82 lines
2.0 KiB
JavaScript
82 lines
2.0 KiB
JavaScript
/**
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@license
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Copyright (c) 2022 trading_peter
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This program is available under Apache License Version 2.0
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*/
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const data = new Map();
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const instancesPerKey = new Map();
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/**
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* # Store
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*
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* A simple key value store.
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*/
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export const Store = function(superClass) {
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return class extends superClass {
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storeSubscribe(keys) {
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if (Array.isArray(keys) === false) {
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keys = [ keys ];
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}
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keys.forEach(key => {
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let targetProperty;
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if (typeof key === 'object') {
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targetProperty = key.targetProperty;
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key = key.key;
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}
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this._addInstance(this, key, targetProperty);
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});
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}
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storeUpdated(key, newValue, targetProperty) {
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this[targetProperty || key] = newValue;
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}
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storeWrite(key, value) {
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this._writeKey(key, value);
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}
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disconnectedCallback() {
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super.disconnectedCallback();
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// Clean up all references to this instance.
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instancesPerKey.forEach((instances, key) => {
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const remainingInstances = instances.filter(entry => entry.instance !== this);
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if (remainingInstances.length === 0) {
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instancesPerKey.delete(key);
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} else {
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instancesPerKey.set(key, remainingInstances);
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}
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});
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}
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_addInstance(instance, key, targetProperty) {
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if (instancesPerKey.has(key) === false) {
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instancesPerKey.set(key, [ { instance, targetProperty } ]);
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} else {
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instancesPerKey.get(key).push({ instance, targetProperty });
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}
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if (data.has(key)) {
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this._notifyInstance(instance, key, data.get(key), targetProperty);
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}
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}
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_writeKey(key, value) {
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data.set(key, value);
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const instances = instancesPerKey.get(key);
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if (Array.isArray(instances)) {
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instances.forEach(entry => {
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this._notifyInstance(entry.instance, key, value, entry.targetProperty);
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});
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}
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}
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_notifyInstance(instance, key, value, targetProperty) {
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instance.storeUpdated(key, value, targetProperty);
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}
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};
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}
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