https://github.com/strojure/memoize-one
Clojure library for memoization of the single value.
https://github.com/strojure/memoize-one
cache clojure memoization
Last synced: 10 months ago
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Clojure library for memoization of the single value.
- Host: GitHub
- URL: https://github.com/strojure/memoize-one
- Owner: strojure
- License: unlicense
- Created: 2022-06-01T13:39:06.000Z (over 3 years ago)
- Default Branch: default
- Last Pushed: 2023-03-09T14:47:42.000Z (almost 3 years ago)
- Last Synced: 2025-02-08T23:27:38.045Z (11 months ago)
- Topics: cache, clojure, memoization
- Language: Clojure
- Homepage:
- Size: 22.5 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
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README
# memoize-one
Clojure library for memoization of the single value.
[](https://clojars.org/com.github.strojure/memoize-one)
## Design goals
* Simple utility for caching single value accessed from concurrent threads.
* Lazy initialization of the cached value on access.
* Performant access to the cached value.
* Optional cache expiration.
* Native implementation without external dependencies.
## Basic usage
```clojure
(ns readme.manual
"Example of using of the manual cache."
(:require [strojure.memoize-one.core :as memoize]
[strojure.memoize-one.manual-cache :as cache]))
(defn- test-cache
[side-effect]
(cache/memoize (fn [] (let [v (System/currentTimeMillis)]
(println (str "Create val " v " " (rand-int 100)))
(side-effect)
v))))
(comment
(let [c (test-cache #(Thread/sleep 100))]
(dotimes [i 10]
(future
(Thread/sleep (* i 50))
(let [v (memoize/get-ref c)]
@v
(memoize/evict v)))))
(def c (test-cache #(Thread/sleep 100)))
(def c (test-cache #(when (pos? (rand-int 2)) (throw (Exception. "Oops")))))
(memoize/get-ref c)
(deref (memoize/get-ref c)) ; Execution time mean : 7.299272 ns
#_1654093121258
(.deref (memoize/get-ref c)) ; Execution time mean : 6.074256 ns
(memoize/get-value c) ; Execution time mean : 6.343759 ns
(doto (memoize/get-ref c) (deref) (memoize/evict))
)
```
```clojure
(ns readme.expiring
"Example of using of the expiring cache."
(:require [strojure.memoize-one.core :as memoize]
[strojure.memoize-one.expiring-cache :as cache]))
(def ^:private test-fn
(fn []
(let [v (System/currentTimeMillis)]
(println (str "Create val " v " " (rand-int 100)))
(Thread/sleep 100)
#_(when (pos? (rand-int 2))
(throw (Exception. "Oops")))
v)))
(def ttl-cache
"TTL cache for 20 seconds."
(cache/memoize-ttl 20000 test-fn))
(comment
(deref (memoize/get-ref ttl-cache)) ; Execution time mean : 17,081336 ns
;Create val 1654094164999 12
#_1654094164999
(memoize/evict (memoize/get-ref ttl-cache))
#_nil
)
(defn- odd-test-fn
[x]
(fn [] (odd? x)))
(def odd-cache
"Cache expiring using `odd-test-fn`."
(cache/memoize-with odd-test-fn test-fn))
(comment
(deref (memoize/get-ref odd-cache)) ; Execution time mean : 16,548488 ns
;Create val 1654094271591 0
#_1654094271591
(memoize/evict (memoize/get-ref odd-cache))
#_nil
)
(defn- combined-test-fn
"Expiration test for TTL or `odd`."
[ttl]
(fn [x] (let [p1 ((cache/ttl-test-fn ttl) x)
p2 (odd-test-fn x)]
(fn []
(or (p1) (p2))))))
(def combined-cache
"Cache expiring using `combined-test-fn`."
(cache/memoize-with (combined-test-fn 20000) test-fn))
(comment
(deref (memoize/get-ref combined-cache)) ; Execution time mean : 26,168754 ns
;Create val 1654094360990 6
#_1654094360990
(memoize/evict (memoize/get-ref combined-cache))
#_nil
)
```