https://github.com/marianoguerra/rate-meter.clj

measure ocurrence of things at custom granularities
https://github.com/marianoguerra/rate-meter.clj

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measure ocurrence of things at custom granularities

• Host: GitHub
• URL: https://github.com/marianoguerra/rate-meter.clj
• Owner: marianoguerra
• Created: 2013-04-05T12:28:29.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-04-05T12:28:40.000Z (over 11 years ago)
• Last Synced: 2024-06-01T12:23:13.167Z (6 months ago)
• Language: Clojure
• Size: 102 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.rest

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README

        
rate-meter

==========

A Clojure library designed to measure rates of activity for things in customizable

time segments.

Usage

-----

first you need to define markers, markers are functions that take a joda

DateTime instance as argument and return a value that represents the time segment

they measure, for example, if you want to measure all the activity in one minute

you can use the provided *minute-mark*::

        user=> (require '[marianoguerra.rate-meter :as rm])

        user=> (require '[clj-time.core :as time])

        user=> (rm/minute-mark (time/now))

        "2013-04-05T12:13"

        user=> (rm/minute-mark (time/plus (time/now) (time/minutes 2)))

        "2013-04-05T12:15"

if you want to measure activity in something larger than one minute you can use

the provided *minute-step-mark*::

        user=> (def four-minute-mark (rm/minute-step-mark 4))

        #'user/four-minute-mark

        user=> (four-minute-mark (time/now))

        "2013-04-05T12:12"

        user=> (time/now)

        #

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 4)))

        "2013-04-05T12:20"

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 2)))

        "2013-04-05T12:16"

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 3)))

        "2013-04-05T12:16"

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 5)))

        "2013-04-05T12:20"

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 7)))

        "2013-04-05T12:20"

        user=> (four-minute-mark (time/plus (time/now) (time/minutes 9)))

        "2013-04-05T12:24"

as you can see the four-minute-mark returns the same value for all the time

between 4 minutes.

the returned value doesn't have to be a string nor a date, it can be anything you

want, but the provided functions return dates formatted as strings.

you can create your own markers for some weirder measurements.

after you have the markers you can instantiate a rate-store, that is an object

that will allow you to mark activity on things and query the rate for a given marker.

let's see an example

first create the markers we will use::

        user=> (def markers {:one-min rm/minute-mark :five-mins (rm/minute-step-mark 5)})

now create a in memory rate store::

        user=> (def rate-store (rm/memory-rate-store markers))

get the rate for some id::

        user=> (rm/rate rate-store "spongebob" :one-min)

        0

since there was no activity yet we get 0, but we can change it to another default

value if not found::

        user=> (rm/rate rate-store "spongebob" :one-min :not-found)

        :not-found

now let's mark some activity::

        user=> (rm/mark rate-store "spongebob")

and get it back::

        user=> (rm/rate rate-store "spongebob" :one-min)

        1

        user=> (rm/rate rate-store "spongebob" :five-mins)

        1

let's mark some activity with a value different than one::

        user=> (rm/mark rate-store "spongebob" 6)

and get the results back::

        user=> (rm/rate rate-store "spongebob" :one-min)

        7

        user=> (rm/rate rate-store "spongebob" :five-mins)

        7

one minute passes and we mark again::

        user=> (rm/mark rate-store "spongebob" 3)

we query again and the one minute rate was reseted to 0 since the mark changed

after one minute passed::

        user=> (rm/rate rate-store "spongebob" :one-min)

        3

but the five minute rate keeps acumulating::

        user=> (rm/rate rate-store "spongebob" :five-mins)

        10

that's basically all.

Extending

---------

You can create custom rate-stores by implementing the RateStore protocol, for

example you could store the rates on redis or something similar.

License

-------

Copyright © 2013 marianoguerra

Distributed under the Eclipse Public License, the same as Clojure.