58 lines
1.8 KiB
JavaScript
58 lines
1.8 KiB
JavaScript
|
/*
|
||
|
|
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 };
|