复合二进制文档

复合二进制文档（CFBF），簡称复合文档，^[1]英文全名 Composite Document File V2 Document^[2]，是微软开发、用於实现COM结构化存储的文件格式，用于把多个对象内容存放在同一个硬盘文件。^[3][4][5]

Microsoft已经开放了这个文件格式。广泛用于Microsoft Word与Microsoft Access。也是Advanced Authoring Format（英语：Advanced Authoring Format）的基础。^[6]

文件结构

CFBF文件头部是512字节，随后跟着是保存数据的扇区。扇区的长度在文件头部指定，通常是512字节或4096字节。

CFBF的扇区类型:

• FAT扇区
• MiniFAT扇区：用于Mini-Stream
• Double-Indirect FAT （DIFAT）扇区 - 包含FAT扇区索引的链表数据
• Directory扇区
• Stream扇区 - 包含数据内容
• Range Lock扇区 - 包含大文件的上锁的字节范围

CFBF文件头

CFBF头是该文件的最前的512字节。对应于C语言数据结构为：

 typedef unsigned long ULONG; // 4 Bytes  typedef unsigned short USHORT; // 2 Bytes  typedef short OFFSET; // 2 Bytes  typedef ULONG SECT; // 4 Bytes  typedef ULONG FSINDEX; // 4 Bytes  typedef USHORT FSOFFSET; // 2 Bytes  typedef USHORT WCHAR; // 2 Bytes  typedef ULONG DFSIGNATURE; // 4 Bytes  typedef unsigned char BYTE; // 1 Byte  typedef unsigned short WORD; // 2 Bytes  typedef unsigned long DWORD; // 4 Bytes  typedef ULONG SID; // 4 Bytes  typedef GUID CLSID; // 16 Bytes  struct StructuredStorageHeader { // [offset from start (bytes), length (bytes)]  BYTE _abSig[8]; // [00H,08] {0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1,  // 0x1a, 0xe1} for current version  CLSID _clsid; // [08H,16] reserved must be zero (WriteClassStg/  // GetClassFile uses root directory class id)  USHORT _uMinorVersion; // [18H,02] minor version of the format: 33 is  // written by reference implementation  USHORT _uDllVersion; // [1AH,02] major version of the dll/format: 3 for  // 512-byte sectors, 4 for 4 KB sectors  USHORT _uByteOrder; // [1CH,02] 0xFFFE: indicates Intel byte-ordering  USHORT _uSectorShift; // [1EH,02] size of sectors in power-of-two;  // typically 9 indicating 512-byte sectors  USHORT _uMiniSectorShift; // [20H,02] size of mini-sectors in power-of-two;  // typically 6 indicating 64-byte mini-sectors  USHORT _usReserved; // [22H,02] reserved, must be zero  ULONG _ulReserved1; // [24H,04] reserved, must be zero  FSINDEX _csectDir; // [28H,04] must be zero for 512-byte sectors,  // number of SECTs in directory chain for 4 KB  // sectors  FSINDEX _csectFat; // [2CH,04] number of SECTs in the FAT chain  SECT _sectDirStart; // [30H,04] first SECT in the directory chain  DFSIGNATURE _signature; // [34H,04] signature used for transactions; must  // be zero. The reference implementation  // does not support transactions  ULONG _ulMiniSectorCutoff; // [38H,04] maximum size for a mini stream;  // typically 4096 bytes  SECT _sectMiniFatStart; // [3CH,04] first SECT in the MiniFAT chain  FSINDEX _csectMiniFat; // [40H,04] number of SECTs in the MiniFAT chain  SECT _sectDifStart; // [44H,04] first SECT in the DIFAT chain  FSINDEX _csectDif; // [48H,04] number of SECTs in the DIFAT chain  SECT _sectFat[109]; // [4CH,436] the SECTs of first 109 FAT sectors  }; 

FAT扇区

每个FAT条目长度4字节，包含下个FAT链表条目的扇区号，或下述特定值：

• FREESECT (0xFFFFFFFF) - 未用扇区
• ENDOFCHAIN (0xFFFFFFFE) - FAT链表最后一个扇区
• FATSECT (0xFFFFFFFD) - 用于FAT数据存储
• DIFSECT (0xFFFFFFFC) - 用于DIFAT数据存储

词汇表

• FAT - 文件分配表，也称 SAT - 扇区分配表
• DIFAT - Double-Indirect File Allocation Table
• FAT Chain - 一群FAT条目指出分配给一个流的那些扇区
• Stream - 一个数据对象的内容
• Sector - 扇区，占据512或4096个字节

参见

• COM结构化存储

参考文献

1. . POI Project. [10 May 2011]. （原始内容存档于2011-04-26）. 
2. . [25 Nov 2016]. （原始内容存档于2019-09-21）. 
3. Compound Files (Windows). Microsoft Developers Network (MSDN) library – COM SDK. Microsoft Corporation. 20 November 2008 [23 September 2009]. （原始内容于2016-03-07）. 
4. Containers: Compound Files. Microsoft Developers Network (MSDN) library – Visual Studio 2008 documentation. Microsoft Corporation. [23 September 2009]. （原始内容于2012-10-18）. 
5. Understand Compound Files. Microsoft Developers Network (MSDN) library – ActiveDirectory Rights Management. 25 June 2009 [23 September 2009]. （原始内容于2016-03-09）. 
6. AMW Association (formerly AAF Association) 互联网档案馆的，存档日期15 August 2000.

外部链接

• Microsoft Compound Document File Format (PDF). OpenOffice.org CFBF description. [2006-05-22]. （原始内容存档 (PDF)于2011-10-12）. 
• (PDF). Microsoft Structured Storage version 3 specification (PDF). [2006-05-22]. （原始内容 (PDF)存档于2011-08-09）.