@balena/udif

中文文档

1.1.2发布于 2021/10/07MITCommonJS近 30 天下载 1.1万

苹果通用磁盘图像格式(UDIF/DMG)

文档目录12 节

通过无
用于
使用量
打开 .dmg 图像
确定未压缩大小
创建可读流
提取原始磁盘图像
分层流
使用自定义文件系统
检查UDIF页脚
检查 XML 元数据
参考资料

苹果通用磁盘图像格式(UDIF/DMG)

通过无

$ npm install --save @balena/udif

用于

伊彻支持 Apple 磁盘图像格式 (.dmg)

使用量

import * as UDIF from '@balena/udif';

打开 .dmg 图像

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    // ...
});

确定未压缩大小

注意图像必须打开来确定未压缩大小, 因为它是从资源分叉读取的.

return await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    return await image.getUncompressedSize();
});

创建可读流

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    const readableStream = await image.createReadStream();
});

提取原始磁盘图像

提取未压缩的原始磁盘图像 .dmg 文件变得与以下文件一样容易:

import * as UDIF from '@balena/udif';
import { pipeline } from 'stream';
import { promisify } from 'util';

const pipelineAsync = promisify(pipeline);

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    await pipelineAsync(
        await image.createReadStream(),
        fs.createWriteStream('/path/to/destination.img'),
    );
});

分层流

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    const sparseStream = await image.createSparseReadStream();
});

Sparse 读取流在 objectMode 将射出形状的物体 { buffer, position }。。。 . 这表示你需要一个写字的溪流同时在 objectMode 并知道如何处理这些. 为了简洁起见,以下例子仅表明将块属性传递给 fs.write()· ;

sparseStream.on('data', (chunk) => {
    fs.writeSync(fd, chunk.buffer, 0, chunk.buffer.length, chunk.position);
})

使用自定义文件系统

import * as UDIF from '@balena/udif';
import * as fs from 'fs';

const fd = fs.openSync('path/to/image.dmg', 'r');
const size = fs.fstatSync(fd).size;

const dmg = new UDIF.Image({
    size,
    createReadStream: async (start: number, end: number) => {
        return fs.createReadStream('', { fd, start, end, autoClose: false });
    },
})
await dmg.ready;

// ...

fs.closeSync(fd);

页脚( aka "Koly Block" ) 中包含指向 XML 元数据, 数据分叉和资源分叉以及校验和.

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    console.log(image.footer)
});

KolyBlock {
  signature: 1802464377,
  version: 4,
  headerSize: 512,
  flags: 1,
  runningDataForkOffset: 0,
  dataForkOffset: 0,
  dataForkLength: 6585140266,
  resourceForkOffset: 0,
  resourceForkLength: 0,
  segmentNumber: 1,
  segmentCount: 1,
  segmentId: <Buffer 18 66 9e 31 fa 6 d 4 f 7 d aa d0 f2 50 12 8 f 49 54>,
  dataChecksum: Checksum { type: 2, bits: 32, value: 'c2208200' },
  xmlOffset: 6585140266,
  xmlLength: 1752206,
  reserved1: <Buffer 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ...>,
  checksum: Checksum { type: 2, bits: 32, value: '3f40bb47' },
  imageVariant: 1,
  sectorCount: 15178432,
  reserved2: 0,
  reserved3: 0,
  reserved4: 0,
}

检查 XML 元数据

XML 数据为属性列表,(或列表),其中包含块图 resource-fork.blkx。。。 .

await UDIF.withOpenImage('path/to/image.dmg', async (image) => {
    console.log(image.resourceFork)
});

{
  blkx: [{
    id: -1,
    attributes: 80,
    name: 'Driver Descriptor Map (DDM : 0)',
    coreFoundationName: 'Driver Descriptor Map (DDM : 0)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 0,
      sectorCount: 1,
      dataOffset: 0,
      buffersNeeded: 520,
      blockDescriptorCount: 0,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: '698a85ed' },
      blockCount: 2,
      blocks: [
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 1,
          compressedOffset: 0,
          compressedLength: 22
        },
        Block {
          type: 4294967295,
          description: 'TERMINATOR',
          comment: '',
          sectorNumber: 1,
          sectorCount: 0,
          compressedOffset: 22,
          compressedLength: 0
        }
      ]
    }
  }, {
    id: 0,
    attributes: 80,
    name: 'WINDOWSSUPPORT (Apple_ISO : 1)',
    coreFoundationName: 'WINDOWSSUPPORT (Apple_ISO : 1)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 1,
      sectorCount: 3,
      dataOffset: 0,
      buffersNeeded: 520,
      blockDescriptorCount: 1,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: '6c1ce17e' },
      blockCount: 2,
      blocks: [
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 3,
          compressedOffset: 22,
          compressedLength: 24
        },
        Block {
          type: 4294967295,
          description: 'TERMINATOR',
          comment: '',
          sectorNumber: 3,
          sectorCount: 0,
          compressedOffset: 46,
          compressedLength: 0
        }
      ]
    }
  }, {
    id: 1,
    attributes: 80,
    name: 'Apple (Apple_partition_map : 2)',
    coreFoundationName: 'Apple (Apple_partition_map : 2)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 4,
      sectorCount: 60,
      dataOffset: 0,
      buffersNeeded: 520,
      blockDescriptorCount: 2,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: '115fc68e' },
      blockCount: 2,
      blocks: [
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 60,
          compressedOffset: 46,
          compressedLength: 358
        },
        Block {
          type: 4294967295,
          description: 'TERMINATOR',
          comment: '',
          sectorNumber: 60,
          sectorCount: 0,
          compressedOffset: 404,
          compressedLength: 0
        }
      ]
    }
  }, {
    id: 2,
    attributes: 80,
    name: 'Macintosh (Apple_Driver_ATAPI : 3)',
    coreFoundationName: 'Macintosh (Apple_Driver_ATAPI : 3)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 64,
      sectorCount: 2020420,
      dataOffset: 0,
      buffersNeeded: 520,
      blockDescriptorCount: 3,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: 'b2bb86f8' },
      blockCount: 3948,
      blocks: [
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 512,
          compressedOffset: 404,
          compressedLength: 25147
        },
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 512,
          sectorCount: 512,
          compressedOffset: 25551,
          compressedLength: 29149
        },
        ... more items
      ]
    }
  }, {
    id: 3,
    attributes: 80,
    name: ' (Apple_Free : 4)',
    coreFoundationName: ' (Apple_Free : 4)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 2020484,
      sectorCount: 4,
      dataOffset: 0,
      buffersNeeded: 0,
      blockDescriptorCount: 4,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: '00000000' },
      blockCount: 2,
      blocks: [
        Block {
          type: 2,
          description: 'FREE (unallocated)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 4,
          compressedOffset: 984141554,
          compressedLength: 0
        },
        Block {
          type: 4294967295,
          description: 'TERMINATOR',
          comment: '',
          sectorNumber: 4,
          sectorCount: 0,
          compressedOffset: 984141554,
          compressedLength: 0
        }
      ]
    }
  }, {
    id: 4,
    attributes: 80,
    name: 'Mac_OS_X (Apple_HFS : 5)',
    coreFoundationName: 'Mac_OS_X (Apple_HFS : 5)',
    map: BlockMap {
      signature: 1835627368,
      version: 1,
      sectorNumber: 2020488,
      sectorCount: 13157944,
      dataOffset: 0,
      buffersNeeded: 520,
      blockDescriptorCount: 5,
      reserved1: 0,
      reserved2: 0,
      reserved3: 0,
      reserved4: 0,
      reserved5: 0,
      reserved6: 0,
      checksum: Checksum { type: 2, bits: 32, value: '39ce04b6' },
      blockCount: 25387,
      blocks: [
        Block {
          type: 2147483646,
          description: 'COMMENT',
          comment: '+beg',
          sectorNumber: 0,
          sectorCount: 0,
          compressedOffset: 984141554,
          compressedLength: 0
        },
        Block {
          type: 2147483653,
          description: 'UDZO (zlib-compressed)',
          comment: '',
          sectorNumber: 0,
          sectorCount: 512,
          compressedOffset: 984141554,
          compressedLength: 1812
        },
        ... more items
      ]
    }
  }],
  cSum: [{
    Attributes: '0x0000',
    Data: <Buffer 01 00 02 00 00 00 00 00 00 00>,
    ID: '0',
    Name: null
  }, {
    Attributes: '0x0000',
    Data: <Buffer 01 00 02 00 00 00 10 fc a8 3f>,
    ID: '1',
    Name: null
  }, {
    Attributes: '0x0000',
    Data: <Buffer 01 00 02 00 00 00 10 37 71 ef>,
    ID: '2',
    Name: null
  }],
  nsiz: [{
    Attributes: '0x0000',
    Data: <Buffer 3 c 3 f 78 6 d 6 c 20 76 65 72 73 69 6 f 6e 3 d 22 31 2e 30 22 20 65 6e 63 6 f 64 69 6e 67 3 d 22 55 54 46 2 d 38 22 3 f 3e 0 a 3 c 21 44 4 f 43 54 59 50 45 20 70 ...>,
    ID: '0',
    Name: null
  }, {
    Attributes: '0x0000',
    Data: <Buffer 3 c 3 f 78 6 d 6 c 20 76 65 72 73 69 6 f 6e 3 d 22 31 2e 30 22 20 65 6e 63 6 f 64 69 6e 67 3 d 22 55 54 46 2 d 38 22 3 f 3e 0 a 3 c 21 44 4 f 43 54 59 50 45 20 70 ...>,
    ID: '1',
    Name: null
  }, {
    Attributes: '0x0000',
    Data: <Buffer 3 c 3 f 78 6 d 6 c 20 76 65 72 73 69 6 f 6e 3 d 22 31 2e 30 22 20 65 6e 63 6 f 64 69 6e 67 3 d 22 55 54 46 2 d 38 22 3 f 3e 0 a 3 c 21 44 4 f 43 54 59 50 45 20 70 ...>,
    ID: '2',
    Name: null
  }],
  plst: [{
    Attributes: '0x0050',
    Data: <Buffer 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ...>,
    ID: '0',
    Name: null
  }],
  size: [{
    Attributes: '0x0000',
    Data: <Buffer 05 00 01 00 00 00 00 60 8 c 91 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ...>,
    ID: '2',
    Name: null
  }]
}

参考资料

版本与发布记录

@balena/udif 共发布 19 个版本，首次发布于 2020/07/24；过去 12 个月发布了 0 个版本。

版本	发布日期	距今
`1.1.2`latest	2021/10/07	5 年前
`1.1.2-dont-use-github-packages-56b5b039720f094353f68b4fb71512da7e37e88b`	2021/10/07	5 年前
`1.1.2-dont-use-github-packages-5f40f1aafb261724dc263a4e619e3a8b8c255fa6`	2021/10/07	5 年前
`1.1.1`	2020/12/01	5 年前
`1.1.1-add-versionbot-changelog-6c9517c47f5b00db1d74597e2414b172eb382df6`	2020/12/01	5 年前
`1.1.0`	2020/08/21	6 年前

关于 @balena/udif 的常见问题

@balena/udif 是什么？

苹果通用磁盘图像格式(UDIF/DMG)

如何安装 @balena/udif？

在项目目录运行 npm install @balena/udif，或使用 pnpm add / yarn add / bun add。

@balena/udif 支持 TypeScript 吗？

该包的 package.json 没有声明类型入口。需要类型提示时，可以在 npm 上查找社区维护的 @types/balena__udif 是否存在。

@balena/udif 支持 ESM 还是 CommonJS？

以 CommonJS 形式发布，可以直接 require()；在 ES Module 项目中也可以用 import 引入（Node.js 会把 module.exports 作为默认导出）。

@balena/udif 可以商用吗？

@balena/udif 使用 MIT 许可。宽松许可：允许商业使用、修改和再分发，通常只需在分发时保留原版权与许可声明。以上为概括，不构成法律意见，请以许可原文为准。

@balena/udif 的下载量有多少？

根据 npm 官方下载统计，@balena/udif 在 2026/10/08 – 2026/11/06 这 30 天内被下载 10,577 次，日均约 353 次。下载量会把 CI 构建、镜像同步和作为其他包依赖的安装一并计入，适合横向比较热度，不能直接等同于使用人数。

@balena/udif 还在维护吗？

最新版本 1.1.2 发布于 2021/10/07（5 年前）；至今共发布 19 个版本，其中过去 12 个月发布了 0 个；首次发布于 2020/07/24。发布频率只是参考信号：功能稳定的工具可能很少需要更新，建议结合源码仓库的 issue 和提交记录判断。

@balena/udif

苹果通用磁盘图像格式(UDIF/DMG)

通过 无

用于

使用量

打开 .dmg 图像

确定未压缩大小

创建可读流

提取原始磁盘图像

分层流

使用自定义文件系统

检查UDIF页脚

检查 XML 元数据

参考资料

版本与发布记录

关于 @balena/udif 的常见问题

@balena/udif 是什么？

如何安装 @balena/udif？

@balena/udif 支持 TypeScript 吗？

@balena/udif 支持 ESM 还是 CommonJS？

@balena/udif 可以商用吗？

@balena/udif 的下载量有多少？

@balena/udif 还在维护吗？

通过无