48 lines
1.9 KiB
JavaScript
48 lines
1.9 KiB
JavaScript
/*
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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 { WorkboxError } from 'workbox-core/_private/WorkboxError.js';
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import { assert } from 'workbox-core/_private/assert.js';
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import '../_version.js';
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/**
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* @param {string} rangeHeader A Range: header value.
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* @return {Object} An object with `start` and `end` properties, reflecting
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* the parsed value of the Range: header. If either the `start` or `end` are
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* omitted, then `null` will be returned.
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*
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* @private
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*/
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function parseRangeHeader(rangeHeader) {
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if (process.env.NODE_ENV !== 'production') {
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assert.isType(rangeHeader, 'string', {
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moduleName: 'workbox-range-requests',
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funcName: 'parseRangeHeader',
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paramName: 'rangeHeader',
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});
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}
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const normalizedRangeHeader = rangeHeader.trim().toLowerCase();
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if (!normalizedRangeHeader.startsWith('bytes=')) {
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throw new WorkboxError('unit-must-be-bytes', { normalizedRangeHeader });
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}
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// Specifying multiple ranges separate by commas is valid syntax, but this
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// library only attempts to handle a single, contiguous sequence of bytes.
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// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range#Syntax
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if (normalizedRangeHeader.includes(',')) {
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throw new WorkboxError('single-range-only', { normalizedRangeHeader });
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}
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const rangeParts = /(\d*)-(\d*)/.exec(normalizedRangeHeader);
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// We need either at least one of the start or end values.
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if (!rangeParts || !(rangeParts[1] || rangeParts[2])) {
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throw new WorkboxError('invalid-range-values', { normalizedRangeHeader });
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}
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return {
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start: rangeParts[1] === '' ? undefined : Number(rangeParts[1]),
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end: rangeParts[2] === '' ? undefined : Number(rangeParts[2]),
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};
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}
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export { parseRangeHeader };
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