2.3.2.1 BTHHEADER
The BTHHEADER contains the BTH metadata, which instructs the reader how to access the other objects of the BTH structure.
Unicode / ANSI:
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bType |
cbKey |
cbEnt |
bIdxLevels |
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hidRoot |
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bType (1 byte): MUST be bTypeBTH.
cbKey (1 byte): Size of the BTree Key value, in bytes. This value MUST be set to 2, 4, 8, or 16.
cbEnt (1 byte): Size of the data value, in bytes. This MUST be greater than zero and less than or equal to 32.
bIdxLevels (1 byte): Index depth. This number indicates how many levels of intermediate indices exist in the BTH. Note that this number is zero-based, meaning that a value of zero actually means that the BTH has one level of indices. If this value is greater than zero, then its value indicates how many intermediate index levels are present.
hidRoot (4 bytes): This is the HID that points to the BTH entries for this BTHHEADER. The data consists of an array of BTH records. This value is set to zero if the BTH is empty.