@Memo

Straightforward memoization

Abstract

@Memo is an implementation of the memoize design pattern using AOP. When a method is annotated with the @Memo() annotation, its return value will be stored in cache, so that further method call with the same set of parameters returns the cached result instead of invoking the real method. This is particular useful for compute-intensive or time-consuming tasks (eg: fetch calls).

For more details & usage, please read the documentation

Installation

npm install --save @aspectjs/core
npm install --save @aspectjs/memo

Simple usage

You must enable the MemoAspect in order for @Memo() to work. The simplest way to do is to register the default Memo profile:

import { MEMO_PROFILE } from '@aspectjs/memo';
MEMO_PROFILE.register();

You can now use @Memo() annotation to memoize any method:

import { Memo } from '@aspectjs/memo';

class MyMemoizedClass {
    @Memo()
    heavyCompute(arg1, arg2) {
        return [arg1, arg2].join(', ').toUpperCase();
    }

    @Memo()
    heavyComputePeople(firstName, lastName) {
        // this also works for non-primitive objects,
        // but you need the @Cacheable() annotation above custom classes
        return new People(firstName, lastName.toUpperCase());
    }
}

@Cacheable()
class People {
    constructor(firstName, lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }
}

const c = new MyMemoizedClass();
c.heavyCompute('hello', 'world'); // computes 'HELLO, WORLD'
c.heavyCompute('hello', 'world'); // returns cached 'HELLO, WORLD'

c.heavyComputePeople('John', 'Doe'); // computes People {'John DOE'}
c.heavyComputePeople('John', 'Doe'); // returns cached People {'John DOE'}

MIT Licensed