three
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JavaScript 3D library
345 lines (223 loc) • 7.28 kB
JavaScript
import { Cache } from './Cache.js';
import { Loader } from './Loader.js';
const loading = {};
class HttpError extends Error {
constructor( message, response ) {
super( message );
this.response = response;
}
}
/**
* A low level class for loading resources with the Fetch API, used internally by
* most loaders. It can also be used directly to load any file type that does
* not have a loader.
*
* This loader supports caching. If you want to use it, add `THREE.Cache.enabled = true;`
* once to your application.
*
* ```js
* const loader = new THREE.FileLoader();
* const data = await loader.loadAsync( 'example.txt' );
* ```
*
* @augments Loader
*/
class FileLoader extends Loader {
/**
* Constructs a new file loader.
*
* @param {LoadingManager} [manager] - The loading manager.
*/
constructor( manager ) {
super( manager );
/**
* The expected mime type.
*
* @type {string}
*/
this.mimeType = '';
/**
* The expected response type.
*
* @type {('arraybuffer'|'blob'|'document'|'json'|'')}
* @default ''
*/
this.responseType = '';
}
/**
* Starts loading from the given URL and pass the loaded response to the `onLoad()` callback.
*
* @param {string} url - The path/URL of the file to be loaded. This can also be a data URI.
* @param {function(any)} onLoad - Executed when the loading process has been finished.
* @param {onProgressCallback} [onProgress] - Executed while the loading is in progress.
* @param {onErrorCallback} [onError] - Executed when errors occur.
* @return {any|undefined} The cached resource if available.
*/
load( url, onLoad, onProgress, onError ) {
if ( url === undefined ) url = '';
if ( this.path !== undefined ) url = this.path + url;
url = this.manager.resolveURL( url );
const cached = Cache.get( url );
if ( cached !== undefined ) {
this.manager.itemStart( url );
setTimeout( () => {
if ( onLoad ) onLoad( cached );
this.manager.itemEnd( url );
}, 0 );
return cached;
}
// Check if request is duplicate
if ( loading[ url ] !== undefined ) {
loading[ url ].push( {
onLoad: onLoad,
onProgress: onProgress,
onError: onError
} );
return;
}
// Initialise array for duplicate requests
loading[ url ] = [];
loading[ url ].push( {
onLoad: onLoad,
onProgress: onProgress,
onError: onError,
} );
// create request
const req = new Request( url, {
headers: new Headers( this.requestHeader ),
credentials: this.withCredentials ? 'include' : 'same-origin',
// An abort controller could be added within a future PR
} );
// record states ( avoid data race )
const mimeType = this.mimeType;
const responseType = this.responseType;
// start the fetch
fetch( req )
.then( response => {
if ( response.status === 200 || response.status === 0 ) {
// Some browsers return HTTP Status 0 when using non-http protocol
// e.g. 'file://' or 'data://'. Handle as success.
if ( response.status === 0 ) {
console.warn( 'THREE.FileLoader: HTTP Status 0 received.' );
}
// Workaround: Checking if response.body === undefined for Alipay browser #23548
if ( typeof ReadableStream === 'undefined' || response.body === undefined || response.body.getReader === undefined ) {
return response;
}
const callbacks = loading[ url ];
const reader = response.body.getReader();
// Nginx needs X-File-Size check
// https://serverfault.com/questions/482875/why-does-nginx-remove-content-length-header-for-chunked-content
const contentLength = response.headers.get( 'X-File-Size' ) || response.headers.get( 'Content-Length' );
const total = contentLength ? parseInt( contentLength ) : 0;
const lengthComputable = total !== 0;
let loaded = 0;
// periodically read data into the new stream tracking while download progress
const stream = new ReadableStream( {
start( controller ) {
readData();
function readData() {
reader.read().then( ( { done, value } ) => {
if ( done ) {
controller.close();
} else {
loaded += value.byteLength;
const event = new ProgressEvent( 'progress', { lengthComputable, loaded, total } );
for ( let i = 0, il = callbacks.length; i < il; i ++ ) {
const callback = callbacks[ i ];
if ( callback.onProgress ) callback.onProgress( event );
}
controller.enqueue( value );
readData();
}
}, ( e ) => {
controller.error( e );
} );
}
}
} );
return new Response( stream );
} else {
throw new HttpError( `fetch for "${response.url}" responded with ${response.status}: ${response.statusText}`, response );
}
} )
.then( response => {
switch ( responseType ) {
case 'arraybuffer':
return response.arrayBuffer();
case 'blob':
return response.blob();
case 'document':
return response.text()
.then( text => {
const parser = new DOMParser();
return parser.parseFromString( text, mimeType );
} );
case 'json':
return response.json();
default:
if ( mimeType === '' ) {
return response.text();
} else {
// sniff encoding
const re = /charset="?([^;"\s]*)"?/i;
const exec = re.exec( mimeType );
const label = exec && exec[ 1 ] ? exec[ 1 ].toLowerCase() : undefined;
const decoder = new TextDecoder( label );
return response.arrayBuffer().then( ab => decoder.decode( ab ) );
}
}
} )
.then( data => {
// Add to cache only on HTTP success, so that we do not cache
// error response bodies as proper responses to requests.
Cache.add( url, data );
const callbacks = loading[ url ];
delete loading[ url ];
for ( let i = 0, il = callbacks.length; i < il; i ++ ) {
const callback = callbacks[ i ];
if ( callback.onLoad ) callback.onLoad( data );
}
} )
.catch( err => {
// Abort errors and other errors are handled the same
const callbacks = loading[ url ];
if ( callbacks === undefined ) {
// When onLoad was called and url was deleted in `loading`
this.manager.itemError( url );
throw err;
}
delete loading[ url ];
for ( let i = 0, il = callbacks.length; i < il; i ++ ) {
const callback = callbacks[ i ];
if ( callback.onError ) callback.onError( err );
}
this.manager.itemError( url );
} )
.finally( () => {
this.manager.itemEnd( url );
} );
this.manager.itemStart( url );
}
/**
* Sets the expected response type.
*
* @param {('arraybuffer'|'blob'|'document'|'json'|'')} value - The response type.
* @return {FileLoader} A reference to this file loader.
*/
setResponseType( value ) {
this.responseType = value;
return this;
}
/**
* Sets the expected mime type of the loaded file.
*
* @param {string} value - The mime type.
* @return {FileLoader} A reference to this file loader.
*/
setMimeType( value ) {
this.mimeType = value;
return this;
}
}
export { FileLoader };