58 lines
1.2 KiB
JavaScript
58 lines
1.2 KiB
JavaScript
goog.provide('ol.TileCache');
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goog.require('ol.Tile');
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goog.require('ol.TileRange');
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goog.require('ol.structs.LRUCache');
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/**
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* @define {number} Default high water mark.
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*/
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ol.DEFAULT_TILE_CACHE_HIGH_WATER_MARK = 2048;
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/**
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* @constructor
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* @extends {ol.structs.LRUCache}
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* @param {number=} opt_highWaterMark High water mark.
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*/
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ol.TileCache = function(opt_highWaterMark) {
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goog.base(this);
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/**
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* @private
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* @type {number}
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*/
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this.highWaterMark_ = goog.isDef(opt_highWaterMark) ?
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opt_highWaterMark : ol.DEFAULT_TILE_CACHE_HIGH_WATER_MARK;
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};
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goog.inherits(ol.TileCache, ol.structs.LRUCache);
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/**
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* @return {boolean} Can expire cache.
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*/
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ol.TileCache.prototype.canExpireCache = function() {
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return this.getCount() > this.highWaterMark_;
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};
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/**
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* @param {Object.<string, ol.TileRange>} usedTiles Used tiles.
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*/
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ol.TileCache.prototype.expireCache = function(usedTiles) {
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var tile, zKey;
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while (this.canExpireCache()) {
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tile = /** @type {ol.Tile} */ (this.peekLast());
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zKey = tile.tileCoord.z.toString();
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if (zKey in usedTiles && usedTiles[zKey].contains(tile.tileCoord)) {
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break;
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} else {
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this.pop();
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}
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}
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};
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