67 lines
3.0 KiB
OCaml
67 lines
3.0 KiB
OCaml
(*****************************************************************************)
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(* *)
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(* Open Source License *)
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(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
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(* *)
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(* Permission is hereby granted, free of charge, to any person obtaining a *)
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(* copy of this software and associated documentation files (the "Software"),*)
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(* to deal in the Software without restriction, including without limitation *)
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(* the rights to use, copy, modify, merge, publish, distribute, sublicense, *)
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(* and/or sell copies of the Software, and to permit persons to whom the *)
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(* Software is furnished to do so, subject to the following conditions: *)
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(* *)
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(* The above copyright notice and this permission notice shall be included *)
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(* in all copies or substantial portions of the Software. *)
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(* *)
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(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
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(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *)
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(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *)
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(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
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(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *)
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(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *)
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(* DEALINGS IN THE SOFTWARE. *)
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(* *)
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(*****************************************************************************)
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(** Moving averages.
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This module implements bandwidth counters based on (cumulative)
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exponential moving average. Each counter is identified by an
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integer. They are stored in an internal hash table.
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See i.e.
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https://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
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for the algorithm.
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*)
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type t
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(** Type of one bandwidth counter. *)
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val create: init:int -> alpha:float -> t
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(** [create ~init ~alpha] is a counter with initial value [init] and
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factor [alpha]. *)
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val destroy: t -> unit
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(** [destroy t] removes counter [t] from the internal hash table. *)
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val add: t -> int -> unit
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(** [add t id] adds [t] in the internal hash table under identifies
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[id]. *)
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val on_update: (unit -> unit) -> unit
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(** [of_update f] registers [f] to be called on each update of the
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internal worker (currently every 1s). *)
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val updated: unit Lwt_condition.t
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(** [updated] is a condition variable that gets signaled on each
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update of the internal worker (currently every 1s). *)
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type stat = {
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total: int64 ;
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average: int ;
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}
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val stat: t -> stat
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(** [stat t] is a stat record reflecting the state of [t] at the time
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of the call. *)
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