hexo/node_modules/workbox-range-requests/utils/calculateEffectiveBoundarie...

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2023-10-03 11:14:36 +08:00
/*
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 '../_version.js';
/**
* @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) {
if (process.env.NODE_ENV !== 'production') {
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('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,
};
}
export { calculateEffectiveBoundaries };