

        limit->dispatched += n;

        return 0;

    } else {

        limit->dispatched = n;

        return limit->next_slice_time - now;

    }

}

static inline void ratelimit_set_speed(RateLimit *limit, uint64_t speed,

                                       uint64_t slice_ns)

{

    limit->slice_ns = slice_ns;

    limit->slice_quota = ((double)speed * slice_ns)/1000000000ULL;

}

#endif