xo-vmdk-to-vhd/dist/definitions.js

JS lib reading and writing .vmdk and .ova files

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.compressionNone = exports.compressionDeflate = exports.SECTOR_SIZE = exports.MARKER_GT = exports.MARKER_GD = exports.MARKER_FOOTER = exports.MARKER_EOS = void 0;
exports.createStreamOptimizedHeader = createStreamOptimizedHeader;
exports.parseFlags = parseFlags;
exports.parseU64b = parseU64b;
exports.unpackHeader = unpackHeader;
const SECTOR_SIZE = exports.SECTOR_SIZE = 512;
const compressionDeflate = exports.compressionDeflate = 'COMPRESSION_DEFLATE';
const compressionNone = exports.compressionNone = 'COMPRESSION_NONE';
const MARKER_EOS = exports.MARKER_EOS = 0;
const MARKER_GT = exports.MARKER_GT = 1;
const MARKER_GD = exports.MARKER_GD = 2;
const MARKER_FOOTER = exports.MARKER_FOOTER = 3;
const compressionMap = [compressionNone, compressionDeflate];
function parseFlags(flagBuffer) {
  const number = flagBuffer.readUInt32LE(0);
  return {
    newLineTest: !!(number & 1 << 0),
    useSecondaryGrain: !!(number & 1 << 1),
    useZeroedGrainTable: !!(number & 1 << 2),
    compressedGrains: !!(number & 1 << 16),
    hasMarkers: !!(number & 1 << 17)
  };
}
function parseS64b(buffer, offset, valueName) {
  const extraBits = buffer.readIntLE(offset + 6, 2);
  const value = buffer.readIntLE(offset, 6);
  const hadValueInHighBytes = !(extraBits === 0 || extraBits === -1);
  const readWrongSign = Math.sign(value) * Math.sign(extraBits) < 0;
  if (hadValueInHighBytes || readWrongSign) {
    throw new Error('Unsupported VMDK, ' + valueName + ' is too big');
  }
  return value;
}
function parseU64b(buffer, offset, valueName) {
  const extraBits = buffer.readUIntLE(offset + 6, 2);
  const value = buffer.readUIntLE(offset, 6);
  if (extraBits > 0) {
    throw new Error('Unsupported VMDK, ' + valueName + ' is too big');
  }
  return value;
}
function unpackHeader(buffer) {
  const magicString = buffer.slice(0, 4).toString('ascii');
  if (magicString !== 'KDMV') {
    throw new Error('not a VMDK file');
  }
  const version = buffer.readUInt32LE(4);
  if (version !== 1 && version !== 3) {
    throw new Error('unsupported VMDK version ' + version + ', only version 1 and 3 are supported');
  }
  const flags = parseFlags(buffer.slice(8, 12));
  const capacitySectors = parseU64b(buffer, 12, 'capacitySectors');
  const grainSizeSectors = parseU64b(buffer, 20, 'grainSizeSectors');
  const descriptorOffsetSectors = parseU64b(buffer, 28, 'descriptorOffsetSectors');
  const descriptorSizeSectors = parseU64b(buffer, 36, 'descriptorSizeSectors');
  const numGTEsPerGT = buffer.readUInt32LE(44);
  const rGrainDirectoryOffsetSectors = parseS64b(buffer, 48, 'rGrainDirectoryOffsetSectors');
  const grainDirectoryOffsetSectors = parseS64b(buffer, 56, 'grainDirectoryOffsetSectors');
  const overheadSectors = parseS64b(buffer, 64, 'overheadSectors');
  const compressionMethod = compressionMap[buffer.readUInt16LE(77)];
  const l1EntrySectors = numGTEsPerGT * grainSizeSectors;
  return {
    magicString,
    version,
    flags,
    compressionMethod,
    grainSizeSectors,
    overheadSectors,
    capacitySectors,
    descriptorOffsetSectors,
    descriptorSizeSectors,
    grainDirectoryOffsetSectors,
    rGrainDirectoryOffsetSectors,
    l1EntrySectors,
    numGTEsPerGT
  };
}
function createStreamOptimizedHeader(capacitySectors, descriptorSizeSectors, grainDirectoryOffsetSectors = -1, rGrainDirectoryOffsetSectors = 0) {
  const headerBuffer = Buffer.alloc(SECTOR_SIZE);
  Buffer.from('KDMV', 'ascii').copy(headerBuffer, 0);
  headerBuffer.writeUInt32LE(3, 4);
  const flags = 1 | 1 << 1 | 1 << 16 | 1 << 17;
  headerBuffer.writeUInt32LE(flags, 8);
  headerBuffer.writeBigUInt64LE(BigInt(capacitySectors), 12);
  const grainSizeSectors = 128;
  headerBuffer.writeBigUInt64LE(BigInt(grainSizeSectors), 20);
  const descriptorOffsetSectors = 1;
  headerBuffer.writeBigUInt64LE(BigInt(descriptorOffsetSectors), 28);
  headerBuffer.writeBigUInt64LE(BigInt(descriptorSizeSectors), 36);
  const numGTEsPerGT = 512;
  headerBuffer.writeUInt32LE(numGTEsPerGT, 44);
  headerBuffer.writeBigInt64LE(BigInt(rGrainDirectoryOffsetSectors), 48);
  headerBuffer.writeBigInt64LE(BigInt(grainDirectoryOffsetSectors), 56);
  const grainDirectoryEntries = Math.ceil(Math.ceil(capacitySectors / grainSizeSectors) / numGTEsPerGT);
  const grainTableEntries = grainDirectoryEntries * numGTEsPerGT;
  const grainDirectorySizeSectors = Math.ceil(grainDirectoryEntries * 4 / SECTOR_SIZE);
  const grainTableSizeSectors = Math.ceil(grainTableEntries * 4 / SECTOR_SIZE);
  let overheadSectors = 1 + descriptorSizeSectors;
  if (grainDirectoryOffsetSectors > 0) {
    overheadSectors += grainDirectorySizeSectors + grainTableSizeSectors;
  }
  headerBuffer.writeBigInt64LE(BigInt(overheadSectors), 64);
  headerBuffer.write('\n \r\n', 73, 4, 'ascii');
  headerBuffer.writeUInt16LE(1, 77);
  return {
    buffer: headerBuffer,
    grainDirectorySizeSectors,
    grainTableSizeSectors,
    grainDirectoryEntries,
    grainTableEntries
  };
}
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