1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
# FIFO memoization
A First-In-First-Out memoization cache is one that uses queuing logic for its backing store, expunging the elements at the front of the queue when a predetermined threshold is exceeded.
> In simple terms, the FIFO memoization cache will remove the element that has been in the cache the longest.
## General use
To create a core.memoize FIFO-backed memoized function use the `clojure.core.memoize/fifo` function with an optional seed map or a `:fifo/threshold` parameter:
(memo/fifo function <seed> <:fifo/threshold number>)
Example code is as follows:
```clojure
(ns your.lib
(:require [clojure.core.memoize :as memo]))
(def memoized-fun
(memo/fifo identity {} :fifo/threshold 3))
```
The default `:fifo/threshold` value is 32 and refers to the number of elements in the cache required before the FIFO logic is applied.
Please read the [clojure.core.cache information regarding FIFO caches](https://github.com/clojure/core.cache/wiki/FIFO) for more detailed information, use cases and usage patterns.
As always, you should measure your system's characteristics to determine the best eviction strategy for your purposes.
|
