etcher-sdk
Version:
50 lines • 2.18 kB
JavaScript
;
/*
* Copyright 2018 balena.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.GZipSource = void 0;
const zlib_1 = require("zlib");
const compressed_source_1 = require("./compressed-source");
const source_destination_1 = require("./source-destination");
const ISIZE_LENGTH = 4;
class GZipSource extends compressed_source_1.CompressedSource {
createTransform() {
return (0, zlib_1.createGunzip)();
}
async getSize() {
const sizeFromPartitionTable = await this.getSizeFromPartitionTable();
if (await this.source.canRead()) {
const sourceMetadata = await this.source.getMetadata();
if (sourceMetadata.size !== undefined) {
const { buffer } = await this.source.read(Buffer.allocUnsafe(ISIZE_LENGTH), 0, ISIZE_LENGTH, sourceMetadata.size - ISIZE_LENGTH);
const sizeFromFooter = buffer.readUInt32LE(0);
// The size from the gzip footer can't be larger than 4GiB (it is stored in 4 bytes)
// Use the size from the partition table is it is larger (and available)
return {
size: Math.max(sizeFromFooter, sizeFromPartitionTable || 0),
isEstimated: true,
};
}
}
else if (sizeFromPartitionTable !== undefined) {
return { size: sizeFromPartitionTable, isEstimated: true };
}
}
}
exports.GZipSource = GZipSource;
GZipSource.mimetype = 'application/gzip';
source_destination_1.SourceDestination.register(GZipSource);
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