85 lines
2.4 KiB
JavaScript
85 lines
2.4 KiB
JavaScript
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/**
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* Implements a simple priority queue
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*/
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class FetchQueue {
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constructor() {
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this._queue = {}
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// this._debug = true
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}
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/**
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* Adds item to the queue
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*
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* @param {string} id ID for the queue item
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* @param {*} data Data for the item
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* @param {int} priority Priority in the queue (the lower the number the higher the priority)
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*/
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add(id, data, priority) {
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// @BOGUS only happens on actual plasma desktop, never in the simulator
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if (typeof(data) === 'undefined') {
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return
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}
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if (this._queue[id] && this._queue[id].priority < priority) {
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// Already exists with higher priority, don't lower it by accident
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return
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}
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this._queue[id] = {
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// Looks silly. But alas sometimes if you just do a "data: data" it will
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// store the whole queue-item as empty and therefore undefined. Don't know
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// why. Looks like there could be an issue if the key is a file-ID instead
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// of the album?? - Spend to much time on it already. This works.
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data: {
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"album": data.album,
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"albumartist": data.albumartist,
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"artist": data.artist,
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"file": data.file,
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},
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priority: priority
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}
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this._debugMsg(`Added ${id} with priority ${priority}`)
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}
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/**
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* Returns the next item in the queue by highest priority
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*
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* @returns Data of the item in the queue
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*/
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next() {
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let keys = Object.keys(this._queue);
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if (!keys || keys.length === 0)
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return false;
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let nextItem
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// let nextItem = this._queue[keys[0]]
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keys.forEach(key => {
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if (!nextItem) {
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nextItem = this._queue[key]
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}
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else {
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if (this._queue[key].priority < nextItem.priority) {
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nextItem = this._queue[key]
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}
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}
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}, this)
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this._debugMsg(`next() returned ${nextItem.data.file} with priority ${nextItem.priority}`)
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return nextItem.data
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}
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/**
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* Deletes item from queue
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*
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* @param {string} id Id in queue
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*/
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delete(id) {
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delete this._queue[id]
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}
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_debugMsg(msg) {
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if (!this._debug) {
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return
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}
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console.log("FetchQueue - " + msg)
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}
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}
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