Files
openlayers/src/ol/TileCache.js

57 lines
1.3 KiB
JavaScript

/**
* @module ol/TileCache
*/
import {inherits} from './util.js';
import LRUCache from './structs/LRUCache.js';
import {fromKey, getKey} from './tilecoord.js';
/**
* @constructor
* @extends {module:ol/structs/LRUCache.<module:ol/Tile>}
* @param {number=} opt_highWaterMark High water mark.
* @struct
*/
const TileCache = function(opt_highWaterMark) {
LRUCache.call(this, opt_highWaterMark);
};
inherits(TileCache, LRUCache);
/**
* @param {!Object.<string, module:ol/TileRange>} usedTiles Used tiles.
*/
TileCache.prototype.expireCache = function(usedTiles) {
while (this.canExpireCache()) {
const tile = this.peekLast();
const zKey = tile.tileCoord[0].toString();
if (zKey in usedTiles && usedTiles[zKey].contains(tile.tileCoord)) {
break;
} else {
this.pop().dispose();
}
}
};
/**
* Prune all tiles from the cache that don't have the same z as the newest tile.
*/
TileCache.prototype.pruneExceptNewestZ = function() {
if (this.getCount() === 0) {
return;
}
const key = this.peekFirstKey();
const tileCoord = fromKey(key);
const z = tileCoord[0];
this.forEach(function(tile) {
if (tile.tileCoord[0] !== z) {
this.remove(getKey(tile.tileCoord));
tile.dispose();
}
}, this);
};
export default TileCache;