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Diffstat (limited to 'node_modules/mem')
| -rw-r--r-- | node_modules/mem/index.js | 55 | ||||
| -rw-r--r-- | node_modules/mem/license | 21 | ||||
| -rw-r--r-- | node_modules/mem/package.json | 45 | ||||
| -rw-r--r-- | node_modules/mem/readme.md | 147 |
4 files changed, 268 insertions, 0 deletions
diff --git a/node_modules/mem/index.js b/node_modules/mem/index.js new file mode 100644 index 000000000..aa5a07398 --- /dev/null +++ b/node_modules/mem/index.js @@ -0,0 +1,55 @@ +'use strict'; +const mimicFn = require('mimic-fn'); + +const cacheStore = new WeakMap(); + +const defaultCacheKey = function (x) { + if (arguments.length === 1 && (x === null || x === undefined || (typeof x !== 'function' && typeof x !== 'object'))) { + return x; + } + + return JSON.stringify(arguments); +}; + +module.exports = (fn, opts) => { + opts = Object.assign({ + cacheKey: defaultCacheKey, + cache: new Map() + }, opts); + + const memoized = function () { + const cache = cacheStore.get(memoized); + const key = opts.cacheKey.apply(null, arguments); + + if (cache.has(key)) { + const c = cache.get(key); + + if (typeof opts.maxAge !== 'number' || Date.now() < c.maxAge) { + return c.data; + } + } + + const ret = fn.apply(null, arguments); + + cache.set(key, { + data: ret, + maxAge: Date.now() + (opts.maxAge || 0) + }); + + return ret; + }; + + mimicFn(memoized, fn); + + cacheStore.set(memoized, opts.cache); + + return memoized; +}; + +module.exports.clear = fn => { + const cache = cacheStore.get(fn); + + if (cache && typeof cache.clear === 'function') { + cache.clear(); + } +}; diff --git a/node_modules/mem/license b/node_modules/mem/license new file mode 100644 index 000000000..654d0bfe9 --- /dev/null +++ b/node_modules/mem/license @@ -0,0 +1,21 @@ +The MIT License (MIT) + +Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (sindresorhus.com) + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. diff --git a/node_modules/mem/package.json b/node_modules/mem/package.json new file mode 100644 index 000000000..a492892c8 --- /dev/null +++ b/node_modules/mem/package.json @@ -0,0 +1,45 @@ +{ + "name": "mem", + "version": "1.1.0", + "description": "Memoize functions - An optimization used to speed up consecutive function calls by caching the result of calls with identical input", + "license": "MIT", + "repository": "sindresorhus/mem", + "author": { + "name": "Sindre Sorhus", + "email": "sindresorhus@gmail.com", + "url": "sindresorhus.com" + }, + "engines": { + "node": ">=4" + }, + "scripts": { + "test": "xo && ava" + }, + "files": [ + "index.js" + ], + "keywords": [ + "memoize", + "function", + "mem", + "memoization", + "cache", + "caching", + "optimize", + "performance", + "ttl", + "expire", + "promise" + ], + "dependencies": { + "mimic-fn": "^1.0.0" + }, + "devDependencies": { + "ava": "*", + "delay": "^1.1.0", + "xo": "*" + }, + "xo": { + "esnext": true + } +} diff --git a/node_modules/mem/readme.md b/node_modules/mem/readme.md new file mode 100644 index 000000000..7ebab84f0 --- /dev/null +++ b/node_modules/mem/readme.md @@ -0,0 +1,147 @@ +# mem [](https://travis-ci.org/sindresorhus/mem) + +> [Memoize](https://en.wikipedia.org/wiki/Memoization) functions - An optimization used to speed up consecutive function calls by caching the result of calls with identical input + + +## Install + +``` +$ npm install --save mem +``` + + +## Usage + +```js +const mem = require('mem'); + +let i = 0; +const counter = () => ++i; +const memoized = mem(counter); + +memoized('foo'); +//=> 1 + +// cached as it's the same arguments +memoized('foo'); +//=> 1 + +// not cached anymore as the arguments changed +memoized('bar'); +//=> 2 + +memoized('bar'); +//=> 2 +``` + +##### Works fine with promise returning functions + +```js +const mem = require('mem'); + +let i = 0; +const counter = () => Promise.resolve(++i); +const memoized = mem(counter); + +memoized().then(a => { + console.log(a); + //=> 1 + + memoized().then(b => { + // the return value didn't increase as it's cached + console.log(b); + //=> 1 + }); +}); +``` + +```js +const mem = require('mem'); +const got = require('got'); +const memGot = mem(got, {maxAge: 1000}); + +memGot('sindresorhus.com').then(() => { + // this call is cached + memGot('sindresorhus.com').then(() => { + setTimeout(() => { + // this call is not cached as the cache has expired + memGot('sindresorhus.com').then(() => {}); + }, 2000); + }); +}); +``` + + +## API + +### mem(fn, [options]) + +#### fn + +Type: `Function` + +Function to be memoized. + +#### options + +##### maxAge + +Type: `number`<br> +Default: `Infinity` + +Milliseconds until the cache expires. + +##### cacheKey + +Type: `Function` + +Determines the cache key for storing the result based on the function arguments. By default, if there's only one argument and it's a [primitive](https://developer.mozilla.org/en-US/docs/Glossary/Primitive), it's used directly as a key, otherwise it's all the function arguments JSON stringified as an array. + +You could for example change it to only cache on the first argument `x => JSON.stringify(x)`. + +##### cache + +Type: `Object`<br> +Default: `new Map()` + +Use a different cache storage. Must implement the following methods: `.has(key)`, `.get(key)`, `.set(key, value)`, and optionally `.clear()`. You could for example use a `WeakMap` instead. + +### mem.clear(fn) + +Clear all cached data of a memoized function. + +#### fn + +Type: `Function` + +Memoized function. + + +## Tips + +### Cache statistics + +If you want to know how many times your cache had a hit or a miss, you can make use of [stats-map](https://github.com/SamVerschueren/stats-map) as a replacement for the default cache. + +#### Example + +```js +const mem = require('mem'); +const StatsMap = require('stats-map'); +const got = require('got'); + +const cache = new StatsMap(); +const memGot = mem(got, {cache}); + +memGot('sindresorhus.com') + .then(() => memGot('sindresorhus.com')) + .then(() => memGot('sindresorhus.com')); + +console.log(cache.stats); +//=> {hits: 2, misses: 1} +``` + + +## License + +MIT © [Sindre Sorhus](https://sindresorhus.com) |