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author | Minteck <contact@minteck.org> | 2022-11-28 17:14:38 +0100 |
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committer | Minteck <contact@minteck.org> | 2022-11-28 17:14:38 +0100 |
commit | 18efd30a263ec0d79a26a82cbd8c90c9f81056b7 (patch) | |
tree | aea01bf3506dda706719fc68eb37b77ed9ef3fe8 /node_modules/async/memoize.js | |
download | autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.tar.gz autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.tar.bz2 autoreport-18efd30a263ec0d79a26a82cbd8c90c9f81056b7.zip |
Diffstat (limited to 'node_modules/async/memoize.js')
-rw-r--r-- | node_modules/async/memoize.js | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/node_modules/async/memoize.js b/node_modules/async/memoize.js new file mode 100644 index 0000000..6003e41 --- /dev/null +++ b/node_modules/async/memoize.js @@ -0,0 +1,91 @@ +'use strict'; + +Object.defineProperty(exports, "__esModule", { + value: true +}); +exports.default = memoize; + +var _setImmediate = require('./internal/setImmediate.js'); + +var _setImmediate2 = _interopRequireDefault(_setImmediate); + +var _initialParams = require('./internal/initialParams.js'); + +var _initialParams2 = _interopRequireDefault(_initialParams); + +var _wrapAsync = require('./internal/wrapAsync.js'); + +var _wrapAsync2 = _interopRequireDefault(_wrapAsync); + +function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } + +/** + * Caches the results of an async function. When creating a hash to store + * function results against, the callback is omitted from the hash and an + * optional hash function can be used. + * + * **Note: if the async function errs, the result will not be cached and + * subsequent calls will call the wrapped function.** + * + * If no hash function is specified, the first argument is used as a hash key, + * which may work reasonably if it is a string or a data type that converts to a + * distinct string. Note that objects and arrays will not behave reasonably. + * Neither will cases where the other arguments are significant. In such cases, + * specify your own hash function. + * + * The cache of results is exposed as the `memo` property of the function + * returned by `memoize`. + * + * @name memoize + * @static + * @memberOf module:Utils + * @method + * @category Util + * @param {AsyncFunction} fn - The async function to proxy and cache results from. + * @param {Function} hasher - An optional function for generating a custom hash + * for storing results. It has all the arguments applied to it apart from the + * callback, and must be synchronous. + * @returns {AsyncFunction} a memoized version of `fn` + * @example + * + * var slow_fn = function(name, callback) { + * // do something + * callback(null, result); + * }; + * var fn = async.memoize(slow_fn); + * + * // fn can now be used as if it were slow_fn + * fn('some name', function() { + * // callback + * }); + */ +function memoize(fn, hasher = v => v) { + var memo = Object.create(null); + var queues = Object.create(null); + var _fn = (0, _wrapAsync2.default)(fn); + var memoized = (0, _initialParams2.default)((args, callback) => { + var key = hasher(...args); + if (key in memo) { + (0, _setImmediate2.default)(() => callback(null, ...memo[key])); + } else if (key in queues) { + queues[key].push(callback); + } else { + queues[key] = [callback]; + _fn(...args, (err, ...resultArgs) => { + // #1465 don't memoize if an error occurred + if (!err) { + memo[key] = resultArgs; + } + var q = queues[key]; + delete queues[key]; + for (var i = 0, l = q.length; i < l; i++) { + q[i](err, ...resultArgs); + } + }); + } + }); + memoized.memo = memo; + memoized.unmemoized = fn; + return memoized; +} +module.exports = exports['default'];
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