@loaders.gl/tiles/dist/tileset/format-i3s/i3s-tile-manager.js

Common components for different tiles loaders.

import { I3SPendingTilesRegister } from "./i3s-pending-tiles-register.js";
const STATUS = {
    REQUESTED: 'REQUESTED',
    COMPLETED: 'COMPLETED',
    ERROR: 'ERROR'
};
// A helper class to manage tile metadata fetching
export class I3STileManager {
    _statusMap;
    pendingTilesRegister = new I3SPendingTilesRegister();
    constructor() {
        this._statusMap = {};
    }
    /**
     * Add request to map
     * @param request - node metadata request
     * @param key - unique key
     * @param callback - callback after request completed
     * @param frameState - frameState data
     */
    add(request, key, callback, frameState) {
        if (!this._statusMap[key]) {
            const { frameNumber, viewport: { id } } = frameState;
            this._statusMap[key] = { request, callback, key, frameState, status: STATUS.REQUESTED };
            // Register pending request for the frameNumber
            this.pendingTilesRegister.register(id, frameNumber);
            request()
                .then((data) => {
                this._statusMap[key].status = STATUS.COMPLETED;
                const { frameNumber: actualFrameNumber, viewport: { id } } = this._statusMap[key].frameState;
                // Deregister pending request for the frameNumber
                this.pendingTilesRegister.deregister(id, actualFrameNumber);
                this._statusMap[key].callback(data, frameState);
            })
                .catch((error) => {
                this._statusMap[key].status = STATUS.ERROR;
                const { frameNumber: actualFrameNumber, viewport: { id } } = this._statusMap[key].frameState;
                // Deregister pending request for the frameNumber
                this.pendingTilesRegister.deregister(id, actualFrameNumber);
                callback(error);
            });
        }
    }
    /**
     * Update request if it is still actual for the new frameState
     * @param key - unique key
     * @param frameState - frameState data
     */
    update(key, frameState) {
        if (this._statusMap[key]) {
            // Deregister pending request for the old frameNumber
            const { frameNumber, viewport: { id } } = this._statusMap[key].frameState;
            this.pendingTilesRegister.deregister(id, frameNumber);
            // Register pending request for the new frameNumber
            const { frameNumber: newFrameNumber, viewport: { id: newViewportId } } = frameState;
            this.pendingTilesRegister.register(newViewportId, newFrameNumber);
            this._statusMap[key].frameState = frameState;
        }
    }
    /**
     * Find request in the map
     * @param key - unique key
     * @returns
     */
    find(key) {
        return this._statusMap[key];
    }
    /**
     * Check it there are pending tile headers for the particular frameNumber
     * @param viewportId
     * @param frameNumber
     * @returns
     */
    hasPendingTiles(viewportId, frameNumber) {
        return !this.pendingTilesRegister.isZero(viewportId, frameNumber);
    }
}