etcher-sdk
Version:
132 lines • 5.15 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.DmgSource = void 0;
const udif_1 = require("@balena/udif");
const source_destination_1 = require("./source-destination");
const source_source_1 = require("./source-source");
const block_transform_stream_1 = require("../block-transform-stream");
const constants_1 = require("../constants");
const errors_1 = require("../errors");
const shared_1 = require("../sparse-stream/shared");
const sparse_transform_stream_1 = require("../sparse-stream/sparse-transform-stream");
class DmgSource extends source_source_1.SourceSource {
constructor(source) {
super(source);
}
async canCreateReadStream() {
return true;
}
async canCreateSparseReadStream() {
return true;
}
async createReadStream({ start = 0, end, alignment, numBuffers, } = {}) {
if (start !== 0) {
throw new errors_1.NotCapable();
}
const stream = await this.image.createReadStream(end);
return block_transform_stream_1.BlockTransformStream.alignIfNeeded(stream, alignment, numBuffers);
}
async createSparseReadStream({ alignment, numBuffers, } = {}) {
const blocks = await this.getBlocks();
const stream = Object.assign(await this.image.createSparseReadStream(), {
blocks,
});
if (alignment !== undefined) {
const transform = new sparse_transform_stream_1.ProgressSparseTransformStream({
blocks,
chunkSize: constants_1.CHUNK_SIZE,
alignment,
numBuffers,
});
stream.on('error', transform.emit.bind(transform, 'error'));
stream.pipe(transform);
return transform;
}
else {
return stream;
}
}
async getBlocks() {
const result = [];
for (const blk of this.image.resourceFork.blkx) {
const childBlocks = blk.map.blocks.filter((b) => DmgSource.mappedBlockTypes.includes(b.type));
if (childBlocks.length === 0) {
continue;
}
let checksumType;
let checksum;
if (blk.map.checksum.type === udif_1.CHECKSUM_TYPE.CRC32) {
checksumType = 'crc32';
checksum = blk.map.checksum.value;
}
const blocks = [];
result.push({ checksumType, checksum, blocks });
let lastBlock;
for (const childBlk of childBlocks) {
const offset = (blk.map.sectorNumber + childBlk.sectorNumber) * udif_1.SECTOR_SIZE;
const length = childBlk.sectorCount * udif_1.SECTOR_SIZE;
if (lastBlock === undefined) {
// First iteration of the loop
lastBlock = { offset, length };
}
else if (lastBlock.offset + lastBlock.length === offset) {
// Last block and this block are adjacent, increase last block's length
lastBlock.length += length;
}
else {
// Last block and this block are not adjacent:
blocks.push(lastBlock);
lastBlock = { offset, length };
}
}
// ! because we know lastBlock can't be undefined
blocks.push(lastBlock);
}
return result;
}
async _getMetadata() {
const blocks = await this.getBlocks();
const blockmappedSize = (0, shared_1.blocksLength)(blocks);
const compressedSize = (await this.source.getMetadata()).size;
const size = await this.image.getUncompressedSize();
return { blocks, blockmappedSize, compressedSize, size };
}
async _open() {
await super._open();
this.image = new udif_1.Image({
size: (await this.source.getMetadata()).size,
createReadStream: async (start, end) => {
return await this.source.createReadStream({ start, end });
},
});
await this.image.ready;
}
}
exports.DmgSource = DmgSource;
DmgSource.mappedBlockTypes = [
udif_1.BLOCK.ZEROFILL,
udif_1.BLOCK.RAW,
udif_1.BLOCK.UDCO,
udif_1.BLOCK.UDZO,
udif_1.BLOCK.UDBZ,
udif_1.BLOCK.LZFSE,
];
DmgSource.requiresRandomReadableSource = true;
DmgSource.mimetype = 'application/x-apple-diskimage';
source_destination_1.SourceDestination.register(DmgSource);
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