AS ISO IEC 19784.2:2010 pdf download – Information technology — Biometric application programming interface — Part 2: Biometric archive function provider interface.
Description This function returns an array of BioAPI Unit schemas (see 7.55 of ISO/IEC 1 9784-1 :2006), which are managed by the given BAFP and are currently in the inserted state. NOTE When the BSP calls the function BioAFPI_QueryUnits of a BFP, the BFP allocates memory for the data to be returned to the BSP. In some implementation architectures, the BSP will simply pass to the framework the data and the addresses exactly as returned by the BFP because the framework will interpret the addresses in the same way as the BFP and will be able to access the data that the BFP has placed at those addresses. In other implementation architectures, the BSP will need to move all the data returned by the BFP to newly allocated memory blocks accessible to the framework, and will call BioAFPI_Free after copying each memory block but before returning from the BioSPI_QueryUnits call. In the former case, when the framework calls BioSPI_Free, the BSP will make a corresponding call to BioAFPI_Free. In the latter case, the calls to BioSPI_Free will be handled internally by the BSP. However, such differences in the behavior of the BSP are not visible to the Framework. The memory block containing the array shall be freed by the BSP via a call to BioAFPI_Free when it is no longer needed by the BSP. The memory block pointed to by the UnitProperty member within each element of the array shall also be freed by the BSP via a call to BioAFPI_Free when it is no longer needed by the BSP. This function shall only be called after BioAFPI_Load has been called for the specified BFP, and shall not be called after BioAFPI_Unload has been called for the BFP. There is no requirement that a unit ID, returned by this function for a given BioAPI unit, be made available with the same unit ID value by the BSP to the framework. A BSP is free to translate any unit ID value (provided by a BFP) into a different unit ID value before providing it to the framework. The purpose of such a translation would be to avoid the existence of duplicate unit IDs within the scope of the BSP, which might happen when a BSP is using two or more BFPs of the same category, or when a BSP is using an archive BFP while also directly managing archive units. Parameters BafpUuid (input) – The unique identifier for the BAFP for which the information is to be returned. UnitSchemaArray (output) – A pointer to an address of the array of elements of type BioAPI_UNIT_SCHEMA (allocated by the BSP – but see note above) containing the unit schema information. NumberOfElements (output) – A pointer to the number of elements in the array, which are managed by the given BAFP and are currently in the inserted state. Return Value A BioAPI_RETURN value indicating success or specifying a particular error condition. The value BioAPI_OK indicates success. All other values represent an error condition.
AS ISO IEC 19784.2:2010 pdf download – Information technology — Biometric application programming interface — Part 2: Biometric archive function provider interface
