You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

83 lines
2.2 KiB
JavaScript

import defined from "../Core/defined.js";
import DoublyLinkedList from "../Core/DoublyLinkedList.js";
/**
* Stores tiles with content loaded.
*
* @private
*/
function Cesium3DTilesetCache() {
// [head, sentinel) -> tiles that weren't selected this frame and may be removed from the cache
// (sentinel, tail] -> tiles that were selected this frame
this._list = new DoublyLinkedList();
this._sentinel = this._list.add();
this._trimTiles = false;
}
Cesium3DTilesetCache.prototype.reset = function () {
// Move sentinel node to the tail so, at the start of the frame, all tiles
// may be potentially replaced. Tiles are moved to the right of the sentinel
// when they are selected so they will not be replaced.
this._list.splice(this._list.tail, this._sentinel);
};
Cesium3DTilesetCache.prototype.touch = function (tile) {
var node = tile.cacheNode;
if (defined(node)) {
this._list.splice(this._sentinel, node);
}
};
Cesium3DTilesetCache.prototype.add = function (tile) {
if (!defined(tile.cacheNode)) {
tile.cacheNode = this._list.add(tile);
}
};
Cesium3DTilesetCache.prototype.unloadTile = function (
tileset,
tile,
unloadCallback
) {
var node = tile.cacheNode;
if (!defined(node)) {
return;
}
this._list.remove(node);
tile.cacheNode = undefined;
unloadCallback(tileset, tile);
};
Cesium3DTilesetCache.prototype.unloadTiles = function (
tileset,
unloadCallback
) {
var trimTiles = this._trimTiles;
this._trimTiles = false;
var list = this._list;
var maximumMemoryUsageInBytes = tileset.maximumMemoryUsage * 1024 * 1024;
// Traverse the list only to the sentinel since tiles/nodes to the
// right of the sentinel were used this frame.
//
// The sub-list to the left of the sentinel is ordered from LRU to MRU.
var sentinel = this._sentinel;
var node = list.head;
while (
node !== sentinel &&
(tileset.totalMemoryUsageInBytes > maximumMemoryUsageInBytes || trimTiles)
) {
var tile = node.item;
node = node.next;
this.unloadTile(tileset, tile, unloadCallback);
}
};
Cesium3DTilesetCache.prototype.trim = function () {
this._trimTiles = true;
};
export default Cesium3DTilesetCache;