48 lines
1.5 KiB
JavaScript
48 lines
1.5 KiB
JavaScript
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/*
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Copyright 2018 Google LLC
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Use of this source code is governed by an MIT-style
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license that can be found in the LICENSE file or at
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https://opensource.org/licenses/MIT.
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*/
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import {createPartialResponse} from './createPartialResponse.mjs';
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import './_version.mjs';
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/**
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* The range request plugin makes it easy for a request with a 'Range' header to
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* be fulfilled by a cached response.
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*
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* It does this by intercepting the `cachedResponseWillBeUsed` plugin callback
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* and returning the appropriate subset of the cached response body.
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*
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* @memberof workbox.rangeRequests
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*/
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class Plugin {
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/**
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* @param {Object} options
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* @param {Request} options.request The original request, which may or may not
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* contain a Range: header.
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* @param {Response} options.cachedResponse The complete cached response.
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* @return {Promise<Response>} If request contains a 'Range' header, then a
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* new response with status 206 whose body is a subset of `cachedResponse` is
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* returned. Otherwise, `cachedResponse` is returned as-is.
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*
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* @private
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*/
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async cachedResponseWillBeUsed({request, cachedResponse}) {
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// Only return a sliced response if there's something valid in the cache,
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// and there's a Range: header in the request.
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if (cachedResponse && request.headers.has('range')) {
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return await createPartialResponse(request, cachedResponse);
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}
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// If there was no Range: header, or if cachedResponse wasn't valid, just
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// pass it through as-is.
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return cachedResponse;
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}
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}
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export {Plugin};
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