NAME
CSSM_DL_DataGetNext — Get next data record (CDSA)
SYNOPSIS
# include <cssm.h>
API:
CSSM_RETURN CSSMAPI CSSM_DL_DataGetNext
(CSSM_DL_DB_HANDLE DLDBHandle,
CSSM_HANDLE ResultsHandle,
CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR Attributes,
CSSM_DATA_PTR Data,
CSSM_DB_UNIQUE_RECORD_PTR *UniqueId)
SPI:
CSSM_RETURN CSSMDLI DL_DataGetNext
(CSSM_DL_DB_HANDLE DLDBHandle,
CSSM_HANDLE ResultsHandle,
CSSM_DB_RECORD_ATTRIBUTE_DATA_PTR Attributes,
CSSM_DATA_PTR Data,
CSSM_DB_UNIQUE_RECORD_PTR *UniqueId) |
LIBRARY
Common Security Services Manager library (cdsa$incssm300_shr.exe)
PARAMETERS
| DLDBHandle (input) |
| | | The handle pair that describes the add-in data storage
library module to be used to perform this function, and the open
data store from which records were selected by the initiating query. |
| ResultsHandle (input) |
| | | The handle identifying a set of records retrieved
by a query executed by the CSSM_DL_DataGetFirst() function. |
| Attributes (optional-input/output) |
| | | If the Attributes structure pointer
is NULL, no values are returned. Otherwise, the DataRecordType, NumberOfAttributes and AttributeData fields
are read. AttributeData must be an array of NumberOfAttributes CSSM_DB_RECORD_ATTRIBUTE
elements. Only the Info field of each element
is used on input. The AttributeFormat field of
the Info field is ignored on input. On output, a CSSM_DB_RECORD_ATTRIBUTE structure containing
a list of all or the requested attribute values (subset) from the
retrieved record. The SemanticInformation field
is set. For each CSSM_DB_ATTRIBUTE_DATA contained in the AttributeData array,
the NumberOfValues field is set to reflect the
size of the Value array which is allocated by
the DL using the application specified allocators. Each CSSM_DATA
in the Value array will have it's Data field
as a pointer to data allocated using the application specified allocators
containing the attributes value, and have it's Length set
to the length of the value. All values for an attribute are returned (this could be 0).
All fields in the Info field of the CSSM_DB_ATTRIBUTE_DATA
are left unchanged except for the AttributeFormat field, which
is set to reflect the schema. |
| Data (optional-input/output) |
| | | Data values contained in the referenced memory are
ignored during processing and are overwritten with the retrieved
opaque object. On output, a CSSM_DATA structure containing the opaque
object stored in the retrieved record. If the pointer is data structure pointer
is NULL, the opaque object is not returned. |
| UniqueId (output) |
| | | If successful and (at least) a record satisfying
the query has been found, then this parameter returns a pointer
to a CSSM_UNIQUE_RECORD_PTR structure containing a unique identifier
associated with the retrieved record. This unique identifier structure
can be used in future references to this record using this DLDBHandle pairing.
It may not be valid for other DLHandles targeted
to this DL module or to other DBHandles targeted
to this data store. If there are no more records satisfying the
query, then this pointer is NULL and CSSM_DL_DataGetNext() must return CSSM_DL_ENDOFDATA; in this case a normal termination
condition has occurred. The CSSM_DL_FreeUniqueRecord() must be used to deallocate this structure. |
DESCRIPTION
This function returns the next data record referenced by the ResultsHandle.
The ResultsHandle references a set of records
selected by an invocation of the DataGetFirst function.
The Attributes parameter can specify a subset of the attributes
to be returned. If Attributes specifies an attribute
that is not defined in the database's meta-information, an error
condition is returned. The record values are returned in the Attributes and Data parameters.
The output buffers for the retrieved record are allocated by this
function using the memory management functions provided during the
module attach operation. The function also returns a unique record
identifier for the return record.
The data storage module supports one of two retrieval models:
transactional or file system scan. The transactional model freezes
the set of records to be retrieved at query initiation. The file
system scan model selects from a potentially changing set of records
during the retrieval process. The EndOfDataStore() function indicates when all matching records have been
retrieved. The caller can determine which retrieval model is supported
by examining the encapsulated product description for this data
storage module. Once a user has finished using a certain query,
it must call CSSM_DataAbortQuery() for releasing resources that CSSM uses. If all records
satisfying the query have been retrieved, then query is automatically
terminated.
RETURN VALUE
A CSSM_RETURN value indicating success or specifying a particular
error condition. The value CSSM_OK indicates success. All other
values represent an error condition.
ERRORS
Errors are described in the CDSA Technical Standard.
CSSMERR_DL_ENDOFDATA
CSSMERR_DL_FIELD_SPECIFIED_MULTIPLE
CSSMERR_DL_INCOMPATIBLE_FIELD_FORMAT
CSSMERR_DL_INVALID_DB_HANDLE
CSSMERR_DL_INVALID_FIELD_NAME
CSSMERR_DL_INVALID_RECORDTYPE
CSSMERR_DL_INVALID_RECORD_UID
CSSMERR_DL_INVALID_RESULTS_HANDLE |
SEE ALSO
Books
Intel CDSA Application Developer's Guide
Online Help
Functions for the CSSM API:
CSSM_DL_DataGetFirst, CSSM_DL_DataAbortQuery
Functions for the DL SPI:
DL_DataGetFirst, DL_DataAbortQuery
