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Veritas NetBackup™ DataStore SDK Programmer's Guide for XBSA 1.1.0

Last Published: 2021-01-01

Product(s): NetBackup (9.0.0.1, 9.0)

BSA_DataBlock32

The BSA_DataBlock32 structure is used to pass data between an XBSA application and the NetBackup XBSA interface. It is defined as follows:

typedef struct {
       BSA_UInt32  bufferLen;
       BSA_UInt32  numBytes;
       BSA_UInt32  headerBytes;
       BSA_ShareId shareId;
       BSA_UInt32  shareOffset;
       void       *bufferPtr
} BSA_DataBlock32;

The usage of the structure fields is defined as follows:

Table: BSA_DataBlock32 Structure Fields

Field Name	Definition
bufferLen	Length of the allocated buffer
numBytes	Actual number of bytes read from or written to the buffer, or the minimum number of bytes needed
headerBytes	Number of bytes used at start of buffer for header information (offset to data portion of buffer)
shareId	Value used to identify a shared memory block.
shareOffset	Specifies the offset of the buffer in the shared memory block.
bufferPtr	Pointer to the buffer

The values assigned to the various structure fields would always obey the following relationships:

bufferLen >= headerBytes + numBytes

trailerBytes == (bufferLen - numBytes - headerBytes)

The header and trailer portions of the buffer are reserved for the use of the NetBackup XBSA interface, and should not be modified by the XBSA application. The XBSA application should only write to the data portion of the buffer, which is the only portion used for transferring application data.

The sizes for the header and trailer portions of the buffer that are required by the NetBackup XBSA interface are obtained by calling BSACreateObject() or BSAGetObject().