moize is a powerful memoization library for JavaScript that helps optimize performance by caching the results of function calls. It supports various features such as custom cache handling, expiration, and serialization.
Basic Memoization
This feature allows you to memoize a function so that its results are cached based on the arguments provided. Subsequent calls with the same arguments will return the cached result.
const moize = require('moize');
const add = (a, b) => a + b;
const memoizedAdd = moize(add);
console.log(memoizedAdd(1, 2)); // 3
console.log(memoizedAdd(1, 2)); // 3, retrieved from cacheCustom Cache Handling
This feature allows you to use a custom cache implementation. You can specify the maximum size of the cache and other options.
const moize = require('moize');
const customCache = new Map();
const memoizedFunction = moize({
maxSize: 5,
isPromise: false,
cache: {
create: () => customCache
}
})(functionToMemoize);
memoizedFunction(args);Expiration
This feature allows you to set an expiration time for the cached results. After the specified time, the cache will be invalidated.
const moize = require('moize');
const memoizedFunction = moize({
maxAge: 1000 // cache expires after 1 second
})(functionToMemoize);
memoizedFunction(args);Serialization
This feature allows you to serialize the arguments before caching. This is useful for functions that take complex objects as arguments.
const moize = require('moize');
const memoizedFunction = moize({
serializer: (args) => JSON.stringify(args)
})(functionToMemoize);
memoizedFunction(args);lodash.memoize is a memoization function from the Lodash library. It provides basic memoization capabilities but lacks some of the advanced features like custom cache handling and expiration that moize offers.
memoizee is a full-featured memoization library that offers a wide range of options including cache expiration, custom cache size, and promise support. It is similar to moize in terms of functionality but has a different API and configuration options.
fast-memoize is a high-performance memoization library focused on speed. It provides basic memoization features and is optimized for performance, but it does not offer as many configuration options as moize.
moize
moize is a consistently blazing fast memoization library for JavaScript. It handles multiple parameters (including default values) without any additional configuration, and offers a large number of options to satisfy any number of potential use-cases.
$ npm i moize --save
import moize from 'moize';
import moize from 'moize/mjs/index.mjs';
const moize = require('moize');
import moize from 'moize';
const method = (a: number, b: number) => a + b;
const memoized = moize(method);
memoized(2, 4); // 6
memoized(2, 4); // 6, pulled from cache
All parameter types are supported, including circular objects, functions, etc. There are also a number of shortcut methods to memoize for unique use-cases.
moize optionally accepts an object of options as either the second parameter or as the first step in a curried function:
// inline
moize(fn, options);
// curried
moize(options)(fn);
The full shape of these options:
type Options = {
// is the cache based on deep equality of each key argument
isDeepEqual: boolean;
// is the result a promise
isPromise: boolean;
// is the result a React component
isReact: boolean;
// should the parameters be serialized instead of directly referenced
isSerialized: boolean;
// is the cache based on shallow equality of each key argument
isShallowEqual: boolean;
// custom method to compare equality between two key arguments
matchesArg: (cachedKeyArg: any, keyArg: any) => boolean;
// custom method to compare equality across all key arguments
matchesKey: (cachedKey: any[], key: any[]) => boolean;
// amount of time in milliseconds before the cache will expire
maxAge: number;
// maximum number of arguments passed to use as key for caching
maxArgs: number;
// maximum size of cache for this method
maxSize: number;
// method fired when a new entry is added to cache
onCacheAdd: (
cache: moize.Cache,
options: moize.Options,
moized: (...args: any[]) => any
) => void;
// method fire when either a new entry is added to cache or the LRU ordering of the cache has changed
onCacheChange: (
cache: moize.Cache,
options: moize.Options,
moized: (...args: any[]) => any
) => void;
// method fired when an existing entry in cache is used
onCacheHit: (
cache: moize.Cache,
options: moize.Options,
moized: (...args: any[]) => any
) => void;
// method to fire when a cache entry expires (in combination with maxAge)
onExpire: (key: any[]) => void;
// the unique identifier to give the memoized method when collecting statistics
profileName: string;
// method to serialize the arguments to build a unique cache key
serializer: (key: any[]) => string;
// method to transform the args into a custom format for key storage in cache
transformArgs: (key: any[]) => any[];
// should the cache entry be refreshed by calling the underlying function with the same parameters and
// updating the value stored in cache to be the new result
updateCacheForKey: (key: any[]) => boolean;
// should the cache entry's expiration be refreshed when the cache entry is hit (in combination with maxAge)
updateExpire: boolean;
};
All default values can be found here.
defaults to false
Should deep equality be used to compare cache each key argument.
type Arg = {
one: {
nested: string;
};
two: string;
};
const fn = ({ one, two }: Arg) => [one, two];
const memoized = moize(fn, { isDeepEqual: true });
memoized({ one: { nested: 'one' }, two: 'two' });
memoized({ one: { nested: 'one' }, two: 'two' }); // pulls from cache
This is also available via the shortcut method of moize.deep
const memoized = moize.deep(fn);
defaults to false
Is the computed value in the function a Promise.
const fn = async (item: Promise<string>) => await item;
const memoized = moize(fn, { isPromise: true });
This is also available via the shortcut method of moize.promise.
const memoized = -moize.promise(fn);
The Promise itself will be stored in cache, so that cached returns will always maintain the Promise contract. For common usage reasons, if the Promise is rejected, the cache entry will be deleted.
defaults to false
Is the function passed a stateless functional React component.
type Props = {
one: string;
two: number;
};
const Component = ({ one, two }: Props) => (
<div>
{one}: {two}
</div>
);
const MemoizedFoo = moize(Component, { isReact: true });
This is also available via the shortcut method of moize.react.
const MemoizedFoo = moize.react(Component);
The method will do a shallow equal comparison of both props and legacy context of the component based on strict equality. If you want to do a deep equals comparison, set isDeepEqual to true.
NOTE: This will memoize on each instance of the component passed, which is equivalent to PureComponent or React.memo. If you want to
memoize on all instances (which is how this option worked prior to version 6), use the following options:
const memoized = moize(Component, { isShallowEqual: true, maxArgs: 2 });
defaults to false
Serializes the parameters passed into a string and uses this as the key for cache comparison.
const fn = (mutableObject: { one: Record<string, any> }) =>
mutableObject.property;
const memoized = moize(fn, { isSerialized: true });
This is also available via the shortcut method of moize.serialize.
const memoized = moize.serialize(fn);
If serialize is combined with either maxArgs or transformArgs, the following order is used:
maxArgs (if applicable)transformArgs (if applicable)serializerNOTE: This is much slower than the default key storage, and usually the same requirements can be meet with isDeepEqual, so use at your discretion.
defaults to false
Should shallow equality be used to compare cache each key argument.
type Arg = {
one: string;
two: string;
};
const fn = ({ one, two }: Arg) => [one, two];
const memoized = moize(fn, { isShallowEqual: true });
memoized({ one: 'one', two: 'two' });
memoized({ one: 'one', two: 'two' }); // pulls from cache
This is also available via the shortcut method of moize.shallow
const memoized = moize.shallow(fn);
defaults to SameValueZero equality
Custom method used to compare equality of keys for cache purposes by comparing each argument.
type Arg = {
one: string;
two: string;
};
const fn = ({ one, two }: Arg) => [one, two];
const hasOneProperty = (cacheKeyArg: Arg, keyArg: Arg) =>
Object.keys(cacheKeyArg).length === 1 && Object.keys(keyArg).length === 1;
const memoized = moize(fn, { matchesArg: hasOneProperty });
memoized({ one: 'two' };
memoized({ two: 'three' }); // pulls from cache
This is also available via the shortcut method of moize.matchesArg
const memoized = moize.matchesArg(hasOneProperty)(fn);
NOTE: This comparison is used iteratively on each argument, rather than comparing the two keys as a whole. If you want to compare the key as a whole, you should use matchesKey.
Custom method used to compare equality of keys for cache purposes by comparing the entire key.
type Arg = {
one: string;
two: string;
};
const fn = ({ one, two }: Arg) => [one, two];
const isFooEqualAndHasBar = (cacheKey: [Arg], key: [Arg]) =>
cacheKey[0].one === key[0].one &&
cacheKey[1].hasOwnProperty('two') &&
key[1].hasOwnProperty('two');
const memoized = moize(fn, { matchesKey: isFooEqualAndHasBar });
memoized({ one: 'two' }, { two: null });
memoized({ one: 'two' }, { two: 'three' }); // pulls from cache
This is also available via the shortcut method of moize.matchesKey
const memoized = moize.matchesKey(isFooEqualAndHasBar)(fn);
NOTE: This comparison uses the two keys as a whole, which is usually less performant than the matchArg comparison used iteratively on each argument. Generally speaking you should use the matchArg option for equality comparison.
The maximum amount of time in milliseconds that you want a computed value to be stored in cache for this method.
const fn = (item: Record<string, any>) => item;
const MAX_AGE = 1000 * 60 * 5; // five minutes;
const memoized = moize(fn, { maxAge: MAX_AGE });
This is also available via the shortcut method of moize.maxAge.
const memoized = moize.maxAge(MAX_AGE)(fn);
TIP: A common usage of this is in tandom with isPromise for AJAX calls, and in that scenario the expected behavior is usually to have the maxAge countdown begin upon resolution of the promise. If this is your intended use case, you should also apply the updateExpire option.
The maximum number of arguments (starting from the first) used in creating the key for the cache.
const fn = (item1: string, item2: string, item3: string) =>
item1 + item2 + item3;
const memoized = moize(fn, { maxArgs: 2 });
memoize('one', 'two', 'three');
memoize('one', 'two', 'four'); // pulls from cache, as the first two args are the same
This is also available via the shortcut method of moize.maxArgs.
const memoized = moize.maxArgs(2)(fn);
If maxArgs is combined with either serialize or transformArgs, the following order is used:
maxArgstransformArgs (if applicable)serializer (if applicable)defaults to 1
The maximum number of values you want stored in cache for this method. Clearance of the cache once the maxSize is reached is on a Least Recently Used basis.
const fn = (item: string) => item;
const memoized = moize(fn, { maxSize: 5 });
This is also available via the shortcut method of moize.maxSize.
const memoized = moize.maxSize(5)(fn);
Method to fire when an item has been added to cache. Receives the cache, options, and memoized function as a parameters.
const fn = (one: string, two: string) => [one, two];
const logCacheKeys = (
cache: Cache,
options: Options,
moized: Moized<typeof fn>
) => console.log(cache.keys);
const moized = moize(fn, { maxSize: 2, onCacheAdd: logCacheKeys });
moized('one', 'two'); // [["one","two"]]
moized('one', 'two');
moized('two', 'one'); // [["two","one"], ["one","two"]]
moized('one', 'two');
NOTE: When combined with onCacheChange, this method will always fire first.
Method to fire when an item has been either added to cache, or existing cache was reordered based on a cache hit. Receives the cache, options, and memoized function as a parameters.
const fn = (one: string, two: string) => [one, two];
const logCacheKeys = (
cache: Cache,
options: Options,
moized: Moized<typeof fn>
) => console.log(cache.keys);
const moized = moize(fn, { maxSize: 2, onCacheChange: logCacheKeys });
moized('one', 'two'); // [["one","two"]]
moized('one', 'two');
moized('two', 'one'); // [["two","one"], ["one","two"]]
moized('one', 'two'); // [["one","two"], ["two","one"]]
NOTE: When combined with onCacheAdd or onCacheHit, this method will always fire last.
Method to fire when an existing cache item is found. Receives the cache, options, and memoized function as a parameters.
const fn = (one: string, two: string) => [one, two];
const logCacheKeys = (
cache: Cache,
options: Options,
moized: Moized<typeof fn>
) => console.log(cache.keys);
const moized = moize(fn, { maxSize: 2, onCacheHit: logCacheKeys });
moized('one', 'two');
moized('one', 'two'); // [["one","two"]]
moized('two', 'one');
moized('one', 'two'); // [["two","one"], ["one","two"]]
NOTE: When combined with onCacheChange, this method will always fire first.
A callback that is called when the cached entry expires.
const fn = (item: string) => item;
const logKey = (key: Key<string>) => console.log(key);
const memoized = moize(fn, { maxAge: 10000, onExpire: logKey });
If you return false from this method, it will prevent the key's removal and refresh the expiration in the same vein as updateExpire based on maxAge:
const fn = (item: string) => item;
let expirationAttempts = 0;
const limitExpirationAttempts = (key: Key<string>) => {
expirationAttempts += 1;
return expirationAttempts < 2;
};
const memoized = moize(fn, {
maxAge: 10000,
onExpire: limitExpirationAttempts,
});
memoized('one'); // will expire key after 30 seconds, or 3 expiration attempts
NOTE: You must set a maxAge for this option to take effect.
defaults to function name when it exists, or Anonymous {count} otherwise
Name to use as unique identifier for the function when collecting statistics.
moize.collectStats();
const fn = (item: string) => item;
const memoized = moize(fn, { profileName: 'my fancy identity' });
This is also available via the shortcut method of moize.profile.
const memoized = moize.profile('profile-name')(fn);
NOTE: You must be collecting statistics for this option to provide value, as it is the identifier used for statistics collection.
defaults to serializeArguments in utils.js
Method used in place of the internal serializer when serializing the parameters for cache key comparison. The function accepts a single argument, the Array of args, and must also return an Array.
const fn = (one: string, two: string) => [one, two];
const customSerializer = (args: string[]) => [JSON.stringify(args[0])];
const memoized = moize(fn, {
isSerialized: true,
serializer,
});
This is also available via the shortcut method of moize.serializeWith.
const memoized = moize.serializeWith(customSerializer)(fn);
NOTE: You must set isSerialized for this option to take effect.
Transform the arguments passed before it is used as a key. The function accepts a single argument, the Array of args, and must also return an Array.
const fn = (one: string | null, two: string | null, three: string | null) => [
two,
three,
];
const ignoreFirstArg = (args: (string | null)[]) => args.slice(1);
const moized = moize(fn, { transformArgs: ignoreFirstArg });
moize('one', 'two', 'three');
moize(null, 'two', 'three'); // pulled from cache
This is also available via the shortcut method of moize.transformArgs.
const memoized = moize.transformArgs(argTransformer)(fn);
If transformArgs is combined with either maxArgs or serialize, the following order is used:
maxArgs (if applicable)transformArgsserializer (if applicable)If you want to update the cache for a given key instead of leverage the value currently stored in cache.
const fn = (item: string) => item;
let lastUpdate = Date.now();
const memoized = moize(fn, {
updateCacheForKey([item]: [string]) {
const now = Date.now();
const last = lastUpdated;
lastUpdate = now;
// its been more than 5 minutes since last update
return last + 300000 < now;
},
});
memoized('one');
memoized('one'); // pulled from cache
// 5 minutes later
memoized('one'); // re-calls method and updates cache
This is also available via the shortcut method of moize.updateCacheForKey.
const memoized = moize.updateCacheForKey(shouldCacheUpdate)(fn);
When a maxAge is set, clear the scheduled expiration of the key when that key is retrieved, setting a new expiration based on the most recent retrieval from cache.
const fn = (item: string) => item;
const MAX_AGE = 1000 * 60 * 5; // five minutes
const memoized = moize(fn, { maxAge: MAX_AGE, updateExpire: true });
memoized('one');
setTimeout(() => {
/**
* hits cache, which updates the expire to be 5 minutes
* from this run instead of the first
*/
memoized('one');
}, 1000 * 60);
Pre-applies the isDeepEqual option.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.deep(fn);
Pre-applies the maxSize option with Infinity.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.infinite(fn);
NOTE: This mimics default behavior of moize prior to version 6.
Pre-applies the matchesArg option as a curriable method.
import moize from 'moize';
const isEqualOrFoo = (cacheKeyArg: string, keyArg: string) =>
cacheKeyArg === keyArg || keyArg === 'one';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.matchesArg(isEqualOrFoo)(fn);
Pre-applies the matchesKey option as a curriable method.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
const isEqualOrHasFoo = (cacheKey: Key<string>, key: Key<string>) =>
key.every((keyArg, index) => keyArg === cacheKey[index]) ||
key.some((keyArg) => keyArg === 'one');
export default moize.matchesKey(isEqualOrHasFoo)(fn);
Pre-applies the maxAge option as a curriable method.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.maxAge(5000)(fn);
Pre-applies the maxArgs option as a curriable method.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.maxArgs(1)(fn);
Pre-applies the maxSize option as a curriable method.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.maxSize(5)(fn);
Pre-applies the profileName option as a curriable method.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.profile('my fancy identity')(fn);
NOTE: You must be collecting statistics for this option to provide value, as it is the identifier used for statistics collection.
Pre-applies the isPromise and updateExpire options. The updateExpire option does nothing if maxAge is not also applied, but ensures that the expiration begins at the resolution of the promise rather than the instantiation of it.
import moize from 'moize';
const fn = async (one: string, two: Record<string, any>) =>
await someApiCall(one, two);
export default moize.promise(fn);
NOTE: If you do not want the promise to update its expiration when the cache is hit, then you should use the isPromise option directly instead.
Pre-applies the isReact) option for memoizing functional components in React. Key comparisons are based on a shallow equal comparison of both props and legacy context.
import moize from 'moize';
type Props = {
one: string;
two: number;
};
const Component = ({ one, two }: Props) => (
<div>
{one} {two}
</div>
);
export default moize.react(Component);
NOTE: This method will not operate with components made via the class instantiation, as they do not offer the same referential transparency.
Pre-applies the isSerialized option.
import moize from 'moize';
const fn = (one: Record<string, any>, two: Record<string, any>) => ({
one,
two,
});
export default moize.serialize(fn);
NOTE: If you want to provide a custom serializer, you should use moize.serializeWith:
moize.serializeWith(customSerializer)(fn);
Pre-applies the isSerialized and serializer options.
import moize from 'moize';
const fn = (one: Record<string, any>, two: Record<string, any>) => ({
one,
two,
});
export default moize.serializeWith(JSON.stringify)(fn);
NOTE: If you want to use the default serializer, you should use moize.serialize:
moize.serialize(customSerializer)(fn);
Pre-applies the isShallowEqual option.
import moize from 'moize';
const fn = (one: string, two: string) => `${one} ${two}`;
export default moize.shallow(fn);
Pre-applies the transformArgs option.
import moize from 'moize';
const fn = ([one, two]: string[]) => [`${one} ${two}`];
export default moize.transformArgs(fn);
Pre-applies the updateCacheForKey option.
import moize from 'moize';
let lastUpdated = Date.now();
const fn = () => {
const now = Date.now();
const last = lastUpdated;
lastUpdate = now;
// its been more than 5 minutes since last update
return last + 300000 < now;
};
export default moize.updateCacheForKey(fn);
If you are using React 16.8+ and are using hooks, you can easily create a custom useMoize hook for your project:
import { useRef } from 'react';
export function useMoize(fn, args, options) {
const moizedFnRef = useRef(moize(fn, options));
return moizedFnRef.current(...args);
}
Which can then be used as such:
import React from 'react';
import { useMoize } from './moize-hooks';
function MyComponent({ first, second, object }) {
// standard usage
const sum = useMoize((a, b) => a + b, [first, second]);
// with options
const deepSum = useMoize((obj) => obj.a + obj.b, [object], {
isDeepEqual: true,
});
return (
<div>
Sum of {first} and {second} is {sum}. Sum of {object.a} and{' '}
{object.b} is {deepSum}.
</div>
);
}
Naturally you can tweak as needed for your project (default options, option-specific hooks, etc).
NOTE: This is very similar to useCallback built-in hook, with two main differences:
options passed to moize)In both useCallback and useMemo, the array is a list of dependencies which determine whether the funciton is called. These can be different than the arguments, although in general practice they are equivalent. The decision to use them directly was both for this common use-case reasons, but also because the implementation complexity would have increased substantially if not.
Starting with version 2.3.0, you can compose moize methods. This will create a new memoized method with the original function that shallowly merges the options of the two setups. Example:
import moize from 'moize';
const Component = (props: Record<string, any>) => <div {...props} />;
// memoizing with react, as since 2.0.0
const MemoizedFoo = moize.react(Component);
// creating a separately-memoized method that has maxSize of 5
const LastFiveFoo = moize.maxSize(5)(MemoizedFoo);
You can also create an options-first curriable version of moize if you only pass the options:
import moize from 'moize';
// creates a function that will memoize what is passed
const limitedSerializedMoize = moize({ maxSize: 5, serialize: true });
const getWord = (bird) => `${bird} is the word`;
const moizedGetWord = limitedSerializedMoize(getWord);
You can also combine all of these options with moize.compose to create moize wrappers with pre-defined options.
import moize from 'moize';
// creates a moizer that will have the options of
// {isReact: true, maxAge: 5000, maxSize: 5}
const superLimitedReactMoize = moize.compose(
moize.react,
moize.maxSize(5),
moize.maxAge(5000)
);
As-of version 5, you can collect statistics of moize to determine if your cached methods are effective.
import moize from 'moize';
moize.collectStats();
const fn = (one: string, two: string) => [one, two];
const moized = moize(fn);
moized('one', 'two');
moized('one', 'two');
moized.getStats(); // {"calls": 2, "hits": 1, "usage": "50%"}
NOTE: It is recommended not to activate this in production, as it will have a performance decrease.
Cear statistics on moized functions.
moize.clearStats(); // clears all stats
moize.clearStats('profile-name'); // clears stats only for 'profile-name'
Set whether collecting statistics on moized functions.
moize.collectStats(true); // start collecting stats
moize.collectStats(); // same as passing true
moize.collectStats(false); // stop collecting stats
NOTE: If collecting statistics, it is recommended to provide a custom profileName or use moize.profile() for all memoized functions. This allows easier mapping of resulting statistics to their origin function when it has a common name or is anonymous.
Get the statistics for a specific function, or globally.
moize.collectStats();
const fn = (one: string, two: string) => [one, two];
const moized = moize(fn);
const otherFn = (one: string[]) => one.slice(0, 1);
const otherMoized = moize(otherFn, { profileName: 'otherMoized' });
moized('one', 'two');
moized('one', 'two');
moized.getStats(); // {"calls": 2, "hits": 1, "usage": "50%"}
otherMoized(['three']);
moize.getStats('otherMoized'); // {"calls": 1, "hits": 0, "usage": "0%"}
moize.getStats();
/*
{
"calls": 3,
"hits": 1,
"profiles": {
"fn at Object..src/utils.js (http://localhost:3000/app.js:153:68)": {
"calls": 2,
"hits": 1,
"usage": "50%"
},
"otherMoized": {
"calls": 1,
"hits": 0,
"usage": "0%"
}
},
"usage": "33.3333%"
}
*/
Are statistics being collected on memoization usage.
moize.collectStats(true);
moize.isCollectingStats(); // true
moize.collectStats(false);
moize.isCollectingStats(); // false
Is the function passed a moized function.
const fn = () => {};
const moizedFn = moize(fn);
moize.isMoized(fn); // false
moize.isMoized(moizedFn); // true
The cache is available on the moized function as a property, and while it is not recommended to modify it directly, that option is available for edge cases.
The shape of the cache is as follows:
type Cache = {
keys: any[][];
size: number;
values: any[];
};
Regardless of how the key is transformed, it is always stored as an array (if the value returned is not an array, it is coalesced to one).
NOTE: The order of keys and values should always align, so be aware when manually manipulating the cache that you need to manually keep in sync any changes to those arrays.
The cache is mutated internally for performance reasons, so logging out the cache at a specific step in the workflow may not give you the information you need. As such, to help with debugging you can request the cacheSnapshot, which has the same shape as the cache but is a shallow clone of each property for persistence.
There are also convenience methods provided on the moized function which allow for programmatic manipulation of the cache.
This will manually add the value at key in cache if key does not already exist. key should be an Array of values, meant to reflect the arguments passed to the method.
// single parameter is straightforward
const memoized = moize((item: string) => item: string);
memoized.add(['one'], 'two');
// pulls from cache
memoized('one');
NOTE: This will only add keys that do not exist in the cache, and will do nothing if the key already exists. If you want to update keys that already exist, use update.
This will clear all values in the cache, resetting it to an empty state.
const memoized = moize((item: string) => item);
memoized.clear();
Returns the value in cache if the key matches, else returns undefined. key should be an Array of values, meant to reflect the arguments passed to the method.
const memoized = moize((one: string, two: string) => [one, two);
memoized('one', 'two');
console.log(memoized.get(['one', 'two'])); // ["one","two"]
console.log(memoized.get(['two', 'three'])); // undefined
Returns the statistics for the function.
moize.collectStats();
const memoized = moize((one: string, two: string) => [one, two);
memoized('one', 'two');
memoized('one', 'two');
console.log(memoized.getStats()); // {"calls": 2, "hits": 1, "usage": "50%"}
NOTE: You must be collecting statistics for this to be populated.
This will return true if a cache entry exists for the key passed, else will return false. key should be an Array of values, meant to reflect the arguments passed to the method.
const memoized = moize((one: string, two: string) => [one, two]);
memoized('one', 'two');
console.log(memoized.has(['one', 'two'])); // true
console.log(memoized.has(['two', 'three'])); // false
This will return a list of the current keys in cache.
const memoized = moize.maxSize(2)((item: any) => item);
memoized('one');
memoized({ two: 'three' });
const keys = memoized.keys(); // [['one'], [{two: 'three'}]]
This will remove the provided key from cache. key should be an Array of values, meant to reflect the arguments passed to the method.
const memoized = moize((item: { one: string }) => item);
const arg = { one: 'one' };
memoized(arg);
memoized.remove([arg]);
// will re-execute, as it is no longer in cache
memoized(arg);
NOTE: This will only remove keys that exist in the cache, and will do nothing if the key does not exist.
This will manually update the value at key in cache if key exists. key should be an Array of values, meant to reflect the arguments passed to the method.
// single parameter is straightforward
const memoized = moize((item: string) => item);
memoized.add(['one'], 'two');
// pulls from cache
memoized('one');
NOTE: This will only update keys that exist in the cache, and will do nothing if the key does not exist. If you want to add keys that do not already exist, use add.
This will return a list of the current values in cache.
const memoized = moize.maxSize(2)((item: string | { two: string }) => ({
item,
}));
memoized('one');
memoized({ two: 'three' });
const values = memoized.values(); // [{item: 'one'}, {item: {two: 'three'}}]
All values provided are the number of operations per second calculated by the Benchmark suite, where a higher value is better. Each benchmark was performed using the default configuration of the library, with a fibonacci calculation based on a starting parameter of 35, using single and multiple parameters with different object types. The results were averaged to determine overall speed across possible usage.
NOTE: lodash, ramda, and underscore do not support multiple-parameter memoization without use of a resolver function. For consistency in comparison, each use the same resolver that returns the result of JSON.stringify on the arguments.
| Name | Overall (average) | Single (average) | Multiple (average) | single primitive | single array | single object | multiple primitive | multiple array | multiple object |
|---|---|---|---|---|---|---|---|---|---|
| moize | 71,177,801 | 98,393,482 | 43,962,121 | 139,808,786 | 97,571,202 | 57,800,460 | 44,509,528 | 44,526,039 | 42,850,796 |
| lru-memoize | 48,391,839 | 64,270,849 | 32,512,830 | 77,863,436 | 59,876,764 | 55,072,348 | 29,917,027 | 33,308,028 | 34,313,435 |
| mem | 42,348,320 | 83,158,473 | 1,538,166 | 128,731,510 | 73,473,478 | 47,270,433 | 2,012,120 | 1,565,253 | 1,037,126 |
| fast-memoize | 33,145,713 | 64,942,152 | 1,349,274 | 190,677,799 | 2,149,467 | 1,999,192 | 1,718,229 | 1,297,911 | 1,031,683 |
| lodash | 25,700,293 | 49,941,573 | 1,459,013 | 67,513,655 | 48,874,559 | 33,436,506 | 1,861,982 | 1,402,532 | 1,112,527 |
| memoizee | 21,546,499 | 27,447,855 | 15,645,143 | 29,701,124 | 27,294,197 | 25,348,244 | 15,359,792 | 15,855,421 | 15,720,217 |
| ramda | 18,804,380 | 35,919,033 | 1,689,727 | 101,557,928 | 1,895,956 | 4,303,215 | 2,305,025 | 1,597,131 | 1,167,025 |
| memoizerific | 6,745,058 | 7,382,030 | 6,108,086 | 8,488,885 | 6,427,832 | 7,229,375 | 5,772,461 | 6,278,344 | 6,273,453 |
| underscore | 6,701,695 | 11,698,265 | 1,705,126 | 18,249,423 | 4,695,658 | 12,149,714 | 2,310,412 | 1,630,769 | 1,174,197 |
| addy-osmani | 4,926,732 | 6,370,152 | 3,483,311 | 12,506,809 | 3,568,399 | 3,035,249 | 6,898,542 | 2,009,089 | 1,542,304 |
moize is fairly small (~3.86KB when minified and gzipped), however it provides a large number of configuration options to satisfy a number of edge cases. If filesize is a concern, you may consider using micro-memoize. This is the memoization library that powers moize under-the-hood, and will handle most common use cases at 1/4 the size of moize.
Standard stuff, clone the repo and npm install dependencies. The npm scripts available:
benchmark => run the benchmark suite pitting moize against other libraries in common use-casesbenchmark:alternative => run the benchmark suite for alternative forms of cachingbenchmark:array => run the benchmark suite for memoized methods using single and multiple array parametersbenchmark:object => run the benchmark suite for memoized methods using single and multiple object parametersbenchmark:primitive => run the benchmark suite for memoized methods using single and multiple object parametersbenchmark:react => run the benchmark suite for memoized React componentsbuild => run rollup to build the distributed files in distclean:dist => run rimraf on the dist folderclean:docs => run rimraf on the docs folderclean:mjs => run rimraf on the mjs foldercopy:mjs => run clean:mjs and the es-to-mjs scriptcopy:types => copy internal types to be available for consumerdev => run webpack dev server to run example app (playground!)dist => runs clean:dist and builddocs => runs clean:docs and builds the docs via jsdocflow => runs flow check on the files in srclint => runs ESLint against all files in the src folderlint:fix => runs lint, fixing any errors if possibletest => run jest test functions with NODE_ENV=testtest:coverage => run test but with code coveragetest:watch => run test, but with persistent watchertypecheck => run tsc against source code to validate TypeScriptFAQs
Blazing fast memoization based on all parameters passed
The npm package moize receives a total of 193,646 weekly downloads. As such, moize popularity was classified as popular.
We found that moize demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 2 open source maintainers collaborating on the project.
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