71 lines
1.6 KiB
JavaScript
71 lines
1.6 KiB
JavaScript
"use strict";
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var indexOf = require("es5-ext/array/#/e-index-of")
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, create = Object.create;
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module.exports = function (length) {
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var lastId = 0, map = [[], []], cache = create(null);
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return {
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get: function (args) {
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var index = 0, set = map, i;
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while (index < length - 1) {
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i = indexOf.call(set[0], args[index]);
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if (i === -1) return null;
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set = set[1][i];
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++index;
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}
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i = indexOf.call(set[0], args[index]);
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if (i === -1) return null;
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return set[1][i] || null;
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},
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set: function (args) {
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var index = 0, set = map, i;
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while (index < length - 1) {
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i = indexOf.call(set[0], args[index]);
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if (i === -1) {
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i = set[0].push(args[index]) - 1;
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set[1].push([[], []]);
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}
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set = set[1][i];
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++index;
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}
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i = indexOf.call(set[0], args[index]);
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if (i === -1) {
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i = set[0].push(args[index]) - 1;
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}
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set[1][i] = ++lastId;
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cache[lastId] = args;
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return lastId;
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},
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delete: function (id) {
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var index = 0, set = map, i, path = [], args = cache[id];
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while (index < length - 1) {
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i = indexOf.call(set[0], args[index]);
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if (i === -1) {
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return;
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}
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path.push(set, i);
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set = set[1][i];
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++index;
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}
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i = indexOf.call(set[0], args[index]);
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if (i === -1) {
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return;
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}
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id = set[1][i];
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set[0].splice(i, 1);
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set[1].splice(i, 1);
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while (!set[0].length && path.length) {
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i = path.pop();
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set = path.pop();
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set[0].splice(i, 1);
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set[1].splice(i, 1);
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}
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delete cache[id];
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},
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clear: function () {
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map = [[], []];
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cache = create(null);
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}
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};
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};
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