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- /*
- Copyright 2018 Google LLC
- Use of this source code is governed by an MIT-style
- license that can be found in the LICENSE file or at
- https://opensource.org/licenses/MIT.
- */
- import { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
- import { assert } from 'workbox-core/_private/assert.js';
- import { logger } from 'workbox-core/_private/logger.js';
- import { calculateEffectiveBoundaries } from './utils/calculateEffectiveBoundaries.js';
- import { parseRangeHeader } from './utils/parseRangeHeader.js';
- import './_version.js';
- /**
- * Given a `Request` and `Response` objects as input, this will return a
- * promise for a new `Response`.
- *
- * If the original `Response` already contains partial content (i.e. it has
- * a status of 206), then this assumes it already fulfills the `Range:`
- * requirements, and will return it as-is.
- *
- * @param {Request} request A request, which should contain a Range:
- * header.
- * @param {Response} originalResponse A response.
- * @return {Promise<Response>} Either a `206 Partial Content` response, with
- * the response body set to the slice of content specified by the request's
- * `Range:` header, or a `416 Range Not Satisfiable` response if the
- * conditions of the `Range:` header can't be met.
- *
- * @memberof module:workbox-range-requests
- */
- async function createPartialResponse(request, originalResponse) {
- try {
- if (process.env.NODE_ENV !== 'production') {
- assert.isInstance(request, Request, {
- moduleName: 'workbox-range-requests',
- funcName: 'createPartialResponse',
- paramName: 'request',
- });
- assert.isInstance(originalResponse, Response, {
- moduleName: 'workbox-range-requests',
- funcName: 'createPartialResponse',
- paramName: 'originalResponse',
- });
- }
- if (originalResponse.status === 206) {
- // If we already have a 206, then just pass it through as-is;
- // see https://github.com/GoogleChrome/workbox/issues/1720
- return originalResponse;
- }
- const rangeHeader = request.headers.get('range');
- if (!rangeHeader) {
- throw new WorkboxError('no-range-header');
- }
- const boundaries = parseRangeHeader(rangeHeader);
- const originalBlob = await originalResponse.blob();
- const effectiveBoundaries = calculateEffectiveBoundaries(originalBlob, boundaries.start, boundaries.end);
- const slicedBlob = originalBlob.slice(effectiveBoundaries.start, effectiveBoundaries.end);
- const slicedBlobSize = slicedBlob.size;
- const slicedResponse = new Response(slicedBlob, {
- // Status code 206 is for a Partial Content response.
- // See https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/206
- status: 206,
- statusText: 'Partial Content',
- headers: originalResponse.headers,
- });
- slicedResponse.headers.set('Content-Length', String(slicedBlobSize));
- slicedResponse.headers.set('Content-Range', `bytes ${effectiveBoundaries.start}-${effectiveBoundaries.end - 1}/` +
- originalBlob.size);
- return slicedResponse;
- }
- catch (error) {
- if (process.env.NODE_ENV !== 'production') {
- logger.warn(`Unable to construct a partial response; returning a ` +
- `416 Range Not Satisfiable response instead.`);
- logger.groupCollapsed(`View details here.`);
- logger.log(error);
- logger.log(request);
- logger.log(originalResponse);
- logger.groupEnd();
- }
- return new Response('', {
- status: 416,
- statusText: 'Range Not Satisfiable',
- });
- }
- }
- export { createPartialResponse };
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