49 lines
1.1 KiB
JavaScript
49 lines
1.1 KiB
JavaScript
'use strict';
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var has = require('has');
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var uniq = require('uniqs');
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function LayerCache (opts) {
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if (!(this instanceof LayerCache)) {
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return new LayerCache(opts);
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}
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this._values = [];
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this._startIndex = opts.startIndex || 1;
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}
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function ascending (a, b) {
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return a - b;
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}
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function reduceValues (list, value, index) {
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list[value] = index + this._startIndex;
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return list;
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}
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LayerCache.prototype._findValue = function (value) {
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if (has(this._values, value)) {
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return this._values[value];
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}
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return false;
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};
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LayerCache.prototype.optimizeValues = function () {
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this._values = uniq(this._values).sort(ascending).reduce(reduceValues.bind(this), {});
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};
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LayerCache.prototype.addValue = function (value) {
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var parsedValue = parseInt(value, 10);
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// pass only valid values
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if (!parsedValue || parsedValue < 0) {
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return;
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}
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this._values.push(parsedValue);
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};
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LayerCache.prototype.getValue = function (value) {
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var parsedValue = parseInt(value, 10);
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return this._findValue(parsedValue) || value;
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};
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module.exports = LayerCache;
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