workbox-range-requests.dev.js
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this.workbox = this.workbox || {};
this.workbox.rangeRequests = (function (exports, WorkboxError_js, assert_js, logger_js) {
'use strict';
try {
self['workbox:range-requests:5.1.4'] && _();
} catch (e) {}
/*
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.
*/
/**
* @param {Blob} blob A source blob.
* @param {number} [start] The offset to use as the start of the
* slice.
* @param {number} [end] The offset to use as the end of the slice.
* @return {Object} An object with `start` and `end` properties, reflecting
* the effective boundaries to use given the size of the blob.
*
* @private
*/
function calculateEffectiveBoundaries(blob, start, end) {
{
assert_js.assert.isInstance(blob, Blob, {
moduleName: 'workbox-range-requests',
funcName: 'calculateEffectiveBoundaries',
paramName: 'blob'
});
}
const blobSize = blob.size;
if (end && end > blobSize || start && start < 0) {
throw new WorkboxError_js.WorkboxError('range-not-satisfiable', {
size: blobSize,
end,
start
});
}
let effectiveStart;
let effectiveEnd;
if (start !== undefined && end !== undefined) {
effectiveStart = start; // Range values are inclusive, so add 1 to the value.
effectiveEnd = end + 1;
} else if (start !== undefined && end === undefined) {
effectiveStart = start;
effectiveEnd = blobSize;
} else if (end !== undefined && start === undefined) {
effectiveStart = blobSize - end;
effectiveEnd = blobSize;
}
return {
start: effectiveStart,
end: effectiveEnd
};
}
/*
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.
*/
/**
* @param {string} rangeHeader A Range: header value.
* @return {Object} An object with `start` and `end` properties, reflecting
* the parsed value of the Range: header. If either the `start` or `end` are
* omitted, then `null` will be returned.
*
* @private
*/
function parseRangeHeader(rangeHeader) {
{
assert_js.assert.isType(rangeHeader, 'string', {
moduleName: 'workbox-range-requests',
funcName: 'parseRangeHeader',
paramName: 'rangeHeader'
});
}
const normalizedRangeHeader = rangeHeader.trim().toLowerCase();
if (!normalizedRangeHeader.startsWith('bytes=')) {
throw new WorkboxError_js.WorkboxError('unit-must-be-bytes', {
normalizedRangeHeader
});
} // Specifying multiple ranges separate by commas is valid syntax, but this
// library only attempts to handle a single, contiguous sequence of bytes.
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range#Syntax
if (normalizedRangeHeader.includes(',')) {
throw new WorkboxError_js.WorkboxError('single-range-only', {
normalizedRangeHeader
});
}
const rangeParts = /(\d*)-(\d*)/.exec(normalizedRangeHeader); // We need either at least one of the start or end values.
if (!rangeParts || !(rangeParts[1] || rangeParts[2])) {
throw new WorkboxError_js.WorkboxError('invalid-range-values', {
normalizedRangeHeader
});
}
return {
start: rangeParts[1] === '' ? undefined : Number(rangeParts[1]),
end: rangeParts[2] === '' ? undefined : Number(rangeParts[2])
};
}
/*
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.
*/
/**
* 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 ("dev" !== 'production') {
assert_js.assert.isInstance(request, Request, {
moduleName: 'workbox-range-requests',
funcName: 'createPartialResponse',
paramName: 'request'
});
assert_js.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_js.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) {
{
logger_js.logger.warn(`Unable to construct a partial response; returning a ` + `416 Range Not Satisfiable response instead.`);
logger_js.logger.groupCollapsed(`View details here.`);
logger_js.logger.log(error);
logger_js.logger.log(request);
logger_js.logger.log(originalResponse);
logger_js.logger.groupEnd();
}
return new Response('', {
status: 416,
statusText: 'Range Not Satisfiable'
});
}
}
/*
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.
*/
/**
* The range request plugin makes it easy for a request with a 'Range' header to
* be fulfilled by a cached response.
*
* It does this by intercepting the `cachedResponseWillBeUsed` plugin callback
* and returning the appropriate subset of the cached response body.
*
* @memberof module:workbox-range-requests
*/
class RangeRequestsPlugin {
constructor() {
/**
* @param {Object} options
* @param {Request} options.request The original request, which may or may not
* contain a Range: header.
* @param {Response} options.cachedResponse The complete cached response.
* @return {Promise<Response>} If request contains a 'Range' header, then a
* new response with status 206 whose body is a subset of `cachedResponse` is
* returned. Otherwise, `cachedResponse` is returned as-is.
*
* @private
*/
this.cachedResponseWillBeUsed = async ({
request,
cachedResponse
}) => {
// Only return a sliced response if there's something valid in the cache,
// and there's a Range: header in the request.
if (cachedResponse && request.headers.has('range')) {
return await createPartialResponse(request, cachedResponse);
} // If there was no Range: header, or if cachedResponse wasn't valid, just
// pass it through as-is.
return cachedResponse;
};
}
}
exports.RangeRequestsPlugin = RangeRequestsPlugin;
exports.createPartialResponse = createPartialResponse;
return exports;
}({}, workbox.core._private, workbox.core._private, workbox.core._private));
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