Compound File Binary Format - Structure

Structure

The CFBF file consists of a 512-Byte header record followed by a number of sectors whose size is defined in the header. The literature defines Sectors to be either 512 or 4096 bytes in length, although the format is potentially capable of supporting sectors ranging in size from 128-Bytes upwards in powers of 2 (128, 256, 512, 1024, etc.). The lower limit of 128 is the minimum required to fit a single directory entry in a Directory Sector.

There are several types of sector that may be present in a CFBF:

  • File Allocation Table (FAT) Sector - contains chains of sector indices much as a FAT does in the FAT/FAT32 filesystems
  • MiniFAT Sectors - similar to the FAT but storing chains of mini-sectors within the Mini-Stream
  • Double-Indirect FAT (DIFAT) Sector - contains chains of FAT sector indices
  • Directory Sector - contains directory entries
  • Stream Sector - contains arbitrary file data
  • Range Lock Sector - contains the byte-range locking area of a large file

More detail is given below for the header and each sector type.

Read more about this topic:  Compound File Binary Format

Famous quotes containing the word structure:

    Why does philosophy use concepts and why does faith use symbols if both try to express the same ultimate? The answer, of course, is that the relation to the ultimate is not the same in each case. The philosophical relation is in principle a detached description of the basic structure in which the ultimate manifests itself. The relation of faith is in principle an involved expression of concern about the meaning of the ultimate for the faithful.
    Paul Tillich (1886–1965)

    Just as a new scientific discovery manifests something that was already latent in the order of nature, and at the same time is logically related to the total structure of the existing science, so the new poem manifests something that was already latent in the order of words.
    Northrop Frye (b. 1912)

    The question is still asked of women: “How do you propose to answer the need for child care?” That is an obvious attempt to structure conflict in the old terms. The questions are rather: “If we as a human community want children, how does the total society propose to provide for them?”
    Jean Baker Miller (20th century)