63 lines
2 KiB
TypeScript
63 lines
2 KiB
TypeScript
import { IdbLocalStorage } from "../../Web/IdbLocalStorage"
|
|
import { UIEventSource } from "../../UIEventSource"
|
|
|
|
/**
|
|
* A class which allows to read/write a tile to local storage.
|
|
*
|
|
* Does the heavy lifting for LocalStorageFeatureSource and SaveFeatureToLocalStorage
|
|
*/
|
|
export default class TileLocalStorage<T> {
|
|
private static perLayer: Record<string, TileLocalStorage<any>> = {}
|
|
private readonly _layername: string
|
|
private readonly cachedSources: Record<number, UIEventSource<T>> = {}
|
|
|
|
private constructor(layername: string) {
|
|
this._layername = layername
|
|
}
|
|
|
|
public static construct<T>(layername: string): TileLocalStorage<T> {
|
|
const cached = TileLocalStorage.perLayer[layername]
|
|
if (cached) {
|
|
return cached
|
|
}
|
|
|
|
const tls = new TileLocalStorage<T>(layername)
|
|
TileLocalStorage.perLayer[layername] = tls
|
|
return tls
|
|
}
|
|
|
|
/**
|
|
* Constructs a UIEventSource element which is synced with localStorage
|
|
* @param layername
|
|
* @param tileIndex
|
|
*/
|
|
public getTileSource(tileIndex: number): UIEventSource<T> {
|
|
const cached = this.cachedSources[tileIndex]
|
|
if (cached) {
|
|
return cached
|
|
}
|
|
const src = UIEventSource.FromPromise(this.GetIdb(tileIndex))
|
|
src.addCallbackD((data) => this.SetIdb(tileIndex, data))
|
|
this.cachedSources[tileIndex] = src
|
|
return src
|
|
}
|
|
|
|
private SetIdb(tileIndex: number, data): void {
|
|
try {
|
|
IdbLocalStorage.SetDirectly(this._layername + "_" + tileIndex, data)
|
|
} catch (e) {
|
|
console.error(
|
|
"Could not save tile to indexed-db: ",
|
|
e,
|
|
"tileIndex is:",
|
|
tileIndex,
|
|
"for layer",
|
|
this._layername
|
|
)
|
|
}
|
|
}
|
|
|
|
private GetIdb(tileIndex: number): Promise<any> {
|
|
return IdbLocalStorage.GetDirectly(this._layername + "_" + tileIndex)
|
|
}
|
|
}
|